Cardiovascular Physiology

Question 1

List the functions of the heart

Answer 1

• Generates blood pressure
  
  • Routing blood: separates pulmonary and systemic circulations
  • Ensures one-way blood flow: valves
  • Regulates blood supply
  • Changes in contraction rate and force match blood delivery to changing metabolic needs

Question 2

The cardiovascular system is divided into how many circuits?

Answer 2

2 circuits.

Question 3

Name the two circuits of the cardiovascular system.

Answer 3

*Pulmonary circuit
* Systemic circuit

Question 4

What does the pulmonary circuit involve?

Answer 4

Blood to and from the lungs.

Question 5

What does the systemic circuit involve?

Answer 5

Blood to and from the rest of the body.

Question 6

What do vessels do in the circulatory system?

Answer 6

Carry the blood through the circuit.

Question 7

What do arteries do?

Answer 7

Carry blood away from the heart.

Question 8

What do veins do?

Answer 8

Carry blood to the heart.

Question 9

What is the function of capillaries?

Answer 9

Permit exchange.

Question 10

Describe the structure of cardiac muscle cells

Answer 10

Elongated, branching cells containing 1-2 centrally located nuclei.

Question 11

What protein filaments do cardiac muscle cells contain?

Answer 11

Actin and myosin myofilaments.

Question 12

What are intercalated discs?

Answer 12

Specialized cell-cell contacts in cardiac muscle

Question 13

What is the arrangement of cell membranes in cardiac muscle?

Answer 13

Cell membranes interdigitate

Question 14

What is the role of desmosomes in cardiac muscle?

Answer 14

Hold cells together.

Question 15

What is the function of gap junctions in cardiac muscle?

Answer 15

Allow action potentials to move from one cell to the next.

Question 16

Electrically, how are the cardiac muscles of the atria and ventricles related?

Answer 16

Behave as a single unit

Question 17

What percentage of the cell volume do mitochondria comprise in cardiac muscle?

Answer 17

30%

Question 18

What is an important function of the heart that makes it unable for it to feel fatigue?

Answer 18

De-fatigue

Question 19

What is a structural difference between the left and right sides of the heart?

Answer 19

The left side of the heart is more muscular than the right.

Question 20

The left side of the heart is more muscular than the right because …..

Answer 20

It has to pump blood to the entire body whereas the right side only pumps to the lungs •

Question 21

What is the function of AV valves?

Answer 21

Prevent backflow of blood from the ventricles to the atria

Question 22

What is the function of semilunar valves?

Answer 22

Prevents backflow into the ventricles from the pulmonary trunk .

Question 23

How is cardiac muscle stimulated?

Answer 23

Is stimulated by nerves and is self-excitable (automaticity) .

Question 24

How does cardiac muscle contract?

Answer 24

Contracts as a unit, no motor units.

Question 25

What is the duration of the absolute refractory period in cardiac muscle?

Answer 25

Has a long (250 ms) absolute refractory period.

Question 26

How is cardiac muscle contraction similar to skeletal muscle contraction?

Answer 26

Contraction, i.e., sliding-filaments.

Question 27

How is action potential conducted in cardiac muscle compared to skeletal muscle?

Answer 27

Cardiac: It is conducted from cell to cell. Skeletal: Conducted along the length of a single skeletal muscle fiber.