1. Lymphatic vessels and nodes of the neck

2. System of internal jugular vein

3. Superficial veins of the neck

 

Lesson No 27

Theme 1. Lymphatic vessels and nodes of the neck

Lymphatic system subdivides into primary lymphatic organs (marrow medulla ossium and thymus), secondary lymphatic organs (spleen, lymphatic pharyngeal ring, lymphatic nodes). Beside lymphatic organs, a lymphatic system has close vessel system and is part of vascular system. Lymph is a liquid, like a blood plasma it brings out the metabolic products from tissues.

Function of lymphatic system:

          taking of lymph from tissues to venous channel (drainage);

          lymphopoetic (marrow, thymic gland, lymphatic nodes);

          immune

          barrier (neutralizing foreign elements which got to organism).

Malignant cells spread (metastasis) by lymphatic channels.

Lymphatic system the following attributes, which make it like a venous system:

          vessels have the valves;

          lymph flows from tissues to heart.

Characteristics which differ lymphatic system from venous one:

          lymphatic nodes are situated on course of lymphatic channels;

          lymphatic system is tubular vessel system, which is close on one hand, and second - open into venous flow.

Lymphatic vessels are absent in central nervous system, spleen parenchyma, skin epithelium, cartilage, cornea, lens, placenta, hypophysis, and internal ear.



Scheme showing relative positions of primary lymph sacs

 

Vessel portion of lymphatic system consists of: 1) capillary networks which collect the lymph in the various organs and tissues; 2) vessels, 3) trunks, 4) ducts on which ways 5) nodes are located.

The Capillaries have the lateral recesses and form close net. In volumetric organs (kidneys, liver) they have three dimensions structure. In flat walls of hollow organs they are disposed in plane. Their wall consists of one layer of endothelial cells.



Lymph capillaries of the human conjunctiva: a, conjunctiva corneæ; b, conjunctiva scleroticæ

 

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The Vessels subdivide into intraorganc and extraorganc, which subdivide into deep and superficial. Vessels have the valves, their wall consists of following layers: 1) endotelial (internal membrane); 2) muscular; 3) external membrane.

The Lymphatic nodes dispose on course of lymphatic vessels. They are organs of lymphopoesis and formation of antibodies, in pursuance the role of lymphoreticular filter.

Follow nodes are distinguished:

1.     regional are the that carry a lymph from some body area or organ;

2.     nodes have a name of accompany vessels;

3.     superficial nodes;

4.     deep nodes are situated under fascia;

5.     visceral nodes are situated in body cavities;

6.     parietal nodes are situated in walls of body cavities.

Each ganglion is covered outer by fibrous envelope - capsule, from which a frame-work of processes (trabeculæ) proceeds inward. On node surface carries the concave place - hilus, where arteries and nerves enter into node, and the veins and efferent lymphatic vessels leave the interior. Node is built from stroma and parenchyma. Stroma of node consists of reticular tissue, where blood cells (mainly lymphocytes) disposed in loops. Cortex and medulla represent node parenchyma. Medullar sinuses are situated in lymphoid tissue, they are disposed between trabeculae and by bands of medulla, where lymph flows. The afferent vessels carry lymph into node and sinuses, efferent vessels commences from interior and transport lymph to the next lymphatic nodes, trunks and ducts.

Lymphatic Trunks:

1) subclavian trunk (right and left); 2) jugular trunk (right and left); 3) bronch-mediastinal trunk (right and left). They collect lymph from suitable half of head, neck, upper limbs, left or right half of thoracic cavity. These trunks fall into right venous angle or into left venous angle are these venous angles which are formed by subclavian vein and internal jugular vein. 4) lumbar trunk (right and left) collects lymph from lower limbs.

Lymphatic Ducts:

Thoracic duct forms in abdominal cavity on level of ղ thoracic - lumbar vertebrae by the confluence of right and left lumbar lymphatic trunks. There is triangular dilatation, the cisterna chyli or cistern of thoracic duct in this spot. Duct has abdominal part, thoracic part, cervical part and arch of thoracic duct. Last rounds a pleura cupola and ends by opening into the angle of junction of the left subclavian vein with the left internal jugular vein. In thoracic cavity a thoracic duct is situated in posterior mediastinum. It collects lymph from both lower limbs, abdominal, pelvic and left half of thoracic cavities.

Right lymphatic duct is short, by length 10-12 mm, which is formed by confluence of right subclavian trunk, jugular trunk and bronch-mediastinal trunk and runs into right venous angle. This duct transports lymph from right half of head, neck, right upper limb, right half of thoracic cavity. Frequently this duct can be absent, then the trunks independently fall into right venous angle or into terminal portion of thoracic duct.

The Lymphatics of the Head, Face, and Neck

Lymph from head and neck gathers into right and left jugular lymphatic trunks, which pass on each side near internal jugular vein and fall: right - into right lymphatic duct or into right venous angle and left - into thoracic duct or immediately into left venous angle. Before duct lymph passes through regional lymphatic nodes.

Lymph from head runs into nodes positioned on boundary between head and neck. They include the following: 1) occipital nodes, 2) mastoid nodes, 3) superficial parotid nodes, 4) deep parotid nodes, 5) submandibular nodes, 6) facial nodes, 7) submental. Efferent vessels from these nodes extend in deep cervical nodes.

There are two groups of lymphatic nodes on neck - anterior cervical nodes and lateral

cervical nodes, which subdivide into superficial and deep. Anterior deep lymphatic nodes: prelaryngeal nodes, thyroid nodes, pretracheal nodes, paratracheal nodes. The superficial lateral nodes lie along external jugular vein, and deep - along internal jugular vein.

The lymph nodes of the head are arranged in the following groups:

Occipital.

Facial.

Posterior Auricular.

Deep Facial.

Anterior Auricular.

Lingual.

Parotid.

Retropharyngeal.

  The occipital nodes (lymphoglandulæ occipitales), one to three in nu ber, are placed on the back of the head close to the margin of the Trapezius and resting on the insertion of the Semispinalis capitis. Their afferent vessels drain the occipital region of the scalp, while their efferents pass to the superior deep cervical glands.

