Blood Vessels and Circulation Vocabulary

Flashcards for reviewing blood vessels and circulation, covering arteries, veins, capillaries, blood pressure regulation, and fetal circulation.

Tunica intima or tunica interna

Innermost layer of arteries and veins, composed of endothelial cells with connective tissue and elastic fibers.

Tunica media

Middle layer of arteries and veins, contains concentric sheets of smooth muscle.

Tunica externa or tunica adventitia

Outermost layer of arteries and veins; a connective tissue sheath that anchors the vessel to surrounding tissues.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that return blood to the heart.

Capillaries

Smallest blood vessels, consisting of a tube of endothelial cells with a delicate basement membrane.

Capillary bed

Interconnected network of capillaries

Vasodilators

Local chemicals that increase blood flow.

Venoconstriction

Contraction of smooth muscle fibers in veins to maintain blood volume in the arterial system.

Blood pressure

Pressure within the cardiovascular system as a whole

Peripheral resistance

Force that opposes movement of blood

Venous return

Amount of blood arriving at the right atrium each minute

Total peripheral resistance

Resistance of entire cardiovascular system

Vascular resistance

Opposition to blood flow in vessels

Viscosity

Resistance to flow caused by interactions of solutes and suspended materials in a liquid.

Turbulence

Type of fluid flow with eddies and swirls

Pressure gradient

Difference in pressure from one end of vessel to other

Systolic pressure

Peak arterial pressure during ventricular contraction

Diastolic pressure

Minimum arterial pressure during ventricular relaxation.

Pulse pressure

Difference between systolic and diastolic pressure

Mean arterial pressure (MAP)

Adding 1/3 of pulse pressure to diastolic pressure

CHP

Capillary hydrostatic pressure

Diffusion

Net movement of substances from an area of higher concentration to lower concentration

BCOP

Blood colloid osmotic pressure

Net filtration pressure (NFP)

Difference between capillary hydrostatic and blood colloid osmotic pressure.

Edema

Fluid builds up in peripheral tissues

Tissue perfusion

Blood flow through tissues

Homeostatic mechanisms

Ensure adequate tissue perfusion (blood flow through tissues)

Autoregulation

Changes in blood flow within capillary beds

Central regulation

Involves both neural and endocrine mechanisms

Baroreceptor reflexes

Respond to changes in blood pressure

Chemoreceptor reflexes

Respond to changes in blood and cerebrospinal fluid

Umbilical arteries

Pair of arteries that carry blood from the fetus to the placenta

Umbilical vein

Carries blood from the placenta

Ductus venosus

Vascular connection to veins within the liver

Foramen ovale or interatrial opening

Allows blood to pass from right atrium to left atrium

Ductus arteriosus

Bypass between pulmonary trunk and aorta