CSF and Circulation (1)

Question 1

Where and by what is CSF produced?

Answer 1

choroid plexus in the lateral and 3rd ventricles mostly but a little in the 4th ventricle as well

Question 2

What is the flow of CSF?

Answer 2

lateral thru interventricular foramen (Monroe) to the 3rd thru cerebral aqueduct to the 4th then either out foramen of Magende into cerebromedullary cistern up to cistern of great cerebral vein or spinal column down to the lumbar cistern; or out the foramen Luschka to pontine cistern up to interpeduncular cistern

Question 3

How do the choroid plexus cells create CSF? How can you clinically decrease CSF production?

Answer 3

Pulls Na, Cl, HCO3 and H2O out; CA inside the cells makes HCO3 out of H2O and CO2 and pumps it out of both sides; can inhibit CA

Question 4

What are the components of the blood brain barrier?

Answer 4

tight junctions in capillary endothelium, tight junctions between choroid plexus cells, tight junctions in the arachnoid membrane, the ependymal next to the circumventricular organs; glia and astrocytes induce the tight junctions of the arteries but are not the BBB

Question 5

What is the composition of CSF macromolecules?

Answer 5

small proteins, much less than blood, lipophilic substances diffuse more readily than hydrophilic, facilitated diffusion- glucose and certain AA

Question 6

What is the function of CSF?

Answer 6

preserve brain homeostasis, mechanical protection- reduces effective brain weight (buoyant), pathway for removal of metabolites

Question 7

When is brain metabolites cleared mostly?

Answer 7

at night during sleep

Question 8

What are the different types of hydrocephalus?

Answer 8

non-communicating: obstruction within ventricular system, communicating: obstruction within subarachnoid space

Question 9

What are the features of aqueductal stenosis?

Answer 9

obstruction at level of cerebral aqueduct, bulging fontanel, and split sutures, craniofacial distortion

Question 10

What is the dandy-walker malformation?

Answer 10

obstruction at the outlet of the 4th ventricle plus cerebellar hypoplasia, often associated with malformations of other parts of the brain

Question 11

What is a Chiari malformation?

Answer 11

small posterior fossa, tonsils well below foramen magnum, stenosis of cerebral aqueduct often with it, 90% with a myelomeningocele

Question 12

What are the common causes of acquired hydrocephalus?

Answer 12

tumor, hemorrhage, or infection

Question 13

If there is an obstruction of CSF where is there dilation?

Answer 13

proximal to the obstruction

Question 14

What are the cerebral branches off the internal carotid?

Answer 14

middle cerebral, anterior cerebral, posterior communicating

Question 15

What are the branches off of the middle cerebral artery?

Answer 15

lenticulostriate (several small)

Question 16

What are the branches off of the anterior cerebral?

Answer 16

anterior communicating, medial striate, and pericollassal artery

Question 17

What are the components of the circle of willis?

Answer 17

posterior cerebral, posterior communicating, internal carotid, anterior cerebral, and anterior communicating

Question 18

What are the branches of the vertebral arteries?

Answer 18

join to form basilar, posterior inferior cerebellar, a joint anterior spinal

Question 19

What are the branches off the basilar inferior to superior?

Answer 19

anterior inferior cerebellar, internal acoustic, several pontine, superior cerebellar and posterior cerebral

Question 20

What are the branches off of the posterior cerebral?

Answer 20

posterior communicating

Question 21

where is the posterior spinal artery found? Supplies?

Answer 21

parallel to posterolateral sulci, supplies the dorsal funiculus, portion of lateral funiculi, and the posterior horn

Question 22

Where is the anterior spinal artery found? what does it supply?

Answer 22

along the anterior median fissure, ventral and much of the lateral funiculi, and anterior gray matter, gives of sulcal arteries

Question 23

What arteries also supply the spinal cord? What do they branch from?

Answer 23

radicular branches, from vertebrals, ascending cervicals, intercostals, and lumbar arteries, not at all levels, run along with exiting spinal nerves

Question 24

Where is the great vein of Galen?

Answer 24

empties into the meeting of inferior sagittal sinus and straight sinus, deep

Question 25

Where is the inferior anastomotic vein located?

Answer 25

aka Labbe, runs along the lateral sulcus and empties into the transverse sinus

Question 26

Where does the superior anastomotic vein run?

Answer 26

along central sulcus connecting superior sagittal sinus with inferior anastomotic vein of Labbe

Question 27

Where does the cavernous sinus drain to?

Answer 27

2 paths one to the transverse sinus and the second to the sigmoid sinus

Question 28

What are the veins along the posterior of the spinal cord?

Answer 28

posterior spinal vein running along the posterior median sulcus, two posterolateral spinal veins running by the posterior spinal arteries

Question 29

What are the veins along the anterior spinal cord?

Answer 29

anterior spinal vein along the anterior spinal artery

Question 30

Where do the anterior and posterior spinal veins drain?

Answer 30

radicular veins into a plexus of veins in the epidural space, through vertebral foramina to external plexus to lumbar, vertebral and intercostal veins