Term | Definition |
arteries | carry blood away from the heart |
veins | return blood to the heart |
capillaries | connect the smallest arteries (arterioles) to the smallest veins (venules) |
tunica intima | inner layer, helps prevent blood clots, produces chemicals that cause the blood vessels to dilate or constrict, lines all blood vessels |
tunica media | middle layer, allows blood vessels to change diameter |
tunica externa | outer layer, supports and protects blood vessels |
conducting arteries (elastic arteries) | closest to the heart, greatest ability to expand and recoil |
distributing arteries | deliver blood to specific organs |
aterioles | smallest arteries, dilate or constrict to maintain blood pressure |
Venules | smallest veins, collect blood from capillaries |
categories of veins | venules, medium sized, and large veins |
capillaries | hormones are transferred between blood and tissue, have thin walls, only in endothelium and basement membrane |
capillaries are organized into networks called | capillary beds |
Filtration occurs | close to the arterial side of the capillary bed |
high pressure in capillaries | pushes plasma and dissolve nutrients through capillary wall and into surround fluid |
pulmonary circulation function | to bring deoxygenated blood to the alveoli for gas exchange |
pulmonary circulation blood flow | right ventr-pulmonary arteries-lobar arteries-capillary bed-lobar veins-pulmonary vein-left artium |
ascending aorta | right and left coronary arteries branch off to supply blood to myocardium |
abdominal aorta | branches into the right and left common illiac arteries, which supply blood to the lower pelvis and the legs |
aortic arch | branches into three major arteries, brachiocephalic, common carotid, and left subclavian |
superior and inferior mesenteric arteries | supply blood to the small and large intestines |
abdominal aorta and its branches | supply blood to the abdomen and lower extremities and liver |
common carotid arteries | provide most of the brains blood supply |
superior vena cava | receives blood from above the heart |
inferior vena cava | receives blood from below the level of the heart |
factors affecting blood pressure | cardiac output, blood volume, resistance |
peripheral resistance | resistance to flow results from friction of blood against walls of vessels |
amount of friction depends upon | blood viscosity and vessel diameter |
blood viscosity | typically stable |
vessel diameter | adjusting diameter of the vessels is the body's chief way of controlling peripheral resistance |
blood velocity | diameter of vessel affects how fast blood flows |
greater the diameter of vessel | faster it flows |
blood flows slowest in capillaries due to | cross-sectional area and narrow diameter |
neural regulation of blood pressure | medulla sends impulses via autonomic nervous system to alter blood vessel diameter and therefore blood pressure |