Hemodynamics

Question 1

Where is mitral valve?

Answer 1

Between left atrium and left ventricle

Question 2

Where is tricuspid valve?

Answer 2

Between right atrium and right ventricle

Question 3

What is function of papillary muscles?

Answer 3

Papillary muscles contract when ventricles contract to prevent prolapse of valves

Question 4

What is function of right atrium?

Answer 4

Receives deoxygenated blood from superior/inferior vena cava and coronary vein and sinus

Question 5

What is function of right ventricle?

Answer 5

Pumps blood through pulmonary valve into pulmonary arteries of pulmonary circuit

Question 6

What is function of left atrium?

Answer 6

Receives oxygenated blood from lungs via pulmonary vein

Question 7

What is function of left ventricle?

Answer 7

Pumps blood to aorta and systemic circuit

Question 8

What are the coronary arteries?

Answer 8

1. Right coronary artery (follows coronary sulcus around heart. Supplies blood to right atrium, portions of both ventricles, SA node and AV node.)
2. Marginal arteries (branch off right coronary artery and moves down right ventricle)
3. Posterior interventricular artery
4. Left coronary artery (supplies blood to left ventricle, left atrium, interventricular septum)
5. Circumflex artery (curves to left around coronary sulcus)
6. Anterior interventricular artery

Question 9

What are the cardiac veins?

Answer 9

1. Great cardiac vein (begins in anterior interventricular sulcus, curves around coronary sulcus, empties into coronary sinus)
2. Posterior cardiac vein (drains area served by circumflex artery)
3. Small cardiac vein (Receives blood from posterior surfaces of right atrium and ventricle)
4. Anterior cardiac veins (drain anterior surface of right ventricle)

Question 10

What is pathway of blood through heart and lungs?

Answer 10

1. Superior/Inferior vena cava
2. Right atrium
3. Tricuspid valve
4. Right ventricle
5. Pulmonary valve
6. Pulmonary arteries
7. Lungs
8. Pulmonary veins
9. Left atrium
10. Mitral valve
11. Left ventricle
12. aortic valve
13. Aorta

Question 11

What are unique attributes of cardiac muscle?

Answer 11

Cardiac muscle cells are interconnected by intercalated discs, interlocking membranes of adjacent cells held together by desmosomes and linked by gap junctions. Cardiac has small size, single nucleus.

Question 12

What is relationship between SA node and AV node?

Answer 12

SA node sends out regular electrical impulses from the right atrium causing it to contract and pump blood into the ventricles. Electrical impulse is conducted to AV node, which slows impulse conduction to allow complete atrial contraction before ventricular contraction begins

Question 13

What is p wave?

Answer 13

Depolarization of atria (begins atrial contraction)

Question 14

What is QRS complex?

Answer 14

Depolarization of ventricles, ventricles begin contracting shortly after peak of R wave

Question 15

What is T wave?

Answer 15

Ventricular repolarization

Question 16

How does body regulate blood pressure?

Answer 16

1. Angiotensin II (increased vasoconstriction, aldosterone secretion, thirst, ADH)
2. ADH (increased thirst, retention of water in kidneys)

Question 17

How are arteries different from veins?

Answer 17

Arteries have thicker walls (thicker tunica media). Veins contain valves to prevent backflow, veins collapse during dissection

Question 18

What are mechanisms of venous return?

Answer 18

1. Contracting skeletal muscles compress veins

2. Respiratory pump: Inhaling and exhaling push blood into the inferior vena cava and right atrium

Question 19

What are the heart sounds?

Answer 19

S1: “lubb” 1st detectable sound (start of ventricular contraction, AV valves close and semilunar valves open)

S2: “dupp” 2nd detectable sound (beginning of ventricular filling when semilunar valves close and AV open

S3: blood flowing into ventricles
S4: Atrial contraction

Question 20

What is stroke volume?

Answer 20

Volume of blood pumped by the heart with each contraction. SV=EDV-ESV

Question 21

What is cardiac output?

Answer 21

Amount of blood pumped by a ventricle each minute. CO=SVxHR

Question 22

What is Cardiac Index?

Answer 22

CO divided by body surface area in m2

Question 23

What is ejection fraction?

Answer 23

Stroke volume at rest as a percentage of end-diastolic volume. SVx100/EDV=EF

Question 24

What is Preload?

Answer 24

Preload is measured clinically as end-diastolic volume or pressure. Increased preload=increased force during systole

Question 25

What is afterload?

Answer 25

Afterload is measured clinically as peak ventricular pressure or vascular resistance. Increased afterload=decreased stroke volume

Question 26

What is inotropy?

Answer 26

Strength of cardiac contraction. Positive inotropic agents stimulate calcium entry into cardiac muscle cells thus increasing force and duration of ventricular contractions (epinephrine, norepinephrine, thyroid hormones, glucagon, dopamine). Negative inotropic agents include beta blockers, calcium channel blockers

Question 27

What is Chronotropy?

Answer 27

Heart rate.

Question 28

What is the Frank-Starling relationship?

Answer 28

A family of curves, each for a given heart rate and functional state, that relates to preload and cardiac output. Normal hear responds to changing cardiac output demands by changing heart rate and force of contractility.