1.
Adrenal
glands. Structure and topography of ureter and urіnary bladder.
2.
Male
reproductive organs. Structure of testis and epididimis. Spermatic ducts and
accessory reproductive glands.
3.
External
reproductive organs. Spermatic cord. Layers of scrotal wall. Structure of
masculine urethra. Topography of small pelvis organs on male
Lesson No 16
Theme 1.
Adrenal glands. Structure and topography of ureter and
urіnary bladder
The Adrenal gland is a pair endocrine gland, which lies
on superior extremity of right and left kidneys on level of the Th 11 – Th 12 vertebrae. Each
adrenal gland has triangle shape and has anterior surface, posterior surface
and renal surface and superior margin and medial margin, and also has the hilus and consists of cortex and medulla matter. Cortex
produces mineralocorticoids (aldosterone), glucocorticoids and androgens.
Medulla of adrenal glands produces adrenalin and noradrenalin.
Suprarenal glands viewed from the front.
Suprarenal glands viewed from behind.
The
urogenital apparatus consists of (a)
the urinary organs for the secretion
and discharge of the urine, and (b)
the genital organs, which are
concerned with the process of reproduction.
Development of the Urinary and
Generative Organs—The urinary
and generative organs are developed from the intermediate cell-mass which is
situated between the primitive segments and the lateral plates of mesoderm. The
permanent organs of the adult are preceded by a set of structures which are
purely embryonic, and which with the exception of the ducts disappear almost
entirely before the end of fetal life. These embryonic structures are on either
side; the pronephros, the mesonephros, the metanephros, and the Wolffian and Müllerian ducts. The pronephros
disappears very early; the structural elements of the mesonephros
mostly degenerate, but in their place is developed the genital gland in
association with which the Wolffian duct remains as
the duct of the male genital gland, the Müllerian
as that of the female; some of the tubules of the metanephros
form part of the permanent kidney.
The Pronephros
and Wolffian Duct.—In the outer
part of the intermediate cell-mass, immediately under the ectoderm, in the
region from the fifth cervical to the third thoracic segments, a series of
short evaginations from each segment grows dorsalward and extends caudalward,
fusing successively from before backward to form the pronephric duct. This continues to grow caudalward
until it opens into the ventral part of the cloaca; beyond the pronephros it is termed the Wolffian duct.
The
original evaginations form a series of transverse
tubules each of which communicates by means of a funnel-shaped ciliated opening
with the celomic cavity, and in the course of each
duct a glomerulus also is developed. A secondary glomerulus is formed ventral
to each of these, and the complete group constitutes the pronephros. The pronephros undergoes rapid atrophy
and disappears.
The Mesonephros,
Müllerian Duct, and Genital Gland.—On
the medial side of the Wolffian duct, from the sixth
cervical to the third lumbar segments, a series of tubules, the Wolffian tubules, is developed; at a later
stage in development they increase in number by outgrowths from the original
tubules. These tubules first appear as solid masses of cells, which later
become hollowed in the center; one end grows toward and finally opens into the Wolffian duct, the other dilates and is invaginated
by a tuft of capillary bloodvessels to form a
glomerulus. The tubules collectively constitute the mesonephros or Wolffian body. By the fifth or sixth week this
body forms an elongated spindle-shaped structure, termed the urogenital fold, which
projects into the celomic cavity at the side of the
dorsal mesentery, reaching from the septum transversum
in front to the fifth lumbar segment behind; in this fold the reproductive
glands are developed. The Wolffian bodies persist and
form the permanent kidneys in fishes and amphibians, but in reptiles, birds,
and mammals, they atrophy and for the most part disappear coincidently with the
development of the permanent kidneys. The atrophy begins during the sixth or
seventh week and rapidly proceeds, so that by the beginning of the fifth month
only the ducts and a few of the tubules remain.
In
the male the Wolffian duct persists, and forms the
tube of the epididymis, the ductus deferens and the
ejaculatory duct, while the seminal vesicle arises during the third month as a
lateral diverticulum from its hinder end. A large part of the head end of the mesonephros atrophies and disappears; of the remainder the
anterior tubules form the efferent ducts of the testis; while the posterior
tubules are represented by the ductuli aberrantes, and by the paradidymis,
which is sometimes found in front of the spermatic cord above the head of the
epididymis.
In
the female the Wolffian bodies and ducts atrophy. The
remains of the Wolffian tubules are represented by
the epoöphoron
or organ of Rosenmüller,
and the paroöphoron, two small collections of rudimentary
blind tubules which are situated in the mesosalpinx.
The lower part of the Wolffian duct disappears, while
the upper part persists as the longitudinal duct of the epoöphoron
or duct of Gärtner.
The Müllerian
Ducts.—Shortly after the formation
of the Wolffian ducts a second pair of ducts is
developed; these are named the Müllerian ducts.
Each arises on the lateral aspect of the corresponding Wolffian
duct as a tubular invagination of the cells lining the celom.
The orifice of the invagination remains patent, and undergoes enlargement and
modification to form the abdominal ostium of the
uterine tube. The ducts pass backward lateral to the Wolffian
ducts, but toward the posterior end of the embryo they cross to the medial side
of these ducts, and thus come to lie side by side between and behind the
latter—the four ducts forming what is termed the genital cord. The Müllerian ducts
end in an epithelial elevation, the Müllerian
eminence, on the ventral part of the cloaca between the orifices of the Wolffian ducts; at a later date they open into the cloaca
in this situation.
In
the male the Müllerian ducts atrophy, but traces
of their anterior ends are represented by the appendices testis (hydatids of Morgagni), while their terminal fused portions form the
utriculus in the floor of the prostatic portion of
the urethra.
In
the female the Müllerian ducts persist and
undergo further development. The portions which lie in the genital core fuse to
form the uterus and vagina; the parts in front of this cord remain separate,
and each forms the corresponding uterine tube—the abdominal ostium
of which is developed from the anterior extremity of the original tubular
invagination from the celom. The fusion of the Müllerian ducts begins in the third month, and the
septum formed by their fused medial walls disappears from below upward, and
thus the cavities of the vagina and uterus are produced. About the fifth month
an annular constriction marks the position of the neck of the uterus, and after
the sixth month the walls of the uterus begin to thicken. For a time the vagina
is represented by a solid rod of epithelial cells. A ring-like outgrowth of
this epithelium occurs at the lower end of the uterus and marks the future
vaginal fornices; about the fifth or sixth month the
lumen of the vagina is produced by the breaking down of the central cells of
the epithelium. The hymen represents the remains of the Müllerian
eminence.
Kidney
Kidney
he kidneys
are bean-shaped
excretory
organs in vertebrates.
Part of the urinary system, the kidneys filter wastes
(especially urea)
from the blood
and excrete them, along with water, as urine. The medical field
that studies the kidneys and diseases affecting the kidney is called nephrology,
from the Ancient Greek name for kidney; the adjective
meaning "kidney-related" is renal, from Latin.
In humans, the kidneys are
located in the posterior part of the abdomen.
There is one on each side of the spine;
the right kidney sits just below the liver, the left below the diaphragm and adjacent to the spleen. Above
each kidney is an adrenal gland (also called the suprarenal gland). The asymmetry within the abdominal
cavity caused by the liver results in the right kidney being slightly lower
than the left one.
The kidneys are retroperitoneal,
which means they lie behind the peritoneum,
the lining of the abdominal cavity. They are approximately at the
vertebral
level T12 to L3. The upper parts of the kidneys are partially protected by the
eleventh and twelfth ribs,
and each whole kidney is surrounded by two layers of fat (the perirenal and pararenal fat)
which help to cushion it. Congenital absence of one or both kidneys, known as
unilateral or bilateral renal agenesis occurs. In very rare cases, it
is possible to have developed three or even four kidneys.[1]
In a normal human adult, each kidney
is about
The outer portion of the kidney
is called the renal cortex, which sits directly beneath the
kidney's loose connective tissue/fibrous capsule.
Deep to the cortex lies the renal medulla,
which is divided into 10-20 renal pyramids in humans. Each pyramid together
with the associated overlying cortex forms a renal lobe. The tip of each
pyramid (called a papilla) empties into a calyx, and the calices
empty into the renal pelvis. The pelvis transmits urine to the
urinary
bladder via the ureter.
