LESSON #25 (6 HOURS)
Theme. Internal carotid artery. Blood vessels of orbit. I, II, III, IV, VI cranial nerves, areas of distribution.
I division of V cranial nerve, areas of distribution. Ciliary ganglion
Aіm: Study the structural and topographical peculіarіtіes of internal carotid and subclavian arteries. and their branches.
Professional orientation of students: Vascular diseases of the brain, caused by the affliction of the branches of internal carotid artery, are leading among diseases of nervous system and are often the cause of death, invalidity, and severe conditions, which require urgent aid of a doctor of any speciality. The need of a brain of oxygen is 20 % of the need of oxygen of the whole organism (though the weight of a brain - on the average 1,4 kgs - is only 2 % of the weight of a body), and, consequently, if compared to the other organs the brain has increased sensitivity to hypoxia. Knowledge the topography and innervating regions of the 3rd, 4th, 6th cranial nerves is the base for understanding of neurophysiology and neuropathology. Anatomical peculiarities of the oculomotor, trochlear and abducens nerves are necessary for ophthalmology, neurological therapy and surgery in brain, also for traumatology and oncology.
I. Practical work – 9:00-12:00 am (4 hours)
Work 1. Dissection of internal carotid artery and its branches. Transverse section is made between two auricle by cutting the soft tissues of head. Then skin is detached and pulled down to superciliary arches and pulled up to superior nuchal line. The top of cranium is cut away, with the bone saw, at the level of base of the skull. Then dura matter is cut with parasaggital section, separated and pulled away laterally to the base of the skull. Now the superio-lateral surface of hemispheres can be seen together with superficial vessels. After dissection of sickle of cerebrum and setting apart the superior margins of cerebrum, the anterior cerebral arteries and their branches can be viewed on the medial surface of both hemispheres. In order to observe the branches of medial cerebral artery the web tissue and the lateral sulcus of hemispheres had been separated and set apart.
Work 2. Preparation of lacrimal nerve. Students under the teacher’s directions conduct skin cuts on the right part of face along the lateral wall of orbit.
Work 3. Develop graphic scheme of branching of orbital nerve.
Basic Level: Roman (Latin) terminology.
1. Skeleton of thoracis cage, neck and skull.
2. Muscles of the neck and head.
3. Organs of the neck and head.
Demonstrate on preparations:
1) Demonstrate on preparations
1. Corpse with prepared vessels and heart: internal carotid artery to its entry into skull, subclavian artery (from the left, from the right), interscalene space, vessels, which go from subclavian artery in prescalene space - vertebral artery, thyroid trunk, internal thoracic artery; in interscalene space - costocervical trunk; in extrascalene space - transverse artery of a neck.
2. Damp preparation of a basis of a brain with preserved arachnoidal membrane: basic artery, posterior brain artery, internal carotid artery, anterior, middle arteries of a brain, posterior connecting artery, Vilisian circle.
3. Skull, cervical vertebrae: vertebral foramina on transverse processes, carotid channel, lacerated foramen, sulcus caroticus.
II. Seminar discussion 12:30 am – 14:00 pm (2 hours)
1) Special attention should be paid to the following questions:
