Unit 3 Quiz 3 Material

Question 1

What is cardiac output? how is it calculated? What is the normal value?

Answer 1

the volume of blood coming out of each ventricle per unit time, usually expressed as Liters/min
CO = HR x SV
5L/min

Question 2

What are the typical effects of parasympathetic output?

Answer 2

-slows heart rate
-reduces cardiac output
-decreases SA frequency
-decreases AV conduction velocity
-decreases atrial kick

Question 3

What are the typical effects of sympathetic output?

Answer 3

-increases HR
-increases SV and CO
-increases SA frequency
-increases conduction velocity– all cells
-increases atrial kick
-increases stroke volume (SV)

Question 4

What is the Frank-Starling Relationship?

Answer 4

As you stretch the cardiac chamber, it gets stronger

Question 5

What are the implications of the Frank-Starling Relationship?

Answer 5

-control EDV, prevent ESV from increasing (prevent clotting)
-matching of LV and RV output, output from right and left sides of the heart remain equal
-prevention of rise in venous pressure
-prevents blood from backing up into veins/capillaries

Question 6

What determines EDV?

Answer 6

venous return

Question 7

What leads to increased contractility in extrinsic vs. intrinsic?

Answer 7

adding NE and E

Question 8

Describe the similarities and differences between extrinsic and intrinsic mechanism of regulation?

Answer 8

both have the same EDV but extrinsic has higher SV due to sympathetic stimulation

Question 9

What is the ejection fraction and what does it represent?

Answer 9

EF = SV/ EDV
higher EF represents a more complete ejection of EDV

Question 10

At rest, what percent of troponin is bound with Ca 2+? What does the addition of sympathetic output do?

Answer 10

30%
increased L-Ca2+ current, ie bigger trigger
more calcium into cytosol, more troponin saturation

Question 11

What is THE POINT of the signal transduction pathway?

Answer 11

-faster and more calcium release
-faster calcium removal
-stronger, briefer contraction

Question 12

Define Chronotropy

Answer 12

regulation of heart rate by autonomic NS

Question 13

Define Dromotropy

Answer 13

conduction velocity through AV node

Question 14

Define Inotropy

Answer 14

tension or force development (twitch)

Question 15

Describe what a large artery consists of.

Answer 15

several elastic layers- allows for recoil
endothelium - smooth lining, commonly damaged
many layers of smooth muscle (radius and flow) and connective tissues (support and strength)
lumen

Question 16

Describe what an arteriole consists of

Answer 16

endothelium
smooth muscle cells
lumen

Question 17

Describe what a capillary consists of

Answer 17

single layer of endothelial cells
lumen

Question 18

Describe what a venule consists of

Answer 18

endothelium
connection tissue
lumen

Question 19

Describe what a large vein consists of

Answer 19

few elastic layers (floppy)
endothelium
wide lumen
few layers of smooth muscle and connective tissue

Question 20

Name the 5 main types of blood vessels and what their main functions are

Answer 20

1. Large artery- low resistance, conducting vessels
2. Arteriole - flow regulators
3. Capillary - functional unit of the CV system
4. Venule - WBC’s released into tissues during inflammation and infection; capacitance vessels
5. Large vein- low resistance, high-capacitance vessels, house 2/3 of blood in veins

Question 21

What happens in response to pulsatile contraction of the heart?

Answer 21

waves of pressure move throughout the vasculature, decreasing in amplitude with distance

Question 22

What causes the dicrotic notch?

Answer 22

result of semilunar valve closing

Question 23

Where do oscillations stop or cease to exist?

Answer 23

venules

Question 24

Define compliance

Answer 24

how easy to expand

Question 25

What happens when blood is pumped into arteries?

Answer 25

the volume pumped out with single heart beat stretches out the arteries; their recoil then continues to push on the blood, keeping it moving during diastole

Question 26

Describe elastic recoil

Answer 26

strength of snap back

Question 27

Why are arteries described as a pressure reservoir?

Answer 27

very high in elastin

Question 28

How is Pulse Pressure calculated?

Answer 28

pulse pressure = systolic - diastolic

Question 29

How is Mean Arterial Pressure Calculated?

