CHAPTER 20 Flashcards
the stiffening of the arteries with age
arteriosclerosis
efferent vessels of the cardiovascular system; vessels that carry blood away from the heart
arteries
simple squamous epithelium overlying a basement membrane ; make up the tunica interna
endothelium
short vessels that link arterioles and capillaries
metarterioles
number of tunics in arteries and veins
three
arterial sense organs that are chemoreceptors; monitor blood ph, and carbon dioxide and oxyen levels;; located near the branch of the common carotids
carotid bodies
lines the vessles and is exposed to blood ; tunica intima; thinnest tunic
tunica interna
afferent vessels that carry blood back to the the heart
veins
collective name for arterioles, capillaries, and venules, microcirculation
microvasculature
the changing in the diameter of a blood vessel due to the action of the smooth muscle in the tunica media
vasomotion
type of aneurysm in which blood accumulates between the tunics of an artery and separates them; usually because of the degeneration of the tunia media
dissecting
arterial sense organs that are pressure sensors that respond to changes in blood pressure; located in the wall of the internal carotid artery
carotid sinuses
a weak point in an artery or in the heart wall; forms a bulging cas that pulsates with each beat of the heart and may eventually rupture
aneurysm
arterial sense organs that are chemoreceptors; located in the aortic arch
aortic bodies
type of capilary in most tissues; their endothelial cells are held together by tight junctions and form a continuus tube
continuous
smooth muscle cells of the metarteriole that encircles the entrance to one capillary
precapillary sphinters
another name for arteries because they have a relatively strong, resilient tissue structure
resistance vessels
small gaps between endothelial cells of continuous capillaries
intercellular clefts
capillaries are absent from _____ and the cornea and lens of the eyes
epithelia
another name for capillaries; the business end of the cardiovascular system; rest of the system exists to serve the exchange process that occurs here
exchange vessels
muscular or medium arteries; distribute blood to specific organs
distributing arteries
type of capillaries that have endothelial cells riddled with patches of filtration pores; fenestrtions
fenestrated
small blood vessels that supply the tissue of the larger vessels; norish at least the outer half of large vessels
vasa vasorum
small arteries; usually dont have individual names
resistance arteries
outermost layer ; consists of loose connective tiisue; anchors vessels and provides passage of small nerves , lymphatic vessles and mall blood vessels, tunicaadvetitia
tunica externa
the biggest; elastic or large arteries; have layer of elastic tissue between the interna and the media; expand during ventricular systole to receive blood, and recoil during diastole
conducting arteries
microscopic, thin-walled vessles that connect the smallest arteries to the smallest veins
capillaries
layers of blood vessles walls
tunics
middle layer; usually thickest; consists of smooth muscle, collagen and smotimes elastic tissue; capable of changing the diameter of the blood vessel.
tunica media
type of anastomoses in which two arteries merge providing collateral route of blood supply to a tissue
arterial
the artery most frequently used to take blood pressure;
brachial
flaps extending into the lumen of many medium veins; keeps blood from flowing backwards
venous valves
the difference between the systolic and diastolic pressure
pulse pressure
smallest veins; receive blood from the capillaries; more porous than capillaries; exchange fluid with the surrounding tissues
postcapillary venules
receive blood from the postcapillary venules
muscular venules
circulatory route in which the blood flows through two consecutive capillary networks before returning to the heart
portal system
most common anastomoes; provide alternative routes of drainage from an organ
venous
relatively thin walled and flaccid vessels; expand easily to accommodate an increased volume of blood; veins
capacitance vessels
receives blood from the muscular venules
medium veins
capillaries are organized into networks
capillary beds
commonly considered to be a chronic resting blood pressure higher than 140/90; high blood pressure
hypertension
the physical principles of blood flow
hemodynamics
veins with especially thin walls, large lumens and no smooth muscle; not capable of vasomotion; coronary sinus of the heart and dural sinus of the brain
venous sinuses
continuation of the metarteriole through the capillary bed directly to the venule
thoroughfare channel
a point where two blood vessels merge
anastomosic
the amount of blood flowing through an organ, tissue, or blood vessel in a given time
flow
one of the two pressures recorded in blood pressure; the minimum arterial BP occurring during the ventricular relaxation between heartbeats
diastolic