Blood supply
Each kidney receives its blood supply
from the renal artery, two of which branch from the
abdominal aorta.
Upon entering the hilum of the kidney, the renal artery divides into smaller interlobar arteries situated between the renal papillae. At
the outer medulla, the interlobar arteries branch
into arcuate arteries, which course along the border
between the renal medulla and cortex, giving off still smaller branches, the
cortical radial arteries (sometimes called interlobular arteries).
Branching off these cortical arteries are the afferent arterioles supplying the
glomerular capillaries, which drain into efferent arterioles. Efferent
arterioles divide into peritubular capillaries that
provide an extensive blood supply to the cortex. Blood from these capillaries
collects in renal venules and leaves the kidney via
the renal vein.
Efferent arterioles of glomeruli closest to the medulla (those that belong to juxtamedullary nephrons)
send branches into the medulla, forming the vasa recta. Blood supply is intimately
linked to blood pressure.
The basic functional unit of the
kidney is the nephron,
of which there are more than a million within the cortex and medulla of each
normal adult human kidney. Nephrons regulate water and soluble matter
(especially electrolytes) in the body by first filtering
the blood under pressure, and then reabsorbing some necessary fluid and
molecules back into the blood while secreting other, unneeded molecules.
Reabsorption and secretion are accomplished with both cotransport
and countertransport
mechanisms established in the nephrons and associated collecting ducts.
Collecting duct system
The fluid flows from the nephron
into the collecting duct system. This segment of
the nephron is crucial to the process of water conservation by the organism. In
the presence of antidiuretic hormone (ADH; also called
vasopressin), these ducts become permeable to water and facilitate its
reabsorption, thus concentrating the urine and reducing its volume. Conversely,
when the organism must eliminate excess water, such as after excess fluid
drinking, the production of ADH is decreased and the collecting tubule becomes
less permeable to water, rendering urine dilute and abundant. Failure of the
organism to decrease ADH production appropriately, a condition known as syndrome of inappropriate ADH
(SIADH), may lead to water retention and dangerous dilution of body fluids,
which in turn may cause severe neurological damage. Failure to produce ADH (or
inability of the collecting ducts to respond to it) may cause excessive
urination, called diabetes insipidus
(DI).
A second major function of the
collecting duct system is the maintenance of acid-base homeostasis.
After being processed along the
collecting tubules and ducts, the fluid, now called urine, is drained into the
bladder
via the ureter,
to be finally excluded from the organism.
Excretion of waste products
The kidneys excrete a variety of waste products produced by metabolism,
including the nitrogenous wastes: urea (from protein catabolism) and uric acid
(from nucleic acid metabolism).
Homeostasis
Embryology
The mammalian kidney develops
from intermediate mesoderm. Kidney development,
also called nephrogenesis, proceeds through a
series of three successive phases, each marked by the development of a more
advanced pair of kidneys: the pronephros, mesonephros, and metanephros.[2] (The plural
forms of these terms end in -oi.)
Pronephros
During approximately day 22 of
human gestation,
the paired pronephroi appear towards the cranial end
of the intermediate mesoderm. In this region, epithelial
cells arrange themselves in a series of tubules called nephrotomes and join laterally with the pronephric duct, which does not reach the outside of
the embryo. Thus the pronephros is considered
nonfunctional in mammals because it cannot excrete waste from the embryo.
Mesonephros
Each pronephric
duct grows towards the tail of the embryo, and in doing so induces intermediate
mesoderm in the thoracolumbar area to become epithelial tubules called mesonephric tubules.
Each mesonephric tubule receives a blood supply from
a branch of the aorta,
ending in a capillary tuft analogous to the glomerulus of the definitive nephron.
The mesonephric tubule forms a capsule around the
capillary tuft, allowing for filtration of blood. This filtrate flows through
the mesonephric tubule and is drained into the
continuation of the pronephric duct, now called the mesonephric duct or Wolffian duct. The nephrotomes
of the pronephros degenerate while the mesonephric duct extends towards the most caudal end of the
embryo, ultimately attaching to the cloaca. The
mammalian mesonephros is similar to the kidneys of aquatic
amphibians and fishes.
Metanephros
During the fifth week of gestation,
the mesonephric duct develops an outpouching,
the ureteric bud,
near its attachment to the cloaca. This bud, also called the metanephrogenic diverticulum, grows posteriorly and towards
the head of the embryo. The elongated stalk of the ureteric bud, the metanephric duct,
later forms the ureter.
As the cranial end of the bud extends into the intermediate mesoderm, it
undergoes a series of branchings to form the collecting duct system of the kidney. It
also forms the major and minor calyces
and the renal pelvis.
The portion of the intermediate
mesoderm in contact with the tips of the branching ureteric bud is known as the
metanephrogenic blastema.
Signals released from the ureteric bud induce the differentiation of the metanephrogenic blastema into the
renal tubules.
As the renal tubules grow, they come into contact and join with connecting
tubules of the collecting duct system, forming a continuous passage
for flow from the renal tubule to the collecting duct. Simultaneously,
precursors of vascular endothelial cells begin to take their position at the
tips of the renal tubules. These cells differentiate into the cells of the
definitive glomerulus.
The URETERS are
pair organ length 25-З0 cm, which lies retroperitoneally.
Ureter has abdominal part, pelvic part and intramural part. Last
lies in the wall of urinary bladder and opens on its fundus by foramen. Ureters
wall consists of external membrane, muscular membrane and mucous membrane.
Muscular membrane has external circular and internal longitudinal layers.
Ureter
has follow narrow places:
• at transition of renal pelvis into ureter;
• at transition of abdominal part into pelvic part;
• at transition of ureters into urinary bladder.
Posterior abdominal wall, after removal
of the peritoneum, showing kidneys, suprarenal capsules, great vessels and
ureters.
The URINARY BLADDER lies in cavity of lesser pelvis
behind pubic symphysis. It has an apex, body
and fundus, which is directed down and posterior. Inferior part
forms а neck, which continues into urethra. Empty urinary bladder lies extraperitoneally. Full bladder covered by peritoneum
anteriorly, laterally and posteriorly - mesoperitoneal
position. Fundus of the bladder in male adjoins from below to prostate gland,
seminal vesicles and ampoule of ductus deferens, and
behind - to ampoule of rectum. In female urinary bladder behind adjoins to
vagina and uterus.
The
urinary bladder is a musculomembranous sac which acts as a reservoir for the
urine; and as its size, position, and relations vary according to the amount of
fluid it contains, it is necessary to study it as it appears (a) when empty,
and (b) when distended.) In both conditions the position of the
bladder varies with the condition of the rectum, being pushed upward and
forward when the rectum is distended.
The Empty Bladder.—When
hardened in situ, the empty bladder has the form of a flattened
tetrahedron, with its vertex tilted forward. It presents a fundus, a vertex, a
superior and an inferior surface. The fundus
is triangular in shape, and is directed downward and backward toward the
rectum, from which it is separated by the rectovesical
fascia, the vesiculæ seminales,
and the terminal portions of the ductus deferentes. The vertex
is directed forward toward the upper part of the symphysis
pubis, and from it the middle umbilical ligament is continued upward on the
back of the anterior abdominal wall to the umbilicus. The peritoneum is carried
by it from the vertex of the bladder on to the abdominal wall to form the
middle umbilical fold. The superior
surface is triangular, bounded on either side by a lateral border which
separates it from the inferior surface, and behind by a posterior border,
represented by a line joining the two ureters, which intervenes between it and
the fundus.
The
lateral borders extend from the ureters to the vertex, and from them the
peritoneum is carried to the walls of the pelvis. On either side of the bladder
the peritoneum shows a depression, named the paravesical fossa. The superior surface is
directed upward, is covered by peritoneum, and is in relation with the sigmoid
colon and some of the coils of the small intestine. When the bladder is empty
and firmly contracted, this surface is convex and the
lateral and posterior borders are rounded; whereas if the bladder be relaxed it
is concave, and the interior of the viscus, as seen
in a median sagittal section, presents the appearance of a V-shaped slit with a
shorter posterior and a longer anterior limb—the apex of the V corresponding
with the internal orifice of the urethra. The inferior surface is directed downward and is uncovered by
peritoneum. It may be divided into a posterior or prostatic area and two infero-lateral surfaces. The prostatic area is somewhat triangular:
it rests upon and is in direct continuity with the base of the prostate; and
from it the urethra emerges. The infero-lateral
portions of the inferior surface are directed downward and lateralward:
in front, they are separated from the symphysis pubis
by a mass of fatty tissue which is named the retropubic pad; behind, they are in contact with
the fascia which covers the Levatores ani and Obturatores interni.
