Microcirculation

Question 1

List the 4 starling forces components when related to capillaries

Answer 1

hydrostatic pressure within capillary and interstitial hp outside
Oncotic pressure within capillary & interstitial osmotic pressure

Question 2

Under normal conditions which have more and less pressure inside and outside the capillary

Answer 2

Both interstitial hydrostatic pressure & osmotic pressure are lower than inside capillary.

Question 3

In terms of arterioles & veins- when does filtration dominate and absorption dominate?

Answer 3

Filtration in arterioles & absorption in venous side

Question 4

Describe a few of the lymphatic systems role in circulation

Answer 4

absorp the 10% interstitial fluid not reabsorbed by capillaries, move it throughout the body. Lymph nodes contain immune cells that respond to infection

Question 5

Whats the most common cause of lymphedema world wide?

Answer 5

Filariasis (parasitic roundworm); others include surgery & breast cancer

Question 6

what are some examples of things causing swelling/edema/erythema in regards to the capillaries

Answer 6

epinephrine, and NITRIC OXIDE (vasodilator) histamine/bradykinins may be released by trauma, infections causing dilation of arterioles/venules. This may lead to leaky capillaries

Question 7

This hormone/vasoactive substance can cause vascular spasms, implicated as part of pathology in migraines

Answer 7

Serotonin

Question 8

prostaglandins

Answer 8

cause vasoconstriction or vasodilation

Question 9

This is a endothelial generated vasodilator

Answer 9

nitric oxide

Question 10

Define/Describe autoregulation

Answer 10

the ability to maintain a relatively constant flow on a wide range of changing arterial pressure (50-150)

Question 11

which organs in particular use autoregulation

Answer 11

heart, kidneys, and the brain

Question 12

define hypoxic pulmonary vasoconstriction and why it is different than the “norm”

Answer 12

when lungs are experiencing low O2 there vascular beds constrict vs. the rest of the vascular beds in body would rather dilate.

Question 13

Can you list the two mechanisms for autoregulation

Answer 13

myogenic and metabolic hypothesis

Question 14

what is the myogenic hypothesis in reference to explaining autoregulation

Answer 14

when vascular smooth muscle is stretched, it contracts

Question 15

whats the metabolic hypothesis in reference to autoregulation

Answer 15

accumulation of metabolic byproducts such as CO2, H+, lactate, cause vasodilation of arterioles

Question 16

This would be termed for right ventricle heart failure & it also gives indication as to where the problem would be

Answer 16

core pulmonic (in lungs)

Question 17

what causes leaky capillaries

Answer 17

histamine, which acts to dilate vascular beds

Question 18

What’s the difference between gas exchange in normal capillaries throughout the body vs. alveolar gas exchange in lungs when it comes to hypoxic conditions

Answer 18

Capillaries throughout the bodies dilate
vs.
Lungs/alveoli constrict

Question 19

explain why hypoxic pulmonary vasoconstriction is an exception to all other vascular beds

Answer 19

Normally capillaries want to dilate and increase O2 to the tissues, but in lungs= low O2 wants to be avoided so that blood shunts that area to get a better gas exchange elsewhere