Chapter 13

Question 1

What does the Cardiovascular System consist of?

Answer 1

Heart and blood vessels

Question 2

What does the Circulatory system consist of?

Answer 2

Heart, Blood vessels AND blood

Question 3

What is Cardiology?

Answer 3

Study of the heart, clinical evaluation of its functions and disorders, and treatment of cardiac diseases.

Question 4

What are the 2 major divisions of the Cardiovascular System?

Answer 4

1) Pulmonary Circuit –> Carries blood to the lungs for gas exchange and returns it to the heart
2) Systemic Circuit –> Supplies blood to all organs of the body, including the lungs and the wall of the heart itself.

Question 5

Which side of the heart supplies the Pulmonary Circuit?

Answer 5

The Right Side which receives oxygen-poor blood from the body and pumps it into the Pulmonary Trunk. From there the oxygen-poor blood is distributed to the lungs, where it unloads CO2 and picks up a fresh load of O2. It then returns this now oxygen-rich blood to the left side via pulmonary veins.

Question 6

Which side of the heart supplies the Systemic Circuit?

Answer 6

The Left Side which pumps blood into the aorta which gives off branches that ultimately deliver O2 to every organ of the body. After the blood has picked up CO2 from the tissues, it returns to the Right heart via The superior vena cava which drains the upper body and the inferior vena cava which drains everything below the diaphragm.

Question 7

What is the largest artery?

Answer 7

Aorta

Question 8

What are the Muscle Cells of the Heart Called?

Answer 8

Cardiomyocytes –> short stocky cells typically 50-100 long and 10-20 wide

Question 9

The nucleus of the Cardiomyocytes are often surrounded by what?

Answer 9

Glycogen

Question 10

What are Intercalcated Discs?

Answer 10

Ends where 2 cardiomyocytes meet

Question 11

How much does the Heart weigh?

Answer 11

300 grams

Question 12

How much ATP does the Heart produce and use?

Answer 12

5kg per day

Question 13

Cardiomyocytes make ATP by Anaerobic or Aerobic respiration?

Answer 13

Aerobic Respiration –> therefore very resistant to fatigue

Question 14

Mitochondria makes up how much of the cell?

Answer 14

25%

Question 15

Cardiomyocytes are rich in what oxygen-storing pigment?

Answer 15

Myoglobin

Question 16

Why is the heart described as “Autorhythmic”?

Answer 16

It beats as its own rhythm without need of stimuli from the nervous system

Question 17

What causes the heart to be Autorhythmic?

Answer 17

Modified cardiomyoctes that have lost the ability to contract and are instead specialized to depolarize spontaneously at regular time intervals. Cells are concentrated in the sinoatrial and atrioventricular nodes.

Question 18

Describe the pathway through the Cardiac Conduction System

Answer 18

1) Sinoatrial (SA) node –> The pacemaker of the heart. it fires
2) Internodal conduction –> Excotatopms spreads through atrial myocardium
3) Atrioentricular Node –> Fires
4) Atriventricular (AV) Bundle (bundle of his) –> Excitation spreads down this. Signal speeds up here
5) Purkinje Fibers –> Distribute excitation through ventricular myocardium

Question 19

What are the events of the Endocardiogram (ECG)?

Answer 19

• P Wave –> Reflects depolarization of atria

- QRS Complex –>