Circulatory System Flashcards
The three layers or tunics of blood vessels are called: (from lumen side to periphery)
tunica intima
tunica media
tunica adventitia
Large vessels have other smaller vessels called ___ ___ branching through adventitia. Veins have ____ of these vessels than arteries
vasa vasorum
more
larger vessels may have lymphatic vessels and nerves in the adventitia as well. Nerves running through the adventitia are called
nervi vascularis .
tunica ____ =fibroelastic connective tissue (dense irregular CT plus small amounts of elastic fiber)
adventitia
Tunica ____ = endothelium + underlying subdendothelial connective tissue. It includes ____ elastic lamina in larger vessels
intima
internal
tunica ____ = primarily smooth muscle cells and also ____ elastic lamina
media
external
Large arteries are classified as _____, medium size are ____, and small are _____
elastic
muscular
arterioles
____ (conducting) arteries conduct blood to muscular arteries. Examples include aorta, pulmonary, brachiocephalic
Elastic
Arteries: Elastic fibers of intima form an incomplete ____ elastic lamina. _____ layer of loose CT contains collagen, elastic fibers, and fibroblasts
internal
subendothelial
Arteries: Thick media is made of 40-70 concentric ____ sheets. Thin adventitia is made of ____ and ____ fibers.
elastic
collagen elastic
____ arteries distribute blood to organs. These have an intima that is _____ than that of elastic arteries and a well developed ____ elastic lamina
muscular
thinner
internal
in the intima, subendothelial connective tissue of muscular arteries lack ____ ____ cells. The tunica media is up to 40 circular layers of ____ _____ cells
smooth muscle
smooth muscle
A thick ____ elastic lamina lies at the edge of the tunica media in muscular arteries.
external
___ have very sparse subendothelial connective tissue
arterioles
the tunic media of arterioles has 1-3 layers of ___ ___ cells with occasional ____ fibers
smooth muscle
elastic
The adventitia of arterioles consists of a layer of ____ _____ tissue with longitudinally arranged ____ and elastic fibers
loose connective
collagenous
___ are more rounded and contain more smooth muscle while ____ have an irregularly shaped lumen and less smooth muscle
arterioles
venules
____ have a single layer of endothelial cells. They are surrounded by a thin sheath of ____ and collagenous fibers and some ____ (mesenchymal like stem cells)
capillaries
reticular
pericytes
In wound healing, _____ from capillaries may differentiate into fibroblasts or smooth muscle cells
pericytes
____ capillaries have a continous endothelium and basal lamina and no _____. They contain numerous ______ vesicles for transcytosis
continous
fenestrations
pincytotic
continuous capillaries are located in ____, ____, ____, _____, and _____
muscle, connective tissue, CNS, exocrine pancreas, gonads
In the CNS, ____ capillaries have a type of tight junction that contributes to the blood brain barrier
continuous
Fenestrated capillaries have an ____ epithelium with large fenestrae closed by thin _____
attenuated
diaphragms
Location of fenestrated capillaries: (5)
mucosa of GI tract, endocrine glands, renal glomerular/peritubular capillaries, choroid plexus, ciliary bodies
Fenestrated endothelium in the ____ capillaries have no diaphragms
glomerular
_____ (_____) capillaries have wide gaps between cells, irregular tortuous walls, and an incomplete basal lamina.
Discontinous (sinusoidal)
Sinusoidal capillaries are found in ____, ____, and _____
liver
bone marrow and spleen (homopoietic organs)
The three types of capillaries are ____ ____ and ____
continuous
fenestrated
discontinuous
_____ venules receive blood from capillaries and have an incomplete layer of ____
postcapillary
pericytes
post capillary venules are an important site of activity in _____. Vasoactive compounds such as ____ and ____ affect fluid extravasation and migration of WBC
inflammation
serotonin, histamine
The intima of a venule consists of ____ cells. The media has ___ layers of smooth muscle cells and the adventiita has several layers of ____ fibers
endothelial
1-2
collagen
<p>\_\_\_\_ venules have NO pericytes and 1-2 layers of smooth muscle with a thin tunica adventitia</p>
<p>muscular</p>
____ of small to medium size veins may have a thin subendothelial connective tissue layer
intima
small/medium sized Veins have a thin media with some ___ and ___ fibers interspersed with ____ ____ cells
reticular, elastic
smooth muscle
small to medium sized Veins have a well developed ____ with multiple layers of collagenous fibers with a few smooth muscle cells and elastic fibers
adventitia
Large veins include the ____, ____, and ____. They have a ____ adventitia with collagenous fibers and longitudinal arranged smooth muscle cells
superior vena cava, inferior vena cava, portal trunk
thick
Small to medium sized veins may have valves to prevent ____ blood flow (primarily in lower limbs). Valves are paired, semilunar folds of _____ covered with endothelium
retrograde
intima
____ ____ are connections primarily between arterioles and venules.
Arteriovenous anastamoses
at the anastamoses of arteioles and venules, there is a specialized tunic ____ with a _____
media
sphincter
When the arterivenous anastomoses sphincter is closed, arterial blood flows into the ____. When the shunt is open, blood flows into the ____
capillary bed
vein
Some microvascular beds have a _____ _____ which controls the amount of blood flowing into the capillary
precapillary sphincter
Fluid scavenged by the lymphatic system is filtered by lymph ____ and recycled back into the venous circulation at the base of the ____
nodes
neck
____ in the intestine are an important route of fat absorption
lacteals
Lymphatic vessels are an ______ lined vessel. Lymph flows in __ direction.