Median
sagitta section of male
pelvis.
1, corpus cavernosum 2, corpus spongiosum
(bulb of the penis) 3, ramus ischium 4, ischiocavernosus
m. 5, anal canal 6, sphincter ani externus
m. 7, gluteus maximus m.
When
the bladder is empty it is placed entirely within the pelvis, below the level
of the obliterated hypogastric arteries, and below
the level of those portions of the ductus deferentes which are in contact with the lateral wall of
the pelvis; after they cross the ureters the ductus deferentes come into contact with the fundus of the
bladder. As the viscus fills, its fundus, being more
or less fixed, is only slightly depressed; while its superior surface gradually
rises into the abdominal cavity, carrying with it its peritoneal covering, and
at the same time rounding off the posterior and lateral borders.
When the bladder is moderately full it contains about
The Bladder in the Child—In the newborn child the internal urethral
orifice is at the level of the upper border of the symphysis
pubis; the bladder therefore lies relatively at a much higher level in the
infant than in the adult. Its anterior surface “is in contact with about the
lower two-thirds of that part of the abdominal wall
which lies between the symphysis pubis and the
umbilicus”. Its fundus is clothed with peritoneum as far as the level of the
internal orifice of the urethra. Although the bladder of the infant is usually
described as an abdominal organ, Symington has pointed out that only about
one-half of it lies above the plane of the superior aperture of the pelvis. Disse maintains that the internal urethral orifice sinks
rapidly during the first years, and then more slowly until the ninth year,
after which it remains sta when it again slowly
descends and reaches its adult position.
Sagittal section through the pelvis of a newly born male child.
1,
rectus abdominis m. 2, bladder 3, pubis 4, ischium 5,
testis 6, corpus cavernosum
1,
rectus abdominis m. 2, symphysis
pubis 3, corpus cavernosum 4, corpus spongiosum 5, prostate 6, bladder 7,seminal vesicle 8,
rectum 9, sacrum
Sagittal section through the pelvis of a newly born female child.
The Female Bladder—In the
female, the bladder is in relation behind with the uterus and the upper part of
the vagina. It is separated from the anterior surface of the body of the uterus
by the vesicouterine excavation, but below
the level of this excavation it is connected to the front of the cervix uteri
and the upper part of the anterior wall of the vagina by areolar tissue. When
the bladder is empty the uterus rests upon its superior surface. The female
bladder is said by some to be more capacious than that of the male, but
probably the opposite is the case.
Median
sagittal section of female pelvis.
Ligaments.—The bladder is connected to
the pelvic wall by the fascia endopelvina. In front
this fascial attachment is strengthened by a few
muscular fibers, the Pubovesicales, which extend from the back of the
pubic bones to the front of the bladder; behind, other muscular fibers run from the fundus of the bladder to the sides of
the rectum, in the sacrogenital folds, and constitute
the Rectovesicales.
The
vertex of the bladder is joined to the umbilicus by the remains of the urachus which forms the middle umbilical ligament, a fibromuscular
cord, broad at its attachment to the bladder but narrowing as it ascends.
From
the superior surface of the bladder the peritoneum is carried off in a series
of folds which are sometimes termed the false
ligaments of the bladder. Anteriorly there are three folds: the middle umbilical fold on the middle
umbilical ligament, and two lateral
umbilical folds on the obliterated hypogastric
arteries. The reflections of the peritoneum on to the side walls of the pelvis
form the lateral false ligaments, while the sacrogenital
folds constitute posterior false ligaments.
Interior of the Bladder—The mucous
membrane lining the bladder is, over the greater part of the viscus, loosely attached to the muscular coat, and appears
wrinkled or folded when the bladder is contracted: in the distended condition
of the bladder the folds are effaced. Over a small triangular area, termed the trigonum vesicæ,
immediately above and behind the internal orifice of the urethra, the mucous
membrane is firmly bound to the muscular coat, and is always smooth. The
anterior angle of the trigonum vesicæ
is formed by the internal orifice of the urethra: its postero-lateral
angles by the orifices of the ureters. Stretching behind the latter openings is
a slightly curved ridge, the torus uretericus, forming the base of the trigone and produced by an underlying bundle of non-striped
muscular fibers. The lateral parts of this ridge
extend beyond the openings of the ureters, and are named the plicæ uretericæ;
they are produced by the terminal portions of the ureters as they traverse
obliquely the bladder wall. When the bladder is illuminated the torus uretericus appears as a pale band and forms an important
guide during the operation of introducing a catheter into the ureter.
The interior of bladder.
The
orifices of the ureters are
placed at the postero-lateral angles of the trigonum vesicæ, and are
usually slit-like in form. In the contracted bladder they are about
The
internal urethral orifice is
placed at the apex of the trigonum vesicæ, in the most dependent part of the bladder,
and is usually somewhat crescentic in form; the
mucous membrane immediately behind it presents a slight elevation, the uvula vesicæ,
caused by the middle lobe of the prostate.
Structure—The bladder is composed of
the four coats: serous, muscular, submucous, and mucous coats.
The
serous coat (tunica serosa)
is a partial one, and is derived from the peritoneum. It invests the superior
surface and the upper parts of the lateral surfaces, and is reflected from
these on to the abdominal and pelvic walls.
The
muscular coat (tunica muscularis) consists of three layers of unstriped muscular fibers: an
external layer, composed of fibers having for the
most part a longitudinal arrangement; a middle layer, in which the fibers are arranged, more or less, in a circular manner;
and an internal layer, in which the fibers have a
general longitudinal arrangement.
The
fibers of the external layer arise from
the posterior surface of the body of the pubis in both sexes (musculi pubovesicales),
and in the male from the adjacent part of the prostate and its capsule.
They pass, in a more or less longitudinal manner, up the inferior surface of
the bladder, over its vertex, and then descend along its fundus to become
attached to the prostate in the male, and to the front of the vagina in the
female. At the sides of the bladder the fibers are
arranged obliquely and intersect one another. This layer
has been named the Detrusor urinæ muscle.
The
fibers of the middle circular layer are
very thinly and irregularly scattered on the body of the organ, and, although
to some extent placed transversely to the long axis of the bladder, are for the
most part arranged obliquely. Toward the lower part of the bladder, around the
internal urethral orifice, they are disposed in a thick circular layer, forming
the Sphincter vesicæ,
which is continuous with the muscular fibers of the
prostate.
The
internal longitudinal layer is thin, and its fasciculi have a reticular
arrangement, but with a tendency to assume for the most part a longitudinal
direction. Two bands of oblique fibers, originating
behind the orifices of the ureters, converge to the back part of the prostate,
and are inserted by means of a fibrous process, into the middle lobe of that
organ. They are the muscles of the
ureters, described by Sir C. Bell, who supposed that during the
contraction of the bladder they serve to retain the oblique direction of the
ureters, and so prevent the reflux of the urine into them.
The
submucous coat (tela
submucosa) consists of a layer of areolar tissue,
connecting together the muscular and mucous coats, and intimately united to the
latter.
Vertical section of bladder wall.
The
mucous coat (tunica mucosa)
is thin, smooth, and of a pale rose color. It is
continuous above through the ureters with the lining membrane of the renal
tubules, and below with that of the urethra. The loose texture of the submucous layer allows the mucous coat to be thrown into
folds or rugæ when the bladder is empty.
Over the trigonum vesicæ
the mucous membrane is closely attached to the muscular coat, and is not thrown
into folds, but is smooth and flat. The epithelium covering it is of the
transitional variety, consisting of a superficial layer of polyhedral flattened
cells, each with one, two, or three nuclei; beneath these is a stratum of large
club-shaped cells, with their narrow extremities directed downward and wedged
in between smaller spindle-shaped cells, containing oval nuclei. The epithelium
varies according as the bladder is distended or contracted. In the former
condition the superficial cells are flattened and those of the other layers are
shortened; in the latter they present the appearance described above. There are
no true glands in the mucous membrane of the bladder, though certain mucous
follicles which exist, especially near the neck of the bladder, have been regarded
as such.
