Blood vessel Flashcards
BP =
cardiac output x total peripheral resistance
what are collateral arteries?
blood supply that develops overtime to support others that aren’t working
what are functional end arteries?
ineffectual anastomoses
what is the tunica interna?
inner most layer of blood vessels
-simple squamous
what is tunica media?
thickest layer of blood vessels
-smooth muscle fibers
what is the tunic externa (adventitia)?
outer layer of blood vessels
-areolar CT (collagen and elastic fibers)
what is a vaso vasorum?
blood vessel that feeds a blood vessel
what autonomic innervation do peripheral blood vessels have?
ONLY sympathetic
- controlled by increase or decrease of sympathetic input
- relative vasodilation
how are veins different than arteries?
arteries have thicker tunica media
veins have thicker tunica externa
arteries lumen remains open
veins lumen may collapse
what is a sinus?
thin walled venous vessel without valves
do you have perfusion during diastole?
yes, when elastic arteries recoil after being filled
when do you use MAP?
iCU heart medicine
what is arteriosclerosis?
stiffening of the arteries that occurs with age
which type of vessel contributes most to blood pressure?
arterioles
what is the job of the arterioles?
regulates blood flow into the capillary beds
what is the relationship between flow (F) and pressure (P) and resistance (R)
INC F = INC P
INC F = DEC R
when would you have active hyperemia?
when increased metabolism is present
what local factors would cause arteriolar smooth muscle relaxation?
decreased oxygen increased CO2 increased H+ increased adenosine increased K+ increased eicosanoids increased bradykinin increased NO increase osmotically active products
what are eicosanoids?
prostaglandins and leukokines
where would active hyperemia be needed most?
skeletal muscle
cardiac muscle
glands
what is the idea of flow autoregulation?
homeostasis of the blood flow in the arteriole that supplies that particular organ
what is a myogenic response?
when a vessel stretches it automatically contracts
what causes a myogenic response?
changes in Ca movement in the smooth muscle
what is a continuous capillary?
intercellular clefts
tight junctions
found in skeletal muscles, smooth muscles, skin, lungs, CNS
***most common type
what is a fenestrated capillary?
contains pores along with intercellular clefts
found in kidney (glomerulus) , microvilli, choroid plexus, ciliary body of the eye and glands
what is a sinusoid capillary?
large intercellular clefts and discontinuous capillaries, interrupted basement membrane
found in red bone marrow, spleen**, liver, adenohypophysis, parathyroid, adrenal
when does a venule become a vein?
when it reaches diameter of 100 micrometers
which are the peripheral veins?
those that are outside the chest cavity
where is most of the blood at any given time?
venous system (64%)
what four things cause venous blood to flow?
valves
skeletal muscle contraction
respiratory contractions
pressure gradient between venous system and RA
what is the function of bulk flow?
distribution of the extracellular fluid volume
where is most of the fluid in the body?
intracellular
where is most of the extracellular fluid?
interstitial fluid
what is net filtration pressure?
difference between capillary pressure and interstitial fluid
= 10mmHg at the artery end
=-9 mmHg at the venous edn
what causes edema/ascites?
lack of albumin causes fluid to stay outside the plasma and not get sucked back in
where are baroreceptors located?
aortic arch
carotid sinus
what CN do baroreceptors use to communicate?
CN IX and X
where do parasympathetic fibers go to the heart?
SA and AV node
what is the response when baroreceptors are stretched?
increased para sympathetic (lower heart rate) decreased sympathetic (normalize blood vessel diameter)
what is the response when baroreceptors decrease stretch?
decrease parasympathetic increase sympathetic (travel to SA, AV and myocardial cells, peripheral blood vessels-alpha1 receptor)
