Physiology 1.12 Flashcards Preview

NMSK-B I > Physiology 1.12 > Flashcards

Flashcards in Physiology 1.12 Deck (18):
1

What populates the subarachnoid space?

blood vessels

2

Where is CSF produced?

secreted by choroid plexus; turned over 3-4 times per day

3

What pushes CSF through its path?

spinal cord movements

4

How does Na+ enter the epithelial cells on the capillary side of the choroid plexus?

-Na+/H+ exhange
-Na+/Cl- co-transport

5

How does Na+ enter the ventricles on the ventricular surface of the choroid plexus?

-active Na+/K+ ATPase exchange of Na+ and K+
-Na+ enter the ventricle

6

How does HCO3- and Cl- enter the ventricles of the choroid plexus?

-HCO3- and Cl- antiporter moves HCO3- into the epithelial cell and Cl- out
-SCO3- forms from hydration of CO2 in the epithelial cell
-HCO3- and Cl- concentrations are higher in epithelial cells and flow down electrochemical gradients into ventricles

7

Where is the CSF absorbed?

arachnoid villi of the superior saggital sinus

8

Which volume of CSF does absorption stop in the superior saggital sinus?

68 mm

9

Which volume of CSF does absorption equal formation?

112 mm

10

What are the functions of the CSF?

-remove brain metabolites
-regulates brain tissue
-adds buoyancy of brain

11

What is the main difference between brain capillaries versus general capillaries?

-tighter junctions to keep blood in vessel

12

Where is exchange vessel continuous endothelium found?

skin
skeletal, smooth, cardiac muscle
lungs

13

Where is exchange vessel fenestrated endothelium found?

GI mucosa
glands
renal glomerular and peritubular capillaries

14

Where is exchange-vessel discontinuous endothelium found?

hepatic and bone marrow sinusoids
speen sinusoids

15

Where is exchange-vessel tight-junction endothelium found?

CNS**
retina

16

What is the Monro-Kellie doctrine?

increase in volume of brain tissue, blood, CSF or other brain fluid will produce increase in intracranial pressue because:
-bony calvarium fixes the total cranial volume
-mass lesions can increase intracranial pressure through associated edema

17

What are the causes of increased intracranial pressure?

edema
hydrocephalus (increase CSF volume)

18

What is the most common form of edema in the brain?

vasogenic edema [broken BBB]

(cytotoxic edema when neurons, glia, endothelial cells injured)