Vessels and Nerves.—The arteries supplying the bladder are the
superior, middle, and inferior vesical, derived from
the anterior trunk of the hypogastric. The obturator and inferior gluteal arteries also supply small
visceral branches to the bladder, and in the female additional branches are
derived from the uterine and vaginal arteries.
The
veins form a complicated plexus
on the inferior surface, and fundus near the prostate, and end in the hypogastric veins.
The
nerves of the bladder are (1)
fine medullated fibers from
the third and fourth sacral nerves, and (2) non-medullated
fibers from the hypogastric
plexus. They are connected with ganglia in the outer and submucous
coats and are finally distributed, all as non-medullated
fibers, to the muscular layer and epithelial lining
of the viscus.
Abnormalities.—A defect of
development, in which the bladder is implicated, is known under the name of extroversion
of the bladder. In this condition the lower part of the abdominal wall and
the anterior wall of the bladder are wanting, so that the fundus of the bladder
presents on the abdominal surface, and is pushed forward by the pressure of the
viscera within the abdomen, forming a red vascular tumor
on which the openings of the ureters are visible. The penis, except the glans,
is rudimentary and is cleft on its dorsal surface, exposing the floor of the
urethra, a condition known as epispadias.
The pelvic bones are also arrested in development.
Wall of urinary bladder is formed by mucous membrane and well
developed submucous stratum, thanks it
mucous membrane forms the numerous folds. Between orifices of ureters and
internal urethral ostium submucous
base absent, so there are no folds here. This place called as triangle of
bladder. It is limited above interureteric fold of
mucous membrane. Middle membrane of urinary bladder is a muscular membrane,
where muscles are arranged in three layers: internal and external longitudinal
and middle - circular. The muscular layers form in area of the body muscle-detrussor of bladder, and a circular layer most
developed in area of internal urethral ostium, forms
an internal urethral muscle-sphincter (involuntary).
The URINARY BLADDER lies in cavity of lesser pelvis
behind pubic symphysis. It has an apex, body
and fundus, which is directed down and posterior. Inferior part
forms а neck, which continues into urethra. Empty urinary bladder lies extraperitoneally. Full bladder covered by peritoneum
anteriorly, laterally and posteriorly - mesoperitoneal
position. Fundus of the bladder in male adjoins from below to prostate gland,
seminal vesicles and ampoule of ductus deferens, and
behind - to ampoule of rectum. In female urinary bladder behind adjoins to
vagina and uterus.
The
urinary bladder is a musculomembranous sac which acts as a reservoir for the
urine; and as its size, position, and relations vary according to the amount of
fluid it contains, it is necessary to study it as it appears (a) when empty,
and (b) when distended.) In both conditions the position of the
bladder varies with the condition of the rectum, being pushed upward and
forward when the rectum is distended.
The Empty Bladder.—When
hardened in situ, the empty bladder has the form of a flattened
tetrahedron, with its vertex tilted forward. It presents a fundus, a vertex, a
superior and an inferior surface. The fundus
is triangular in shape, and is directed downward and backward toward the
rectum, from which it is separated by the rectovesical
fascia, the vesiculæ seminales,
and the terminal portions of the ductus deferentes. The vertex
is directed forward toward the upper part of the symphysis
pubis, and from it the middle umbilical ligament is continued upward on the
back of the anterior abdominal wall to the umbilicus. The peritoneum is carried
by it from the vertex of the bladder on to the abdominal wall to form the
middle umbilical fold. The superior
surface is triangular, bounded on either side by a lateral border which
separates it from the inferior surface, and behind by a posterior border,
represented by a line joining the two ureters, which intervenes between it and
the fundus.
The
lateral borders extend from the ureters to the vertex, and from them the
peritoneum is carried to the walls of the pelvis. On either side of the bladder
the peritoneum shows a depression, named the paravesical fossa. The superior surface is
directed upward, is covered by peritoneum, and is in relation with the sigmoid
colon and some of the coils of the small intestine. When the bladder is empty
and firmly contracted, this surface is convex and the
lateral and posterior borders are rounded; whereas if the bladder be relaxed it
is concave, and the interior of the viscus, as seen
in a median sagittal section, presents the appearance of a V-shaped slit with a
shorter posterior and a longer anterior limb—the apex of the V corresponding
with the internal orifice of the urethra. The inferior surface is directed downward and is uncovered by
peritoneum. It may be divided into a posterior or prostatic area and two infero-lateral surfaces. The prostatic area is somewhat
triangular: it rests upon and is in direct continuity with the base of the
prostate; and from it the urethra emerges. The infero-lateral
portions of the inferior surface are directed downward and lateralward:
in front, they are separated from the symphysis pubis
by a mass of fatty tissue which is named the retropubic pad; behind, they are in contact with
the fascia which covers the Levatores ani and Obturatores interni.
Median
sagitta section of male
pelvis.
1, corpus cavernosum 2, corpus spongiosum
(bulb of the penis) 3, ramus ischium 4, ischiocavernosus
m. 5, anal canal 6, sphincter ani externus
m. 7, gluteus maximus m.
Posterior abdominal wall, after removal
of the peritoneum, showing kidneys, suprarenal capsules, great vessels and
ureters.
The URINARY BLADDER lies in cavity of lesser pelvis
behind pubic symphysis. It has an apex, body
and fundus, which is directed down and posterior. Inferior part
forms а neck, which continues into urethra. Empty urinary bladder lies extraperitoneally. Full bladder covered by peritoneum
anteriorly, laterally and posteriorly - mesoperitoneal
position. Fundus of the bladder in male adjoins from below to prostate gland,
seminal vesicles and ampoule of ductus deferens, and
behind - to ampoule of rectum. In female urinary bladder behind adjoins to
vagina and uterus.
The
urinary bladder is a musculomembranous sac which acts as a reservoir for the
urine; and as its size, position, and relations vary according to the amount of
fluid it contains, it is necessary to study it as it appears (a) when empty,
and (b) when distended.) In both conditions the position of the bladder
varies with the condition of the rectum, being pushed upward and forward when
the rectum is distended.
The Empty Bladder.—When
hardened in situ, the empty bladder has the form of a flattened
tetrahedron, with its vertex tilted forward. It presents a fundus, a vertex, a
superior and an inferior surface. The fundus
is triangular in shape, and is directed downward and backward toward the
rectum, from which it is separated by the rectovesical
fascia, the vesiculæ seminales,
and the terminal portions of the ductus deferentes. The vertex
is directed forward toward the upper part of the symphysis
pubis, and from it the middle umbilical ligament is continued upward on the
back of the anterior abdominal wall to the umbilicus. The peritoneum is carried
by it from the vertex of the bladder on to the abdominal wall to form the
middle umbilical fold. The superior
surface is triangular, bounded on either side by a lateral border which
separates it from the inferior surface, and behind by a posterior border,
represented by a line joining the two ureters, which intervenes between it and
the fundus.
The
lateral borders extend from the ureters to the vertex, and from them the
peritoneum is carried to the walls of the pelvis. On either side of the bladder
the peritoneum shows a depression, named the paravesical fossa. The superior surface is
directed upward, is covered by peritoneum, and is in relation with the sigmoid
colon and some of the coils of the small intestine. When the bladder is empty
and firmly contracted, this surface is convex and the
lateral and posterior borders are rounded; whereas if the bladder be relaxed it
is concave, and the interior of the viscus, as seen
in a median sagittal section, presents the appearance of a V-shaped slit with a
shorter posterior and a longer anterior limb—the apex of the V corresponding
with the internal orifice of the urethra. The inferior surface is directed downward and is uncovered by
peritoneum. It may be divided into a posterior or prostatic area and two infero-lateral surfaces. The prostatic area is somewhat
triangular: it rests upon and is in direct continuity with the base of the
prostate; and from it the urethra emerges. The infero-lateral
portions of the inferior surface are directed downward and lateralward:
in front, they are separated from the symphysis pubis
by a mass of fatty tissue which is named the retropubic pad; behind, they are in contact with
the fascia which covers the Levatores ani and Obturatores interni.
