Cerebral Vasculature and Brain Homeostasis

Question 1

Where is the Na/K ATPase located in the choroid plexus?

Answer 1

Apical side

Question 2

Where is NCBE located in brain?

Answer 2

Basolateral

Question 3

What is the purpose of the NCBE and Na/K atpase?

Answer 3

Creates transmembrane gradient that pulls water into the ventricle

Question 4

What happens with Cl?

Answer 4

Accumulates intracellularly, forming an electrochemical gradient, then leaves cell through apically located chloride channels.

Question 5

What is the overall movement of ions?

Answer 5

Na, Cl and HCO3 moves from blood into ventricles. Water fluxes through AQP.

Question 6

What is the Na osmolarity between CSF and Serum?

Answer 6

Similar

Question 7

CSF has a greater concentration of what compared to Serum?

Answer 7

Cl, CO2, H

Question 8

Serum has a greater concentration of what compared to CSF?

Answer 8

Protein, Glucose, OH, K, Ca, Mg, HCO3.

Question 9

Where is CSF reabsorbed?

Answer 9

arachnoid villi and pinocytosis

Question 10

What is the pressure needed for absorption to occur?

Answer 10

Greater than 68 mm

Question 11

What regulates CBF?

Answer 11

CO2 regulation, H+ concentration, O2 concentration and Astrocyte metabolites

Question 12

What are the sympathetic neurotransmitters?

Answer 12

NE and NPY, alpha adrenergic receptors

Question 13

What are the parasympathetic neurotransmitters?

Answer 13

Ach, VIP, CGRP, SP

Question 14

What do sympathetics do to CBF?

Answer 14

Vasoconstriction when systemic CO and BP increases

Question 15

Whath do parasympathetics do to CBF?

Answer 15

Leads to vasodilation when systemic cardiac output/BP decreases

Question 16

What are the neurotransmitters of cerebral circulation?

Answer 16

SP, NKA, CGRP

Question 17

How does ICP affect CBF?

Answer 17

Increased ICP decreases CBF

Question 18

What is the purpose of vasoconstriction?

Answer 18

protects BBB and capillaries

Question 19

What happens during reduced brain perfusion?

Answer 19

Vasomotor centers activates, systemic BP increases, blood goes to brain.

Question 20

What does anemia do to CBF?

Answer 20

Increases

Question 21

What does polycythemia do to CBF?

Answer 21

decreases it

Question 22

What does high Pa CO2 do to CBF?

Answer 22

Increases it

Question 23

What does very low Pa O2 do to CBF?

Answer 23

Increases CBF

Question 24

What are the effects of acidosis on CBF?

Answer 24

Increases CBF

Question 25

Effects of alkalosis on CBF?

Answer 25

Decreases CBF

Question 26

Function of BBB

Answer 26

Maintains CSF electrolyte composition, excludes toxins, and contains neurotransmitters

Question 27

Components of BBB

Answer 27

tight junctions, endothelial cells, basement membrane and Endfoots of Astrocytes, pericytes

Question 28

What is the major energy source for the brain?

Answer 28

glucose

Question 29

How does glucose cross the BBB?

Answer 29

transport proteins

Question 30

Function of P-glycoprotein?

Answer 30

Move drugs that don't belong that crossed BBB back into blood

Question 31

Function of Na K 2Cl

Answer 31

transports ions from csf to blood

Question 32

Function of GlutI

Answer 32

transports glucose from blood

Question 33

Is Glut I insulin dependent or independent

Answer 33

insulin dependent

Question 34

What is Na K 2 Cl expression tied to?

Answer 34

endothelin 1 and 3

Question 35

What is endothelin production tied to with Na K 2 Cl?

Answer 35

Astrocyte signals and possibly K in CSF

Question 36

Glut 3 is found on what cell?

Answer 36

Neurons

Question 37

Glut 5 is found on what cells?

Answer 37

Microglia

Question 38

Glut I 45 kd is found on what cells?

Answer 38

Astrocytes

Question 39

GlutI 55 kD is found on what cells?

Answer 39

microvessels, choroid plexus, ependymal cells

Question 40

What are the four circumventricular organs?

Answer 40

posterior pituitary, area postrema, organum vasculosum of the lamina terminalis, subfornical organ

Question 41

Function of posterior pituitary

Answer 41

secretory, endocrine

Question 42

Function of area postrema

Answer 42

sensory initiation of vomiting in response to chemotactic triggers

Question 43

function of OVLT

Answer 43

sensory; regulation of total body water and thirst, target of Angiotensin II

Question 44

Function of subfornical organ

Answer 44

sensory