  The posterior auricular nodes (lymphoglandulæ auriculares; mastoid glands), usually two in number, are situated on the mastoid insertion of the Sternocleidomastoideus, beneath the Auricularis posterior. Their afferent vessels drain the posterior part of the temporoparietal region, the upper part of the cranial surface of the auricula or pinna, and the back of the external acoustic meatus; their efferents pass to the superior deep cervical glands.



Superficial lymph glands and lymphatic vessels of head and neck.

 

  The anterior auricular nodes (lymphoglandulæ auriculares anteriores; superficial parotid or preauricular nodes), from one to three in number, lie immediately in front of the tragus. Their afferents drain the lateral surface of the auricula and the skin of the adjacent part of the temporal region; their efferents pass to the superior deep cervical nodes.

  The parotid nodes (lymphoglandulæ parotideæ), form two groups in relation with the parotid salivary gland, viz., a group imbedded in the substance of the gland, and a group of subparotid nodes lying on the lateral wall of the pharynx. Occasionally small nodes are found in the subcutaneous tissue over the parotid gland. Their afferent vessels drain the root of the nose, the eyelids, the frontotemporal region, the external acoustic meatus and the tympanic cavity, possibly also the posterior parts of the palate and the floor of the nasal cavity. The efferents of these nodes pass to the superior deep cervical nodes. The afferents of the subparotid glands drain the nasal part of the pharynx and the posterior parts of the nasal cavities; their efferents pass to the superior deep cervical glands.

  The facial nodes comprise three groups: (a) infraorbital or maxillary, scattered over the infraorbital region from the groove between the nose and cheek to the zygomatic arch; (b) buccinator, one or more placed on the Buccinator opposite the angle of the mouth; (c) supramandibular, on the outer surface of the mandible, in front of the Masseter and in contact with the external maxillary artery and anterior facial vein. Their efferent vessels drain the eyelids, the conjunctiva, and the skin and mucous membrane of the nose and cheek; their efferents pass to the submandibular glands.

  The deep facial nodes (lymphoglandulæ faciales profunda; internal maxillary glands) are placed beneath the ramus of the mandible, on the outer surface of the Pterygoideus externus, in relation to the internal maxillary artery. Their afferent vessels drain the temporal and infratemporal fossæ and the nasal part of the pharynx their efferents pass to the superior deep cervical glands.

  The lingual nodes (lymphoglandulæ linguales) are two or three small nodules lying on the Hyoglossus and under the Genioglossus. They form merely glandular substations in the course of the lymphatic vessels of the tongue.



Lymphatics of pharynx.

 

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  The retropharyngeal nodes (603), from one to three in number, lie in the buccopharyngeal fascia, behind the upper part of the pharynx and in front of the arch of the atlas, being separated, however, from the latter by the Longus capitis. Their afferents drain the nasal cavities, the nasal part of the pharynx, and the auditory tubes; their efferents pass to the superior deep cervical glands.

  The lymphatic vessels of the scalp are divisible into (a) those of the frontal region, which terminate in the anterior auricular and parotid glands; (b) those of the temporoparietal region, which end in the parotid and posterior auricular glands; and (c) those of the occipital region, which terminate partly in the occipital glands and partly in a trunk which runs down along the posterior border of the Sternocleidomastoideus to end in the inferior deep cervical glands.

  The lymphatic vessels of the auricula and external acoustic meatus are also divisible into three groups: (a) an anterior, from the lateral surface of the auricula and anterior wall of the meatus to the anterior auricular glands; (b) a posterior, from the margin of the auricula, the upper part of its cranial surface, the internal surface and posterior wall of the meatus to the posterior auricular and superior deep cervical glands; (c) an inferior, from the floor of the meatus and from the lobule of the auricula to the superficial and superior deep cervical glands.

  The lymphatic vessels of the face (604) are more numerous than those of the scalp. Those from the eyelids and conjunctiva terminate partly in the submandibular but mainly in the parotid glands. The vessels from the posterior part of the cheek also pass to the parotid glands, while those from the anterior portion of the cheek, the side of the nose, the upper lip, and the lateral portions of the lower lip end in the submandibular glands. The deeper vessels from the temporal and infratemporal fossæ pass to the deep facial and superior deep cervical nodes. The deeper vessels of the cheek and lips end, like the superficial, in the submandibular glands. Both superficial and deep vessels of the central part of the lower lip run to the submental glands.



The lymphatics of the face.

 

 

Lymphatic Vessels of the Nasal Cavities.Those from the anterior parts of the nasal cavities communicate with the vessels of the integument of the nose and end in the submandibular glands; those from the posterior two-thirds of the nasal cavities and from the accessory air sinuses pass partly to the retropharyngeal and partly to the superior deep cervical glands.

 

Lymphatic Vessels of the Mouth.The vessels of the gums pass to the submandibular glands; those of the hard palate are continuous in front with those of the upper gum, but pass backward to pierce the Constrictor pharyngis superior and end in the superior deep cervical and subparotid glands; those of the soft palate pass backward and lateralward and end partly in the retropharyngeal and subparotid, and partly in the superior deep cervical glands. The vessels of the anterior part of the floor of the mouth pass either directly to the inferior glands of the superior deep cervical group, or indirectly through the submental glands; from the rest of the floor of the mouth the vessels pass to the submandibular and superior deep cervical glands.

  The lymphatic vessels of the palatine tonsil, usually three to five in number, pierce the buccopharyngeal fascia and constrictor pharyngis superior and pass between the Stylohyoideus and internal jugular vein to the uppermost of the superior deep cervical glands. They end in a gland which lies at the side of the posterior belly of the Digastricus, on the internal jugular vein; occasionally one or two additional vessels run to small glands on the lateral side of the vein under cover of the Sternocleidomastoideus.



Lymphatics of the tongue.

 

  The lymphatic vessels of the tongue (605) are drained chiefly into the deep cervical glands lying between the posterior belly of the Digastricus and the superior belly of the Omohyoideus; one gland situated at the bifurcation of the common carotid artery is so intimately associated with these vessels that it is known as the principal node of the tongue. The lymphatic vessels of the tongue may be divided into four groups: (1) apical, from the tip of the tongue to the suprahyoid glands and principal gland of the tongue; (2) lateral, from the margin of the tonguesome of these pierce the Mylohyoideus to end in the submandibular glands, others pass down on the Hyoglossus to the superior deep cervical glands; (3) basal, from the region of the vallate papillæ to the superior deep cervical glands; and (4) median, a few of which perforate the Mylohyoideus to reach the submandibular glands, while the majority turn around the posterior border of the muscle to enter the superior deep cervical glands.

