1. Overview of the Brain, Cranial Nerves, Blood Supply and Meninges

2. Objectives
Name the parts of the brain and describe their main anatomical features
Describe the attachments of the cranial nerves to the surface of the brain
Describe the course and list the main branches of the vertebral, basilar and internal carotid arteries
Name the arteries that form the cerebral arterial circle (of Willis)
Indicate the location of the septa formed by the crania dura mater
Indicated the location of the dural venous sinuses and understand the direction of blood flow through them
Describe the anatomical relations of the cavernous sinus

3. Parts of the Brain brainstem: medulla oblongata pons midbrain
cerebellum
diencephalon:
thalamus
hypothalamus
telencephalon (cerebral hemispheres)

4. thalamus
hypothalamus

7. subcortical white matter
cerebellar nuclei
subcortical white matter
cerebellar cortex

8. hypothalamus
thalamus

9. hypothalamus

10. right thalamus
left thalamus

11. Medial Surface of the Left Cerebral Hemisphere

14. central sulcus
lateral sulcus
insula

15. Lateral Ventricles there are 2 of them, 1 in each cerebral hemisphere
parts:
anterior (frontal) horn
body (within parietal lobe)
inferior (temporal) horn
posterior (occipital) horn
trigone (atrium)  area where body, inferior horn and posterior horn meet each other
each lateral ventricle communicates with 3rd ventricle via interventricular foramen (of Monro)

17. Arterial Supply of the Brain
it is provided by 2 pairs of arteries: vertebral and internal carotid
vertebral artery:
enters cranial cavity via foramen magnum
right and left vertebral arteries join each other at pontomedullary junction to form basilar artery
basilar artery runs along midline of anterior surface of pons and ends at upper end of pons by dividing into 2 posterior cerebral arteries
vertebral and basilar arteries give branches that supply spinal cord, brainstem, cerebellum and posterior parts of cerebral hemispheres

18. Cerebral Arterial Circle (of Willis)
formed by large cerebral arteries and their interconnections on ventral surface of the brain
components:
anterior communicating a.
anterior cerebral a.
internal carotid a.
posterior communicating a.
posterior cerebral a.
serves as a potential vascular shunt, assisting in development of collateral circulation if one of the proximal vessels is occluded

22. Arterial Supply of the Brain
internal carotid artery:
begins at bifurcation of common carotid artery (at level of upper border of thyroid cartilage)
parts:
cervical (from origin to base of the skull)
petrous (within carotid canal in petrous part of temporal bone)
cavernous (within cavernous sinus the dural venous sinus located in middle cranial fossa, just lateral to sella turcica)
cerebral (from the point it exits cavernous sinus to its termination, where it divides into anterior and middle cerebral arteries)

23. cerebral part
cavernous part
petrous part
cervical part

24. cerebral part of internal carotid artery
cavernous part of internal carotid artery

25. Arterial Supply of the Brain
internal carotid artery (cont.):
main branches:
ophthalmic artery enters orbit via optic canal together with optic nerve
posterior communicating artery joins posterior cerebral artery
2 terminal branches: anterior and middle cerebral arteries (right and left anterior cerebral arteries are connected by anterior communicating artery)

32. Aneurysms

33. Patient Case
Patient is a 65 yo male who presented after having an acceleration/deceleration injury from a MVA 1 week ago. He c/o right neck pain and feel like he keeps dropping things with his right hand. What do you want to know?

34. You do an adjustment! & Request that he return in 1 week

35. He doesn’t show for his next appointment
He doesn’t show for his next appointment. When you call to ask him about it, you find he has been admitted to the hospital on the evening of your first encounter.

37. Hollnehorst plaque on fundoscopic exam

46. Dura Mater of the Brain layers:
endosteal (outer layer)  equivalent to periosteum covering inner surface of skull bones
meningeal (inner layer)  dura mater proper, faces the brain
the two layers are closely united, except where they separate to form dural venous sinuses

47. endosteal layer of dura mater
meningeal layer of dura mater

48. Dura Mater of the Brain
meningeal layer forms 4 septa  divide cranial cavity into freely communicating compartments
cerebral falx (falx cerebri)  sickle-shaped fold that lies in the midline between two cerebral hemispheres
cerebellar tentorium (tentorium cerebelli)  crescent-shaped fold that roofs over posterior cranial fossa (separates cerebellum from occipital lobes of cerebral hemispheres)
tentorial notch  space between anterior, free border of tentorium cerebelli and dorsum sellae  filled mostly by midbrain
cerebellar falx (falx cerebelli)  small sickle-shaped fold in posterior cranial fossa that projects between two cerebellar hemispheres
sellar diaphragm (diaphragma sellae)  small circular fold that roofs over sella turcica (has small opening for pituitary stalk)

51. Dural Venous Sinuses
located between inner and outer layers of dura mater
receive blood from brain (via superficial and deep cerebral veins) as well as cerebrospinal fluid from subarachnoid space (via arachnoid granulations)
blood collected by dural venous sinuses drains ultimately into internal jugular veins

52. Dural Venous Sinuses
superior sagittal sinus: runs along upper border of falx cerebri  begins anteriorly at foramen cecum and terminates posteriorly in confluence of the sinuses (over internal occipital protuberance)
inferior sagittal sinus: runs along lower, free border of falx cerebri, joins great cerebral vein (largest of the deep cerebral veins) to form straight sinus
straight sinus: runs in midline, along junction of falx cerebri and tentorium cerebelli  terminates posteriorly in confluence of the sinuses

53. Dural Venous Sinuses
transverse sinus: begins in confluence of the sinuses and runs along posterior border of tentorium cerebelli  when it reaches petrous part of temporal bone, it turns down to become continuous with sigmoid sinus
sigmoid sinus: direct continuation of transverse sinus  terminates in jugular foramen, where it becomes continuous with internal jugular vein
occipital sinus: small sinus that runs along posterior border of falx cerebelli  ends superiorly in confluence of the sinuses and inferiorly communicates with internal vertebral venous plexus (within vertebral canal)

54. Dural Venous Sinuses cavernous sinus:
located in middle cranial fossa, one on each side of sella turcica
drains contents of orbit, parts of cerebral hemisphere, pituitary gland and sphenoparietal sinus
internal carotid artery and abducens nerve are located inside cavernous sinus
cranial nerves III and IV and V1 and V2 divisions of trigeminal nerve are embedded in lateral wall of sinus
it is drained posteriorly by superior and inferior petrosal sinuses

55. Dural Venous Sinuses
superior petrosal sinus: runs along superior border of petrous part of temporal bone  connects cavernous sinus with terminal part of transverse sinus
inferior petrosal sinus: runs along inferior border of petrous part of temporal bone (between petrous part and occipital bone)  connects cavernous sinus with internal jugular vein
sphenoparietal sinus: small sinus that runs along posterior border of lesser wing of sphenoid  drains into cavernous sinus