blood vessels Flashcards
every human has _______ miles of blood vessels
60,000
true/false: you can see most blood vessels
false (most are microscopic)
type of vessel: closest to the heart; carry blood AWAY from the heart
artery
2 types of arteries:
- elastic
- muscular
type of artery with the largest diameter and less resistance, walls have elastic CT which enables it to bounce back and continue to push the pressure
elastic artery
type of vessel: littel arteries
arterioles
type of vessel: site of gas and nutrient exchange
capillaries
type of vessel: little veins; bring blood back now
venules
type of vessel: furthest from the heart; bring blood back to the hearty
veins
as you move away from the heart, what trends occur in blood vessels (2)?
- diameter decreases
- less elastin, more muscle fibers
arteries have more ____ _____ than veins
smooth muscle
sympathetic nervous system uses ______ to stimulate smooth mucle contraction and ultimately VASOCONSTRICTION
norepinephrine
you can change the diameter of blood vessels (and where blood goes) _____ and ______
chemically and neurally
endocardium layer of blood vessels is made out of ____ _____ _____ tissue
simple squamous epithelium
layers of blood vessels (4):
- tunica interna
- tunica media
- tunica externa
- lumen
layer of blood vessel: superifical layer; lines the lumen; made of simple squamous epithelium tissue; connected so its a smooth, flat surface
tunica interna
tunica interna becomes _____ so it is still made out of simple squamous epithelium
endocardium
layer of blood vessel: middle layer; smooth muscle
tunica media
tunica media is made out of _____ _____ tissue
smooth muscle
layer of blood vessel: outer layer; lots of collagen; ANCHORS blood vessels in place
tunica externa
blood vessels in the walls of very thick-walled blood vessles; in tunica externa
vasa vasorum
tunica externa has lots of _____
collagen
layer of blood vessel: most “deep;” space within blood vessels
lumen
capillaries only have _____ ____ layer for exchange purposes, while all other blood vessles have all of the layers
tunica interna
microscopic blood vessels; cells have to go through single file; makes exhange more efficient; only have tunica interna
capillaries
extra cells that stablize capillaries
pericytes
type of capillary: MOST COMMON; contains endothelial cell junctions and pinocytic vessels
continuous capillaries
continous capillaries are tightly packed except for spaces for fluid exchange called ____ _____ _____
endothelial cell junction
vessicles that transport liquids; continuous capillaries use these
pinocytic vessicles
types of capillaries (3):
- continuous
- fenestrated
- sinuosoidal
type of capillary: have holes; much more permeable; greater rate of exchange; don’t allow BIG things to pass; found in areas where filtration and absorption occur
fenestrated capillaries
what are the holes within fenestrated capillaries called?
fenestrations
examples where fenestrated capillaries are found (3):
- endocrine organs
- capillaries in intestines (absorption)
- capillaries in kidneys (filtration)
type of capillary: have BIGGER holes; allow proteins and cells to pass
sinusoidal cappilaries
what are the holes within sinusoidal capillaries called?
