Ex. Phys. Cardiovascular System Flashcards
cardiovascular system main purposes
deliver O2, nutrients, hormones, etc. to tissues via the blood circulation
remove CO2, waste products, metabolic intermediates, etc. from the tissues via the blood circulation
cardiovascular system structures
myocardium heart chambers heart valves heart innervation blood vessels
myocardium
primary muscle tissue of the heart
contains short, branched, single-nucleated cells (myocytes)
myocytes utilize gap junctions to propagate electrical signals quickly for synchronized cardiac contraction
myocytes are involuntarily and automatically controlled
heart chambers
RA
RV
LA
LV
RA
collects de-oxygenated venous blood from systemic curculation via the superior and inferior vena cava and pumps it into the right ventricle
RV
recieved de-oxygenated blood from the right atrium and pumps it through the pulmonary artery to lungs
LA
collects oxygenated blood from lungs via the pulmonary vein and pumps it into the left ventricle
LV
received oxygenated blood from the left atrium and pumps it through the aorta into systemic circulation
heart valves
-subsets
atrioventricular (AV) valves -tricuspid valve -mitral (bicuspid) valve semilunar (SL) valves -pulmonary valve -aortic valve
tricuspid
allows blood to flow from the RA into the RV
mitral
allows blood to flow from the LA into the LV
pulmonary
allows blood to flow from the right ventricle into the pulmonary artery (then to the lungs for reoxygenation)
aortic
allows blood to flow from the left ventricle into the aorta (then out to the systemic circulation)
heart innervation
sinoatrial node
-located in right atrium; heartbeat is initiated here via depolarization of atria
-spontaneously depolarizes at a regular rhythm, hence its nickname as the “pacemaker” of the heart
-ANS also innervates the SA node to influence node activity, and can, therefore, control HR
atrioventricular node
-located in RA
-receives action potential “wave” from SA node and delays it to give both atria time to contract before sending the signal to the bundle of His
Bundle of His
-located in between the R and L atria and ventricles
-gives rise to bundle branches in the intraventricular septum
-bundles relay action to depolarize the purkinje fibers
Purkinje fibers
-terminal innervations within the myocardium of the R and L ventricles
-receive action potential to depolarize and stimulate both ventricles to contract
blood vessels
arteries arterioles capillaries venules veins
arteries
largest vessels for systemic blood delivery
have thick, muscular walls that can contract (due to autonomic innervation) to direct blood flow, yet are highly elastic to withstand high pressures
arterioles
smaller branch of arteries
have thin, but muscular walls that can contract to direct blood flow
capillaries
smallest vessels
thin walls permit gas exchange, but have no muscle to control blood flow
venules
smaller branch of veins
thin, compliant walls help store a lot of blood, and one-way valves to facilitate blood flow back to heart
veins
largest vessels for systemic blood return
have compliant, muscular walls and one-way valves to facilitate blood return to heart