Understanding the Arterial Systems of the Brain

1. Question: What are the 2 arterial systems of the brain? Answer: 1) The vertebral system 2) The internal carotid system

2. Question: what are the portions of the internal carotid artery? Answer: carotid siphon, cavernous portion(which runs in the cavernous sinus), clinoid portion (on the medial side of the anterior clinoid process).

3. Question: What are the arteries that arise from the internal carotid before it’s bifurcation in the brain? Answer: 1) Hypophysial arteries 2) Opthalmic artery 3) Posterior communicating artery 4) Anterior choroidal artery

4. Question: what are the origin, destination and course of the hypophyseal arteries? Answer: Origin: internal carotid, the cavernous and the postclinoid portions Course: supplies the neurohypophiseal infundibulum, as well as the median eminence of the thalamus.Latter then connect to the adenohypohphysis as the hypophiseal portal system. Anastomosis:

5. Question: what are the origin, destination and course of the ophthalmic a artery? Answer: Origin: Internal carotid, immediately after enterance into the subarachnoid Course: Enters through the optic foramen into the orbit, supplies the eye and other orbital contents, frontal area of the scalp, frontal and ethmoid paranasal sinuses and parts of the nose. Anastomosis:

6. Question: what are the origin, destination and course of the posterior communicating artery? Answer: Origin: Internal carotid near terminal bifurcation Course: runs backwards and connects to the posterior cerebral artery. Anastomosis:

7. Question: what are the origin, destination and course of the anterior choroidal artery? Answer: Origin: distal part of the internal carotid or the proximal part of the middle cerebral Course: Passes back along the optic tract and the choroid fissure along the medial edge of the temporal lobe Besides supplying the choroid plexus of 3rd ventricle, it supplies the optic tract, uncus, amygdala, hippocampus, GP and the ventral part of the internal capsule. Anastomosis:

8. Question: what are the origin, destination and course of the middle cerebral artery? Answer: Origin: Internal carotid’s terminal large branch Course: passes deep in the lateral (sylvian) sulcus. Sends frontal, temporal and parietal branches that supply large area of these lobes’ cortex. Includes motor and general sensory area of all organs, but lower limbs and perineum. Occlusion results in massive damage in cast cortical areas and is the primary reason for aphasia Anastomosis:

9. Question: what are the origin, destination and course of the anterior cerebral artery? Answer: Origin: internal carotid’s bifurcation Course: Directed medially, above the optic nerve. After the connection by the anterior communicating arteries, it ascends in the longitudinal fissure, bends backwards around the genu of the CC. Branches near the connection by ant.com.art supply the medial portion of the orbital surface of the frontal lobe, including the olfactory bulb and olfactory tract. Anastomosis:

10. Question: What are the branches of the anterior cerebral artery? Answer: 1) Anterior communicating 2) Branches to olfactory bulb (no name) 3) Pericallosal branch (continues on the upper side of the CC) 4) Callosomarginal artery (along the cingulate gyrus) 5) Recurrent branch of Hubner (medial striate artery) – just proximal to the anterior communicating artery.

11. Question: what are the origin, destination and course of the vertebral artery? Answer: Origin: Subclavian artery Course: Ascends in the foramina of the transverse processes of the upper 6 cervical vertebrae. Enters the subarachnoid space at the level of the foramen magnum. Joins with it’s fellow @ the caudal border of the pons to form the basilar artery. Anastomosis:

12. Question: What are the branches of the vertebral arteries? Answer: 1) Spinal arteries (single anterior and two posterior) 2) PICA

13. Question: what are the origin, destination and course of the spinal arteries? Answer: Origin: Vertebral arteries Course: Two posterior and one anterior. Descend down the spinal cord, throughout it’s length. Anastomosis:

14. Question: what are the origin, destination and course of the PICA artery? Answer: PICA = posterior inferior cerebellar artery Origin: from the vertebral arteries Course: between the medulla and the cerebellum. Branches to the cerebellar hemisphere, inferior vermis, central nuclei of cerebellum, choroid plexus of the 4th ventricle. Has also branches to the dorsolateral part of the medulla.. Anastomosis:

15. Question: What are the branches of the basilar artery? Answer: 1) Labyrinthine artery 2) Pontine arteries 3) Anterior inferior cerebellar 4) Superior cerebellar 5) Posterior cerebral

16. Question: what are the origin, destination and course of the superior cerebellar artery? Answer: Origin: Basilar artery Course: Ramifies over the dorsal surface of the cerebellum and supplies it’s cortex, medullary part and the central nuclei. Branches from the proximal part (the one on the pons) ore distributed to the pons, superior cerebellar peduncle and Anastomosis:

17. Question: What are the branches of the posterior cerebral arteries? Answer: 1) temporal branches 2)Calcarine branches 3) Parietooccipital branches 4) Posterior chorodial artery

18. Question: what are the origin, destination and course of the posterior choroidal artery? Answer: Origin: posterior cerebral Course: comes off the posterior cerebral artery in the region of the splenium of the CC and runs forward in the transverse fissure beneath the CC. It supplies the choroid plexus of the central part of the lateral ventricles, of the 3rd ventricle as well as the posterior parts of the thalamus, fornix and tectum of the midbrain. Anastomosis:

19. Question: what are the groups of central arteries from the circle of Willis? Answer: 1) Posterolateral from the posterior cerebral artery 2) Posteromedial from the posterior cerebral and posterior communicating 3) Anterolateral from the middle and anterior cerebral arteries 4) Anteromedial from the anterior cerebral and anterior communicating

20. Question: What are the vessels supplying the striatum ? Answer: Anterolateral central, recurrent of Heubner

21. Question: What are the vessels supplying GP? Answer: Anterolateral central, anterior choroidal

22. Question: What are the vessels supplying the thalamus ? Answer: posteromedial and posterolateral central; anterior and posterior choroidal.

23. Question: What are the vessels supplying the subthalamus ? Answer: Anterior choroidal, posteromedial central

24. Question: What are the vessels supplying hypothalamus ? Answer: anteromedial, posteromedial and anterolateral central arteries.

25. Question: What are the vessels supplying the pineal gland? Answer: posterolateral central arteries

26. Question: What are the vessels supplying the internal capsule? Answer: Antero and postero lateral central arteries, anterior choroidal artery, recurrent artery of Heubner.

27. Question: What are the vessels supplying the amygdala, uncus and the hyppocampal formation ? Answer: Anterior choroidal artery, temporal branches of posterior cerebral artery

28. Question: What are the vessels supplying the external capsule and the claustrum ? Answer: anteriolateral central arteries

29. Question: What are the vessels supplying the tectum of the midbrain? Answer: posterolateral and posteromedial central arteries, posterior choroidal artery, superior cerebellar artery.

30. Question: What are the vessels supplying the cerebral peduncle? Answer: posteromedial and posterolateral central arteries, anterior choroidal artery.

31. Question: What are the vessels draining the cerebellum and the brain stem ? Answer: Unnamed veins to the sinuses adjacent to the posterior cranial fossa.

32. Question: What are the venous systems draining the brain? Answer: Internal and external cerebral veins External include: 1)Superior cerebral veins (8-12), 2) Superficial and deep middle cerebral veins 3) Anterior cerebral vein 4) Basal vein (of Rosenthal) (deep mid. + anterior cerebral vein) Internal include: 1) Thalamostriate vein (vena terminalis) 2) Choroidal vein 3) Internal cerebral vein (1+2) 4) Great cerebral vein (of Galen) (3 from both sides)