Advertisement Upgrade to remove ads

artery

a blood vessel that carries blood away from the heart to other organs

arteriole

a small, almost microscopic, artery that delivers blood to a capillary

capillary

a microscopic blood vessel located between an arteriole and a venule through which materials are exchanged between blood and interstitial fluid

vein

a blood vessel that conveys blood from tissues back to the heart

angiogenesis

the formation and growth of new blood vessels

tunica interna (intima)

the deep coat of an artery or vein, consisting of a lining of endothelium, basement membrane, and internal elastic lamina

lumen

the interior space of a blood vessel

tunica media

the intermediate coat of an artery or vein, composed of smooth muscle and elastic fibers

vasoconstriction

a decrease in the diameter of the lumen of a blood vessel due to contraction of smooth muscle fibers in the vessel wall

vasodilation

an increase in the diameter of the lumen of a blood vessel due to relaxation of smooth muscle fibers in the vessel wall

elastic artery

an artery having the largest diameter, but with relatively thin walls, that functions in conducting blood from the heart to muscular arteries during ventricular relaxation (diastole); also called conducting artery

pressure reservoir

the brief storage of potential energy by elastic arteries as their walls are stretched by the incoming surge of blood, and the subsequent release of kinetic energy as the vessels recoil, which moves blood through the arteries

muscular artery

a medium-sized, thick-walled artery with a thicker tunica media that functions in stronger vasoconstriction and vasodilation to adjust the rate of blood flow to the arterioles; also called distributing artery

capillary bed

a network of 10-100 capillaries that arises from a single metarteriole

sinusoid

a large, thin-walled, and leaky type of capillary, having large intercellular clefts that may allow proteins and blood cells to pass from a tissue into the bloodstream; in the liver, spleen, anterior pituitary gland, red bone marrow

portal system

the circulation of blood from one capillary network into another through a vein

superficial vein

veins that travel through the subcutaneous layer unaccompanied by parallel arteries

deep vein

veins that travel between the skeletal muscles

varicose vein

a vein that is dilated and twisted in appearance due to leaky venous valves

blood reservoir

systemic veins and venules that contain large amounts of blood that can be moved quickly to parts of the body requiring the blood

capillary exchange

the movement of substances between the blood and interstitial fluid

filtration

pressure-driven movement of fluid and solutes from blood capillaries into interstitial fluid

reabsorption

pressure-driven movement of fluid and solutes from interstitial fluid into blood capillaries

edema

an abnormal increase in interstitial fluid volume that can result from either excess filtration or inadequate reabsoprtion

blood flow

the volume of blood that travels through any tissue in a given time period (in mL/min)

blood pressure (BP)

the hydrostatic pressure exerted by blood on the walls of a blood vessel (usually the arteries in clinical use), determined by cardiac output, blood volume, and vascular resistance

systolic blood pressure

the highest arterial blood pressure during contraction

diastolic blood pressure

the lowest arterial blood pressure during relaxation

mean arterial pressure (MAP)

the average blood pressure in arteries, roughly one-third of the pressure between the diastolic and systolic pressures

vascular resistance

the opposition to blood flow due to friction between blood and the walls of blood vessels

venous return

the volume of blood flowing back to the heart through the systemic veins

skeletal muscle pump

helps move blood from the lower body back to the heart through the contraction and relaxation of leg muscles which alternatingly compress and decompress veins (milking)

respiratory pump

the alternating compression and decompression of veins in the thoracic cavity due to the pressure changes generated by breathing that helps bring venous blood back to the heart

circulation time

the measure of how long it takes for a drop of blood to pass from the right atrium, through the pulmonary circulation, back to the left atrium, through the systemic circulation down to the foot, and back again to the right atrium; is about 1 minute in a resting person

syncope

a suden, temporary loss of consciousness (fainting) that is not due to head trauma, followed by spontaneous recovery; usually due to lack of sufficient blood flow to the brain (cerebral ischemia)

vasomotor nerve

carries impulses from the cardiovascular center to smooth muscle in blood vessel walls

carotid sinus reflex

baroreceptor stimulation that helps regulate blood pressure in the brain

aortic reflex

baroreceptor stimulation that helps maintain normal systemic blood pressure

aldosterone

hormone that increases reabsorption of sodium ions and water by the kidneys, which increases total blood volume, which increases blood pressure

antidiuretic hormone (ADH)

hormone released from the posterior pituitary in response to dehydration or decreased blood volume; increases blood volume, which increases blood pressure; also causes vasoconstriction, which increases blood pressure; also called vasopressin

pulse

the traveling pressure wave created by the alternate expansion and recoil of elastic arteries after each systole of the left ventricle

sphygmomanometer

the instrument used to measure blood pressure

systolic blood pressure (SBP)

the force of blood pressure on arterial walls just after ventricular contraction

diastolic blood pressure (DBP)

the force exerted by the blood remaining in arteries during ventricular relaxation

Korotkoff sounds

the various sounds heard while taking blood pressure

pulse pressure

the difference between systolic and diastolic pressure (normally about 40 mmHg) that provides information about the condition of the cardiovascular system

pulse point

a location where the pulse can be felt, such as the common carotid artery, brachial artery, femoral artery, popliteal artery, radial artery, and dorsalis pedis artery

shock

a failure of the cardiovascular system to deliver enough oxygen and nutrients to meet cellular metabolic needs; characterized by inadequate blood flow to body tissues

hypovolemic shock

shock due to decreased blood volume

cardiogenic shock

shock due to poor heart function

vascular shock

shock due to inappropriate vasodilation

obstructive shock

shock due to obstruction of blood flow

systemic circulation

the arteries and arterioles that carry oxygenated blood from the left ventricle to sytemic capillaries, plus the veins and venules that return deoxygenated blood to the right atrium

hepatic portal circulation

carries venous blood from the gastrointestinal organs and spleen to the liver

portal vein

a vein that carries blood from one capillary network to another

pulmonary circulation

carries deoxygenated blood from the right ventricle to the air sacs (alveoli) within the lungs and returns oxygenated blood from the air sacs to the left atrium

hypertension

persistently high blood pressure that is the major cause of heart failure, kidney disease, and stroke

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set