lecture 18 - vessels and circulation

describe anastomosis 

the convergence of two or more vessels

what anastomose with each other more? what do not form anastomoses?

veins anastomose with each other more and end arteries do not form anastomoses

describe companion vessles

adjacent artieries and veins

what are the largest arteries called? what do they contain and do?

elastic arteries contain many elastic fibers and allow stretch with heart pumps

what are examples of elastic arteries near the heart?

aorta, pulmonary artery, brachiocephalic artery

what are medium sized arteries called and what do they contain?

muscular arteries that contain multiple layers of smooth muscle cells

what are the smallest arteries called?

arterioles

describe vasoconstriction and what it does

sympathetic innervation to muscle fibers of tunica media to help elevate blood pressure and decrease local blood flow

describe capillaries and what they do

smallest blood vessels that allow metabolic exchange between blood and tissues (functional units of cardiovascular system)

describe capillary beds

groups of capillaries 

what do each true capillary have?

precapillary sphincters which are smooth muscle that controls blood flow and connects to postcapillary venule

describe what veins do

drains capillaries and returns blood to heart

blank in veins = blank than arteries

pressure in veins = lower than arteries

about how much of the body’s blood do veins hold at rest?

60%

what are the smallest veins called?

venules (companion vessels with arterioles

what are the smallest venules called? what occurs through the walls of these venules?

postcapillary venules - diapedesis

what do smaller and medium sized veins travel with? what about large veins?

smaller and medium sized veins travel with muscular arteries and large veins travel with elastic arteries

what do most veins contain to prevent pooling when blood pressure is low?

valves

describe the skeletal muscle pump

muscles bulge as they contract and push on veins

what is venous respiratory assisted by and what does it involve?

venous return is assisted by respiratory pump and involves pressure changes (intrathoracic and intra-abdominal)

describe blood pressure

the force of blood against vessel wall

describe arterial blood pressure

blood flow in arteries that pulses with cardiac cycle

describe systolic pressure

ventricle contracts and higher pressure is generated in arteries (they are stretched)

describe diastolic pressure

ventricle relaxes and lowest pressure is generated in arteries (they recoil)

what is a normal blood pressure level and what is high blood pressure called?

normal = 120/80; high blood pressure = hypertension

describe what a pulse is and what is does

throbbing of arterial wall that allows for the determination of heartbeat

describe pulse points and give examples

artery compressed against solid structure - ex. radial, common carotid, femoral, dorsalis pedis