1. Blood supply to the brain The cerebrospinal fluid (CSF)
Mark Kozsurek, M.D., Ph.D.
21/09/2017, EM II.

2. Extremly high demand for oxygen and nutrients: human brain represents 2% of the body weight, but receives 15% of the cardiac output, 20% of total body oxygen consumption and 25% of total body glucose utilization.
Cerebrovascular deseases and stroke are among the major causes of death.

3. I. Arteries supplying the brain

4. 2 sources of blood:
ICA and VA

5. Vertebro-basilar system
CTA: CT angiography
atlas
axis
laterally
upward
backward C6

6. C1 C2 C3 C4 C5 C6 C7
ant. clinoid proc.
cavernous sinus
foramen lacerum
carotid canal
X-ray angiogram

7. C6 C5 C7 C4
(C3)
cavernous sinus C2

8. Another classification:
Majority of these branches will never be seen and is not necessary to note them!

9. Circle of Willis

10. Circle of Willis pituitary stalk optic chiasm oculomotor n.
abducens n.
pituitary stalk
optic chiasm
mamillary bodies

11. Circle of Willis encloses the optic chiasm, pituitary stalk and mamillary bodies.
2. Oculomotor nerve exits between the post. cerebral and sup. cerebellar arteries.
3. Vertebral arteries of the two sides unite to form the basilar artery at the ponto-medullary junction. The root of the abducens nerve and initial segment of the ant. inf. cerebellar artery can also be found here.

12. parietooccipital sulcus
callosomarginal br.
pericallosal br. A3 A2 A1
ant.
communicating

13. Heubner’s

14. parietooccipital sulcus
ACA
PCA
MCA

15. oculomotor n. PCA sca BA aica VA pica sca: superior cerebellar
aica: anterior inferior cerebellar
pica: posterior inferior cerebellar

16. Clinical considerations
Atherosclerosis – brain infarctions
Subarachnoidal hemorrhage

17. Middle cerebral artery
Ant. cerebral artery
Weakness/paralysis of muscles and loss of sensory functions on the lower limbs of the contralateral side.
Middle cerebral artery
Paralysis and sensory disfunction involving head and neck and the upper limbs of the contralateral side. In case of damage of the dominant hemisphere speech disorders are also present.
Post. cerebral artery
Visual field defficiencies or blindness.
Vertebro-basillar system
Eye movement (gaze) disorders, double vision
Anisocoria (pupils are different in size)
Vertigo, loss of balance
Dysphagia and dysphonia (disorder of swallowing and phonation)
Drowsiness or unconsciousness

18. Subarachnoid hemorrhage

19. Aneurism clipping

20. Endovascular coiling

21. Blood-brain barrier (BBB)
The extracellular fluid of the CNS is separated from the blood by the BBB ensuring strictly controlled and mainly carrier protein assisted transport of macromolecules.
Is formed by endothelial cells attached to one other by tight junctions, basement membrane, astrocytic endfeet.
Protects the CNS from possibly toxic agents but makes development of medicines acting on the CNS difficult (e.g. antibiotics in infections).

22. the circumventricular organs
Life outside the BBB:
the circumventricular organs
„Circumventricular” = around the ventricles
Incomplet or missing BBB
Highly capillarized structure
Secretion of neurohormons or detection of hormons, glucose, ions, etc.

24. Subfornical organ
sensory
fluid regulation
Organum vasculosum
sensory, secretory
detects peptides, fluid regulation
Median eminence
secretory
regulates the anterior pituitary through the release of neurohormones
Neurohypophysis
store and secretes the hormones oxytocin and ADH into the blood, but does not synthesize either hormone
Subcommissural organ
secretes certain proteins into the cerebrospinal fluid, its specific function is as yet unknown.
Pineal gland
stimulated by darkness to secrete melatonin and is associated with circadian rhythms
Area postrema
the vomiting centre of the brain (can detect noxious substances in the blood and stimulate vomiting in order to rid the body of these toxic chemicals)

25. II. Veins drainig the brain

26. superior sagittal sinus
SUPERFICIAL VEINS
TROLARD’S VEIN
LABBE’S VEIN
cavernous sinus
transverse sinus

27. DEEP VEINS ant. cerebral v. of septum pell. deep middle cer. choroid
thalamostriate
internal cerebral
basal
great cerebral vein

28. Almost the total volume of veinous blood collected from the brain leaves the skull through the jugular foramen and the internal jugular vein.
If the jugular foramen and/or the internal jugular vein is getting occluded, blood may escape through the diploic and emissary veins connecting the dural sinuses with the veins of the scalp skin.

29. Diploic veins (frontal, anterior and posterior temporal, occipital): form a network between the external and internal compact bony layers of the skull and connect dural sinuses with the external veins.

30. emissary
diploic
Emissary veins (occipital, parietal, condylar, mastoid): pearce the skull directly and connect dural sinuses with external veins.

31. III. The cerebrospinal fluid (CSF)
Provides mechanical protection for the brain and the spinal cord.
When floating in the CSF brain weights only 50g (!) according to the Archimedes’ principle.

32. internal and external CSF spaces
internal = ventricles external = subarachnoidal space

33. Choroid plexus of fourth ventricle
Surface of a choroid plexus

34. ant. choroidal from ICA or MCA
post. choroidal from PCA
choroidal a. of the 4th ventricle from pica

35. (or pontocerebellar) cystern
1 median aperture of Magendi
2 lateral apertures of Luschka
cerebellomedullary
(or great) cystern
lateral pontine
(or pontocerebellar) cystern

36. Site of CSF resorption: arachnoid granulations in the superior sagittal sinus and lateral lacunae.

37. Hydrocephalus
Increased volume and/or pressure of CSF due to accelerated synthesis, blocked circulation or insufficient resorption of liquor.

38. anterior cerebral
middle cerebral
posterior cerebral

39. Thank You !!!