cardiovascular system Flashcards
what are the 3 components of the CVS system?
-the heart
-blood vessels
-the blood
what are the 2 different circulations of the CVS?
the pulmonary and systemic circulation
what are the 3 layers of the heart?
-endocardium (connective tissue)
-myocardium (heart muscle)
-pericardium (fibrous protective sac)
what are the functions of heart valves?
-to prevent blood from flowing backwards
-responds to changes in pressure
-2 valves in the heart are the AV valves and semi lunar valves
what are the 2 semilunar valves?
-the pulmonary valve
-the aortic valve
what are the 2 atrioventricular valves?
-bicuspid/ mitral valve - left side of heart
-tricuspid valve - right side of heart
what is the cardiac cycle divided into?
-diastole - the period of time when the ventricles are relaxed
-systole - the time during which the left and right ventricles contact and eject blood into the aorta and pulmonary artery
what is the heart rate?
the number of cardiac cyclers per minute
what is stroke volume?
the volume of blood ejected by each ventricle in one cycle
what are blood vessels divide into?
arteries - blood carried away from the heart
veins - carry blood to the heart
describe the structure of capillaries
-one cell thick
-this allows nutrients to diffuse easily out of the blood and into the tissues
what is the circulatory supply of the heart called?
the coronary circulation
-right and left coronary arteries arise from the ascending aorta
what is blood pressure?
the amount of force blood uses to get through your arteries
what may happen if the blood pressure is too low or too high?
if too low - there is a risk that brain, kidneys and heart may fail
if too high - there is a risk of vessel damage - clots and CVA
how is blood pressure controlled?
by sensory receptors - baroreceptors & chemoreceptors
-they feed info to the brain and stimulate either the PNS or the SNS to increase or decrease BP
