Circulatory System Flashcards
small veins that lack elastic laminae and smaller ones may lack tunica media
venules
___ are structurally similar similar to valves but endothelial cells are thinner with greater permeability; valves are present; basement membrane and pericytes may be present or absent
lymph vascular system
T/F: Lymph vessels have a very thin tunica media
True
intermittent rings of smooth muscle within walls of arterioles
pre-capillary sphincters
medium muscular veins contain __________ only
internal elastic lamina
T/F: Lymph vascular system lacks intrinsic pump, relies on muscle contraction and body movement
True
________ of blood vessels is due to action of sympathetic, post-ganglionic nerve fibers; act on smooth muscle of tunica media which causes this and decrease lumen diameter
vasoconstriction
veins or arteries directly connecting 2 capillary beds
portal vessels
Conducts blood away from heart to capillary bed
arterial system
Similar to MI that affects brain which leads to cerebral infarct where neurons die and lose function
stroke
Tunica media is made up of
smooth muscle and fibroblastic ct; may have reticulin fibers and elastic fibers
Secondary function of circulatory system
thermoregulation, transport of immune cells/hormones
innermost layer of simple squamous endothelial cells lining lumen; very thin (1-2 cells thick), forms semi-permeable barrier supported by basement membrane
tunica intima
T/F: Connective tissue is more contractile than muscle tissue
False
In general, amount of smooth muscle ______ with increased diameter of vessel and relative amount of connective tissue _______
increases; decreases
inflammation and thickening of AV valves often associated with valvular incompetence which leads to turbulence and regurgitation which leads to
vegetative endocarditis and thromboembolic disease
control smooth muscle contraction in vessel walls
nervi vasculares
2 components of circulatory system
pulmonary and systemic circulation
Since cardiac muscle cells in Go phase are unable to regenerate, all healing occurs via
fibrosis
when endothelium of a vessel is damaged, ____ adheres to exposed proteins
cholesterol
Contraction of ventricles
systole
thin walled vessels; lined by thin single layer of endothelial cells supported by basal lamina and small numbers of pericytes
capillaries
ECS is drained by series of interconnected, blind-ending tubules called
lymphatics
_____ formed as result of high hydrostatic pressure in arterioles; exceeds colloidal oncotic pressure exerted by plasma proteins => leakage of water, electrolytes, & plasma proteins from capillaries into ECS
Lymph
valve failure in legs causes
varicose veins
Sudden occlusion by an embolus leads to
acute ischemic event
vessel layer that consists of loose fibroblastic ct with fibroblasts, collagen and elastic fibers, and smooth muscle; thinner in arteries and thickest in veins; contains vasa vasorum and nervi vasculares
tunica adventitia
Tunica adventitia is composed of
fibroblasts, collagen, elastic fibers, and smooth muscle
(lymph) Immobility may lead to _______
peripheral edema or swollen feet
Thickest vessel layer of 3 layers in veins
tunica adventitia
___ Drain excess fluid (lymph) from ECS & return it to bloodstream
Lymph vascular system
Tunica intima is made up of what types of cells?
simple squamous endothelial
Relaxation of ventricles; decrease of pressure
diastole
derived from same precursor cel as endothelial cells; can differentiate into endothelial cells or smooth muscle cells following injury
pericytes
Specialized discontinuous tight junctions between endothelial cells; allow diapedesis of WBCs
fascia occludens
type of capillaries seen in muscle, lung, and CNS
continuous
concerned with exchange of gases, fluids, nutrients, metabolites, and waste products that occurs primarily within capillaries but also includes arterioles and venules
microcirculation
Chemoreceptors detect changes in _____
O2, CO2 tension, and pH
T/F: The thoracic duct and R lymphatic duct contain tunica media
True
untreated angina which leads to heart muscle death leads to
myocardial infarction
vessel layer that contains smooth muscle and fibroblastic connective tissue; thickest in arteries; may also contain reticulin and elastic fibers
tunica media
Lymphatics converge on largest lymph vessels in the body called
thoracic duct and right lymphatic duct
Lymph returns to bloodstream at _______
junction of L internal jugular V & L subclavian V
External elastic lamina is composed of
elastic fibers
______ in veins prevent backflow especially in limbs and thorax
valves
How many tunic layers are there in blood vessels of circulatory system?
3
type of capillaries seen in endocrine glands and GI tract
fenestrated
controls luminal diameter of muscular veins and valves
smooth muscle in tunica media
large muscular veins contain
internal and external elastic lamina
if present, located between tunica media and adventitia; composed of elastic fibers that are less organized
external elastic lamina
T/F: Tunica intima has variable amounts of subendothelial connective tissue
True
decrease in O2 to heart muscle leads to
chest pain (angia)
Vessel wall of arteries is _____ relative to lumen diameter
thick
most common cause of ischemic heart disease is
atherosclerosis
large and medium sized valves are called
muscular veins
Lymph endothelial cells are highly active in what?
