Cardiovascular System

Question 1

Cardiac Output?

Answer 1

Heart Rate 70bpm x Stroke Volume 70mls = 4900mls - 4.9L/min

Question 2

Factors affecting cardiac output?

Answer 2

Hormones
Preload
Afterload
Gender
Fitness
Stress
Dehydration

Question 3

Coronary arteries?

Answer 3

Supply blood to heart, run along the outside of the heart with branches going into the heart muscle (myocardium)

Question 4

Left main coronary arteries?

Answer 4

Supplies blood to the left side of the heart.

Left anterior descending artery and circumflex artery

Question 5

Right coronary artery?

Answer 5

Supplies the right side of the heart, the SA/ AV nodes with blood.

Right posterior descending artery & acute marginal artery.

Question 6

Valves?

Answer 6

Prevent back flow of blood.

Question 7

Flow of blood through the heart?

Answer 7

Deoxygenated blood returns from the body through the vena cava into the right atrium. It then travels through the tricuspid valve into the right ventricle. It then leaves the heart travelling through the pulmonary valve out the pulmonary artery to the lungs to be oxygenated. Oxygenated blood returns from the lungs to the heart via the pulmonary veins into the left atrium. Then it travels through the bicuspid valve into the left ventricle, leaving the heart via the aortic valve out the aorta to the body.

Question 8

Cardiac cycle?

Answer 8

Systole- contractions of the ventricular heart muscles. Atria relaxes, semi lunar valves (pulmonary & aortic) open, tricuspid and bicuspid valves close, ventricles contract pushing blood to the lungs and body.

Diastole- Heart muscle relaxes. Ventricles relax, semi lunar valves (pulmonary & aortic) closed, tricuspid and bicuspid valves open, atria contracts so ventricles fill with blood.

Question 9

Electrics of the heart?

Answer 9

SA node (pacemaker) fires sending electrical impulses to the right atrium, left atrium and AV node. There is a delay at the AV node allowing the ventricles to fill with blood. The AV node then fires an impulse to the bundle of his and purkinje fibres allowing ventricles to contract sending blood to the lungs and body.

Question 10

ECG

Answer 10

P- impulse from the SA node, depolarisation of the atria.

QRS- depolarisation of ventricles. Electrical activity of purkinje fibres.

T- Repolarisation of ventricles. Ventricles enter diastole and relax.

Question 11

Heart wall?

Answer 11

Pericardium- outer layer
Myocardium- middle muscle layer
Endocardium-inner layer smooth