Special circulation

Question 1

What makes up the blood-brain barrier

Answer 1

tight junctions of endothelial cells and astrocytes

Question 2

What makes up the tight junctions in the blood brain barrier

Answer 2

Claudins, occludins and JAM

Question 3

What makes up the adherens junctions in the blood brain barrier

Answer 3

cadherins and beta catenins

Question 4

blood brain transport is directly proportional to what and indirectly proportional to what

Answer 4

directly proportional to lipid solubility and inversely proportional to charge, water solubility and molecular weight

Question 5

Two examples of molecules that have to be selectively transported across the BBB

Answer 5

Glucose and amino acids

Question 6

Examples of fat-soluble substances that can cross the BBB

Answer 6

alcohol, nicotine, caffeine

Question 7

The active transport of which molecule across the BBB allows for the synthesis of serotonin in the brain

Answer 7

tryptophan

Question 8

What does high pH and low CO2 cause in cerebral arteriolar smooth muscle

Answer 8

make the cerebral arteriolar smooth muscle contract

Question 9

What is the importance of the skeletal muscle redistributing blood flow away from muscle to the GIT

Answer 9

Increases

in GI motility, digestion and absorption.

Question 10

True or false

there is no parasympathetic innervation of aterioles in skeletal muscle circulation

Answer 10

True; there is only sympathetic innervation. Vasodilation occurs only by reduced sympathetic input

Question 11

Arteriole diameter in skeletal muscle circulation is controlled by which neurotransmitter

Answer 11

norepinepherine

Question 12

Systemic arteriole have an abundance of which type of receptor

Answer 12

alpha adrenergic

Question 13

What is released from skeletal muscle arterioles at the BEGINNING of exercise to increase blood flow

Answer 13

release of Ach and M3-mediated release of NO

Question 14

What is released from skeletal muscle DURING exercise to increase blood flow

Answer 14

local production of lactic acid

Question 15

What is the blood flow mechanism underlying fainting

Answer 15

sudden emotional shock causes M3 mediated release of NO which causes blood to pool in the skeletal muscles of the lower limb and thus results in fainting

Question 16

What kind of receptors are on coronary arterioles of epicardium produce vasoconstriction.

Answer 16

alpha-adrenergic

Question 17

Coronary blood flow to the left ventricle is almost zero during ______(systole or diastole)

Answer 17

Systole

Question 18

Blood is shunted to and from which layers of the heart during sytole

Answer 18

From the epicardium via vasoconstriction to the endocardium via vasodilation

Question 19

MI during exercise injures endocardium that extends to the myocardium and epicardium usually produces what change to the ST segment

Answer 19

elevation of the ST segment

Question 20

Injury to the endocardium alone usually produces what

change to ST segment

Answer 20

depression of the ST segment

Question 21

Which type of arteries supply most of the heart muscle

Answer 21

epicardial arteries

Question 22

Which layer of heart has a the greater oxygen demand and flow

Answer 22

the endocardium

Question 23

What is another name for non-transmural ischemia

Answer 23

subendocardial ischemia

Question 24

What is a systolic injury current

Answer 24

results from a greater depolarization in healthier cells

Question 25

The arterioles of the visceral splanchnic circulation possess what kind of receptors

Answer 25

alpha adrenergic receptors

Question 26

pressure flow autoregulation only occur in a metabolically active liver which is during which state?

Answer 26

Postprandial

Question 27

Which organ an hepatic pressure autoregulation occur

Answer 27

liver

Question 28

Which vessel contributes 2/3 of the total hepatic blood flow

Answer 28

Portal vein

Question 29

signs of portal hypertension

Answer 29

1. esophageal varices 2. caput medusae 3. hemorrhoids 4. marked ascites 5. hypersplenism (thrombocytopenia, neutropenia, anemia)

Question 30

What kind of circulation with arteriovenous anastomoses do villi of the GIT have

Answer 30

side by side/parallel

Question 31

How is sepsis related to hypoxic villi

Answer 31

Hypoxic villi can break off and all partially digested food and bacteria into the circulation leading to sepsis

Question 32

Which three factors can cause constriction of vessels in the skin

Answer 32

cold, nicotinic acetylcholine receptors and posterior nucleus of the hypothalamus

Question 33

Which nucleus of the hypothalamus can be inhibited to produce vasoconstriction

Answer 33

anterior nucleus

Question 34

Which receptor is responsible for low skin temperature in smokers

Answer 34

Nicotinic receptors (nAChRs)

Question 35

Which four factors can cause constriction of vessels in the skin

Answer 35

heat beta-adrenergic receptor M3 Ach receptor leads to NO release decrease in posterior hypothalamic nucleus

Question 36

What kind of mechanism is sweating

Answer 36

sudomotor mechanism

Question 37

With type of sympathetic fibers are sweat glands innervated by

Answer 37

adrenergic (for vasoconstriction) and cholinergic (M3 for N release and vasodilation)