BLOOD VESSELS & CIRCULATION

Vessel that carries blood away from the heart

Artery

Vessel that returns blood to the heart

Vein

Smallest blood vessels where exchange occurs

Capillary

Fluid connective tissue of the cardiovascular system

Blood

Pumping organ of the circulatory system

Heart

Inner layer of blood vessels

Tunica intima

Middle layer containing smooth muscle

Tunica media

Outer connective tissue layer

Tunica externa

Space inside a blood vessel

Lumen

Elastic membrane in arteries between layers

Elastic membrane

Large arteries rich in elastic fibers

Elastic arteries

Medium-sized distributing arteries

Muscular arteries

Small resistance vessels controlling blood flow

Arterioles

Narrowing of blood vessel diameter

Vasoconstriction

Widening of blood vessel diameter

Vasodilation

Smallest blood vessels in the body

Capillaries

Exchange between blood and tissues occurs here

Capillaries

Capillaries with pores for rapid exchange

Fenestrated capillaries

Capillaries with gaps for large molecule exchange

Sinusoids

Network of capillaries connecting arteriole and venule

Capillary bed

Muscle controlling entry of blood into capillaries

Precapillary sphincter

Rhythmic contraction of precapillary sphincters

Vasomotion

Formation of new blood vessels

Angiogenesis

Growth factor stimulating new vessels

VEGF

Oxygen-starved condition stimulating angiogenesis

Hypoxia

Small veins collecting blood from capillaries

Venules

Structures preventing backflow in veins

Valves

Twisted swollen veins

Varicose veins

Ability of veins to expand and hold blood

Capacitance

Network storing extra venous blood

Venous reserve

Force driving blood through vessels

Pressure

Difference in pressure between two points

Pressure gradient

Resistance of entire vascular system

Total peripheral resistance

Swirling flow of blood

Turbulence

Thickness of blood affecting resistance

Viscosity

Peak pressure during ventricular contraction

Systolic pressure

Lowest pressure during ventricular relaxation

Diastolic pressure

Difference between systolic and diastolic pressure

Pulse pressure

Average arterial pressure

Mean arterial pressure

Abnormally high blood pressure

Hypertension

Movement of molecules down concentration gradient

Diffusion

Movement of fluid out of capillaries due to pressure

Filtration

Movement of fluid back into capillaries

Reabsorption

Pressure pushing fluid out of capillaries

Capillary hydrostatic pressure

Pressure pulling water back into blood

Blood colloid osmotic pressure

Blood flow through tissues

Perfusion

Local adjustment of blood vessel diameter

Autoregulation

Hormone regulating water balance and blood pressure

ADH

Hormone stimulating red blood cell production

Erythropoietin

Fetal opening between right and left atria

Foramen ovale