CVS anatomy 2 Flashcards
purpose of the elastic arteries
The elastic arteries are closer to the heart and they have far more elastic tissue in their tunica media. This is due to the blood flow these blood vessels receiving being more pulsatile. The idea of the blood vessels being elastic is to absorb energy in systole and then use that energy to recoil and constrict in diastole to put energy into the blood flow to reduce the pulsatile nature of the blood flow we have. The diastolic recoil also pushes some blood backwards so that we can help shut the semilunar valves.
purpose of the muscular arteries
The more muscular arteries are found in the peripheries - where we want to be better able to control the direction of the blood flow. Having a larger muscle mass in the tunica media allows these vessels to expand and contract so that they can alter the flow to tissues well, also the muscle contraction helps reduce pulsatile flow in the more systemic blood vessels as we don’t want systemic flow in the capillary beds.
what blood vessel layer is thickest in arteries and veins, why
the tunica media is the thickest layer in the arteries to allow high amounts of vasoconstriction to alter TPR.
tunica adventitia is the thickest in the veins so that the veins can operate as capacitance vessels and the connective tissues help limit the degree of blood pooling - makes sure the vessels cant comply too much
what are our types of capillary
continuous, fenestrated, sinusoidal
describe the continuous capillaries
continuous basement membrane and endothelium found in skeletal muscle, where diffusion is more limited
describe the fenestrated capillaries
continuous basement membrane fenestrations in the endothelium, found in the glomerulus of the kidneys
describe the sinusoidal capillaries
large holes in the basement membrane and the endothelial layer, liver sinuoids for lots of blood filtering
what transports can each capillary type do
Vesicles, direct diffusion, and diffusion through the intercellular cleft. continuous
Due to their fenestrations the fenestrated and sinusoidal capillaries can do those plus diffusion through the pores and endothelial fenestrations.
what do the auricles do
they are potential spaces that the atria can fill into in times of increased blood flow
what are the three components of an intercollated disc
adhesion belt, desmosome, gap junction
what does it mean that something is an end artery
An end artery or terminal artery is an artery that is the only supply of oxygenated blood to a portion of tissue
describe the path of the left circumflex artery
Wraps around the left artium in the coronary sulcus between the left atrium and left ventricle and has bracnhes off of it -marginal areries typically arise from it. The circumflex artery will end before reaching the posterior interventricular sulcus
what does the right coronary artery supply typically
Right ventricle and posterior left ventricles Sa node and right atrium
what parts of the heart does the left coronary artery supply
The left ventricle and the interventricular septum
what carries PNS innervation to the heart
the vagus nerve