sinuciods
examples of where sinusoidal capillaries are found (3):
- spleen
- liver
- bone marrow
capillary bed: arteriole that FIRST delivers blood to met arteriole
terminal arteriole
capillary bed: short-cut
vascular shunt
capillary bed: first half of short-cut
metarteriole
capillary bed: second half of short-cut
thoroughfare channel
______ + _____ ___ make up the vascular shunt (short-cut) in the capillary bed
metarteriole + thoroughfare channel
capillary bed: rest of capillaries (other than the short-cut)
true cappilaries
capillary bed: regulatory mechanism that opens and closes capillaries; only specific capillaries; regulates amount of blood that passes AND where it goes
precapillary sphincters
capillaries are known as “________ _______”
“microcirculation controllers”
most of our blood at any given second is in our _____
veins
____% of our blood is in our veins at any given second
65%
artery or vein? : thick walls
artery
artery or vein? : small lumen
artery
artery or vein? : thicker tunica media
artery
artery or vein? : lower blood volume
artery
artery or vein? : higher blood pressure
artery
artery or vein? : no valves
artery
artery or vein? : thin walls
veins
artery or vein? : large lumen
vein
artery or vein? : thinner tunica media
vein
artery or vein? : higher blood volume
vein
artery or vein? : lower blood pressure
vein
blood pressure is lowest in ____ _____
large veins
artery or vein? : venous valves
vein
valves that assist in the flow blood back to the heart
venous valves
people who stand a lot get ____ _____
varicose veins
additional modifications that aid in blood flow include (2):
- muscular pump
- respiratory pump
additional modification: contraction of skeletal muscle to aid blood flow back to the heart under LOW blood pressure
muscular pump
additional modification: aid in return of blood back to the heart due to the thoracic changes in chest (pressure changes)
respiratory pump
our chest _____ in low pressure
expands
collateral channels form a _______ (merging of blood vessels)
estimosis
volume of blood that flows through the body at any given time; relatively constant but changes WHERE it goes (ex: after dinner – abdominal organs; a tiger is lose – muscles)
blood flow
blood flow is directional proportionate to differences in blood ______
pressure
increase the difference in blood pressure, the _____ the blood flow
greater
blood flow is inversely proportional to _____ ______
peripheral resistance
opposition of blood flow due to friction
peripheral resistance
peripheral resistance: the smaller the blood vessel, the more _____
friction
type of peripheral resistance: thickness of blood; doesnt change in an instant; could have an effect but NOT a major regulator
blood viscosity
type of peripheral resistance: longer the BV, the more resistance, the slower the flow; NOT changed in an instant
vessel length
the _______ the BV, the more resistance, the slower the flow
longer
type of peripheral resistance: regulator mechanism in bodies; we can change this***
vessel diameter
the bigger the diameter = the ________ resistance and ____ flow
less resistance
greater flow
the smaller the diameter = the ______ resistance and _____ flow
more resitance
less flow
BP _____ as you move away from the heart
decreases
BP is highest in ____
arteries
BP is lowest in _____ _____
large veins
steepest drop in blood pressure occurs in the _______
arterieoles
why does the steepest drop in BP occur in the arterioles?
- super small diameter creates GREATER resistance
- good for exchange; slow for diffusion
difference between diastolic and systolic pressure; disappears as you travel away from heart
pulse pressure
“driving force” that determines where blood goes; pressure that propels blood to tissues
mean arterial pressure (MAP)
MAP (equation) =
diastolic pressure + (pulse pressure / 3)
counteracting brief fluctuations of BP (2):
- alter blood distribution to respond to needs (amount of blood)
- alter vessel diameter (vasoconstriction and vasodilatation)
a portion of the medulla oblongata; SYMPATHETIC nerve fibers; uses NE to cause muscle to constrict and for VASOCONSTRICTION to occur
vasomotor center
vessel diamter is activiely regulated by ______ ______, sympathetic nerve fibers that innervate the bessel’s smooth muscle layer
vasomotor fibers
vasomotor fibers release _____, a powerful vasoconstrictor
norepinephrine
blood vessel diamter is also reulated by blood-borne _______
vasocontrictors
how do you calculate pulse pressure?
systolic pressure - diastolic pressure
average diastolic pressure
80
average pulse pressure
40
everage MAP
93 (below average)
blood goes from _____ MAP to _____ MAP
hi MAP —> low MAP
more blood goes to a _____ difference in MAP
larger
true/false: there is temendous integration of regulators; theres a lot of things that function together to regulate blood
true
there are many ____-term regulators of blood pressure, but only ONE ____-term regulator of BP
many short-term
ONE long-term
vasoconstriction occurs in what 2 ways:
- nerve impulses
- hormones
when vasoconstriction occurs: BP _____
increases
when vasodilation occurs: BP _____
decreases
how does vasoconstriction or vasodilation occur?
smooth muscle (in tunica media) is stimulated to either contract or relax
constant neural impulses that cause blood vessels to be PARTIALLY constricted to allow them to be able to dilate – greater control!
