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Blood supply to the brain The cerebrospinal fluid (CSF) Mark Kozsurek, M.D., Ph.D. 19/09/2011, EM II.

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Presentation on theme: "Blood supply to the brain The cerebrospinal fluid (CSF) Mark Kozsurek, M.D., Ph.D. 19/09/2011, EM II."— Presentation transcript:

1 Blood supply to the brain The cerebrospinal fluid (CSF) Mark Kozsurek, M.D., Ph.D. 19/09/2011, 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 Arteries supplying the brain

4 2 sources of blood: ICA and VA

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

6

7 C2 C4 C5 C6 (C3) C7 cavernous sinus

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

9 caroticotympanic inf. hypophyseal ophthalmic sup. hypophyseal ant. choroidal post. communicating middle cerebralant. cerebral ant. communicating striate

10 Circle of Willis

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12 oculomotor n. abducens n. optic chiasm mamillary bodies pituitary stalk

13 1.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.

14 A1 A2

15 A1 ant. communicating A2 A3 callosomarginal br. pericallosal br. parietooccipital sulcus recurrent artery of Heubner

16 Heubner’s

17 A1 ant. communicating A2 A3 callosomarginal br. pericallosal br. parietooccipital sulcus recurrent artery of Heubner

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20 M2 M3

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22 ACA MCA PCA parietooccipital sulcus

23 PCA

24 anterior cerebral middle cerebral posterior cerebral

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

28 Veins drainig the brain

29 superior cerebral veins inferior cerebral veins Similarly, there are superior and inferior celebellar veins for the cerebellum. superficial middle cerebral vein SUPERFICIAL VEINS

30 Superior cerebral veins open into the superior sagittal sinus or into the adjacent lateral lacunae.

31 Inferior cerebral veins drain mainly into the sphenoparietal (1), cavernous (2), superior petrous (3), and transverse (4) sinuses

32 superior sagittal sinus cavernous sinus transverse sinus TROLARD’S VEIN LABBE’S VEIN

33 ant. cerebral deep middle cerebral basal (Rosenthal) great cerebral (Galen) DEEP VEINS

34 of septum pellucidum thalamostriate choroid * int. cerebral great cerebral

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

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37 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, blodd may escape through the diploic and emissary veins connecting the dural sinuses with the veins of the scalp skin.

38 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.

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

40 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).

41 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.

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43 Subfornical organsensoryfluid regulation Organum vasculosum sensory, secretory detects peptides, fluid regulation Median eminencesecretory regulates the anterior pituitary through the release of neurohormones Neurohypophysissecretory store and secretes the hormones oxytocin and ADH into the blood, but does not synthesize either hormone Subcommissural organ secretory secretes certain proteins into the cerebrospinal fluid, its specific function is as yet unknown. Pineal glandsecretory stimulated by darkness to secrete melatonin and is associated with circadian rhythms Area postremasensory 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)

44 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.

45 internal and external CSF spaces internal = ventricles external = subarachnoidal space

46 Surface of a choroid plexus

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

48 median aperture of Magendi cerebellomedullary (or great) cystern lateral aperture of Luschka lateral pontine (or pontocerebellar) cystern

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

51 Thank You !!!


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