Cardiovascular Anatomy Flashcards
what is the circulatory path of the blood?
begins with LV, blood is pumped thru aorta. from the part , goes into smaller arteries, then even smaller arterioles and still smaller capillaries. blood from the capillaries is collected into venues, which collect into larger veins, which again collect into superior and inferior vena cava.
vena cava empty into right atrium (THIS IS ALL SYSTEMIC CIRCULATION)
pulmonary circulation
right atrium to RV, which pumps blood to pulmonary arteries-> arterioles-> capillaries of the lungs, blood collects in venules, then veins and finally in the pulmonary veins leading to the heart-. empty into left atrium which fills left ventricle
what is the sinoatrial node and what does it do?
speacialized cardiac muscle cells, located in the right atrium. SA node is auto rhythmic (allowing heart to contract automatically). it spreads its contractions to the surrounding cardiac muscles via electrical synapses made from gap junctions.
what does the vagus nerve do?
vagus nerve is parasympathetic, it innervates the SA nose, slowing down the contractions. it innervates the digestive sys too where it will inc the digestive activity in the intestines.
what does the action potential spread by SA node do?
it spreads around both atria causing them to contract together and at the same time spreads to AV node located in the wall of cardiac muscle between the atria. AV node is slower to contract so there’s a delay which allows the atria to finish their contraction and to squeeze their contents into the ventricles before the ventricles begin to contract.
where does the action potential go from the AV node?
moves down conductive fibres called bundle of his (located in walls separating the ventricles). the action potential will branch out thru ventricular walls via conducive fibres called purkinje fibres.
where does the action potential go from purkinje fibres?
spreads thru gap junctions from one cardiac muscle to next
what are the 4 methods for materials to cross capillary walls?
1) pinocytosis
2) diffusion or transport thru capillary cell membranes
3) movement thru pores in the cells
4) movement thru space between cells.
where does the blood move slowest thru?
capillaries (velocity is inversely proportional to the cross sectional area). However, Bernoulli’s equation which says pressure is inversely proportional to cross sectional area is not true in the case of blood vessels ( blood is not an ideal flow)
artery carries blood _ from the heart
away
vein carries blood __ the heart
towards
which arteries carry the most deoxygenated blood in the blood?
pulmonary
