Lecture 29 10/24/23

Question 1

What is bulk flow?

Answer 1

movement of fluid as the result of pressure differences

Question 2

What is diffusion?

Answer 2

movement of dissolved substances as a result of concentration gradients

Question 3

Why is it important that capillaries are a single cell layer?

Answer 3

benefits the function as exchange vessels

Question 4

What substances can be exchanged at the capillary beds as a part of microcirculation?

Answer 4

-water
-lipid soluble substances
-lipid insoluble substances
-large proteins

Question 5

What is oncotic pressure?

Answer 5

osmotic pressure exerted by colloids (usually proteins)

Question 6

What type of forces cause bulk flow?

Answer 6

hydrostatic forces

Question 7

How do lipid soluble substances, like CO2 and O2, cross the capillary wall?

Answer 7

diffusion

Question 8

How does the solubility of CO2 compare to that of O2?

Answer 8

sol. of CO2 > sol. of O2

Question 9

How do non-lipid soluble substances, like H2O, Na+, and glucose cross the capillary wall?

Answer 9

slit pores and channels

Question 10

What other mechanisms allow for trans-endothelial exchange at the capillary?

Answer 10

-active and/or facilitated transport
-transcytosis

Question 11

What is the hydrostatic pressure of the capillary?

Answer 11

force that causes outward movement of fluid

Question 12

What is the hydrostatic pressure of the interstitium?

Answer 12

force that opposes movement of fluid out of the capillary

Question 13

What is the plasma colloid oncotic pressure?

Answer 13

force that retains fluid within the capillary

Question 14

What is interstitium colloid oncotic pressure?

Answer 14

force that opposes the retainment of fluid within the cavity

Question 15

What is the result of the Starling’s forces?

Answer 15

net filtration (small amount)

Question 16

What is the role of the lymphatic system?

Answer 16

return interstitial fluid to intravascular space

Question 17

What are the components of the lymphatic system?

Answer 17

-lymphatic capillaries
-collecting vessels
-lymph nodes
-lymphatic ducts
-thoracic duct

Question 18

What can cause edema?

Answer 18

-increased hydrostatic pressure (in capillary)
-decreased colloid oncotic pressure (in capillary)
-lymphatic obstruction
-increased vascular permeability

Question 19

What can cause an increase in hydrostatic pressure?

Answer 19

cardiac dysfunction

Question 20

What can cause a decrease in colloid oncotic pressure?

Answer 20

hypoalbuminea (from renal loss)

Question 21

What can cause lymphatic obstruction?

Answer 21

masses

Question 22

What can cause an increase in vascular permeability?

Answer 22

inflammatory mediators