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Cardiovascular system consists of
heart and blood vessels
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heart
hollow, muscular organ lying in mediastinum, center of thoracic cavity between lungs
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pumping action of heart propels
blood that contains oxygen, nutrients and other vital products
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arteries
- carry blood away from heart,
- strong and flexible,
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pulse
surge of blood felt in arteries when blood is pumped
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arterial blood contains
high concentration of oxygen and appears bright red
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arterioles
smaller arteries
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walls of arteries and veins have 3 layers called
- tunica externa
- tunica media
- tunica intima
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tunica externa
outer coat composed of connective tissue for strength and elasticity
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tunica media
middle layer composed of smooth muscle
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tunica intima
thin inner lining composed of endothelial cells which provide a smooth surface
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vasoconstriction
when it contracts; decreased blood flow
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vasodilation
when it relaxes; increased blood flow
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capillaries
microscopic vessels that join arterial system with venous system, walls are thing- single layer of endothelial cells
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capillaries allow for the exchange of
water, gasses, macromolecules, metabolites, and waste between the blood and adjacent cells
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capillaries contain
sphincters, that regulate flow of blood into tissues
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veins are formed from
venules that develops from union of capillaries
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veins rely on other methods to return blood to heart such as
- skeletal muscle
- gravity
- respiratory activity
- valves
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blood carried in veins contain
low concentration of oxygen and high concentration of carbon dioxide
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venules
merged capillaries that form larger blood vessels
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veins
vessels that return blood to heart to begin cycle again
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cardiovascular system
- circulates blood,
- delivers oxygen and nutrients to cells
- disposes waste
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conduction system
aids lymphatic system in circulating its substances
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lymphatic system
- drains fluid from tissues
- returns fluid to bloodstream
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artieries carry
oxygenated(red) blood away from heart
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veins carry
deoxygenated(purple) blood back to the heart
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pulmonary arteries carry
deoxygenated blood to lungs
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pulmonary veins carry
oxygenated blood back to heart for circulation
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deoxygenated blood is
purple
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heart is found in
sac called pericardium
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3 distinct layers of pericardium
- endocardium
- myocardium
- epicardium
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endocardium
serous membrane lines 4 chambers and its valves
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myocardium
muscular layer of heart
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epicardium
outermost layer of heart
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upper chambers
collect blood
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lower chambers
pump blood from heart
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2 upper chambers
right atrium(RA) and left atrium(LA)
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2 lower chambers
right ventricle(RV) and left ventricle(LV)
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right ventricle pumps blood
to lungs(pulmonary circulation) FOR exygenation
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left ventricle pumps
oxygenated blood to entire body(systemic circulation)
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superior vena cava (SVC)
collects and returns blood to right atrium from upper body
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inferior vena cava (IVC)
collects and returns blood to right atrium
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left and right pulmonary arteries
carry blood from right ventricle to lungs
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left and right pulmonary veins
carry blood from lungs back to left atrium of the heart
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aorta
carries blood from left ventricle to body
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valves
prevent regurgitation of blood
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coronary arteries
branch from aorta and provide the heart with its own blood supply
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right coronary arteries
provide the right side of the heart with blood
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left coronary arteries
provide left side of heart with blood
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left coronary arteries divide into 2 branches called
- left anterior descending artery
- circumflex artery
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conduction tissue
specialized tissue within heart with sole function of initiating and spreading contraction impulses
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4 masses of specialized cells with nervous and cardiac characteristics
- sinatrial node(SA)
- atrioventricular node(AV)
- bundle of his(AV bundle)
- purkinje fibers
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sinatrial node(SA)
pacemaker of heart
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atrioventricular node (AV)
contract atria
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purkinje fibers
contract ventricles
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blood pressure
measures force of blood against arterial walls
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systole
contraction phase - maximum force
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diastole
relaxation phase - weakest force
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hypertension
high blood pressure
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hypotension
low blood pressure
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