Anatomy II: Cardiovascular Physiology

Question 1

Explain the circuits of blood flow for the Pulmonary Circuit.

Answer 1

1. Deoxygenated blood is pumped to the lungs by the right side of the heart.
2. Gas exchange occurs between air in the alveoli and blood in the pulmonary capillaries.
3. The oxygenated blood is returned to the left side of the heart.

Question 2

Explain the circuit of blood flow for the Systemic Circuit.

Answer 2

1. Oxygenated blood is pumped to the body by the left side of the heart.
2. Gas exchange occurs between tissues and blood in the systemic capillaries.
3. Deoxygenated blood is returned to the right side of the heart.

Question 3

The heart helps maintain ______ of pressure that blood exerts on blood vessels (blood pressure).

Answer 3

HOMEOSTASIS

Question 4

______ and _______ of heart ’s contraction are major factors that influence blood pressure and blood flow to organs

Answer 4

RATE; FORCE

Question 5

What type of organ is the heart (atria) and what does it produce?

Answer 5

Endocrine Organ
Produces atrial natriuretic peptide (ANP)

Question 6

What does Atrial Natriuretic Peptide (ANP) do?

Answer 6

Lowers BP by decreasing sodium ion retention in the kidneys., and reduces osmotic water reabsorption and volume and pressure of blood in the blood vessels.

Question 7

What is the most dangerous consequence/effect of Coronary Artery Disease?

Answer 7

Myocardial Infarction (MI) - Plaque in coronary arteries ruptures, and blood clots form which obstructs blood flow to the myocardium.

Question 8

List Some Symptoms of Myocardial Infarction (MI).

Answer 8

1. Sweating
2. Anxiety
3. Shortness of Breath
4. Nausea
5. Vomiting

WOMEN MAY SUFFER WITH BACK, JAW, OR ARM PAIN INSTEAD OF CHEST PAIN USUALLY*

Question 9

How is CAD DEFINITIVELY Diagnosed?

Answer 9

An Angiogram or Angiography

Question 10

Define: Coronary Angioplasty

Answer 10

Commonly performed invasive procedure to open blocked or narrowed heart arteries.
A small balloon is inflated inside the artery to clear the blockage, often with a stent placed to keep the artery open.
This helps improve blood flow to the heart.

Question 11

Does the heart act voluntarily or involuntarily?

Answer 11

INVOLUNTARILY

Question 12

Define: Coronary Artery Bypass Grafting

Answer 12

More invasive than Angioplasty; It involves taking a healthy blood vessel from another part of the body and using it to create a bypass around blocked or narrowed heart arteries.
This helps restore proper blood flow and reduces the risk of heart problems.

Question 13

Define: Voltage

Answer 13

Difference in electrical potential between two points

Question 14

Define: Membrane Potential

Answer 14

Voltage difference that exists across membranes of all cells.

Question 15

Define: Resting Membrane Potential

Answer 15

Membrane potential of excitable cell when it is not being stimulated.
AVERAGES AROUND -60 TO -90 mV.

Question 16

Define: Current

Answer 16

Flow of ions or electrons with chemical or electrical gradient.

Question 17

Depolarization vs Repolarization

Answer 17

Depolarization is when the heart muscle “fires” to contract, and Repolarization is when the muscle “resets” and relaxes.

Depolarization : Happens when sodium (Na+) ions rush into the cell, making the inside of the cell more positive.
Repolarization: Potassium (K+) ions move out of the cell, restoring the negative charge inside the cell.

Question 18

Describe the steps of an action potential in a contractile cell. (4 Steps)

Answer 18

1. Slow Initial Depolarization Phase: Membrane slowly depolarizes to threshold because more cations leak in than leak out in the HCH channels in the plasma membrane.
2. Full Depolarization Phase: At THRESHOLD, Voltage-gated Ca2+ channels OPEN, and Ca2+ ENTERS the cell, allowing it to DEPOLARIZE.
3. Repolarization Phase: Ca2+ Channels CLOSE, and Voltage-gated K+ channels OPEN, allowing for K+ OUTFLOW and membrane repolarization.
4. Minimum Potential Phase: K+ Channels REMAIN open, and membrane HYPERPOLARIZES. This opens the HCH channels and repeats the cycle.

Question 19

The concentration of sodium and calcium ions in extracellular fluid (ECF) is ______ than in cytosol;
the concentration of potassium ions in ECF is ______ than in cytosol.