Median
sagitta section of male
pelvis.
1, corpus cavernosum 2, corpus spongiosum
(bulb of the penis) 3, ramus ischium 4, ischiocavernosus
m. 5, anal canal 6, sphincter ani externus
m. 7, gluteus maximus m.
When
the bladder is empty it is placed entirely within the pelvis, below the level
of the obliterated hypogastric arteries, and below
the level of those portions of the ductus deferentes which are in contact with the lateral wall of the
pelvis; after they cross the ureters the ductus deferentes come into contact with the fundus of the
bladder. As the viscus fills, its fundus, being more
or less fixed, is only slightly depressed; while its superior surface gradually
rises into the abdominal cavity, carrying with it its peritoneal covering, and
at the same time rounding off the posterior and lateral borders.
When the bladder is moderately full it contains about
The Bladder in the Child—In the newborn child the internal
urethral orifice is at the level of the upper border of the symphysis
pubis; the bladder therefore lies relatively at a much higher level in the
infant than in the adult. Its anterior surface “is in contact with about the
lower two-thirds of that part of the abdominal wall
which lies between the symphysis pubis and the
umbilicus”. Its fundus is clothed with peritoneum as far as the level of the
internal orifice of the urethra. Although the bladder of the infant is usually
described as an abdominal organ, Symington has pointed out that only about
one-half of it lies above the plane of the superior aperture of the pelvis. Disse maintains that the internal urethral orifice sinks
rapidly during the first years, and then more slowly until the ninth year,
after which it remains sta when it again slowly
descends and reaches its adult position.
Theme 2. Male reproductive organs. Structure of
testis and epididimis. Spermatic ducts and accessory reproductive glands
MASCULINE
GENITAL subdivide into internal male sexual organs (testicles, epididymis,
spermatic cord, ductus deferens, seminal vesicles,
prostate gland and bulbourethral gland) and external genital organs (scrotum
and penis). Masculine urethra is not only for passing of urine also for passing
of sperm.
The Testicle is a pair parenchymatic organ, which is situated in scrotum and
produces sperm and masculine sexual hormones. Each testicle has superior
extremity and inferior extremity, medial surface and lateral
surface, anterior margin and posterior margin.
Testicle
is covered by tunica albuginea which on
posterior margin to get in testicle parenchyma and forms testicle mediastinum.
Last gives off septula testis, which
subdivide organ into 150-200 lobules. In each lobule the tubuli seminiferi contorti are situated (1-2), where masculine sexual
cells - spermatozoon produced. Tubuli seminiferi contorti continue into
tubuli seminiferi
recti [straight], and last run into rete testis in mediastinum. Efferent
ductuli (15 - 20) pass from testicle rete
transfixing albuginea membrane, continue into head of
epididymis and form there the lobules of epididymis. Then spermatozoon runs
sufficiently rolled duct of epididymis, which reaches into length
The Epididymis adjoins to
posterior testicle margin. There are head of epididymis, body and
tail of epididymis. Sinus of epididymis is situated between testicle
and body of epididymis.
The
male genitals include the testes,
the ductus deferentes,
the vesiculæ seminales,
the ejaculatory ducts, and the penis, together with the following
accessory structures, viz., the prostate
and the bulbourethral glands.
1. The Testes are two
glandular organs, which secrete the semen; they are suspended in the scrotum by
the spermatic cords. At an early period of fetal life
the testes are contained in the abdominal cavity, behind the peritoneum. Before
birth they descend to the inguinal canal, along which
they pass with the spermatic cord, and, emerging at the subcutaneous inguinal
ring, they descend into the scrotum, becoming invested in their course by
coverings derived from the serous, muscular, and fibrous layers of the
abdominal parietes, as well as by the scrotum.
The
coverings of the testes are, the
Skin
Scrotum.
Cremaster.
Dartos tunic
Infundibuliform fascia.
Intercrural fascia.
Tunica
vaginalis.
The scrotum. On the left side the cavity of the tunica vaginalis has been opened; on the right side only the
layers superficial to the Cremaster have been
removed.
The
Scrotum is a cutaneous pouch
which contains the testes and parts of the spermatic cords. It is divided on
its surface into two lateral portions by a ridge or raphé, which is continued forward to the
under surface of the penis, and backward, along the middle line of the perineum
to the anus. Of these two lateral portions the left hangs lower than the right,
to correspond with the greater length of the left spermatic cord. Its external
aspect varies under different circumstances: thus, under the influence of
warmth, and in old and debilitated persons, it becomes elongated and flaccid;
but, under the influence of cold, and in the young and robust, it is short,
corrugated, and closely applied to the testes.
The
scrotum consists of two layers, the integument
and the dartos tunic.
The
Integument is very thin, of a
brownish color, and generally thrown into folds or rugæ. It is provided with sebaceous follicles, the
secretion of which has a peculiar odor,
and is beset with thinly scattered, crisp hairs, the roots of which are seen
through the skin.
The
Dartos Tunic (tunica dartos)
is a thin layer of non-striped muscular fibers,
continuous, around the base of the scrotum, with the two layers of the
superficial fascia of the groin and the perineum; it sends inward a septum, which
divides the scrotal pouch into two cavities for the testes, and extends between
the raphé and the under surface of the penis,
as far as its root.
Figure
2
(a)
Axial T2- and (b) T1-weighted MR images demonstrating homogenous high T2 and
homogenous intermediate T1 signal intensity in both testes (arrows). (c) Axial
T1-weighted MRI image following administration of IV gadolinium showing
decreased enhancement of the left testis (arrow) compared to the right
(arrowhead). (d) Coronal T1-weighted MRI image demonstrating torsion of left
spermatic cord (arrow).
The scrotum. The penis has been turned upward, and the anterior wall of
the scrotum has been removed. On the right side, the spermatic cord, the infundibuliform fascia, and the Cremaster
muscle are displayed; on the left side, the infundibuliform
fascia has been divided by a longitudinal incision passing along the front of
the cord and the testicle, and a portion of the parietal layer of the tunica vaginalis has been removed to display the testicle and a
portion of the head of the epididymis, which are covered by the visceral layer
of the tunica vaginalis.
The
dartos tunic is closely united to the skin
externally, but connected with the subjacent parts by delicate areolar tissue,
upon which it glides with the greatest facility.
The
Intercrural Fascia (intercolumnar
or external spermatic fascia) is a thin membrane, prolonged downward around
the surface of the cord and testis (see page 411). It is separated from the dartos tunic by loose areolar tissue.
The
Cremaster
consists of scattered bundles of muscular fibers
connected together into a continuous covering by intermediate areolar tissue
(see page 414).
The
Infundibuliform Fascia (tunica vaginalis
communis [testis et funiculi
spermatici]) is a thin layer, which loosely
invests the cord; it is a continuation downward of the transversalis
fascia (see page 418).
The
Tunica Vaginalis
is described with the testes.
Vessels and Nerves.—The arteries supplying the coverings of
the testes are: the superficial and deep external pudendal
branches of the femoral, the superficial perineal
branch of the internal pudendal, and the cremasteric branch from the inferior epigastric.
The veins follow the course of
the corresponding arteries. The lymphatics end in the inguinal lymph glands. The nerves are the ilioinguinal
and lumboinguinal branches of the lumbar plexus, the
two superficial perineal branches of the internal pudendal nerve, and the pudendal
branch of the posterior femoral cutaneous nerve.
The
Inguinal Canal (canalis inguinalis)
is described on page 418.
The
Spermatic Cord (funiculus spermaticus)
extends from the abdominal inguinal ring, where the structures of which it is
composed converge, to the back part of the testis. In the abdominal wall the
cord passes obliquely along the inguinal canal, lying at first beneath the Obliquus internus, and upon the
fascia transversalis; but nearer the pubis, it rests
upon the inguinal and lacunar ligaments, having the aponeurosis
of the Obliquus externus in
front of it, and the inguinal falx behind it. It then
escapes at the subcutaneous ring, and descends nearly vertically into the
scrotum. The left cord is rather longer than the right, consequently the left
testis hangs somewhat lower than its fellow.