 

The Lymph nodes of the NeckThe lymph nodes of the neck include the following groups:

Submandibular.

 

Superficial Cervical.

Submental.

 

Anterior Cervical.

Deep Cervical.

 

  The submandibular nodes (lymphoglandulæ submaxillares) (604), three to six in number, are placed beneath the body of the mandible in the submandibular triangle, and rest on the superficial surface of the submandibular salivary gland. One gland, the middle node of Stahr, which lies on the external maxillary artery as it turns over the mandible, is the most constant of the series; small lymph nodes are sometimes found on the deep surface of the submandibular salivary glands. The afferents of the submandibular glands drain the medial palpebral commissure, the cheek, the side of the nose, the upper lip, the lateral part of the lower lip, the gums, and the anterior part of the margin of the tongue; efferent vessels from the facial and submental glands also enter the submandibular glands. Their efferent vessels pass to the superior deep cervical glands.

  The submental or suprahyoid nodes are situated between the anterior bellies of the Digastrici. Their afferents drain the central portions of the lower lip and floor of the mouth and the apex of the tongue; their efferents pass partly to the submandibular glands and partly to a gland of the deep cervical group situated on the internal jugular vein at the level of the cricoid cartilage.

  The superficial cervical nodes (lymphoglandulæ cervicales superficiales) lie in close relationship with the external jugular vein as it emerges from the parotid gland, and, therefore, superficial to the Sternocleidomastoideus. Their afferents drain the lower parts of the auricula and parotid region, while their efferents pass around the anterior margin of the Sternocleidomastoideus to join the superior deep cervical glands.

  The anterior cervical nodes form an irregular and inconstant group on the front of the larynx and trachea. They may be divided into (a) a superficial set, placed on the anterior jugular vein; (b) a deeper set, which is further subdivided into prelaryngeal, on the middle cricothyroid ligament, and pretracheal, on the front of the trachea. This deeper set drains the lower part of the larynx, the thyroid gland, and the upper part of the trachea; its efferents pass to the lowest of the superior deep cervical glands.

  The deep cervical nodes (lymphoglandulæ cervicales profundæ) (602, 605) are numerous and of large size: they form a chain along the carotid sheath, lying by the side of the pharynx, esophagus, and trachea, and extending from the base of the skull to the root of the neck. They are usually described in two groups: (1) the superior deep cervical glands lying under the Sternocleidomastoideus in close relation with the accessory nerve and the internal jugular vein, some of the glands lying in front of and others behind the vessel; (2) the inferior deep cervical glands extending beyond the posterior margin of the Sternocleidomastoideus into the supraclavicular triangle, where they are closely related to the brachial plexus and subclavian vein. A few minute paratracheal glands are situated alongside the recurrent nerves on the lateral aspects of the trachea and esophagus. The superior deep cervical glands drain the occipital portion of the scalp, the auricula, the back of the neck, a considerable part of the tongue, the larynx, thyroid gland, trachea, nasal part of the pharynx, nasal cavities, palate, and esophagus. They receive also the efferent vessels from all the other glands of the head and neck, except those from the inferior deep cervical glands. The inferior deep cervical glands drain the back of the scalp and neck, the superficial pectoral region, part of the arm (see page 701), and, occasionally, part of the superior surface of the liver, In addition, they receive vessels from the superior deep cervical glands. The efferents of the superior deep cervical glands pass partly to the inferior deep cervical glands and partly to a trunk which unites with the efferent vessel of the inferior deep cervical glands and forms the jugular trunk. On the right side, this trunk ends in the junction of the internal jugular and subclavian veins; on the left side it joins the thoracic duct.

  The lymphatic vessels of the skin and muscles of the neck pass to the deep cervical glands. From the upper part of the pharynx the lymphatic vessels pass to the retropharyngeal, from the lower part to the deep cervical glands. From the larynx two sets of vessels arise, an upper and a lower. The vessels of the upper set pierce the hyothyroid membrane and join the superior deep cervical glands. Of the lower set, some pierce the conus elasticus and join the pretracheal and prelaryngeal glands; others run between the cricoid and first tracheal ring and enter the inferior deep cervical glands. The lymphatic vessels of the thyroid gland consist of two sets, an upper, which accompanies the superior thyroid artery and enters the superior deep cervical glands, and a lower, which runs partly to the pretracheal glands and partly to the small paratracheal glands which accompany the recurrent nerves. These latter glands receive also the lymphatic vessels from the cervical portion of the trachea.

 

Lymphatic annulus of pharynx belongs to secondary lymphatic organs and consists of lingual tonsil, palatine tonsil, pharyngeal tonsil and tubarius tonsil. They have tonsillar cryptae and tonsillar fossulae and lymphatic nodules. These tonsils are described in part pharynx". Tonsils are agglomerations of lymphoid tissue, which is disposed in area of entrance to pharynx and nasopharynx. They are placed around initial portions of high respiratory and digestive paths (lymphoepithelial ring of Pyrohov-Valdeyer).

 

 

 

 

Theme 2. System of internal jugular vein

SYSTEM of internal jugular vein and SUPERIOR VENA CAVA

Superior vena cava is generated by reason of confluence of right and left brachiocephalic veins behind joint of cartilage of first right rib with sternum. Superior vena cava on level of third right cartilage empties into right atrium. Azygos vein empties into superior vena cava from right side.

Brachiocephalic veins form by the confluence of subclavian vein, internal jugular and sometimes External jugular vein. This place is called as venous angle, where thoracic lymphatic duct empties (left side), and right lymphatic duct (right side). Inferior thyroid veins from thyroid plexus, inferior laryngeal vein and thymic vein, pericardial veins from pericardium, bronchic veins and esophageal veins from esophagus fall into brachiocephalic veins.

Azygos vein continues into thoracic cavity from right ascending lumbar vein. Azygos vein receives posterior intercostal veins, esophageal veins, bronchic veins, pericardial veins and mediastinal veins, also hemizygos vein.

Internal jugular vein is a largest vessel, which drainage blood from area of head and neck. Internal jugular vein originates from sygmoid sinus of dura mater encephali, where it begins on level of jugular foramen by superior bulb and lies behind internal carotid artery and vagus nerve. Inferior jugular bulb is situated near the confluence with subclavian vein.