Answer 19

HIGHER; LOWER

Question 20

Describe the steps of a Long Refractory Period in Cardiac Muscles. (4 Steps)

Answer 20

1. Rapid Initial Depolarization Phase: Voltage-gated Na+ Channels activate, and Na+ ions enter, rapidly depolarizing the membrane.
2. Initial Repolarization Phase: Na+ channels are inactivates and some K+ channels Open. K+ ions leak out causing a small initial repolarization.
3. Plateau Phase: Ca2+ channels open and Ca2+ enter as K+ exits, prolonging the depolarization.
4. Repolarization Phase: Na+ and Ca2+ channels close, while K+ continues to exit, causing repolarization.

Question 21

Disturbances in Heart Rate: Bradycardia

Answer 21

Heart rate under 60 beats per minute.

Question 22

Disturbances in Heart Rate: Tachycardia

Answer 22

Heart rate over 100 beats per minute. (Sinustachycardia is regular, fast rhythm)

Question 23

What’s the disturbance in conduction pathways called?

Answer 23

AV Node Blockage

Question 24

What is ventricle-fibrillation?

Answer 24

Immediately life-threatening and manifests on ECG with Chaotic activity.

TREATED WITH ELECTRICAL SHOCK TO THE HEART (DEFIBRILLATION).

Question 25

Describe the cardiac conduction system and its role in contraction (3 steps)

Answer 25

1. SA node generates action potential, which spreads to AV node and atrial cells. 2. Action potential is conducted to AV bundle and then to right and left bundle branches. 3. Action potential spreads from bundle branches to the contractile cells of the ventricle.

Question 26

How do pressure changes lead to valve movement and blood flow in the contracted left ventricle?

Answer 26

- High pressure in ventricle causes aortic valve to OPEN due to blood flow. - High pressure in ventricle causes mitral valve to CLOSE due to upward-rushing blood flow

Question 27

How do pressure changes lead to valve movement and blood flow in the relaxed left ventricle?

Answer 27

- Blood flows backward in the aorta, closing it. - Pressure from blood in the left atrium pushes mitral valve open, allowing blood in the left atrium to drain into the RELAXED ventricle.

Question 28

When does "Heart Murmur" occur and what causes them?

Answer 28

When the heart is turbulent, and are CAUSED by defective valves.

Question 29

Heart undergoes average of _______ cardiac cycles (beats) per minute. This is known as _______.

Answer 29

60-80; HEART RATE

Question 30

Define: Cardiac Output

Answer 30

Amount of blood pumped into pulmonary and systemic circuits in 1 minute (amt. of blood pumped out in 1 min.)

Question 31

Heart rate is one determinant of ______ ________.

Answer 31

CARDIAC OUTPUT

Question 32

What is another determinant of Cardiac Output?

Answer 32

Stroke Volume - Amount of blood pumped in one heartbeat.

Question 33

What are the 3 factors that determine Stroke Volume?

Answer 33

1. Preload 2. Contractility 3. Afterload

Question 34

Explain the 3 factors that determine Stroke Volume.

Answer 34

1. Preload - Determined by volume of blood coming from polmonary circuit. 2. Contractility - Determined by hearts intrinsic pumping ability (heart's contraction force) 3. Afterload - Determined by pressure in systemic circuit (BP in Aorta or Pulmonary Trunk)

Question 35

What is the equation for Cardiac Output?

Answer 35

# Beats/min x # ml/beat = # ml/min Multiple Heart rate by Stroke volume # beats /min ( HR) × # ml /beat (SV) = # ml /min SO, for average person 72 beats/min (HR) x 70 ml/beat (SV) = 5040 ml/min

Question 36

Low preload leads to ____ EDV. (what does this mean?)

Answer 36

LOW This means cardiac muscle cells are much less stretched and thus, contracts weakly.

Question 37

What is the term used to describe any disease regarding the heart?

Answer 37

Cardiomyopathy

Question 38

How does heart failure affect stroke volume?

Answer 38

It DECREASES stroke volume, which in turn REDUCES cardiac output.

Question 39

What is the resting stroke volume for the avg heart? (and equation)

Answer 39

70 ml 120 ml (EDV) - 50 ml (ESV) = 70 ml (SV)

Question 40

Repolarization vs Depolarization (in Cardiovascular context)

Answer 40

Depolarization: Electrical activation where Na⁺ enters cells, making them more positive → triggers contraction; Action potential enters in for Cardiac Muscle cells. (P wave = atria, QRS complex = ventricles). Repolarization: K⁺ exits cells, restoring negative charge → allows relaxation (T wave = ventricles).

Question 41

In ventricular failure, what is it called when blood backs up within the pulmonary circuit?

Answer 41

Pulmonary Congestion

Question 42

Backup of blood flow ________ pressure in these vessels, driving fluid out of pulmonary capillaries and into the lungs; this is called ________ ______.

Answer 42

INCREASES; PULMONARY EDEMA

Question 43

STUDY THE GRAPHS (4 PHASES) CARDIAC CYCLE

Answer 43

WILL BE ON SHORT ANSWER.