Structure of the Spermatic Cord.—The
spermatic cord is composed of arteries, veins, lymphatics,
nerves, and the excretory duct of the testis. These structures are connected
together by areolar tissue, and invested by the layers brought down by the testis in its descent.
The
arteries of the cord are: the
internal and external spermatics; and the artery to
the ductus deferens.
The
internal spermatic artery, a branch of the abdominal aorta, escapes from
the abdomen at the abdominal inguinal ring, and accompanies the other
constituents of the spermatic cord along the inguinal canal and through the
subcutaneous inguinal ring into the scrotum. It then descends to the testis,
and, becoming tortuous, divides into several branches, two or three of which
accompany the ductus deferens and supply the
epididymis, anastomosing with the artery of the ductus
deferens: the others supply the substance of the testis.
The
external spermatic artery is a branch of the inferior epigastric artery. It accompanies the spermatic cord and
supplies the coverings of the cord, anastomosing with the internal spermatic
artery.
The
artery of the ductus deferens, a branch of the
superior vesical, is a long, slender vessel, which
accompanies the ductus deferens, ramifying upon its
coats, and anastomosing with the internal spermatic artery near the testis.
The spermatic cord in the inguinal canal.
The
spermatic veins emerge from the
back of the testis, and receive tributaries from the epididymis: they unite and
form a convoluted plexus, the plexus pampiniformis, which forms the chief mass of the
cord; the vessels composing this plexus are very numerous, and ascend along the
cord in front of the ductus deferens; below the
subcutaneous inguinal ring they unite to form three or four veins, which pass
along the inguinal canal, and, entering the abdomen through the abdominal
inguinal ring, coalesce to form two veins. These again unite to form a single
vein, which opens on the right side into the inferior vena cava, at an acute
angle, and on the left side into the left renal vein, at a right angle.
The
nerves are the spermatic plexus
from the sympathetic, joined by filaments from the pelvic plexus which
accompany the artery of the ductus deferens.
The
scrotum forms an admirable covering for the protection of the testes. These
bodies, lying suspended and loose in the cavity of the scrotum and surrounded
by serous membrane, are capable of great mobility, and can therefore easily
slip about within the scrotum and thus avoid injuries from blows or squeezes.
The skin of the scrotum is very elastic and capable of great distension, and on
account of the looseness and amount of subcutaneous tissue, the scrotum becomes
greatly enlarged in cases of edema, to which this
part is especially liable as a result of its dependent position.
The
Testes are suspended in the
scrotum by the spermatic cords, the left testis hanging somewhat lower than its
fellow. The average dimensions of the testis are from 4 to
The
anterior border and lateral surfaces, as well as both extremities of the organ,
are convex, free, smooth, and invested by the visceral layer of the tunica vaginalis. The posterior border, to
which the cord is attached, receives only a partial investment from that
membrane. Lying upon the lateral edge of this posterior border is a long,
narrow, fiattened body, named the epididymis.
Spermatic veins.
The right testis, exposed by laying open the tunica vaginalis.
The
epididymis consists of a central
portion or body; an upper
enlarged extremity, the head (globus major); and a lower pointed extremity,
the tail (globus
minor), which is continuous with the ductus
deferens, the duct of the testis.
The head is intimately connected with the upper end of the testis by means of
the efferent ductules of the gland; the tail is
connected with the lower end by cellular tissue, and a reflection of the tunica
vaginalis. The lateral surface, head and tail of the
epididymis are free and covered by the serous membrane; the body is also
completely invested by it, excepting along its posterior border; while between
the body and the testis is a pouch, named the sinus of the epididymis (digital fossa). The epididymis is
connected to the back of the testis by a fold of the serous membrane.
Appendages of the Testis and Epididymis.—On
the upper extremity of the testis, just beneath the head of the epididymis, is
a minute oval, sessile body, the appendix
of the testis (hydatid of Morgagni); it is the remnant of the upper end of the Müllerian duct. On the head of the epididymis is a
second small stalked appendage (sometimes duplicated); it is named the appendix of the epididymis (pedunculated hydatid),
and is usually regarded as a detached efferent duct.
The
testis is invested by three tunics: the tunica
vaginalis, tunica albuginea,
and tunica vasculosa.
The
Tunica Vaginalis
(tunica vaginalis propria
testis) is the serous covering of the testis. It is a pouch of serous
membrane, derived from the saccus vaginalis
of the peritoneum, which in the fetus preceded the
descent of the testis from the abdomen into the scrotum. After its descent,
that portion of the pouch which extends from the abdominal inguinal ring to
near the upper part of the gland becomes obliterated; the lower portion remains
as a shut sac, which invests the surface of the testis, and is reflected on to
the internal surface of the scrotum; hence it may be described as consisting of
a visceral and a parietal lamina.
The
visceral lamina (lamina visceralis) covers the greater part of the testis and
epididymis, connecting the latter to the testis by means of a distinct fold.
From the posterior border of the gland it is reflected on to the internal
surface of the scrotum.
The
parietal lamina (lamina parietalis) is far more extensive than the visceral,
extending upward for some distance in front and on the medial side of the cord,
and reaching below the testis. The inner surface of the tunica vaginalis is smooth, and covered by a layer of endothelial
cells. The interval between the visceral and parietal laminæ
constitutes the cavity of the tunica vaginalis.
The
obliterated portion of the saccus vaginalis
may generally be seen as a fibrocellular thread lying
in the loose areolar tissue around the spermatic cord; sometimes this may be
traced as a distinct band from the upper end of the inguinal canal, where it is
connected with the peritoneum, down to the tunica vaginalis;
sometimes it gradually becomes lost on the spermatic cord. Occasionally no
trace of it can be detected. In some cases it happens that the pouch of
peritoneum does not become obliterated, but the sac of the peritoneum
communicates with the tunica vaginalis. This may give
rise to one of the varieties of oblique inguinal hernia (page 1187). In other
cases the pouch may contract, but not become entirely obliterated; it then
forms a minute canal leading from the peritoneum to the tunica vaginalis.
The
Tunica Albuginea
is the fibrous covering of the testis. It is a dense membrane, of a
bluish-white color, composed of bundles of white
fibrous tissue which interlace in every direction. It is covered by the tunica vaginalis, except at the points of attachment of the
epididymis to the testis, and along its posterior border, where the
spermatic vessels enter the gland. It is applied to the tunica vasculosa over the glandular substance of the testis, and,
at its posterior border, is reflected into the interior of the gland, forming
an incomplete vertical septum, called the mediastinum testis (corpus Highmori).
The
mediastinum testis extends from
the upper to near the lower extremity of the gland, and is wider above than
below. From its front and sides numerous imperfect septa (trabeculæ)
are given off, which radiate toward the surface of the organ, and are attached
to the tunica albuginea. They divide the interior of
the organ into a number of incomplete spaces which are somewhat cone-shaped,
being broad at their bases at the surface of the gland, and becoming narrower
as they converge to the mediastinum. The mediastinum supports the vessels and
duct of the testis in their passage to and from the substance of the gland.
The
Tunica Vasculosa
is the vascular layer of the testis, consisting of a plexus of bloodvessels, held together by delicate areolar tissue. It
clothes the inner surface of the tunica albuginea and
the different septa in the interior of the gland, and therefore forms an
internal investment to all the spaces of which the gland is composed.
Vertical section of the testis, to show the arrangement of the ducts.
Structure.—The glandular structure of
the testis consists of numerous lobules. Their number, in a single testis, is
estimated by Berres at 250, and by Krause at 400.
They differ in size according to their position, those in the middle of the
gland being larger and longer. The lobules are conical in shape, the base being
directed toward the circumference of the organ, the apex toward the
mediastinum. Each lobule is contained in one of the intervals between the
fibrous septa which extend between the mediastinum testis and the tunica albuginea, and consists of from one to three, or more,
minute convoluted tubes, the tubuli seminiferi. The tubules may be separately
unravelled, by careful dissection under water, and may be seen to commence
either by free cecal ends or by anastomotic loops.