Internal jugular has the following extracranial influxes:

pharyngeal veins;

lingual vein;

superior thyroid vein;

facial vein, which receives retromandibular vein

retromandibular vein empties into facial vein, or into internal jugular vein.

Follow vessels belong to intracranial tributaries of internal jugular vein:

venous sinuses of dura mater encephali and veins of brain:

The veins of the brain possess no valves, and their walls, owing to the absence of muscular tissue, are extremely thin. They pierce the arachnoid membrane and the inner or meningeal layer of the dura mater, and open into the cranial venous sinuses. They may be divided into two sets, cerebral and cerebellar.

  The cerebral veins (vv. cerebri) are divisible into external and internal groups according as they drain the outer surfaces or the inner parts of the hemispheres.

  The external veins are the superior, inferior, and middle cerebral.

  The Superior Cerebral Veins (vv. cerebri superiores), eight to twelve in number, drain the superior, lateral, and medial surfaces of the hemispheres, and are mainly lodged in the sulci between the gyri, but some run across the gyri. They open into the superior sagittal sinus; the anterior veins runs nearly at right angles to the sinus; the posterior and larger veins are directed obliquely forward and open into the sinus in a direction more or less opposed to the current of the blood contained within it.

  The Middle Cerebral Vein (v. cerebri media; superficial Sylvian vein) begins on the lateral surface of the hemisphere, and, running along the lateral cerebral fissure, ends in the cavernous or the sphenoparietal sinus. It is connected (a) with the superior sagittal sinus by the great anastomotic vein of Trolard, which opens into one of the superior cerebral veins; (b) with the transverse sinus by the posterior anastomotic vein of Labbé, which courses over the temporal lobe.

  The Inferior Cerebral Veins (vv. cerebri inferiores), of small size, drain the under surfaces of the hemispheres. Those on the orbital surface of the frontal lobe join the superior cerebral veins, and through these open into the superior sagittal sinus; those of the temporal lobe anastomose with the middle cerebral and basal veins, and join the cavernous, sphenoparietal, and superior petrosal sinuses.

  The basal vein is formed at the anterior perforated substance by the union of (a) a small anterior cerebral vein which accompanies the anterior cerebral artery, (b) the deep middle cerebral vein (deep Sylvian vein), which receives tributaries from the insula and neighboring gyri, and runs in the lower part of the lateral cerebral fissure, and (c) the inferior striate veins, which leave the corpus striatum through the anterior perforated substance. The basal vein passes backward around the cerebral peduncle, and ends in the internal cerebral vein (vein of Galen); it receives tributaries from the interpeduncular fossa, the inferior horn of the lateral ventricle, the hippocampal gyrus, and the mid-brain.

  The Internal Cerebral Veins (vv. cerebri internæ; veins of Galen; deep cerebral veins) drain the deep parts of the hemisphere and are two in number; each is formed near the interventricular foramen by the union of the terminal and choroid veins. They run backward parallel with one another, between the layers of the tela chorioidea of the third ventricle, and beneath the splenium of the corpus callosum, where they unite to form a short trunk, the great cerebral vein; just before their union each receives the corresponding basal vein.

  The terminal vein (v. terminalis; vena corporis striati) commences in the groove between the corpus striatum and thalamus, receives numerous veins from both of these parts, and unites behind the crus fornicis with the choroid vein, to form one of the internal cerebral veins. The choroid vein runs along the whole length of the choroid plexus, and receives veins from the hippocampus, the fornix, and the corpus callosum.



Velum interpositum.

 

  The Great Cerebral Vein (v. cerebri magna [Galeni]; great vein of Galen) (565), formed by the union of the two internal cerebral veins, is a short median trunk which curves backward and upward around the splenium of the corpus callosum and ends in the anterior extremity of the straight sinus.

  The cerebellar veins are placed on the surface of the cerebellum, and are disposed in two sets, superior and inferior. The superior cerebellar veins (vv. cerebelli superiores) pass partly forward and medialward, across the superior vermis, to end in the straight sinus and the internal cerebral veins, partly lateralward to the transverse and superior petrosal sinuses. The inferior cerebellar veins (vv. cerebelli inferiores) of large size, end in the transverse, superior petrosal, and occipital sinuses.

 

The sinuses of the dura mater are venous channels which drain the blood from the brain; they are devoid of valves, and are situated between the two layers of the dura mater and lined by endothelium continuous with that which lines the veins. They may be divided into two groups: (1) a postero-superior, at the upper and back part of the skull, and (2) an antero-inferior, at the base of the skull.

  The postero-superior group comprises the

Superior Sagittal.

Straight.

Inferior Sagittal.

Two Transverse.

Occipital.

 



Superior sagittal sinus laid open after remova of the skull cap. The chordæ Willisii are clearly seen. The venous lacunæ are also well shown; from two of them probes are passed into the superior sagittal sinus.

 

  The superior sagittal sinus (sinus sagittalis superior; superior longitudinal sinus) (566, 567) occupies the attached or convex margin of the falx cerebri. Commencing at the foramen cecum, through which it receives a vein from the nasal cavity, it runs from before backward, grooving the inner surface of the frontal, the adjacent margins of the two parietals, and the superior division of the cruciate eminence of the occipital; near the internal occipital protuberance it deviates to one or other side (usually the right), and is continued as the corresponding transverse sinus. It is triangular in section, narrow in front, and gradually increases in size as it passes backward. Its inner surface presents the openings of the superior cerebral veins, which run, for the most part, obliquely forward, and open chiefly at the back part of the sinus, their orifices being concealed by fibrous folds; numerous fibrous bands (chordæ Willisii) extend transversely across the inferior angle of the sinus; and, lastly, small openings communicate with irregularly shaped venous spaces (venous lacunæ) in the dura mater near the sinus. There are usually three lacunæ on either side of the sinus: a small frontal, a large parietal, and an occipital, intermediate in size between the other two (Sargent 106). Most of the cerebral veins from the outer surface of the hemisphere open into these lacunæ, and numerous arachnoid granulations (Pacchionian bodies) project into them from below. The superior sagittal sinus receives the superior cerebral veins, veins from the diploë and dura mater, and, near the posterior extremity of the sagittal suture, veins from the pericranium, which pass through the parietal foramina.

