Microcirculation

Question 1

Lymphedema

Answer 1

Damage to lymph ducts causes scarring and fluid buildup w/in tissue
Filariasis (worm) is most common cause

Question 2

Hypoxic pulmonary vasoconstriction

Answer 2

Hypoxic pulmonary capillaries constrict and shunt blood to non-hypoxic alveoli
Problem for premies w/ low O2 tension and COPDers b/c it creates pulmonary hypertension and R heart failure

Question 3

What determines diameter of precapillary sphincters?

Answer 3

ANS
Hormones
Local metabolic substances - epi (d/c), histamines (d), serotonin (vascular spasm), prostaglandins (d/c), nitric oxide (d)
Increased temp

Question 4

Types of autoregulation for blood flow

Answer 4

Myogenic - stretch vascular smooth muscle and it contracts

Metabolic - high CO2, lactate, H+, nitric oxide, etc cause dilation; high O2 causes constriction

Question 5

Pitting edema

Answer 5

Impressions left in skin - nonspecific, may indicate heart failure

Question 6

Nitric oxide as vasodilator

Answer 6

Made by endothelial cells, released triggered by bradykinin

Question 7

Organs that autoregulate blood flow

Answer 7

Brain and kidney - as long as systolic pressure is b/w 50-150 mmHg