heart, circulatory cystem

Question 1

sinoatrial node

Answer 1

specialized cardiac muscle fibres located in wall of the right atrium and generate electric impulses at regular intervals

Question 2

what are the two phases of actions of the heart

Answer 2

systole and diastole

Question 3

systole

Answer 3

state where heart muscles contract

Question 4

diastole

Answer 4

state where heat muscles do not contract

Question 5

atrial systole

Answer 5

passive filling from pulmonary veins and vena cava, the atria contracts and forces blood into ventricles

Question 6

early ventricle systole

Answer 6

ventricles contract, pressure rises and closes AV valves (tricuspid valve). semilunar valves are still closed as pressure in aorta and pulmonary artery is higher than in ventricles

Question 7

late ventricle systole

Answer 7

ventricles continue to contract, pressure in ventricle exceeds pressure in PA and aorta

Question 8

early ventricle diastole

Answer 8

ventricles relax and pressure falls rapidly. semilunar valves close to stop the backdrop of blood. passive ventricular filling starts