  The numerous communications exist between this sinus and the veins of the nose, scalp, and diploë.



Dura mater and its processes exposed by removing part of the right half of the skull, and the brain.

 

  The inferior sagittal sinus (sinus sagittalis inferior; inferior longitudinal sinus) (567) is contained in the posterior half or two-thirds of the free margin of the falx cerebri. It is of a cylindrical form, increases in size as it passes backward, and ends in the straight sinus. It receives several veins from the falx cerebri, and occasionally a few from the medial surfaces of the hemispheres.

  The straight sinus (sinus rectus; tentorial sinus) (567, 569) is situated at the line of junction of the falx cerebri with the tentorium cerebelli. It is triangular in section, increases in size as it proceeds backward, and runs downward and backward from the end of the inferior sagittal sinus to the transverse sinus of the opposite side to that into which the superior sagittal sinus is prolonged. Its terminal part communicates by a cross branch with the confluence of the sinuses. Besides the inferior sagittal sinus, it receives the great cerebral vein (great vein of Galen) and the superior cerebellar veins. A few transverse bands cross its interior.



Sagittal section of the skull, showing the sinuses of the dura.

 



The sinuses at the base of the skull.

 

 

  The transverse sinuses (sinus transversus; lateral sinuses) (569, 570) are of large size and begin at the internal occipital protuberance; one, generally the right, being the direct continuation of the superior sagittal sinus, the other of the straight sinus. Each transverse sinus passes lateralward and forward, describing a slight curve with its convexity upward, to the base of the petrous portion of the temporal bone, and lies, in this part of its course, in the attached margin of the tentorium cerebelli; it then leaves the tentorium and curves downward and medialward to reach the jugular foramen, where it ends in the internal jugular vein. In its course it rests upon the squama of the occipital, the mastoid angle of the parietal, the mastoid part of the temporal, and, just before its termination, the jugular process of the occipital; the portion which occupies the groove on the mastoid part of the temporal is sometimes termed the sigmoid sinus. The transverse sinuses are frequently of unequal size, that formed by the superior sagittal sinus being the larger; they increase in size as they proceed from behind forward. On transverse section the horizontal portion exhibits a prismatic, the curved portion a semicylindrical form. They receive the blood from the superior petrosal sinuses at the base of the petrous portion of the temporal bone; they communicate with the veins of the pericranium by means of the mastoid and condyloid emissary veins; and they receive some of the inferior cerebral and inferior cerebellar veins, and some veins from the diploë. The petrosquamous sinus, when present, runs backward along the junction of the squama and petrous portion of the temporal, and opens into the transverse sinus.

  The occipital sinus (sinus occipitalis) (570) is the smallest of the cranial sinuses. It is situated in the attached margin of the falx cerebelli, and is generally single, but occasionally there are two. It commences around the margin of the foramen magnum by several small venous channels, one of which joins the terminal part of the transverse sinus; it communicates with the posterior internal vertebral venous plexuses and ends in the confluence of the sinuses.

  The Confluence of the Sinuses (confluens sinuum; torcular Herophili) is the term applied to the dilated extremity of the superior sagittal sinus. It is of irregular form, and is lodged on one side (generally the right) of the internal occipital protuberance. From it the transverse sinus of the same side is derived. It receives also the blood from the occipital sinus, and is connected across the middle line with the commencement of the transverse sinus of the opposite side.

  The antero-inferior group of sinuses comprises the

Two Cavernous.

Two Superior Petrosal.

Two Intercavernous

Two Inferior Petrosal.

Basilar Plexus.

  The cavernous sinuses (sinus cavernosus) (570, 571) are so named because they present a reticulated structure, due to their being traversed by numerous interlacing filaments. They are of irregular form, larger behind than in front, and are placed one on either side of the body of the sphenoid bone, extending from the superior orbital fissure to the apex of the petrous portion of the temporal bone. Each opens behind into the petrosal sinuses. On the medial wall of each sinus is the internal carotid artery, accompanied by filaments of the carotid plexus; near the artery is the abducent nerve; on the lateral wall are the oculomotor and trochlear nerves, and the ophthalmic and maxillary divisions of the trigeminal nerve (571). These structures are separated from the blood flowing along the sinus by the lining membrane of the sinus. The cavernous sinus receives the superior ophthalmic vein through the superior orbital fissure, some of the cerebral veins, and also the small sphenoparietal sinus, which courses along the under surface of the small wing of the sphenoid. It communicates with the transverse sinus by means of the superior petrosal sinus; with the internal jugular vein through the inferior petrosal sinus and a plexus of veins on the internal carotid artery; with the pterygoid venous plexus through the foramen Vesalii, foramen ovale, and foramen lacerum, and with the angular vein through the ophthalmic vein. The two sinuses also communicate with each other by means of the anterior and posterior intercavernous sinuses.



Oblique section through the cavernous sinus.

 

  The ophthalmic veins (572), two in number, superior and inferior, are devoid of valves.

  The Superior Ophthalmic Vein (v. ophthalmica superior) begins at the inner angle of the orbit in a vein named the nasofrontal which communicates anteriorly with the angular vein; it pursues the same course as the ophthalmic artery, and receives tributaries corresponding to the branches of that vessel. Forming a short single trunk, it passes between the two heads of the Rectus lateralis and through the medial part of the superior orbital fissure, and ends in the cavernous sinus.

  The Inferior Ophthalmic Vein (v. ophthalmica inferior) begins in a venous net-work at the forepart of the floor and medial wall of the orbit; it receives some veins from the Rectus inferior, Obliquus inferior, lacrimal sac and eyelids, runs backward in the lower part of the orbit and divides into two branches. One of these passes through the inferior orbital fissure and joins the pterygoid venous plexus, while the other enters the cranium through the superior orbital fissure and ends in the cavernous sinus, either by a separate opening, or more frequently in common with the superior ophthalmic vein.



Veins of orbit.

 

  The intercavernous sinuses (sini intercavernosi) (570) are two in number, an anterior and a posterior, and connect the two cavernous sinuses across the middle line. The anterior passes in front of the hypophysis cerebri, the posterior behind it, and they form with the cavernous sinuses a venous circle (circular sinus) around the hypophysis. The anterior one is usually the larger of the two, and one or other is occasionally absent.

