ILO2: describe and explain the stages of the cardiac cycle

what is atrial systole

The SAN (sinoatrial node) sends an electrical impulse across the atria, making them contract. The blood then moves into the ventricles through the AV valves

what is early ventricular systole

The signal reaches the AVN(atrioventricular node) and travels down the septum. ventricles start to contract - AV valves close to stop backflow

what is late ventricular systole

The ventricles fully contract - SL valves open. Blood is pushed into the aorta and pulmonary artery.

what is early ventricular diastole

SL valves close as the pressure drops. ventricle srelax and blood begins filling the atria

What is late ventricular diastole

AV valves open - both atria and ventricles relax. blood flows freely into the ventricles, ready for the next cycle

why is it important to empty the vessels during systole

to avoid clots from platelets pooling left over in the chambers and clotting together ot make clots

explain why it is important for the heart rate to increase during exercise

exercise → more energy → more oxygen → increased HR

state hte part of the brain for regulating heart rate

Medulla - cardio regularity centre (CRC)

describe and explain the role of chemorecepter sna pressure recepters in the process

chemo receptors- detect pH blood level change

pressure receptor - detects changes in blood pressure =, found in the aoric/carotic artery

descirbe and ecplain hoe the SAN is impacted during this process

CRC receives a signal from these receptors.

CRC sends cignals down to the SAN to alter the heart rate