Exam #4: Cardiology

Question 1

What is heart rule number two?

Answer 1

The heart is a muscle.

The myocardium can rapidly depolarize more glycogen for energy and intercalated discs allow it to act as one unit.

Question 2

What is heart rule number four?

Answer 2

The heart has 3 functions

1. Electrical conduction
2. Contraction during systole
3. Relaxation during diastole

Question 3

What are the 3 layers of the heart and what is each layer made of?

Answer 3

• Endocardium: Endothelial cells
• Myocardium: Myocardial cells
• Epicardium: Mesothelial cells

Question 4

What are the 4 valves of the heart?

Answer 4

• Pulmonic Valve: Between right ventricle and pulmonary trunk
• Aortic Valve: Between left ventricle and descending aorta
• Tricuspid Valve: Between right atrium and right ventricle
• Mitral Valve: Between left atrium and left ventricle. You can hear this valve at the costrochondral junction.

Question 5

What is an annulus?

Answer 5

A fibrous ring that conducts electrical impulses

Question 6

What is the contractile unit of the heart?

Answer 6

Sarcomere

Question 7

What are the 2 circulation systems arranged in a series?

Answer 7

• Pulmonary circulation: Includes the right side of the heart, pulmonary arteries, arterioles, capillaries, venules, and veins.
• Systemic Circulation: Includes left side of the heart, systemic arteries, arterioles, capillaries, venules, veins, vena cavae, and aorta.

Question 8

What is rule number 5 of the heart?

Answer 8

Blood is lazy

Question 9

What is cardiac output?

Answer 9

The rate blood is pumped out of the ventricles (Liters/minute)

Question 10

What is heart rule number 1?

Answer 10

There are 2 circulations arranged in a series.

Question 11

What are the 2 things that dictate blood flow?

Answer 11

Pressure gradients and 1 way valves

Question 12

What are the other 2 circulation systems?

Answer 12

• Coronary circulation: Vessels provide oxygenated to the myocardium.
• Bronchial circulation: Vessels provide oxygenated blood to lung tissues (the bronchial artery off the aorta takes blood to the lungs and the brochial vein drains blood from lungs into vena cava)

Question 13

What are the 3 fetal shunting structures?

Answer 13

• Foramen Ovale: Blood moves from right side to left side of heart due to movement of oxygenated blood into the right atrium
• Ductus Arteriosus: Connects pulmonary artery to aorta to allow blood to bypass the lungs.
• Ductus venosus: Connects umbilical vein to caudal vena cava to allow blood to bypass the liver.

Question 14

What structure oxygenates blood and removes metabolic waste during fetal circulation?

Answer 14

The placenta

Question 15

What are the 3 vessel layers of the arteries/veins?

Answer 15

• Tunica Intima: Innermost layer directly surrounding lumen of blood vessel.. The endothelium in this layer makes the lumen slick to allow for easy blood movement.
• Tunica Media: Middle layer made of smooth muscle and elastin. Contributes to autonomic nervous system. Plays a role in blood flow and regulation of blood pressure.
• Tunica Externa: Outermost layer made of collagen which protects and reinforces the blood vessel.

Question 16

What are the structural differences between arteries and veins?`

Answer 16

• Arteries have a more muscular layer with more elastin to allow it to stretch and constrict. Acts as a rubber band which is why compliance is lower. Also smaller allowing less blood flow through it compared to veins. Why capacitance is lower.
• Veins: Have a less muscular wall allowing for higher compliance and a larger lumen allowing for higher capacitance. Valves prevent backflow.

Question 17

Compliance vs Compacitance

Answer 17

• Compliance: Ability for vessel to stretch

- Capacitance: Ability for vessel to hold large volumes of blood without raising blood pressure.