1. Where does the internal carotid artery begin?
2. What position does the internal carotid artery occupy in the structure of a neurovascular fascicle of a neck?
3. What shape has the bend of internal carotid artery at the passage through the cavernous sinus?
4. What arteries supply the brain?
5. What branches does the internal carotid artery give in the carotid channel?
6. Through what foramen does the ophthalmic artery penetrate into the cavity of the orbit?
7. Name branches of the ophthalmic artery.
8. Name terminal branches of the ophthalmic artery.
9. Which arteries supply the lids?
10. Which arteries represent anastomosis between the system of internal and external carotid arteries?
11. Name two terminal branches of internal carotis artery.
12. On what surface of the hemisphere does the anterior brain artery ramify?
13. What parts of the hemisphere of the brain are supplied by brain artery?
14. What artery connects both anterior brain arteries?
15. Which vessels form the Willi’s circle?
16. Where do olfactory nerves enter the cranial cavity?
17. What does belong to peripheral part of olfactory brain?
18. Where are located first neuron of the olfactory tract?
19. Optic nerve, its location and importance.
20. Where is there optic chiasma, why is it incomplete?
21. Where are located oculomotor nerve nuclei?
22. Which branches is oculomotor nerve divided in?
23. What do branches of oculomotor nerve supply?
24. Where are located trochlear nerve nuclei?
25. What does trochlear nerve supply?
26. What does abducens nerve supply?
27. Where are located abducens nerve nuclei?
28. How does trigeminus nerve form? Fibres from which nuclei compose it?
29. Where is located sensory ganglion of trigeminus nerve?
30. Describe the topography of the ophthalmic nerve. Which branches does it give off?
31. Describe the branches of frontal nerve. What do they supply?
32. Describe the branches of lacrimal nerve. What do they supply?
33. Describe the branches of nasociliaris nerve. What do they supply?
34. Where is positioned ciliary ganglion?
35. Which root does ciliary ganglion receive?
36. Which branches does ciliary ganglion give off?
37. What do short ciliary nerves supply?
38. What do long ciliary nerves supply?
ІІІ. Independent students work – 14:15pm – 15:00 pm
1) Situational TASK.
1. For bandaging the external carotid artery it is uncovered on a neck in a site of a carotid triangle. The erroneous bandaging of internal carotid artery may cause severe complication - softening of a substance of a brain. Name anatomic peculiarities, which allow to distinguish internal carotid artery from external one in the borders of this triangle.
2. Patient has paresis of right hand and leg, impaired sensitivity in paretic limbs, motor aphasia - lost ability to utter words owing to impaired articulation of language. The cause of this condition is the disturbance of blood flow in one of branches of internal carotid artery. Name the afflicted vessel.
3. Patient has impaired functions of all oculomotor nerves owing to disturbed blood supply of their nuclei, paresis of both upper and lower limbs, disorder of vital functions (breath and circulation). Impaired blood flow in the pool of which artery is the cause of this condition?
4. Eyelids possess high reparative ability even when smashed or stained. This is predetermined by rich arterial net of lids. Name sources of its formation.
5. Patient has a malignant tumour of the parotid gland. During surgical intervention the bandaging of external carotid artery is necessary. Name anastomosis between branches of external and internal carotid arteries, which provide blood supply in these conditions.
Initial level of knowledge and skills are checked by solving situational tasks for each topic, answers in test evaluations and constructive questions (the instructor has tests & situational tasks).
Student should know:
Structural and topographical peculіarіtіes of internal carotid and subclavian arteries. and their branches. Anatomical peculiarities of the oculomotor, trochlear and abducens nerves
Student should be able to:
1. Internal carotid artery, showing its course, topography in the area of neck and head.
Pay attention, that internal carotid artery, forming a S-shaped bend in the carotid channel, reaches a lacerated foramen of a skull and passes through cavernous sinus.
2. Studying branches of internal carotid artery it is necessary to specify vessels, which supply brain and take part in arterial anastomotic ring (Vilisian circle), final branch - ophthalmic artery, anastomosing with branches of facial artery.
3. Studying subclavian artery, pay attention to the difference of topography of vessels anastomosing on the left and on the right.
4. Specify, into what parts is subclavian artery divided and what branches anastomose in each section.
5. It is necessary to characterize course and topography of vertebral artery as its branches also participate in blood supply of a brain and supplement Vilisian circle.
Correct answers for tests and situational tasks:
1. The answer: а) internal carotid artery does not ramify on a neck of branches; б) internal carotid artery is placed laterally and behind, and then medially from the external carotid artery; в) if the sublingual nerve is uncovered in the area of the carotid triangle, it is seen to cross the internal carotid artery and locate ahead of it.
2. The answer: middle brain artery.
3. The answer: basilar artery.
4. The answer: medial (superior and inferior) arteries of lids (from ophthalmic artery) and lateral (superior and inferior) arteries of eyelids (from lacrimal artery).
5. The answer: а) back artery of a nose (from ophthalmic artery) and angular artery (from facial artery); б) supratrochlear artery (from ophthalmic artery) and frontal branch (from superficial temporal artery); в) internal carotid artery and posterior artery of a brain (through posterior connective artery).
1. Atlas of Human Anatomy/ Frank H. Netter,- 5 edition, - 2011 by Saunders, an Imprint of Elsevior Inc.
3. Materials preparation for lectures
4. Materials preparation for practical classes
2. F.H. Netter. Atlas of Human Anatomy. – Cіba Pharmaceutіcals Dіvіsіon, 1994. – 514 p.
3. Synelnіkov R.D. The atlas of anatomy of the man. Іn 4-th volumes. -: Medіcіna, 1991.
4. Reminetskyy B.Y., Fedonyuk Y.I. Human anatomy. Notes. 136 p.
Methodical instructions have been prepared by: Assistant Prof. Gavlich O. B.
The instruction was discussed and confirmed at the department meeting
12.06.2013. Protocol number 11