vasomotor tone
in the body, their are sensory receptors for _____ AND _____ in order to control BP in a short-term fashion
pressure AND chemicals
sensory receptors for pressure
baroreceptors (neural reflex arc)
sensory receptors for chemicals
chemoreceptors (chemical reflex arc)
neural reflex process (4)
1) baroreceptors detect change in BP (ex: detect high BP)
2) vasomotor center inhibited
3) peripheral resistance reduced = vasodilation
4) pressure reduced
side effects of neural arc when BP is high and then is lowered (5):
1) venous return is reduced (amount of blood going back to the heart is reduced)
2) cardiac output is reduced
3) heart rate is reduced
4) contractile force is reduced (bc of less stretch)
5) MAP declines
true/false: the body is self-correcting whenever BP is very high or very low
true
RESULTS of side effects of neural arc when it corrects hi BP and results in low BP (3):
- reduced MAP initiates vasoconstriction
- increases cardiac output
- BP rises
chemical reflex arc process (
1) chemoreceptors detect drop in:
- drop in oxygen
- pH change
- increase in CO2
2) cardioacceleratory center is stimulate + HR increases
3) vasomotor center stimulated
4) BP increases
what can chemoreceptors detect in the blood (3)?
- oxygen concentrations
- pH
- CO2 concentrations
chemoreceptors detect changes in the ______ of certain molecules or pH
concentration
true/false: we have the same chemoreceptors for monitoring different things in our blood
false! (we have different ones for different things)
chemical reflex arcs cause a ______ event
autoregulatory
when excess CO2 is in the blood, pH ______
decreases
when a lot of CO2 LEAVES the blood, pH _____
increases
other chemical controls (other than oxygen, CO2, and pH)
norepinephrine and epinephrine
epinephrine comes from the _____ ______ and NE is mostly _____
adrenal medulla
neural
vasoconstriction or dilation occur due to certain _______
stressors (aka neural or hormonal)
other chemical controls of BP: chemical secreted by the heart when systolic BP is high and atrial is stretched
Atrial Natriuretic Peptide (ANP)
ANP =
Atrial Natriuretic Peptide
effects of ANP (2):
increased glomerular filtration + increased renal excretion/urinary output
other chemical control of BP: produced by posterior pituitary gland; affects actions of the kidneys; decreases blood volume through greater reabsorption in the kidneys in order to DECREASE blood pressure
antidiuretic hormone (ADH)
ADH =
antidiuretic hormone
other chemical control of BP: produced by the liver and is activated by renin (produced by kidneys); causes vasoconstriction and reabsorption in the kidneys to increase plasma volume (by aldosterone)—-> INCREASE BP
angiotensin II
angiotensin II is ultimately produced by the _____ and is activated by _____ (which is produced by the _____)
liver
renin; kidneys
effects of angiotensin II (2):
- vasoconstriction
- reabsorption in kidneys
other chemical control of BP: chemicals produced and released by blood vessels themselves that change diameter of blood vessels (through cells that line BVs)
endothelium-derived factors
other chemical control of BP: decrease BP (sometimes lethally), increase permeability, and change blood volume; ex: histamine
inflammatory chemicals
other chemical control of BP: toxic chemical you drink
alcohol
effects of alcohol regarding BP (4):
- decrease blood volume
- decrease BP
- inhibits vasomotor center = causes VASODILATION
- also causes direct vasodilation to blood vessels
alcohol ultimately _____ BP
decreases
other chemical control of BP: has the same effects as NE and epinephrine; INCREASES BP
nicotine
ONLY long-term regulation of BP =
renal regulation
effects of renal regulation (3):
- alters blood volume
- changing blood volume decreases BP
- changing blood volume also causes kidneys to eliminate water
hi blood volume = ____ BP and causes _______________-
high BP
kidneys to work to decrease blood volume
two mechanism of renal regulation:
- direct mechanism
- indirect mechanism
type of renal mechanism: INCREASE in blood pressure or volume speeds up filtration and rate in kidneys
direct renal regulation
direct renal regulation, it is ____ itself that causes changes in filtration and urine output e
BP
direct renal regulation: high BP —> more filtration —-> more fluid accumulation —-> more ____ ____
urine production
indirect regal mechanism is also called the ____ _____ _____
renal angiotensin mechanism
type of renal mechanism: stimulated by DECREASE in BP
indirect renal mechanism (renin angiotensin mechanism)
process of renin angiotensin mechanism (indirect renal mechanism -
1) decrease in BP causes kidneys to release renin
2) renin stimulates angiotensin II production
3) angiotensin II stimulates aldosterone production (causes reabsorption of sodium, and then water)
4) BP rises
