CV Part 1

Question 1

What type of blood and where does the vena cava empty?

Answer 1

Mixed venous blood

Right atrium

Question 2

Sequential blood flow (13)

Answer 2

RA → tricuspid valve → RV → pulmonic semilunar valve → pulmonary arteries → lungs → pulmonary veins → LA → mitral valve → LV →aortic semilunar valve →aortic arch → aorta

Question 3

How does the heart function as 2 pumps?

Answer 3

Pulmonary circulation

Systemic circulation

Question 4

Diastole

Answer 4

Ventricular relaxation

Low intraventricular pressure

Question 5

Systole

Answer 5

Ventricular contraction

High intraventricular pressure

Question 6

What is the myocardium?

Answer 6

Cardiac muscle

Question 7

What is the preferred energy in a healthy heart?

Answer 7

Free Fatty Acids

Question 8

Heart has an extensive vascular network made of

Answer 8

Coronary arteries and veins

Question 9

Majority of cardiac mass is (5)

Answer 9

Endothelium
VSM
Fibroblasts
ECM
Interstitium

Question 10

What is the myocardium comprised of?

Answer 10

Myocytes

Question 11

How are cardiac muscle cells and fibers joined?

Answer 11

Gap junctions

Question 12

What do gap junctions allow?

Answer 12

High degree of electrical conductivity

Free diffusion of very small molecules

Question 13

What kind of metabolism do cardiac myocytes use to produce ATP?

Answer 13

Oxidative phosphorylation

Question 14

What are cardiac myocytes rich in?

Answer 14

Mitochondria (serves as intracellular Ca sinks)

Question 15

Like skeletal muscle, what do cardiomyocytes contain? (3)

Answer 15

CK-MB (cardiac specific creatine kinase)
TnI
TnT

Question 16

What are possible diagnostic markers for an MI?

Answer 16

TnI
TnT
CK-MB

Question 17

2 ways cardiac muscle is different from skeletal muscle

Answer 17

Slight stretch causes release of intracellular Ca

Develop more tension from stretch

Question 18

What makes up the majority of myocardial mass?

Answer 18

Ventricles

Question 19

What happens during the beginning of diastole?

Answer 19

Aortic valve closed
Mitral valve ready to open

LV fibers have no load

Question 20

What happens during early diastole?

Answer 20

Mitral valve opens, filling the LV

Question 21

Why does the mitral valve open during early diastole?

Answer 21

Combination of increasing LA filling pressure and the low LV pressure
(Think gradients)

Question 22

What happens during the late stage of diastole?

Answer 22

Atria contract due to SA nodal firing

Question 23

Atrial kick

Answer 23

Atria contribute 20% to ventricular filling

Question 24

What is preload caused by?

Answer 24

Blood induced filling that causes stretch

Question 25

Filling causes

Answer 25

Preload on LV muscle fibers

Question 26

Law of Laplace

Answer 26

T = P x R | Wall tension = pressure x radius

Question 27

What happens if there's a greater wall tension? | Think Law of Laplace

Answer 27

More filling | Upregulate O2 demand

Question 28

What happens during an isovolumetric contraction?

Answer 28

Mitral and aortic valves are closed | LV pressure soars

Question 29

What is afterload in the heart?

Answer 29

Aortic pressure

Question 30

What happens when preload > afterload?

Answer 30

Aortic semilunar valve opens | LV ejects blood

Question 31

What 2 things happen in phase 1?

Answer 31

Diastolic filling | Generation of preload

Question 32

What happens in phase 2?

Answer 32

Isovolumetric contraction (systole)

Question 33

What happens in phase 3?

Answer 33

Systolic ejection

Question 34

What happens in phase 4?

Answer 34

Isovolumetric relaxation

Question 35

What does the end systolic pressure-volume (ESPVR) plot represent?

Answer 35

Max. Ventricular pressure developed at a given inotropic state

Question 36

What happens if we increase the EDV in an ESPVR plot? (3)

Answer 36

Inc. preload Inc. systolic intraventricular pressure Inc. ESV (a little)

Question 37

What happens if we increase afterload in an ESPVR plot? (2)

Answer 37

Inc. systolic intraventricular pressure | Inc. ESV

Question 38

What happens to the EsVPR plot given positive inotropy?

Answer 38

Inc. max. Systolic pressure | Dec. ESV

Question 39

What are inotropic compounds?

Answer 39

Alter the force of cardiac muscle contractility

Question 40

What is the goal of positive inotropic compounds?

Answer 40

Increase cardiac pumping efficiency

Question 41

What do positive inotropic compounds increase? (4)

Answer 41

Ventricular contractile force EDV Contraction velocity May or may not change time interval btwn excitation episodes

Question 42

What is contraction of cardiac muscle dependent on? (2)

Answer 42

APs (induced by Na influx) | Inc. sarcoplasmic [Ca]

Question 43

What does hypocalcemia due to the QT interval?

Answer 43

Lengthens

Question 44

What does hypercalcemia due to the QT interval?

Answer 44

Shortens

Question 45

What does Digoxin do?

Answer 45

Blocks Na/K ATPase → inc. intracellular Na → NCX can't function → intracellular Ca inc. → contraction enhanced

Question 46

What type of effect does digoxin have on the heart?

Answer 46

Positive inotropic effect

Question 47

Digoxin acts as a vagomimetic agent, meaning that it (2)

Answer 47

Slows SA and AV nodal conduction | Sensitized baroreceptors

Question 48

You can raise cardiomyocyte [Ca] by

Answer 48

Activating B1 and B2 adrenoceptors (norepi-dependent)

Question 49

Lusitropy

Answer 49

Increased rate of relaxation due to mobilization of Gi protein-dependent signaling

Question 50

Increased PKA signaling leads to: (3)

Answer 50

Activation of type L channels Phosphorylation of phospholamban Phosphorylation of Troponin I

Question 51

ACh interrupts ______ which _______

Answer 51

Activation of L channels | Slows cardiac muscle contractility

Question 52

Type L channels are dependent on (3)

Answer 52

Na induced AP Catecholamines ACh

Question 53

Where is the SA node located?

Answer 53

Within RA

Question 54

Where is the AV node located?

Answer 54

Between right and left atria and the ventricles

Question 55

SA nodal activity controls

Answer 55

AV nodal activity

Question 56

AV nodal activity initiates

Answer 56

Ventricular depolarization