  The superior petrosal sinus (sinus petrosus superior) (570) small and narrow, connects the cavernous with the transverse sinus. It runs lateralward and backward, from the posterior end of the cavernous sinus, over the trigeminal nerve, and lies in the attached margin of the tentorium cerebelli and in the superior petrosal sulcus of the temporal bone; it joins the transverse sinus where the latter curves downward on the inner surface of the mastoid part of the temporal. It receives some cerebellar and inferior cerebral veins, and veins from the tympanic cavity.

  The inferior petrosal sinus (sinus petrosus inferior) (570) is situated in the inferior petrosal sulcus formed by the junction of the petrous part of the temporal with the basilar part of the occipital. It begins in the postero-inferior part of the cavernous sinus, and, passing through the anterior part of the jugular foramen, ends in the superior bulb of the internal jugular vein. The inferior petrosal sinus receives the internal auditory veins and also veins from the medulla oblongata, pons, and under surface of the cerebellum.

  The exact relation of the parts to one another in the jugular foramen is as follows: the inferior petrosal sinus lies medially and anteriorly with the meningeal branch of the ascending pharyngeal artery, and is directed obliquely downward and backward; the transverse sinus is situated at the lateral and back part of the foramen with a meningeal branch of the occipital artery, and between the two sinuses are the glossopharyngeal, vagus, and accessory nerves. These three sets of structures are divided from each other by two processes of fibrous tissue. The junction of the inferior petrosal sinus with the internal jugular vein takes place on the lateral aspect of the nerves.

  The basilar plexus (plexus basilaris; transverse or basilar sinus) (571) consists of several interlacing venous channels between the layers of the dura mater over the basilar part of the occipital bone, and serves to connect the two inferior petrosal sinuses. It communicates with the anterior vertebral venous plexus.

 

Emissary Veins (emissaria).The emissary veins pass through apertures in the cranial wall and establish communication between the sinuses inside the skull and the veins external to it. Some are always present, others only occasionally so. The principal emissary veins are the following: (1) A mastoid emissary vein, usually present, runs through the mastoid foramen and unites the transverse sinus with the posterior auricular or with the occipital vein. (2) A parietal emissary vein passes through the parietal foramen and connects the superior sagittal sinus with the veins of the scalp. (3) A net-work of minute veins (rete canalis hypoglossi) traverses the hypoglossal canal and joins the transverse sinus with the vertebral vein and deep veins of the neck. (4) An inconstant condyloid emissary vein passes through the condyloid canal and connects the transverse sinus with the deep veins of the neck. (5) A net-work of veins (rete foraminis ovalis) unites the cavernous sinus with the pterygoid plexus through the foramen ovale. (6) Two or three small veins run through the foramen lacerum and connect the cavernous sinus with the pterygoid plexus. (7) The emissary vein of the foramen of Vesalius connects the same parts. (8) An internal carotid plexus of veins traverses the carotid canal and unites the cavernous sinus with the internal jugular vein. (9) A vein is transmitted through the foramen cecum and connects the superior sagittal sinus with the veins of the nasal cavity.

 

diploic veins from skull bones:

The diploic veins (564) occupy channels in the diploë of the cranial bones. They are large and exhibit at irregular intervals pouch-like dilatations; their walls are thin, and formed of endothelium resting upon a layer of elastic tissue.

  So long as the cranial bones are separable from one another, these veins are confined to the particular bones; but when the sutures are obliterated, they unite with each other, and increase in size. They communicate with the meningeal veins and the sinuses of the dura mater, and with the veins of the pericranium. They consist of (1) the frontal, which opens into the supraorbital vein and the superior sagittal sinus; (2) the anterior temporal, which is confined chiefly to the frontal bone, and opens into the sphenoparietal sinus and into one of the deep temporal veins, through an aperture in the great wing of the sphenoid; (3) the posterior temporal, which is situated in the parietal bone, and ends in the transverse sinus, through an aperture at the mastoid angle of the parietal bone or through the mastoid foramen; and (4) the occipital, the largest of the four, which is confined to the occipital bone, and opens either externally into the occipital vein, or internally into the transverse sinus or into the confluence of the sinuses (torcular Herophili).



Veins of the diploë as displayed by the removal of the outer table of the skull.

 

meningeal veins are from cranial dura mater;

superior ophthalmic vein and inferior ophtalmic vein is from sight organ;

labyrinthic veins - from internal ear;

emissary veins from intracranial veins and sinuses of dura mater and communicate with extracranial veins.

External jugular vein is generated by the confluence of occipital vein and posterior auricular vein, which accompany same name arteries. External jugular vein receives anterior jugular vein, which collect blood from anterior neck area and, anastomosing each other, form jugular venous arc.

Subclavian vein continues from axillary vein, lies in same name sulcus of first rib and collects blood from thoracic veins and dorsal scapular vein.

The veins of the head and neck may be subdivided into three groups: (1) The veins of the exterior of the head and face. (2) The veins of the neck. (3) The diploic veins, the veins of the brain, and the venous sinuses of the dura mater.

 

1. The Veins of the Exterior of the Head and FaceThe veins of the exterior of the head and face (557) are:

Frontal.

Superficial Temporal.

Supraorbital.

Internal Maxillary.

Angular.

Posterior Facial.

Anterior Facial.

Posterior Auricular.

Occipital.

 



Veins of the head and neck.

 

 

 

  The frontal vein (v. frontalis) begins on the forehead in a venous plexus which communicates with the frontal branches of the superficial temporal vein. The veins converge to form a single trunk, which runs downward near the middle line of the forehead parallel with the vein of the opposite side. The two veins are joined, at the root of the nose, by a transverse branch, called the nasal arch, which receives some small veins from the dorsum of the nose. At the root of the nose the veins diverge, and, each at the medial angle of the orbit, joins the supraorbital vein, to form the angular vein. Occasionally the frontal veins join to form a single trunk, which bifurcates at the root of the nose into the two angular veins.

  The supraorbital vein (v. supraorbitalis) begins on the forehead where it communicates with the frontal branch of the superficial temporal vein. It runs downward superficial to the Frontalis muscle, and joins the frontal vein at the medial angle of the orbit to form the angular vein. Previous to its junction with the frontal vein, it sends through the supraorbital notch into the orbit a branch which communicates with the ophthalmic vein; as this vessel passes through the notch, it receives the frontal diploic vein through a foramen at the bottom of the notch.

