Physiology 1.12 Flashcards Preview

NMSK-B I > Physiology 1.12 > Flashcards

Flashcards in Physiology 1.12 Deck (18)
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1
Q

What populates the subarachnoid space?

A

blood vessels

2
Q

Where is CSF produced?

A

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

3
Q

What pushes CSF through its path?

A

spinal cord movements

4
Q

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

A
  • Na+/H+ exhange

- Na+/Cl- co-transport

5
Q

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

A
  • active Na+/K+ ATPase exchange of Na+ and K+

- Na+ enter the ventricle

6
Q

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

A
  • 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
Q

Where is the CSF absorbed?

A

arachnoid villi of the superior saggital sinus

8
Q

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

A

68 mm

9
Q

Which volume of CSF does absorption equal formation?

A

112 mm

10
Q

What are the functions of the CSF?

A
  • remove brain metabolites
  • regulates brain tissue
  • adds buoyancy of brain
11
Q

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

A

-tighter junctions to keep blood in vessel

12
Q

Where is exchange vessel continuous endothelium found?

A

skin
skeletal, smooth, cardiac muscle
lungs

13
Q

Where is exchange vessel fenestrated endothelium found?

A

GI mucosa
glands
renal glomerular and peritubular capillaries

14
Q

Where is exchange-vessel discontinuous endothelium found?

A

hepatic and bone marrow sinusoids

speen sinusoids

15
Q

Where is exchange-vessel tight-junction endothelium found?

A

CNS**

retina

16
Q

What is the Monro-Kellie doctrine?

A

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
Q

What are the causes of increased intracranial pressure?

A

edema

hydrocephalus (increase CSF volume)

18
Q

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

A

vasogenic edema [broken BBB]

cytotoxic edema when neurons, glia, endothelial cells injured