Answer 29

MAP = DP + (PP)/3

Question 30

What happens to arterial compliance with increasing age?

Answer 30

decreases, ie arteries get stiff SP trends higher, DP trends lower PP trends higher MAP can stay the same

Question 31

How does an increase in metabolism affect an artery?

Answer 31

increases radius, decreases resistance, increases flow, volume, and pressure in capillaries

Question 32

How does a decrease in metabolism affect an artery?

Answer 32

decreases radius, increases resistance, decreases flow, volume and pressure in capillaries

Question 33

What are the three main job of arterioles?

Answer 33

1. match flow to local tissue/cellular demand (default, get enough blood flow to cells) 2. maintain and protect MAP of whole system (protect brain, protect heart) 3. temperature regulation (skin)

Question 34

Describe the histology of arterioles

Answer 34

thick smooth muscle layer, regulates pressure and flow to downstream capillaries

Question 35

What is an example of a time where the arterioles would need to focus on protecting TPR cooperation and focus blood flow to the heart and brain?

Answer 35

loss of pressure in arteries, hemorrhage

Question 36

What does active hyperemia mean?

Answer 36

more metabolism, increased blood flow

Question 37

What are the factors that tell an arteriole to dialate?

Answer 37

rising CO2 levels, dropping O2, drop in pH, rise in metabolites

Question 38

What is Myogenic Flow Autoregulaton?

Answer 38

protective mechanism against pressure-induced damage

Question 39

What is reactive hyperemia?

Answer 39

high local blood flow after period of deprivation

Question 40

What are local controls?

Answer 40

main regulators of flow to brain and heart muscle

Question 41

Predict what happens must happen in the systemic arteriole for vasodilation to occur in regards to.. O2 CO2 pH ECF K+ Adenosine

Answer 41

decreasing increasing decreasing increasing increasing opposite is true

Question 42

What are the extrinsic controls of the arterioles?

Answer 42

sympathetic innervation of vessels alpha 1 adrenergic receptor agonists induce constriction beta 2 adrenergic receptor agonists induce dilation NE stimulates alpha 1 strongly, causing constricton, reduced radius, reduced flow E stimulates beta 2 receptors strongly, causing dilation, increasing radius and flow (important in skeletal muscle)

Question 43

Describe the effects of low dose vs. high dose of epinephrine

Answer 43

low dose (physiologic) causes vasodilation high dose (injection) causes vasoconstricton

Question 44

Describe the neural controls that alter arteriolar smooth muscle

Answer 44

VASOCONSTRICTORS: sympathetic nerve that release NE, alpha1R VASODILATORS: neurons that release nitric oxide not dual innervation of vasculature: sympathetic only dilation from nitric oxide release, less NE applied

Question 45

Describe the hormonal controls that alter arteriolar smooth muscle

Answer 45

VASOCONSTRICTORS: epinephrine high [] angiotensin II vasopressin = ADH VASODILATORS epinephrine low [] atrial natriuretic peptide = ANP

Question 46

Describe the local controls that alter arteriolar smooth muscle

Answer 46

VASOCONSTRICTORS internal blood pressure (myogenic response) endothelin-1 VASODILATORS drop in O2 rise in K+, CO2, drop in H+ osmolarity adenosine substances released during injury nitric oxide

Question 47

What is the most powerful constrictor measured?

Answer 47

endothelin-1, secreted by endothelial cells

Question 48

Describe Arteriolar Smooth Muscle Control of the... 1.Heart 2. Skeletal Muscle 3. Brain 4. Lungs

Answer 48

1. coronary flow occurs mainly during diastole 2. controlled by local metabolic factors during excersize, Epinephrine causes vasodilation via Beta2-adrenergic receptors when present in low concentration, and vasoconstriction via alpha-adrenergic receptors when present in high concentration 3. influenced relatively little by the autonomic nervous system 4. constriction mediated by local factors in response to low oxygen-concentration- just the opposite of what occurs in the systemic circulation

Question 49

What causes intrinsic mechanism of regulation in Frank Sterling?

Answer 49

change in EDV

Question 50

What causes extrinsic mechanism of regulation in Frank Sterling?

Answer 50

sympathetic stimulation