Week 4 - Vessels & Hemodynamics

Question 1

Identify structural differences between arteries and veins

Answer 1

Arteries have thick elastic muscular walls
Veins have thin non-elastic walls
Veins contain valves to prevent back-flow

Question 2

Identify structural differences & similarities between veins and lymphatic vessels

Answer 2

Lymphatic vessels are lined with smooth muscle
Lymphatic vessels interconnect with lymph nodes
Lymphatic vessels contain valves to prevent back-flow

Question 3

Identify structural differences between elastic arteries and muscular arteries

Answer 3

elastic arteries contain elastic fibers in the tunica media layer
muscular arteries contain smooth muscle tissue in the tunica media layer to allow for vasoconstriction

Question 4

Arterioles are small ____ deliverying ____ to ______

The tunica media of arterioles contains _____

Answer 4

arteries
blood
capillaries
a few layers of muscle

Question 5

Metarterioles form branches into ______

To bypass capillary bed, _____ close and blood flows _____

Answer 5

capillary bed
precapillary sphincters
out of bed into thoroughfare channel

Question 6

Vasomotion is intermittent ________ that allows _______at a rate of _____

Answer 6

intermittent contraction and relaxation of sphincters
filling of capillary bed
5-10 times / minute

Question 7

Continuous capillaries are found in what tissue(s)?

Answer 7

skeletal/smooth muscle, connective tissue, LU

Question 8

Fenestrated capillaries are found in what tissues(s)?

Answer 8

KD, SI, choroid plexuses, ciliary process, endocrine glands

Question 9

Sinusoid capillaries are found in what tissue(s)?

Answer 9

LV, bone marrow, SP, anterior pituitary, parathyroid gland

Question 10

Capillaries are lacking in what tissue(s)?

Answer 10

epithelia, cornea and lens of eye, cartilage

Question 11

The function of capillaries is _______

Answer 11

exchange of nutrients and waste between blood and tissue fluid

Question 12

Describe the structure of a capillary

Answer 12

single layer of simple squamous epithelium and its basement membrane

Question 13

What are the types of capillary exchange?

Answer 13

diffusion
transcytosis
bulk flow

Question 14

Describe bulk flow

Answer 14

filtration and reabsorption

movement of large amount of dissolved or suspended material in same direction

Question 15

Bulk flow is more important for regulation of ______

Answer 15

relative volumes of blood and interstitial fluid

Question 16

Filtration is movement of material into _________ and is promoted by ______

Answer 16

interstitial fluid

blood hydrostatic pressure and interstitial fluid osmotic pressure

Question 17

Reabsorption is movement from ________ into ________ and is promoted by _______

Answer 17

interstitial fluid
capillaries
blood colloid osmotic pressure and interstitial fluid hydrostatic pressure

Question 18

Net filtration pressure is defined as _______

Answer 18

(BHP + IFOP) - (BCOP + IFHP)

Question 19

Blood colloid osmotic pressure is formed by ______ proteins, namely _______

Answer 19

plasma

albumin, globulin, fibrinogen

Question 20

Net filtration pressure in arterial end of capillary is generally ____ while in the venous end it is generally ______

Answer 20

10mmHg

-9mmHg

Question 21

As a result of net filtration pressure about ___% of filtered fluid is returned to the capillary. Escaping fluid and plasma proteins are collected by ______

Answer 21

85%

lymphatic capillaries

Question 22

Edema is _______ and can be a result of _________

Answer 22

abnormal increase in interstitial fluid if filtration exceed reabsorption

excess filtration, inadequate reabsorption

Question 23

Excess filtration can be caused by _________

Answer 23

increased BP

increased permeability of capillaries allows plasma proteins to escape

Question 24

Inadequate reabsorption can be caused by _________

Answer 24

decreased concentration of plasma proteins lowers blood colloid osmotic pressure (LV malfunction, burns, malnutrition, KD disease)

Question 25

What factors affect circulation?

Answer 25

- pressure differences that drive blood flow (blood velocity, blood volume, BP) - resistance to flow (afterload) - venous return

Question 26

How are speed of blood flow and cross-sectional area related? Blood flow becomes _____ when vessels merge to form veins.

Answer 26

inversely related faster

Question 27

Cardiac output is influenced by ______

Answer 27

blood pressure | resistance due to friction between blood cells and blood vessel walls

Question 28

Systemic vascular resistance is determined by _______

Answer 28

average blood vessel radius blood viscosity total blood vessel length

Question 29

There are ____ miles of blood vessels for every pound of fat. HBP can therefore be caused by ______

Answer 29

200 | obesity

Question 30

Arterioles control BP by changing _______

Answer 30

diameter

Question 31

Venous return is _______. Describe the pumps that facilitate venous return?

Answer 31

volume of blood flowing back to HT from systemic veins skeletal muscle pump - contraction of muscles & presence of valves respiratory pump - decreased thoracic pressure and increased abdominal pressure during inhalation, moves blood into thoracic veins and the right atrium

Question 32

Inputs to the cardiovascular center include _______

Answer 32

higher brain centers - cerebral cortex, limbic system, hypothalamus proprioceptors baroreceptors chemoreceptors - acidity, CO2, O2

Question 33

Describe the baroreceptor reflexes

Answer 33

carotid sinus reflex - swellings in internal carotid artery wall, CN IX to cardiovascular center in medulla, maintains normal BP in brain aortic reflex - receptors in wall of ascending aorta, CN X to cardiovascular center in medulla, maintains general systemic BP

Question 34

Which hormone causes vasoconstriction? Where is it produced?

Answer 34

ADH | hypothalamus

Question 35

What is the hormonal response to a decrease in BP or decreased blood flow to KD?

Answer 35

release of renin -> formation of angiotensin II, systemic vasoconstriction, causes release of aldosterone (H2O + Na+ reabsorption)

Question 36

Atrial natriuretic peptide lowers BP by ______

Answer 36

causing vasodilation and loss of salt and water in the urine

Question 37

The _____ nerve speeds up the heart rate via _____ stimulation. The _____ nerve slows down heart rate via ______ stimulation

Answer 37

cardiac accelerator sympathetic vagus (CN X) parasympathetic

Question 38

Describe the functions of chemoreceptor reflexes of carotid bodies and aortic bodies

Answer 38

- detect changes in blood chemistry (O2, CO2, H+) - causes stimulation of CV center - increases sympathetic stimulation to arterioles & veins - vasoconstriction and increase in blood pressure

Question 39

___% of blood in the body is out of circulation. What can push this blood back into circulation?

Answer 39

60% | epinephrine, norepinephrine

Question 40

To regulate blood pressure locally, vasoactive substances such as ______ are released from cell to alter vessel _____

Answer 40

K+, H+, lactic acid, nitric oxide | diameter

Question 41

______ vessels dilate in response to low levels of O2 | ______ vessels constrict in response to low levels of O2

Answer 41

systemic | pulmonary

Question 42

Shock is _______

Answer 42

failure of cardiovascular system to deliver enough O2 and nutrients

Question 43

What mechanisms attempt to return cardiac output & BP to normal in response to shock?

Answer 43

activation of renin-angiotension-aldosterone secretion of ADH activation of sympathetic nervous system release of local vasodilators