Anatomy of Heart 2

Question 1

What determines heart rate of cardiac myocytes?

Answer 1

Leakiness of cell membranes - atria cells beat much faster

Question 2

How does the cardiac skeleton aid conduction in the heart?

Answer 2

Does not conduct electricity - prevents general signal to ventricles.

Question 3

What is the function of the bundle of His?

Answer 3

Slow down transmission of signal from SAN to AVN

Question 4

What is the function of the moderator band?

Answer 4

Helps depolarisation spread to papillary muscles first

Question 5

How does shocking the heart treat ventricular fibrillation?

Answer 5

Stops electrical activity of all cells.

Hopefully only one cell will then pick up the beat.

Question 6

Which nerves affect the heart rate?

Answer 6

PNS - vagus nerve (10th cranial nerve)

SNS - T1-T5

Question 7

Where does the left coronary artery arise from?

Answer 7

Left aortic sinus

Question 8

What is the path of the right coronary artery?

Answer 8

Travels around the back to the crux via the coronary sulcus, gives off branches to SAN and AVN and marginal artery

Question 9

What is the path of the left coronary artery?

Answer 9

1. Travels to back via circumflex artery and gives off left marginal artery.
2. Gives off anterior interventricular artery

Question 10

What is the difference between a right dominant heart and a left dominant heart?

Answer 10

Right dominant heart - posterior descending artery is supplied by the right coronary artery and vv for left

Question 11

What are the 2 parts of the interventricular septum?

Answer 11

Membranous portion

Muscular portion

Question 12

What is the moderator band?

Answer 12

A muscular band of tissue in the right ventricle
It helps the direction of depolarisation spread to hit the papillary muscles first - allows co-ordinated contraction of anterior papillary muscles

Question 13

Which nerve supplies the pericardium of the heart?

Answer 13

Phrenic nerve

Question 14

What are the three aortic sinuses of the heart?

Answer 14

Left
Right
Posterior

Question 15

Which chamber does the coronary sinus drain into?

Answer 15

Right atrium

Question 16

Name 4 branches of the coronary arteries?

Answer 16

Marginal
Circumflex
Left anterior descending artery
Posterior descending artery

Question 17

What happens if the coronary arteries are blocked?

Answer 17

Myocardial infarction (often due to atherosclerosis of the coronary arteries)

Question 18

How is the pain experienced during a heart attack signalled?

Answer 18

It is sympathetic driven (T1-T5)

Question 19

Where is pain experienced during a heart attack?

Answer 19

Pain is referred to the midline (sternum)

Pain is also referred to inside of the left arm

Question 20

What is endocarditis?

Answer 20

Infection of the endocardium (inner lining of heart chambers and valves)
Connected to poor oral hygiene

Question 21

What is the course of the coronary sinus?

Answer 21

It runs along the posterior surface of the heart between the left atrium and the left ventricle