  The angular vein (v. angularis) formed by the junction of the frontal and supraorbital veins, runs obliquely downward, on the side of the root of the nose, to the level of the lower margin of the orbit, where it becomes the anterior facial vein. It receives the veins of the ala nasi, and communicates with the superior ophthalmic vein through the nasofrontal vein, thus establishing an important anastomosis between the anterior facial vein and the cavernous sinus.

  The anterior facial vein (v. facialis anterior; facial vein) commences at the side of the root of the nose, and is a direct continuation of the angular vein. It lies behind the external maxillary (facial) artery and follows a less tortuous course. It runs obliquely downward and backward, beneath the Zygomaticus and zygomatic head of the Quadratus labii superioris, descends along the anterior border and then on the superficial surface of the Masseter, crosses over the body of the mandible, and passes obliquely backward, beneath the Platysma and cervical fascia, superficial to the submandibular gland, the Digastricus and Stylohyoideus. It unites with the posterior facial vein to form the common facial vein, which crosses the external carotid artery and enters the internal jugular vein at a variable point below the hyoid bone. From near its termination a communicating branch often runs down the anterior border of the Sternocleidomastoideus to join the lower part of the anterior jugular vein. The facial vein has no valves, and its walls are not so flaccid as most superficial veins.

 

Tributaries.The anterior facial vein receives a branch of considerable size, the deep facial vein, from the pterygoid venous plexus. It is also joined by the superior and inferior palpebral, the superior and inferior labial, the buccinator and the masseteric veins. Below the mandible it receives the submental, palatine, and submandibular veins, and, generally, the vena comitans of the hypoglossal nerve.

  The superficial temporal vein (v. temporalis superficialis) begins on the side and vertex of the skull in a plexus which communicates with the frontal and supraorbital veins, with the corresponding vein of the opposite side, and with the posterior auricular and occipital veins. From this net-work frontal and parietal branches arise, and unite above the zygomatic arch to form the trunk of the vein, which is joined in this situation by the middle temporal vein, from the substance of the Temporalis. It then crosses the posterior root of the zygomatic arch, enters the substance of the parotid gland, and unites with the internal maxillary vein to form the posterior facial vein.

 

Tributaries.The superficial temporal vein receives in its course some parotid veins, articular veins from the temporomandibular joint, anterior auricular veins from the auricula, and the transverse facial from the side of the face. The middle temporal vein receives the orbital vein, which is formed by some lateral palpebral branches, and passes backward between the layers of the temporal fascia to join the superficial temporal vein.

  The pterygoid plexus (plexus pterygoideus) is of considerable size, and is situated between the Temporalis and Pterygoideus externus, and partly between the two Pterygoidei. It receives tributaries corresponding with the branches of the internal maxillary artery. Thus it receives the sphenopalatine, the middle meningeal, the deep temporal, the pterygoid, masseteric, buccinator, alveolar, and some palatine veins, and a branch which communicates with the ophthalmic vein through the inferior orbital fissure. This plexus communicates freely with the anterior facial vein; it also communicates with the cavernous sinus, by branches through the foramen Vesalii, foramen ovale, and foramen lacerum.

  The internal maxillary vein (v. maxillaris interna) is a short trunk which accompanies the first part of the internal maxillary artery. It is formed by a confluence of the veins of the pterygoid plexus, and passes backward between the sphenomandibular ligament and the neck of the mandible, and unites with the temporal vein to form the posterior facial vein.

  The posterior facial vein (v. facialis posterior; temporomaxillary vein), formed by the union of the superficial temporal and internal maxillary veins, descends in the substance of the parotid gland, superficial to the external carotid artery but beneath the facial nerve, between the ramus of the mandible and the Sternocleidomastoideus muscle. It divides into two branches, an anterior, which passes forward and unites with the anterior facial vein to form the common facial vein and a posterior, which is joined by the posterior auricular vein and becomes the external jugular vein.

  The posterior auricular vein (v. auricularis posterior) begins upon the side of the head, in a plexus which communicates with the tributaries of the occipital, and superficial temporal veins. It descends behind the auricula, and joins the posterior division of the posterior facial vein to form the external jugular. It receive the stylomastoid vein, and some tributaries from the cranial surface of the auricula.

  The occipital vein (v. occipitalis) begins in a plexus at the back part of the vertex of the skull, From the plexus emerges a single vessel, which pierces the cranial attachment of the Trapezius and, dipping into the suboccipital triangle, joins the deep cervical and vertebral veins. Occasionally it follows the course of the occipital artery and ends in the internal jugular; in other instances, it joins the posterior auricular and through it opens into the external jugular. The parietal emissary vein connects it with the superior sagittal sinus; and as it passes across the mastoid portion of the temporal bone, it receives the mastoid emissary vein which connects it with the transverse sinus. The occipital diploic vein sometimes joins it.

 

 

Theme 3. Superficial veins of the neck

The veins of the neck (558), which return the blood from the head and face, are:

External Jugular.

Anterior Jugular.

Posterior External Jugular.

Internal Jugular.

Vertebral.

 

  The external jugular vein (v. jugularis externa) receives the greater part of the blood from the exterior of the cranium and the deep parts of the face, being formed by the junction of the posterior division of the posterior facial with the posterior auricular vein. It commences in the substance of the parotid gland, on a level with the angle of the mandible, and runs perpendicularly down the neck, in the direction of a line drawn from the angle of the mandible to the middle of the clavicle at the posterior border of the Sternocleidomastoideus. In its course it crosses the Sternocleidomastoideus obliquely, and in the subclavian triangle perforates the deep fascia, and ends in the subclavian vein, lateral to or in front of the Scalenus anterior. It is separated from the Sternocleidomastoideus by the investing layer of the deep cervical fascia, and is covered by the Platysma, the superficial fascia, and the integument; it crosses the cutaneous cervical nerve, and its upper half runs parallel with the great auricular nerve. The external jugular vein varies in size, bearing an inverse proportion to the other veins of the neck, it is occasionally double. It is provided with two pairs of valves, the lower pair being placed at its entrance into the subclavian vein, the upper in most cases about 4 cm. above the clavicle. The portion of vein between the two sets of valves is often dilated, and is termed the sinus. These valves do not prevent the regurgitation of the blood, or the passage of injection from below upward.