They are supported by loose connective tissue which contains here and there
groups of “interstitial cells” containing yellow pigment granules. The total
number of tubules is estimated by Lauth at 840, and
the average length of each is 70 to
In
the apices of the lobules, the tubules become less convoluted, assume a nearly
straight course, and unite together to form from twenty to thirty larger ducts,
of about
The
tubuli recti enter the fibrous tissue of the
mediastinum, and pass upward and backward, forming, in their ascent, a close
net-work of anastomosing tubes which are merely channels in the fibrous stroma, lined by flattened epithelium, and having no proper
walls; this constitutes the rete
testis. At the upper end of the mediastinum, the vessels of the rete
testis terminate in from twelve to fifteen or twenty ducts, the ductuli efferentes;
they perforate the tunica albuginea, and carry the
seminal fluid from the testis to the epididymis. Their course is at first
straight; they then become enlarged, and exceedingly convoluted, and form a series
of conical masses, the coni vasculosi, which together constitute the head of the
epididymis. Each cone consists of a single convoluted duct, from 15 to
The
tubuli recti have very thin walls; like the channels
of the rete testis they are lined by a single layer of flattened epithelium.
The ductuli efferentes and
the tube of the epididymis have walls of considerable thickness, on account of
the presence in them of muscular tissue, which is principally arranged in a
circular manner. These tubes are lined by columnar ciliated epithelium.
Peculiarities.—The testis, developed
in the lumbar region, may be arrested or delayed in its transit to the scrotum
(cryptorchism). It may be retained in the
abdomen; or it may be arrested at the abdominal inguinal ring, or in the
inguinal canal; or it may just pass out of the subcutaneous inguinal ring
without finding its way to the bottom of the scrotum. When retained in the
abdomen it gives rise to no symptoms, other than the absence of the testis from
the scrotum; but when it is retained in the inguinal canal it is subjected to
pressure and may become inflamed and painful. The retained testis is probably
functionally useless; so that a man in whom both testes are retained (anorchism) is sterile, though he may not be
impotent. The absence of one testis is termed monorchism.
When a testis is retained in the inguinal canal it is often complicated with a
congenital hernia, the funicular process of the peritoneum not being
obliterated. In addition to the cases above described, where there is some
arrest in the descent of the testis, this organ may descend through the
inguinal canal, but may miss the scrotum and assume some abnormal position. The
most common form is where the testis, emerging at the subcutaneous inguinal
ring, slips down between the scrotum and thigh and comes to rest in the
perineum. This is known as perineal ectopia testis. With each variety of abnormality in the
position of the testis, it is very common to find concurrently a congenital
hernia, or, if a hernia be not actually present, the funicular process is
usually patent, and almost invariably so if the testis is in the inguinal
canal.
The
testis, finally reaching the scrotum, may occupy an abnormal position in it. It
may be inverted, so that its posterior or attached border is directed forward
and the tunica vaginalis is situated behind.
Fluid
collections of a serous character are very frequently found in the scrotum. To
these the term hydrocele is applied. The most common form is the
ordinary vaginal hydrocele, in which the fluid is contained in the sac
of the tunica vaginalis, which is separated, in its
normal condition, from the peritoneal cavity by the whole extent of the
inguinal canal. In another form, the congenital hydrocele, the fluid is
in the sac of the tunica vaginalis, but this cavity
communicates with the general peritoneal cavity, its tubular process remaining
pervious. A third variety known as an infantile hydrocele, occurs in
those cases where the tubular process becomes obliterated only at its upper
part, at or near the abdominal inguinal ring. It resembles the vaginal
hydrocele, except as regards its shape, the collection of fluid extending up
the cord into the inguinal canal. Fourthly, the funicular process may become
obliterated both at the abdominal inguinal ring and above the epididymis,
leaving a central unobliterated portion, which may
become distended with fluid, giving rise to a condition known as the encysted
hydrocele of the cord.
The Ductus deferens has
scrotal part, funicular part, inguinal part and pelvic part. It
enters to composition of spermatic cord, which passes in inguinal canal
to internal ring. Here ductus deferens separates from
seminal funiculus, then it runs under fundus of
urinary bladder. Pelvic part joins with excretorial
duct of seminal vesicles, forming ampoule of ductus
deferens. Attaching ducts generate ejaculatory duct (length
The Spermatic cord is a
formation, which consists of arteries and testicle veins, arteries and veins of
ductus deferens, pampiniform
venous plexus, cremaster muscle, vaginal processes,
nerves, lymphatic vessels and ductus deferens.
The Prostate is a musculо-secretory organ, for shape reminds the chestnut,
has a base of prostate, which adjoins to urinary bladder, and top
of prostate, which is contact with urogenital diaphragm. It has an anterior
surface and posterior surface, right and left lobes of prostate
and isthmus of prostate, that envelops a urethra. Prostate gland consists
of 36 alveolar-tubular glandules, which produce prostate juice and open by
numerous ductuli into prostate part of urethra on
base of seminal tubercle. Muscular apparatus contributes to extrusion of secret
from prostate gland during ejaculation and is as additional (involuntary)
urethral sphincter, which withholds the urine in bladder. Gland in old age
atrophies and its mass diminishes.
Fundus of the bladder with the vesiculæ seminales.
The Seminal vesicles produces a
seminal liquid, it communicate with ductus deferens.
Seminal liquid together with secret of prostate composes part of sperm.
The Bulbourethral gland
is a pair alveolar-tubular gland, which is situated in thickness of urogenital diaphragm.
It has a duct of bulbourethral gland, which passes over bulb of penis and opens
into spongy part of masculine urethra. Gland produces a secret, which protects
mucous membrane of the urethra from irritation by urine.
Theme 3. External reproductive organs. Spermatic
cord. Layers of scrotal wall. Structure of masculine urethra. Topography of
small pelvis organs on male
The Scrotum
is external organ, muscular and fascial sac which
contains testicles and epididymis. Scrotal septum separates right and left
halves. Scrotum is physiological thermostat, which keep temperature of testis
at lower level then temperature of body (necessary for normal spermatogenesis).
Scrotal
wall contains 7 membranes, which cover a testicle and derive from layers of
anterior abdominal wall, namely:
1. Skin - has scrotal raphe, numerous folds, pigmented, with hair
and contains specific sweat and sebaceous glands.
2. Under skin is situated a tunica dartos,
which derives from hypodermic adipose tissue and grows together with skin.
3. External seminal fascia derives from superficial fascia of
anterior abdominal wall.
4. Cremasteric fascia derives
from proper abdominal fascia.
5. Musculus cremaster
derives from internal oblique abdominis and
transversal abdominal muscles.
6. Internal seminal fascia derives from transversal fascia of
abdominal wall.
7. Vaginal tunica is serous membrane (derives from peritoneum)
and consists of visceral plate and parietal plate. Last grows together with albuginea membrane and continues on epididymis. There is
furrow-shaped space between both plates is a vaginal cavity, which is
filled by small amount of serous liquid.
Transverse section through the left side of the scrotum and the left
testis. The sac of the tunica vaginalis is
represented in a distended condition.
The Penis
serves removal of the urine and ejaculation. It has a radix, corpus and
head. Skin which covers the penis in base of head forms the fold – preputium. Last thank to frenulum connects
with skin of head. Penis formed by two cavernous bodies and spongious body. All bodies of penis covered by tunica
albuginea. Spongious
body contains male urethra.
The
penis is a pendulous organ
suspended from the front and sides of the pubic arch and containing the greater
part of the urethra. In the flaccid condition it is cylindrical in shape, but
when erect assumes the form of a triangular prism with rounded angles, one side
of the prism forming the dorsum. It is composed of three cylindrical masses of
cavernous tissue bound together by fibrous tissue and covered with skin. Two of
the masses are lateral, and are known as the corpora cavernosa penis; the third is
median, and is termed the corpus cavernosum urethræ.
The
Corpora Cavernosa
Penis form the greater part of the substance of the penis. For their
anterior three-fourths they lie in intimate apposition with one another, but
behind they diverge in the form of two tapering processes, known as the crura, which are firmly connected to the
rami of the pubic arch. Traced from behind forward, each crus begins by a
blunt-pointed process in front of the tuberosity of the ischium. Just before it
meets its fellow it presents a slight enlargement, named by Kobelt
the bulb of the corpus cavernosum penis. Beyond this point the crus
undergoes a constriction and merges into the corpus cavernosum
proper, which retains a uniform diameter to its anterior end. Each corpus cavernosum penis ends abruptly in a rounded extremity some
distance from the point of the penis.
