Exam 3 (Heart)

Question 1

What are the MAP values for hypertension and hypotension?

Answer 1

hypertension: MAP > 105
hypotension: MAP < 70

Question 2

What is the valve between the left ventricle and the aorta?

Answer 2

aortic semilunar valve

Question 3

What is stenosis?

Answer 3

heart valve doesn’t open properly; could be narrowed

happens before/during LUB

Question 4

Describe the process of electrical conduction in the heart.

Answer 4

1. electrical signal begins at SA node
2. signal is conducted through internodal pathway (fast)
3. conduction stops at fibrous wall between atria and ventricles
4. depolarization through AV bundle and Purkinje fibers (fast)
5. depolarization spreads upward from apex to fibrous wall

Question 5

What is the equation for pulse pressure?

Answer 5

PP = systolic P - diastolic P

Question 6

What effect does norepinephrine have on MAP?

Answer 6

arteriolar smooth muscle → vasoconstriction → increased peripheral resistance → increased MAP

ventricular contractile muscle → increased stroke volume → increased CO → increased MAP

SA node → increased HR → increased CP → increased MAP

Question 7

What are the four components of blood vessels?

Answer 7

1. endothelium (secretion + absorption)
2. elastic tissue (energy storage)
3. smooth muscle (change vessel diameter)
4. fibrous tissue (stiffness; stretch resistance)

Question 8

What is the equation for mean arterial pressure (MAP)?

Answer 8

MAP = DP + 1/3(SP - DP)

Question 9

What is the condition of the heart during the PQ segment?

Answer 9

completion of ventricular filling

atria contract → last 20% of ventricular filling + some backflow to veins (jugular pulse)

Question 10

What are the properties of capillaries?

Answer 10

endothelium

site of exchange

Question 11

What are the valves between the atria and the ventricles?

Answer 11

AV valves

Question 12

What are the properties of venules?

Answer 12

endothelium + fibrous tissue

collecting vessels

Question 13

What effect does ACh have on MAP?

Answer 13

ACh → SA node → increased heart rate → increased cardiac output → increased MAP

Question 14

What are the factors that affect MAP?

Answer 14

1. peripheral resistance
2. cardiac output (CO = HR x stroke volume)
3. blood volume (regulated by kidneys)
4. distribution of blood in circuitry

Question 15

What is the P wave in an ECG?

Answer 15

arterial depolarization

Question 16

What is the ST segment in an ECG?

Answer 16

ventricular contraction

Question 17

What is the PQ/PR segment in an ECG?

Answer 17

atrial contraction

Question 18

What happens during the ST segment?

Answer 18

ventricular ejection → semilunar valves open

Question 19

What are the types of cardiac muscle?

Answer 19

contractile: like skeletal; longer contraction duration excitatory: autorhythmic cells conductive: conduct electrical signals faster than contractile muscle

Question 20

What is the equation for flow rate (Q)?

Answer 20

Q = ΔP/R

Question 21

Which capillary/interstitial pressures affect absorption?

Answer 21

Π_p

Question 22

What is the driving pressure?

Answer 22

fluid pressure created by the ventricles

Question 23

Which capillary/interstitial pressures affect filtration?

Answer 23

P_c, P_if, Π_if

Question 24

What happens during the T wave?

Answer 24

isovolumic ventricular relaxation

ventricular repolarization; retrograde flow → semilunar valves close (DUP)

Question 25

Name the parts of an ECG.

Answer 25

Question 26

What are the causes of edema?

Answer 26

cap_F \>\> cap_A * increase in P_c * increase in Π_if * increase in Π_p (caused by albumin breakdown) * inadequate drainage of lymph

Question 27

What is the condition of the heart before the P wave?

Answer 27

heart at rest atrial and ventricular diastole; atria fill from veins; ventricles fill from gravity

Question 28

What are the two types of pressure in capillaries and interstitial fluid?

Answer 28

1. hydrostatic: based on fluid pressure 2. osmotic: based on solutes

Question 29

What are the properties of arterioles?

Answer 29

endothelium + smooth muscle vasoconstrict or vasodilate site of variable resistance

Question 30

What is cardiac regurgitation?

Answer 30

leaking valve; blood can flow backwards or through closed valve happens *after* LUB

Question 31

Where is the cardiovascular center and what does it do?

Answer 31

medulla oblongata; coordinates BP through autonomic nervous system

Question 32

What is the T wave in an ECG?

Answer 32

ventricular repolarization

Question 33

What is the QRS complex in an ECG?

Answer 33

progressive ventricular depolarization

Question 34

What is the equation for resistance (R)?

Answer 34

R = 1/r⁴

Question 35

What is fibrillation?

Answer 35

arrhythmia of rapid, irregular, and unsynchronized contraction

Question 36

What is elastance, and which blood vessel type has more?

Answer 36

ΔP/ΔV (ability to return to unstretched state) arteries have more elastance

Question 37

What is compliance, and which blood vessel type has more?

Answer 37

ΔV/ΔP (ability to stretch) veins are more compliant

Question 38

What are the right and left heart circuits?

Answer 38

right: pulmonary circuit left: systemic circuit

Question 39

What is artherosclerosis?

Answer 39

plaques in arteries harden them → lower elastance + movement energy → higher BP + lower blood flow

Question 40

What is the equation for flow velocity?

Answer 40

v = Q/A A = cross-sectional area

Question 41

Where are baroreceptors and what do they do?

Answer 41

carotid arteries + aorta; stretch sensitive mechanoreceptors

Question 42

What are systole and diastole?

Answer 42

systole: cardiac muscle contracting diastole: cardiac muscle relaxing

Question 43

What happens during the QRS complex?

Answer 43

isovolumic ventricular contraction Q (depolarization of AV bundle) → S (ventricular depolarization) → AV valves forced closed (LUB)

Question 44

What are the properties of veins?

Answer 44

endothelium + elastic tissue + smooth muscle + fibrous tissue hold 60% of blood; can change diameter

Question 45

What is the pericardium?

Answer 45

fluid filled sack around heart; lubricates and prevents rubbing

Question 46

What is the valve between the right ventricle and the pulmonary artery?

Answer 46

pulmonary semilunar valve

Question 47

What are the properties of arteries?

Answer 47

endothelium + elastic tissue + smooth muscle + fibrous tissue energy required to stretch → stored energy

Question 48

What are the types of pacemaker cells?

Answer 48

sinoatrial node: 70 bpm atrioventricular node: 50 bpm ventricular cells: 35 bpm