 

Tributaries.This vein receives the occipital occasionally, the posterior external jugular, and, near its termination, the transverse cervical, transverse scapular, and anterior jugular veins; in the substance of the parotid, a large branch of communication from the internal jugular joins it.



The veins of the neck, viewed from in front.

 

  The posterior external jugular vein (v. jugularis posterior) begins in the occipital region and returns the blood from the skin and superficial muscles in the upper and back part of the neck, lying between the Splenius and Trapezius. It runs down the back part of the neck, and opens into the external jugular vein just below the middle of its course.

  The anterior jugular vein (v. jugularis anterior) begins near the hyoid bone by the confluence of several superficial veins from the submandibular region. It descends between the median line and the anterior border of the Sternocleidomastoideus, and, at the lower part of the neck, passes beneath that muscle to open into the termination of the external jugular, or, in some instances, into the subclavian vein (557, 558). It varies considerably in size, bearing usually an inverse proportion to the external jugular; most frequently there are two anterior jugulars, a right and left; but sometimes only one. Its tributaries are some laryngeal veins, and occasionally a small thyroid vein. Just above the sternum the two anterior jugular veins communicate by a transverse trunk, the venous jugular arch, which receive tributaries from the inferior thyroid veins; each also communicates with the internal jugular. There are no valves in this vein.

  The internal jugular vein (v. jugularis interna) collects the blood from the brain, from the superficial parts of the face, and from the neck. It is directly continuous with the transverse sinus, and begins in the posterior compartment of the jugular foramen, at the base of the skull. At its origin it is somewhat dilated, and this dilatation is called the superior bulb. It runs down the side of the neck in a vertical direction, lying at first lateral to the internal carotid artery, and then lateral to the common carotid, and at the root of the neck unites with the subclavian vein to form the innominate vein; a little above its termination is a second dilatation, the inferior bulb. Above, it lies upon the Rectus capitis lateralis, behind the internal carotid artery and the nerves passing through the jugular foramen; lower down, the vein and artery lie upon the same plane, the glossopharyngeal and hypoglossal nerves passing forward between them; the vagus descends between and behind the vein and the artery in the same sheath, and the accessory runs obliquely backward, superficial or deep to the vein. At the root of the neck the right internal jugular vein is placed at a little distance from the common carotid artery, and crosses the first part of the subclavian artery, while the left internal jugular vein usually overlaps the common carotid artery. The left vein is generally smaller than the right, and each contains a pair of valves, which are placed about 2.5 cm. above the termination of the vessel.



Veins of the tongue. The hypoglossal nerve has been displaced downward in this preparation.

 

 

Tributaries.This vein receives in its course the inferior petrosal sinus, the common facial, lingual, pharyngeal, superior and middle thyroid veins, and sometimes the occipital. The thoracic duct on the left side and the right lymphatic duct on the right side open into the angle of union of the internal jugular and subclavian veins.

  The Inferior Petrosal Sinus (sinus petrosus inferior) leaves the skull through the anterior part of the jugular foramen, and joins the superior bulb of the internal jugular vein.

  The Lingual Veins (vv. linguales) begin on the dorsum, sides, and under surface of the tongue, and, passing backward along the course of the lingual artery, end in the internal jugular vein. The vena comitans of the hypoglossal nerve (ranine vein), a branch of considerable size, begins below the tip of the tongue, and may join the lingual; generally, however, it passes backward on the Hyoglossus, and joins the common facial.

  The Pharyngeal Veins (vv. pharyngeæ) begin in the pharyngeal plexus on the outer surface of the pharynx, and, after receiving some posterior meningeal veins and the vein of the pterygoid canal, end in the internal jugular. They occasionally open into the facial, lingual, or superior thyroid vein.

  The Superior Thyroid Vein (v. thyreoidea superioris) (560) begins in the substance and on the surface of the thyroid gland, by tributaries corresponding with the branches of the superior thyroid artery, and ends in the upper part of the internal jugular vein. It receives the superior laryngeal and cricothyroid veins.

  The Middle Thyroid Vein (561, 562) collects the blood from the lower part of the thyroid gland, and after being joined by some veins from the larynx and trachea, ends in the lower part of the internal jugular vein.

  The common facial and occipital veins have been described.



The veins of the thyroid gland.

 

  The vertebral vein (v. vertebralis) is formed in the suboccipital triangle, from numerous small tributaries which spring from the internal vertebral venous plexuses and issue from the vertebral canal above the posterior arch of the atlas. They unite with small veins from the deep muscles at the upper part of the back of the neck, and form a vessel which enters the foramen in the transverse process of the atlas, and descends, forming a dense plexus around the vertebral artery, in the canal formed by the foramina transversaria of the cervical vertebræ. This plexus ends in a single trunk, which emerges from the foramen transversarium of the sixth cervical vertebra, and opens at the root of the neck into the back part of the innominate vein near its origin, its mouth being guarded by a pair of valves. On the right side, it crosses the first part of the subclavian artery.

 

Tributaries.The vertebral vein communicates with the transverse sinus by a vein which passes through the condyloid canal, when that canal exists. It receives branches from the occipital vein and from the prevertebral muscles, from the internal and external vertebral venous plexuses, from the anterior vertebral and the deep cervical veins; close to its termination it is sometimes joined by the first intercostal vein.



Diagram showing common arrangement of thyroid veins.

 



The fascia and middle thyroid veins. The veins here designated the inferior thyroid are called by Kocher the thyroidea ima.

 

  The Anterior Vertebral Vein commences in a plexus around the transverse processes of the upper cervical vertebræ, descends in company with the ascending cervical artery between the Scalenus anterior and Longus capitis muscles, and opens into the terminal part of the vertebral vein.



The vertebral vein.

 

  The Deep Cervical Vein (v. cervicalis profunda; posterior vertebral or posterior deep cervical vein) accompanies its artery between the Semispinales capitis and colli. It begins in the suboccipital region by communicating branches from the occipital vein and by small veins from the deep muscles at the back of the neck. It receives tributaries from the plexuses around the spinous processes of the cervical vertebræ, and terminates in the lower part of the vertebral vein.

 

 

 

 

 

Prepared by

Reminetskyy B.Y.