2.6 structure and function of the heart

Question 1

what is the cardiac output and how do you calculate it

Answer 1

The total volume of blood pumped by the heart per minute.
cardiac output = heart rate (HR) x stroke volume (SV)

Question 2

what is diastole and which valves are open/closed

Answer 2

The relaxation phase of the cardiac cycle when the heart muscle is relaxed and the heart fills with blood.
AV valve is opening and SL valve is closed

Question 3

what is atrial and ventricular systole

Answer 3

Atrial systole is when the atria contract pushing blood from the atrium to the ventricles - AV valve open, SL valve closed.
Ventricular systole is when the ventricle contracts and pushes blood into the aorta and the pulmonary artery.

Question 3

What equipment is use to hear heart beat

Answer 3

stethoscope

Question 4

what sets the rate at which the heart contracts

Answer 4

SAN sends electrical impulses spreading though the atrium causing atrial systole. The impulses are picked up by the AVN which travel down conducting fibres in the central wall and then up through the walls of the ventricular muscle causing ventricular systole.

Question 5

white two nerves does the ANS comprise?

Answer 5

Sympathetic - Released noradrenaline which increases the heart rate.
Parasympathetic - Releases acetylcholine which decreases the heart rate.