57 terms

Blood Vessels

a blood vessel that carries blood away from the heart to other organs
a small, almost microscopic, artery that delivers blood to a capillary
a microscopic blood vessel located between an arteriole and a venule through which materials are exchanged between blood and interstitial fluid
a blood vessel that conveys blood from tissues back to the heart
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
the interior space of a blood vessel
tunica media
the intermediate coat of an artery or vein, composed of smooth muscle and elastic fibers
a decrease in the diameter of the lumen of a blood vessel due to contraction of smooth muscle fibers in the vessel wall
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
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
pressure-driven movement of fluid and solutes from blood capillaries into interstitial fluid
pressure-driven movement of fluid and solutes from interstitial fluid into blood capillaries
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
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
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
the traveling pressure wave created by the alternate expansion and recoil of elastic arteries after each systole of the left ventricle
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
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
persistently high blood pressure that is the major cause of heart failure, kidney disease, and stroke