vesicles to ventricles

Question 1

1. Trace the path a corpuscle might take from the internal carotid artery to somatosensory cortex to the jugular vein. Does it matter whether it is the “foot” or “hand” region of somatosensory cortex?

Answer 1

Hand: internal carotid > middle cerebral artery > somatosensory cortex > superior sagittal sinus > sinus confluens > transverse sinus > internal jugular. Foot: internal carotid > anterior cerebral artery >inferior sagittal sinus > straight sinus > sinus confluens > transverse sinus > internal jugular.

Question 2

What are the main blood vessels of the brain (2) and what main structures do they supply?

Answer 2

Internal carotid artery: anterior brain (entire cerebral hemisphere except medial part of occipital lobeand interior part of temporal lobe. Vertebral arteries: supplies rest of brain (brainstem, cerebellum, some cortex)

Question 3

Name the branches of the internal carotid artery and what they supply

Answer 3

1. anterior cerebral artery: anterior two-thirds of the medial face of the cerebral hemisphere, and the orbital cortex. 2. middle cerebral artery: lateral face of the cerebrum including frontal, parietal and temporal lobes. Penetrating branches of middle cerebral artery supply deep cerebral cortex.

Question 4

Name branches of vertebral arteries and what they supply

Answer 4

1. posterior cerebral arteries (medial face of occipital lobe and inferior surface of temporal lobe). 2. Anterior/posterior spinal arteries: rostral part of spinal cord. 3. Circumferential branches: dorsal brainstem and cerebellum

Question 5

What do the 3 main circumferential branches of vertebral artery supply?

Answer 5

Posterior inferior cerebellar artery: caudal part of cerebellum. Anterior inferior cerebellar artery: anterior/inferior cerebellum. Superior cerebellar artery: superior cerebellum

Question 6

2. How might blood from the left vertebral artery reach the frontal lobe of the right side in case of occlusion of an internal carotid artery?

Answer 6

The circle of willis connects the blood vessels from the vertebral artery and internal carotid. Left vertebral a > Basilar a > R. Posterior cerebral artery > Posterior communicating a > middle cerebral a > frontal lobe

Question 7

3. Draw and label the components of the circle of Willis.

Answer 7

ok

Question 8

entire blood flow to the CNS can be
supplied via…entire blood flow to the CNS can be
supplied via…

Answer 8

internal carotid, external carotid, basilar artery

Question 9

4. Trace the path of venous drainage in brain

Answer 9

Superior/inferior sagittal sinuses and straight sinus > sinus confluens > transverse sinuses > jugular vein.

Question 10

Name meninges of brain. Where is CSF located

Answer 10

pia, arachnoid and dura mater. CSF is in the subarachnoid space

Question 11

What is a cistern? Where is the cisterna magna, interpeduncular cistern.

Answer 11

The opening in the subarachnoid space. Cisterna magna is under cerebellum, interpeduncular cistern is at bottom of brain btw peduncles

Question 12

5. Be able to identify on MRI images, CAT scans and sections through the brain: lateral ventricle, third ventricle, fourth ventricle, interventricular foramen, cerebral aqueduct, cisterna magna, interpeduncular cistern.

Answer 12

netters

Question 13

6. Describe the relationship between ependymal cells and capillaries in the choroid plexus and how CSF is formed by this structure.

Answer 13

In brain, capillaries have tight junctions but ventricular ependyma don’t. In Choroid plexus, capillaries are leaky (no tight junctions) and ependyma have tight junctions. Solutes diffuse out of capillaries but must be actively transported across ependymal cells into CSF.

Question 14

Approximately, what is the volume and rate of production of CSF?

Answer 14

500ml CSF is produced each day, 100ml is in subarachnoid space, 25ml in ventricles. The remainder is removed

Question 15

Describe what happens to the composition of CSF as the ionic composition of plasma changes.

Answer 15

Almost no change! CSF ionic composition is regulated very carefully, even if plasma composition changes.

Question 16

7. Distinguish between communicating and non-communicating hydrocephalus.

Answer 16

Non-communicating: obstruction interrupts CSF flow to subarachnoid space. Communicating: CSF gets to subarachnoid space but isnt resorbed properly.

Question 17

8. Describe the difference in physical relationships between the CNS, layers of the meninges and the bone, comparing the situation in the cranium to that for the spinal column.

Answer 17

The dura mater hangs loosely in the spinal colum and only has one later, whereas the dura in the cranium is close to the bone and has two layets

Question 18

9. Trace the path of CSF from its place of formation in the lateral ventricles to its site of resorbtion in the arachnoid granulations.

Answer 18

Brain capillaries >(filtration)> ventricular ependymal cells > Lateral ventricles > interventricular foramen > third ventricle > cerebral aquaduct > fourth ventricle > exit via three aperture into subarachnoid space > arachnoid granulations > dural sinuses