9/1 Cardio Vascular system Flashcards
list the artery types in diminishing size
elaste (conduction) artereis, muscular arteries, arterioles.
list the veins in diminishing size
veins, venules, capillaries.
Where is the start of the circulatory
heart
where do you often get embolism or matastisis of cancer
in the lung since most of the blood goes to the lungs and there are small capillaries there
what do cells see or what are they exposed to?
to the lymph or the extracellular fluid
what is the general structural feaature of the vascular system
the large structrues have three layers, the exchangers have just one layer. and the lymphatics have one layer though it is “messy” organization
what does the vessel need to be able to interact with?
the body and the blood
how does the structure of the velssels change as they interact with different things
the outside layer ineracts with the body. The inside of the blood vessels is keep the blood fluid and keep it from undergojing a clotting cascade (epithelium does this)
The middle layer of the vessels have what main function?
To regulate the size of the blood vessels.
what is the main purpose of the lymphatic system
the purpose is to return liquied to the circulatory
What are the two regions of the heart?
Atrium and Ventricle
How do you identify the atrium region of the vessels
there is a thick layer of endo cardium, and a thick layer of myocardium and a thin layer of epicardium.
how do you indentify the ventricle region of the heart
thick layer of myocardium, full of cardiac musscle. thick layer of epicadrdium, and often has lots of adipose tissue and viens etc. and of course there is a endothelium layer that is thinner in the ventricle
what are the layers of the atrium from the chamber outward
endocardium; myocardium; epicadrdium
what ar the layers of the ventricle from the chamber outwadrd
endocardium, myocardium and epicardium
What type of tissue actually causes the contraction?
the myocadrdium layer of the ventricle or the atrium
What is the generation of the electrical signal in the heart
specialized cardiac myocytes
what is a purkinge fiber?
the fibers that conduct depolarization from the nodes into the ventricles to initiate electrical activity and contraction.
What is the general look of purkinge fibers
very large cells, they have a large amout of glycogen that looks light colored, and have almost a swirly look to them.
how is the heart an endocrine organ
they synethize atrial natriuretic peptide, ANP
what is the purpose of ANP in the heart?
to heljp to control blood pressure
what will cause the release of ANP?
high blood pressure
What does ANP do to lower the blood pressure
stimulates siduum loss from the blood and into the urine, the water will follow sodium, there fore blood volum down and pressure down. relxes vascular smooth muscle. inhibits the secretion of hormones involved in sodium and water retention in the kidneys.
where is ANP stored?
in secretory ganules in myocytes in the heart cells. they look like fuzzy islands of red smeers in the myocites in the atrium.
how does the ANP get released in the body
from the cappilaries in the atrium
What is anoter name for ANP?
ANF (factor)
what is hypertrophy?
cells get bigger
how could hypertrophy happen in the heart?
there is back pressure or other pressure on the heart as it pushes the blood out and the heart responds by makeing the cells much bigger than they would normally be.
what is it called if a tissue responds to stress by increasing the number of cells?
hyperplasia.
what is one of the negative effects of hypertrophy?
the heart is stiffer and the space in the ventricle is smaller and so there is less blood and it is harder to pump the heart therefore it wants to hypertrophy even more!
what is the blood velssel structure in muscular artery
there are three tunics that layer the vessel: tunic intima; tunic media; tunic adventilia
what is the structure of the tunic intima
the endothelium and the inernal elastic lamina
what is the difference in the tunic media and the tunic adventita
the tunic media is thicker for muscular artery, and denser, the adventitia is thinner and less dense with cappilaries etc.
what is the difference in the cross sectionof artery and vein?
the artery has a thick elastic lamina and a much thicker media layer
what is the funciton of the adrteries
regulate the pressure and control ditribution of oxygenated blood. Hold about 20% of the blood
what is the purpose of the capilaies?
hold 10% of the blood and exhangers (this also includes the post capillary venules
whatis the purpose of the veins
low pressure return system about 70% of blood
what is vas basorum
the blood vessels of large vessels
why would the aorta have an elastic element
to smooth out pressure pulses and create a “spreading of that energy” into the rest of the body.
what is the souce of the elastic fibers in the vessels?
the tunica media and the smooth muscle sells found there.
how does the structure change from the aorta to the muscular arteries
there is not so organized or abundant elastic fibers.
explain the layers of the muscular arteries
TI: internal elastic lamina is prominent; TM: many layer of smooth muscle, elastic fibers not as much; TA: external elastic lamina present at border, dense CT with some smooth muscle, lots of collagen
what is the characterasitcs of Moncheberg’s arteriosclerosis
there is calcification of arterial walls in the tunica media. this would stiffen the vessels and increase the blood pressure and lead to myosite incurssion in the heart.
what is the small arteries strucute
contain up to 5 or 6 layers of smooth muscle in TM
what is the strucure of the arterioles
microvasculature and 1 or 2 layers of smooth muscles in the TM.
what is the purpose of the arterioles:
regulate the dileivery of blood to capillaries, redue pressue and controll distribution. they are sometimes calle reistance cvessles and are considered primarily for blood pressure.
what are true cappillaries
the vessesls that control exchange
how is control of flow to the cappilaries
precapillary sphincters of the metarterioles.
what is a direct connection of a metarteriole to a venule?
thoroughfare channel
what are the three types of capillaries?
continuous; fenestrated, and sinusoids
what are the general characteristics of the continuous capillaries
most common type, they are linked by tight junctions (ZO) in the muscle brain and CT
what are the general characteristics of the fenestrated capillaries?
they have little openings and facilitate exhange (kiney glomerules, and choroid plexus)
what are the general characterics and location of the sinusoids capillaries
contain larger openings for even greater exhange: (liver, bone, marrow)
what is a pericytes or periendothelial cells
cells outide of the capillary on the endothelium outside
what is the purpose of the pericytes?
contraction, phagocytosis, small vessel hemostatis. and appear to offer stem cells that will repair and regenerate the cappilaries
who does stuff get in and out of cappilaries?
diffusion across the membrane (gases); samll molecule transporters; transcytosis (high MW) low in CNS; Leaks between the tight junctions (low in CNS)
What seems to be the main type of transport in the capilaries:
the transcytosis esp. in the CNS. but in other tissue and in inflamation then it is leaks between the tight junction
histamine release can case a major fluid ovement from vessels to tissues, which mechanism does it stimulate?
the lossening of the tight junctions
fenestrated capillaries
has small pores that increase fluid exchange
sinusoids
has large opening in the cappilaries to give lots of flow!
Endothelial cells of a capillary bed can regulate the amount of blood flowin into the bed by releasing signaling molecules that affect nearby:
this could be either the mearterioles or the pericytes (the metarterioles is the wanted choice)
what is unique about post capillary venules
they still have major vascular permeability
what is the distiguishing feature of the muscular venule
has a larger and lower pressure than the venule
what is the difference in venule cappilary and muscular venule?
the size of the vessel
waht is the difference in the small vein and artery?
the tunic media is very thin in the vein and the opening in the vein is larger!
what is a similunar valve?
in medium and large veins of lower extremities they are outfoldings of the TI that help prevent backflow of blood.