phagocytosis
contain relatively little smooth muscle; elastic laminae is absent; terminal branches of arterial system that supply capillary beds; major sites of vasoconstriction and vasodilation; regulate distribution of blood to capillaries via pre-capillary sphincters
arterioles
Vasodilation and vasoconstriction is accomplished via smooth muscle contraction in ______ and ________ that causes passive change in capillary diameter
arterioles; precapillary sphincters
T/F: Capillaries exhibit vasomotor activity
False
large conducting vessels, receive blood directly from the heart; have sheets of elastic tissue in tunica media that helps maintain bp between systole and diastole; tunica media is thickest layer; posses both internal and external elastic laminae
elastic artery
as cells within plaque die in later atherosclerosis, it leads to
necrosis and secondary calcification
_____ is controversial; thought to be passive accomplished via INDIRECT parasympathetic innervation; ach causes endothelial cells to release NO which cause smooth muscle cells to relax; results in increased blood flow
vasodilation
Contain lymphoid tissue for antigenic sampling & recognition, activation of immune cells & production of Ab; interspersed among lymph vessels
Lymph nodes
T/F: Expansion and recoil of elastic arteries maintains blood pressure
True
Arteries contain large amount of
elastin and smooth muscle
________ lymph drainage is important in tumor metastasis
asymmetric
direct connections between arterial and venous system; bypass capillary bed
AV shunts
medium sized distributing artery that have more smooth muscle and less elastin in tunica media than elastic artery; tunica media is thickest layer; distinct internal elastic lamina; larger may have external elastic lamina
muscular artery
Decrease function or partial loss of function of heart muscle is due to _______ of the dead heart muscle
fibrosis
Regulation of bp is accompanied by changes in diameter of blood vessels; occurs via ___________ of smooth muscle in vessel walls
sympathetic control
type of capillaries seen in the liver, spleen, bone marrow, and intestines
discontinuous
type of capillary where endothelial cells possess pores within cells
fenestrated capillary
Blood vascular system consists of
heart and blood vessels
gradual narrowing by plaque leads to
thrombosis
Once endothelium heals, the cholesterol patch is reabsorbed; then phagocytosis by macrophages later by endothelial and subintimal cells lead to _______ (atherosclerosis)
foam cells
There are fewer layers of _______ in tunica media of veins compared to similar sized arteries
smooth muscle
3 types of arteries
elastic, muscular, arterioles
type of capillary where the endothelium forms continuous lining; most common
continuous capillary
T/F: Capillaries lack smooth muscle
True
Thickest layer in muscular layer?
Tunica media
blood vessels can dilate to form thin-walled, balloon-like regions called _____; occasionally burst that are common in aorta or brain
aneurisms
has smooth muscle layer in tunica media with a thicker tunica adventitia
muscular venules
both tunica media and adventitia are reduced or absent; these are preferential site for diapedesis; drain into larger collecting ducts
post-capillary venules
As plaque enlargers, or if endothelium damaged, exposes underlying collagen which initiates the clotting cascade which leads to
thrombus formation
Easiest way to identify ________ in section: Thin walled, lack blood, contain smooth, eosinophilic, proteinaceous fluid (lymph), occasional WBC’s
lymph vessels
functions as low pressure collecting system for returning blood from capillary beds to heart; Thinner walled vessels with larger relative luminal diameter; Fewer layers of smooth Mm in tunica media
Venous system
Capillaries only contain which layer of a blood vessel
Tunica intima
type of anastomosis common in skin, function in thermoregulation
AV shunts
Cyclical pumping of heart is called ______
pulsatile blood flow
What is thickest layer of elastic artery?
tunica media
type of capillary where basal lamina not continuous; endothelial cells separated by large gaps between cells; may form sinusoids
discontinuous capillaries
separates tunica media and intima if it is present; composed of elastic fibers
internal elastic lamina
lumen of _____ artery may decrease by 90% in atherosclerosis
coronary
vasoactive substances act on venules to enlarge the intercellular spaces leading to
increased permeability of vessel
passive drainage system for returning extravascular fluid to blood vascular system
lymph vascular system
specialized sensory receptors in blood vessels located in carotid sinus and aortic arch that detect blood pressure
baroreceptors
There is no central pumping mechanism of lymph; movement of lymph is accomplished by ____
skeletal Mm contraction, body movement
most common acquired abnormality of blood vessels
atherosclerosis and plaque formation
Transport occur across capillaries via
fenestrae, transcytosis, or diapedesis
_______ is due decreased diameter of vessel lumen and increased systolic bp
hypertension
small blood vessels that supply the tunica media and adventitia in both large arteries and valves
vasa vasorum
internal elastic lamina is composed of
elastic fibers
Later atherosclerosis is accompanied by proliferation of _______
smooth muscle cells and formation of fibrous ct capsule
small diameter arterioles; intermediate in size between arterioles & capillaries; characterized by discontinuous layer of smooth muscle in tunica media
Metarterioles
specialized sensory receptors in blood vessels located at bifurcation of carotid artery and in aortic bodies in aortic arch; detect changes in O2, CO2 tension, and pH
chemoreceptors
Necrosis and secondary calcification of artery is associated with _______
hypertension
Returns blood from capillaries to heart
venous system
T/F: Capillaries lack outer connective tissue layer
True
Primary function of circulatory system is transport of
O2/CO2 and nutrients/metabolic waste