endothelial 1 (toward the base of the neck)
Lymphatic vessels originate in ____ _____ as anastomosing capillaries. Lymphatic capillaries have no ___ _____
connective tissue
basal lamina
____ and ____ ____ have no lymphatic system.
CNS, bone marrow
In smaller lymph vessels, fine anchoring filaments attached to _____ collagen hold the vessel open. Large vessels have a ____, ____, and ____ like blood vessels
perivascular
intima, media, adventitia
The two main lymphatic vessels are the ____ ____ duct and ____ _____ duct and are structurally similar to veins, with smooth muscle present
main thoracic
right lymphatic
Lymphatic vessels have paired ____ ____ to prevent back flow of lymph
cusp valves
____ _____ has lymphatics only in perimysium
skeletal muscle
_____ is foam cell formation and fatty deposits in the intima which may block the vessel
athersclerosis
____ is due to smooth muscle cell proliferation that follows an angioplasty procedure. It may occlude the vessel
restenosis
an _____ is a ballooning out of an artery. It is due to ___ in the arterial wall. It can be due to atherosclerosis, syphillis, CT disorders
aneurysm
weakness
____ veins are tortuous, dilated veins that are primarily in the ____ of older persons. They are caused by a decrease in muscle tone and failure of venous valves
varicose
legs
LDL acts a _____ molecuoule in atheroma formation. ____ of a blood vessel is correlated with blockage
proinflammatory
calcification
Endothelial cells produce ____ from arachidonic acid. It inhibits platelet adhesion and clot formation
prostacyclin
Endothelial cells secrete ____ ____ which causes smooth muscle in the tunica media to relax and produce _____. _____ is produced by endothelial cells and acts as a vasoconstrictor.
nitric oxide
vasodilation
endothelin 1
Endothelial cells regulate the traffic of inflammatory cells. Early in inflammation, macrophages in surrounding CT secrete ____ which induce expression of _-______ by endothelial cells
cytokines
E-selectin
____ bind to selectins and then extravasate then by migration through the endothelium
neutrophils
____ blood is exchanged between the mother and fetus.
no
Exchange between mother and fetus occurs at the interface where the _____ ____ fuses with the _____
umbillical cord uterine walls (placenta)
the fetal side of blood circulation consists of ______ _______
multinucelated synctiotrophoblasts
What are the three layers of heart? (from interior to exterior)
endocardium
myocardium
epicardium
The endocardium is lined by ____ and is continuous with ___ _____ that enter and leave the heart
endothelium
blood vessels
Endocardium has a subendothelial layer of ____ ____ fibers, a thin layer of dense ____ connective tissue, and a subendocardial layer of ____ connective tissue connected to the myocardium
fine collagenous
fibroelastic
loose
The subendocardial CT contains blood vessels, nerves, and portions of the impulse-conducting system called _____. Endocardium does not contain _____
purkinje fibers
lipid
Cardiac muscle tissue is called _____. In ventricles, it is arranged into ___ and ____ layers
myocardium
superficial, deep
the superficial layer of myocardium has a ____ ____ around the ventricle. The deep fibers have a ____ _____
spiral course
circular course
The outermost coat of epicardium is formed by _____ cells. This is equivalent to the ___ layer of serous pericardium
mesothelial
visceral
The fibrous skeleton of the heart is composed of ____ _____ CT.
dense irregular
the _____ _____ is the fibrous portion of the interventricular septum
septum membranaceum
____ _____ are fibrous rings around the origins of the pulmonary artery, aorta, and AV canals
annuli fibrosi
____ ____ = fibrous tissue between the atrial foramin and AV canals
trigona fibrosa
____ around AV orficies results in electrical discontinuity between myocardial cells of ___ and ____.
annuli
atria, ventricles
Anulli around AV orfices controls communication between the atria and ventricles via specialized conduction tissue called the _____ ____
AV bundle
When the ____ node fires, action potentials spread through the atria. When the ____ node fires, impulses go along conducting fibers
SA
AV
heart valves have both ____ and _____ __ layers surrounded by endothelium
loose, dense CT
The ___ ____ of valves is continuous with the cardiac skeleton
dense CT
The ____ node is the pacemaker of the heart. It contains ____ cardiac muscle cells concentrically arranged around a ____ artery. Impulse spreads from this node via specialized conduction fibers to the ___ node
SA
modified
nodal
AV
the ___ node lies beneath the endocardium of the septal wall of the right _____. This node continues to form a common stem, called the bundle of ____
AV
atrium
His
The AV bundle of His is formed by _____ fibers (cardiac conduction fibers). These penetrate the skeleton and then branch to form right and left ____ branches
purkinje
bundle
Purkinje fibers are made of modified ___ cells filled with ____
muscle
glycogen
Purkinje fibers travel in the subendocardial layer to the heart ____, then reverse direction and branch to make contact and form ___ junctions with cardiac muscle cells.
apex
gap
Atrial cardiac muscle cells are the source of _____ _____
polypeptide hormones
_____ ____ _____ (___) is released from modified atrial muscle cells in response to high blood pressure. The primary effect is to ____ sodium and ____ secretion from the kidney
Atrial natriurietic polypeptide (ANP)
increase, water
