chapter 19

Large blood vessels near the heart with large lumen and lots of elastic fibers

Elastic arteries

Mean Arterial Pressure Equation

(SP + (2DP))/3

Sensory nerve endings that respond to stretch in the arteries

Baroreceptors

Pressure of blood against the capillary wall

Hydrostatic pressure

Pressure supplied by the L ventricle that pumps blood from the heart to the body and back to the heart

Systemic circuit

Systemic arteries that deliver blood to body regions; medium sized

Muscular arteries

Blood vessels with lowest surface area

Aorta and inferior and superior vena cave

Capillaries with large irregular lumen to allow passage of larger molecules and cells; found in the liver and bone marrow

Sinusoidal capillaries

Large branching vessels that conduct blood away from the heart

Arteries

Formed when blood pressure is low, and causes arterial constriction

Angiotensin II

Weak point in artery wall; if it bursts it can cause lack of perfusion to tissues

Aneurysm

Loss of blood pressure due to poor circulation resulting from extreme vasodialation

Vascular shock

Movement of molecules due to concentration gradients

Diffusion

Released when blood pressure is high; causes dilation of blood vessels

Atrial naturetic peptide

The first Korotkoff sound heard when measuring blood pressure

Systolic pressure determination

Blood vessels with lowest blood pressure

Inferior and superior vena cave

Blood vessels with largest surface area

Capillaries

Veins are squeezed during skeletal muscle contraction to help return blood to the heart

Muscular pump

Actual site of exchange of nutrients and waste; branch from the metarteriole

True capillaries

Movement of fluid and solutes due to pressure gradients

Bulk flow

A factor in resistance; the longer the blood vessel the greater the resistance to blood flow

Blood vessel length

site of exchange between blood and tissue

Capillaries

Inner opening of blood vessels

Lumen

Opposition to flow caused by drag of cells on the walls of the vessel

Peripheral resistance

Measure of the "thickness" or "stickiness" of blood

Viscosity

Most common type of capillary; composed of endothelial cells attached to a basement membrane

Continuous capillaries

Blood flow from capillary beds in the small intestine to capillary beds in the liver; helps filter the blood before returning the blood to general circulation

Hepatic portal circulation

Connective tissue that forms the outermost layer of blood vessels

Tunica externa

Large converging vessels that conduct blood toward the heart

Veins

A factor in peripheral resistance that is most easily controlled; the smaller the lumen diameter the greater the resistance to blood flow

Lumen diameter

Released by the posterior pituitary when blood pressure is low; stimulates arterial constriction

ADH

Simple squamous epithelium that lines blood vessels

Endothelium

Causes a constriction of arteries to increase resistance and increase blood pressure

Sympathetic innervation of blood vessels

Contraction of smooth muscle in blood vessel walls which acts to reduce blood vessel diameter and increase resistance

Vasoconstriction

Pulse, blood pressure, respiratory rate, and body temperature

Vital signs

Relaxation of smooth muscle in the blood vessel walls which acts to increase the blood vessel diameter and increase blood flow

Vasodialation

small branching vessels with high resistance

Arterioles

Formation of new blood vessels

Angiogenesis

The force per unit area that blood exerts on vessel walls

Blood pressure

Loss of blood pressure to to large scale loss of blood

Hypovolemic shock

Pressure caused by non-diffusible proteins within the capillary

Osmotic pressure

Deposition of fatty substances in the blood vessel wall

Atherosclerosis

Pressure of blood against the capillary walls; higher on the arterial end than on the venule end; tends to push fluids out of capillary

Hydrostatic pressure

A sustained arterial pressure higher than 140/90

Hypertension

Enzyme released by the kidneys when blood pressure is low; causes the conversion of angiotensogen to angiotensin I

Renin

Heavily innervated small arteries that adjust flow minute-by-minute to specific areas

Arterioles

Fluid outside and around the cells

Interstital fluid

Tunica media can contract and help return blood to the heart

Smooth muscle in veins

Inner layer of blood vessels that is composed of endothelium

Tunica intima

Highest pressure exerted on the arteries when the L ventricle contracts

Systolic pressure

Volume of blood flowing through a tissue in a given period of time; equal to cardiac output

Blood flow

Blood flowing smoothly through an uncompressed artery

Laminar flow

The last Korotkoff sound heard when measuring blood pressure

Diastolic pressure

Loss of blood pressure due to heart damage

Cardiogenic shock

Primary protein responsible for osmotic pressure

Albumin

Veins are squeezed during breathing to help return blood to the heart

Respiratory pump

Blood vessel with highest blood pressure

Aorta

Formed by the elastic fibers in the aorta which compress to force blood through the vessels when the heart is in diastole

Pressure reservoir

Blood rushing up against a compressed artery; produces sounds (Korotkoff) that can be heard with a stethoscope

Turbulent flow

Thoroughfare vessel that connects arteriole to venue

Metarteriole

Causes a dilation of arteries, a decrease in peripheral resistance, and lower blood pressure

Parasympathetic innervation of blood vessels

Cuff of smooth muscle at the root of the true capillary to regulate blood flow to the capillary bed

Precapillary sphincter

Normal MAP

70-100 mmHg

Pressure due to presence of albumin in the capillary; does not change along the length of the capillary and tends to pull fluids in

Osmotic pressure within the capillary

Allow unidirectional flow of blood in veins

Venous valves

Endothelial cells have pores in the membrane to allow filtration; found in the kidneys, small intestines, and endocrine glands

Fenestrated capillaries

Pulse pressure equation

PP = SP - DP

Lowest pressure in the arteries when the heart is relaxed

Diastolic pressure

Sounds heard due to turbulent flow of blood in compressed arteries

Korotkoff sound

Hormone which responds to a decrease in blood pressure by stimulating artery constriction

Epinephrine

Middle layer of blood vessels composed of smooth muscle

Tunica media

Pressure supplied by the R ventricle that pumps blood from the heart to the lungs and back to the heart

Pulmonary circuit

Causes the conversion of angiotensin I to angiotensin II

Angiotensin converting enzyme

small converging vessels that conduct blood back to the heart

Venules