Cardio videos #1 and #2 notes

what is the purpose of the circulatory system?

to move blood, nutrients, hormones, gases, and waste products to and from cells throughout the body.

do all organisms have circ. systems?

no because simpler organisms rely on diffusion for nutrient and gas exchange

what do arteries do

Arteries carry blood away from the heart under high pressure

what do veins do

veins return blood to the heart at a lower pressure

what do capillaries do

capillaries facilitate the exchange of substances between blood and tissues

what is the cardiac cycle

the sequence of events in the heart that occurs from the beginning of one heartbeat to the start of the next

what is the vo2 max

the maximum rate of oxygen consumption measured during incremental exercise

can the vo2 max be shifted with exercise and because of why?

yes because they enhance the body's ability to uptake and utilize oxygen efficiently during physical activity

where is cardiac muscle only found

in the heart

what are cardiac muscle

highly organized striated fibers

what are cardiac muscle fibers self excitable with?

cells that can generate action potentials

where do action potentials spread and through what?

through the heart through gap junctions

what are intercalated disks

they connect cells to each other

what are the intercalated disks made of

desmosomes, gap junctions, and actin

what are the 3 basic components of the circ system

heart, blood vessels, and blood

what are the two blood flow circuits in the circ system

the pulmonary and systemic circulation

what does the heart do in the circ system

dual pump

what do blood vessels do in the circ system

passageways

what does blood do in the circ system

transport 

where does pulmonary circulation go between in the circ system

between the heart and the lungs

where is the systemic circulation between in the circulatory system

between the heart and other body systems

where do veins always bring blood to

the heart

why does the heart pump blood into body cavities in open circulatory systems?

to bathe cells in blood

what is the speed of blood flow in open circulatory systems

slow

where are closed circulatory systems found

inverts and all verts

where are open circulatory systems found

insects, mollusks, and other inverts

why is blood flow faster and more efficient in closed circulatory systems

blood pressure is higher

why is the heart muscle on the left side thicker than the muscle on the right side

because the right side pumps with lower pressure than the left side

do both sides of the heart pump simultaneously?

yes

does each side of the heart pump the same volume of blood

yes

where are the atrioventricular valves

between the atrium and the ventricle

what do the atrioventricular valves do

prevent backflow of blod from ventircles into atria during ventricular contraction

what is the right av valve called

tricuspid valve

what are the two names for the left av valve

bicuspid or mitral valve

where are the semilunar valves

they lie at the juncture where the major artery leaves the ventricle

what do the semilunar valves do

prevent blood from flowing from arteries back into ventricles when the ventricle relaxes

what is the left semilunar valve called

the aortic valve

what is the right semilunar valve called

the pulmonary valve

why are bundles of cardiac muscle arranged spirally around the ventricle

so that when they contract they wring blood from the apex to the base where the major arteries exit