the flow per given volume or mass of tissue
perfusion
type of capillary that are irregular blood filled spaces in the liver, bone marrow, spleen, and some other organs
sinusoids
fainting
syncope
growth of lipid deposits in the arterial walls; can become calcified
atherosclerosis
biggest veins; venae cavae, pulmonary veins, internal jugular and renal veins
large veins
fatty deposits in the arterial walls that can become calcified, and give the arteries a hard, bonelike consistency
complicated plaques
chronic low resting BP
hypotension
the mean pressure you would obtain if you took measurements at several intervals throughout the cardiac cycle
MAP
the force that blood exerts against a vessel wall
blood pressure
the physical force exerted by a liquid against a surface, such as a capillary wall
hydrostatic pressure
substances secreted by platelets, endothelial cells, and the perivascular tissue that stimulate vasomotion
vasoactive chemicals
an autonomic response to reduced perfusion of the brain; medulla monitors its own blood supply; activates corrective reflexs when it senses a state of ischemia
medullary ischemic reflex
the ability of tissues to regulate their own blood supply
autoregulation
blood velocity in the systemic circuit is fastest in largest artery
aorta
veins with irregular dilations and twisted pathways as a result of leaky valves usually in superficial veins
varicose veins
hormone released by the adrenal medulla that stimulates vasoconstriction and raises the blood pressure
epinephrine
varicose veins of the anal canal
hemorrhoids
mechanisms of movement of substances through the capillary wall; endothelial cells pick up material on one side of the plasma membrane
transcytosis
area of the medulla oblongata that exerts sympathetic control over blood vessels
vasomotor center
the opposition to flow that the blood encounters in vessels away from the heart
peripheral resistance
an autonomic, negative feedback response to changes in blood pressure
baroreflex
blood velocity in the systemic circuit is slowest in these smallest vessels
capillaries
the widening of a blood vessel; occurs in response to relaxation of the smooth muscle allowing blood pressure to expand the vessel
vasodilation
a mechanism of venous return in which the veins are surrounded and massaged by the muscles
skeletal muscle pump
the flow of blood back to the heart
venous return
adjusting the radius of the blood vessel
vasomotion
promotes water retention by the kidneys; raise blood pressure
antidiuretic hormone
salt retaining hormone; promotes sodium retention by thee kidneys; water follows sodium osmotically and promotes water retention ; higher blood volume and blood pressure
aldosterone
smooth, silent blood flow; flows in layers; faster near the center of the vessel; slower near the walls here he friction is high
lamina flow
the narrowing of a blood vessel; occurs when smooth muscle pf the tunica media contracts
vasoconstriction
mechanisms of movement of substances through the capillary wall; movement of lipid soluble molecules from a more concentrated area to a less concentrated area
diffusion
a mechanism of venous return in which the thoracic and abdonminal cavities alternate pressure which squeezes blood in the inferior vena cava upward
respiratory pump
growth of new blood vessels
angiogenesis
the accumulation of excess fluid in a tissue; occurs when fluid filters into a tissue faster than it is reabsorbed
edema
an autonomic response to changes in blood chemistry; adjusts respiration in results to changes in blood chemistry; also stimulate vasomotion
chemoreflex
potent vasoconstrictor that raises blood pressure
angiotensin
hormones that antagonize aldosterone and lower blood pressure
natriuretic peptides
type of low venous return shock that occurs when any object compresses a vein and impedes its blood flow
obstructed venous return shock
second portion of the aorta; curves like an inverted “U”; gives off three major arteries; brachiocephalic, left common caroid, and left subclavian
aortic arch
a type of low venous return shock in which too much of the bodys blood accumulates in the lower body
vascular shock
a deeper level of shock in which several life threatening postive feedback loops occur; need medical treatment to reserve the positive feedback
decompensated shock
without oxygen
anoxia
cardiac output is low because too little blood is returning to the heart
LVR shock
any state in which cardiac output is insufficient to meet the body’s metabolic needs
circulatory shock
results from exposure to an antigen to which a person is allergic; antigen-antibody complexes trigger the release of hisamine which causes generalized vasodilation and increased capillary permeability
anaphylactic shock
when a person is still , blood accumulates in the limbs because the venous pressure is not high enough to override the weight of the blood and drive upward
venous pooling
type of low venous return shock produced by excessive blood loss
hypovolumic shock
