the structure and function of the heart Flashcards
what is cardiac output and how is it calculated
the volume of blood pumped through each ventricle per minute
calculated by heart rate x stroke volume
what is that function of diastole
blood returning to the atria floe into the ventricles. the higher pressure in the arteries closes the SL valves
what is the function of atrial systole
transfers the remaining blood through the atrio-ventricular valve to the ventricles
what is the function of ventricular systole
closes the AV valves and pumps blood out through the semi-lunar valves to the aorta and pulmonary artery
what is the role of the sino-atrial node in contraction of the heart
sets the rate at which the heart contracts
what is the role of the atrio-ventricular node in contraction of the heart
impulses from the AVN travel down fibers in the central wall of the heart and then up through the walls of the ventricles causing ventricular systole
what does an electrocardiogram show
the impulses produced by the heart
what role does the medulla have in controlling heart rate
regulates the rate of the sino-atrial node through the antagonistic action of the autonomic nervous system
what are the nerves that releases hormones that affect the heart rate
sympathetic nerve and parasympathetic nerve
what affect do noradrenaline and acetylcholine have on heart rate
noradrenaline increases heart rate
acetylcholine decreases heart rate
how does blood pressure change during the cardiac cycle
blood pressure increases during ventricular systole
blood pressure decreases during diastole
how do you measure blood pressure and what is the standard value for blood pressure
an inflate cuff
120/80
what is hypertension
high blood pressure
why is hypertension dangerous
a major risk factor for many diseases including coronary heart disease
