cardiovascular system

epicardium

external layer of heart

myocardium

middle layer of heart

endocardium

inner layer of heart

pulmonary pump

sends blood to lungs

systemic pump

sends blood to body

tricuspid valve

between right atrium and right ventricle

pulmonary valve

between right ventricle and pulmonary artery

bicuspid (mitral) valve

between left atrium and left ventricle

aortic valve

between left ventricle and aorta

sinoatrial node

natural “pacemaker” of heart which sends electrical signal to AV node, then AV bundle and then purkinje fibres on outer walls to innovate ventricles to contract

atrial systole (depolarisation)

contraction of atria, blood fills ventricles through tricuspid and bicuspid valves

atrial diastole (repolarisation)

relaxation of atria

ventricular systole (depolarisation)

contraction of ventricles, blood pushed into arteries through pulmonary/aortic valves

ventricular diastole (repolarisation)

relaxation of ventricles

capillaries

connect connect arterioles to venules (thin walls allow for exchange of nutrients and wastes etc)

total peripheral resistance

force exerted by blood vessels on circulating blood

MAP

CO (HR x SV) & TPR

vascular spasms

vasoconstriction of blood vessels around open skin to prevent blood leaving

platelet plug formations

platelets stick to collagen fibres to release contents such as calcium to stimulate platelets to plug hole

coagulation

blood transforms from liquid to gel. prothrombinase is activated to get prothrombin, which becomes thrombin. thrombin takes soluble plasma proteins and converts them into fibrin to cause a clot to form from RBCs

clot retraction

platelets contract and pull clot together

repair

platelet derived growth factor (PDGF) stimulates rebuilding of blood vessel walls. stimulated by vascular endothelial growth factor (VEGF), endothelial cells restore lining

fibrinolysis

clot contains plasminogen which results in plasmin after activation and plasmin digests fibrin