The
corpora cavernosa penis are surrounded by a strong
fibrous envelope consisting of superficial and deep fibers.
The superficial fibers are longitudinal in direction,
and form a single tube which encloses both corpora; the deep fibers are arranged circularly around each corpus, and form
by their junction in the median plane the septum of the penis. This is thick and complete behind, but is
imperfect in front, where it consists of a series of vertical bands arranged
like the teeth of a comb; it is therefore named the septum pectiniforme.
The
Corpus Cavernosum
Urethræ (corpus spongiosum)
contains the urethra. Behind, it is expanded to form the urethral bulb, and
lies in apposition with the inferior fascia of the urogenital diaphragm, from
which it receives a fibrous investment. The urethra enters the bulb nearer to
the upper than to the lower surface. On the latter there is a median sulcus,
from which a thin fibrous septum projects into the substance of the bulb and
divides it imperfectly into two lateral lobes
or hemispheres.
The constituent cavernous cylinders of the penis.
The glans and anterior part of the corpus cavernosum
urethræ are detached from the corpora cavernosa penis and turned to one side.
Transverse section of the penis.
The portion of the corpus cavernosum urethræ in front
of the bulb lies in a groove on the under surface of the conjoined corpora cavernosa penis. It is cylindrical in form and tapers
slightly from behind forward. Its anterior end is expanded in the form of an
obtuse cone, flattened from above downward. This expansion, termed the glans penis, is moulded on the rounded
ends of the corpora cavernosa penis,
extending farther on their upper than on their lower surfaces. At the summit of
the glans is the slit-like vertical external urethral orifice. The
circumference of the base of the glans forms a rounded projecting border, the corona glandis,
overhanging a deep retroglandular sulcus, behind which is the neck of the penis.
For
descriptive purposes it is convenient to divide the penis into three regions:
the root, the body, and the extremity.
Vertical section of bladder, penis, and urethra.
The
root (radix penis) of the
penis is triradiate in form, consisting of the
diverging crura, one on either side, and the median
urethral bulb. Each crus is covered by the Ischiocavernosus,
while the bulb is surrounded by the Bulbocavernosus.
The root of the penis lies in the perineum between the inferior fascia of the
urogenital diaphragm and the fascia of Colles. In
addition to being attached to the fasciæ and
the pubic rami, it is bound to the front of the symphysis
pubis by the fundiform and suspensory ligaments. The fundiform ligament springs from the front of
the sheath of the Rectus abdominis and the linea alba; it splits into two fasciculi which encircle the
root of the penis. The upper fibers of the suspensory ligament pass downward from
the lower end of the linea alba, and the lower fibers from the symphysis pubis;
together they form a strong fibrous band, which extends to the upper surface of
the root, where it blends with the fascial sheath of
the organ.
The
body (corpus penis)
extends from the root to the ends of the corpora cavernosa
penis, and in it these corpora cavernosa are
intimately bound to one another. A shallow groove which marks their junction on
the upper surface lodges the deep dorsal vein of the penis, while a deeper and
wider groove between them on the under surface contains the corpus cavernosum urethræ. The
body is ensheathed by fascia, which is continuous above
with the fascia of Scarpa, and below with the dartos tunic of the scrotum and the fascia of Colles.
The
extremity is formed by the glans
penis, the expanded anterior end of the corpus cavernosum
urethræ. It is separated from the body by the
constricted neck, which is overhung by the corona glandis.
The
integument covering the penis is remarkable for its thinness, its dark color, its looseness of connection with the deeper parts of
the organ, and its absence of adipose tissue. At the root of the penis it is
continuous with that over the pubes, scrotum, and perineum. At the neck it
leaves the surface and becomes folded upon itself to form the prepuce or foreskin. The internal layer of the prepuce is directly
continuous, along the line of the neck, with the integument over the glans.
Immediately behind the external urethral orifice it forms a small secondary
reduplication, attached along the bottom of a depressed median raphé, which extends from the meatus to the neck;
this fold is termed the frenulum
of the prepuce. The integument covering the glans is continuous with the
urethral mucous membrane at the orifice; it is devoid of haris,
but projecting from its free surface are a number of small, highly sensitive papillæ. Scattered glands on the corona, neck, glans
and inner layer of the prepuce, the preputial glands,
have been described. They secrete a sebaceous material of very peculiar odor, which probably contains casein, and readily undergoes
decomposition; when mixed with discarded epithelial cells it is called smegma.
The
prepuce covers a variable amount of the glans, and is separated from it by a
potential sac—the preputial sac—which presents two shallow fossæ, one on either side of the frenulum.
Structure of the Penis.
—From
the internal surface of the fibrous envelope of the corpora cavernosa
penis, as well as from the sides of the septum, numerous bands or cords are
given off, which cross the interior of these corpora cavernosa
in all directions, subdividing them into a number of separate compartments, and
giving the entire structure a spongy appearance. These bands and cords are
called trabeculæ, and consist of white fibrous tissue,
elastic fibers, and plain muscular fibers. In them are contained numerous arteries and nerves.
The component fibers which form the trabeculæ are larger and stronger around the
circumference than at the centers of the corpora cavernosa; they are also thicker behind than in front. The
interspaces (cavernous spaces), on the contrary, are larger at the center than at the circumference, their long diameters
being directed transversely. They are filled with blood, and are lined by a
layer of flattened cells similar to the endothelial lining of veins.
The
fibrous envelope of the corpus cavernosum urethræ is thinner, whiter in color,
and more elastic than that of the corpora cavernosa
penis. The trabeculæ are more delicate, nearly
uniform in size, and the meshes between them smaller than in the corpora cavernosa penis: their long diameters, for the most part,
corresponding with that of the penis. The external envelope or outer coat of
the corpus cavernosum urethræ
is formed partly of unstriped muscular fibers, and a layer of the same tissue immediately
surrounds the canal of the urethra.
Vessels and Nerves.—The arteries bringing the blood to the
cavernous spaces are the deep arteries of the penis and branches from the
dorsal arteries of the penis, which perforate the fibrous capsule, along the
upper surface, especially near the forepart of the organ. On entering the cavernous
structure the arteries divide into branches, which are supported and enclosed
by the trabeculæ. Some of these arteries end in
a capillary net-work, the branches of which open directly into the cavernous
spaces; others assume a tendril-like appearance, and form convoluted and
somewhat dilated vessels, which were named by Müller helicine arteries. They open into the spaces, and from them are also given
off small capillary branches to supply the trabecular structure. They are bound
down in the spaces by fine fibrous processes, and are most abundant in the back
part of the corpora cavernosa.
Diagram of the arteries of the penis.
The
blood from the cavernous spaces is returned by a series of vessels, some of
which emerge in considerable numbers from the base of the glans penis and
converge on the dorsum of the organ to form the deep dorsal vein; others pass
out on the upper surface of the corpora cavernosa and
join the same vein; some emerge from the under surface of the corpora cavernosa penis and receiving branches from the corpus cavernosum urethræ, wind
around the sides of the penis to end in the deep dorsal vein; but the greater
number pass out at the root of the penis and join the prostatic plexus.
The
nerves are derived from the pudendal nerve and the pelvic plexuses. On the glans and
bulb some filaments of the cutaneous nerves have Pacinian
bodies connected with them, and, according to Krause, many of them end in
peculiar endbulbs (see page 1060).
Veins of the penis.
Masculine
urethra is a tube of length 16-
Prostatic part passes through the prostate. In this
part on the urethral wall is situated seminal colliculus,
on top of which prostatic utriculus disposed.
Ejaculatory duct opens at last and prostatic ductuli
opens on tubercle base. Intermediate (membranous) part of urethra
shorter, it passes through urogenital diaphragm. Described two parts have to
fixed position within pelvis and perineum. Spongy part of urethra lies
in spongious body of penis and opens by external
urethral ostium on head top.
Male urethra
has following constrictions: external urethral ostium
on head of penis; membranous part of urethra; internal urethral ostium. Also a urethra has such expansions: all
prostatic part; expansion in bulb of penis; scaphoid fossa in head of penis.
Prepared
by
A.V. MIZ