lecture 11 Flashcards
what are arteries
they carry blood away from the heart
do ubeliecal vesselsof the heart carry oxygentated blood
no
what are carpillaries
they contact tissues cells , they directly serve cellular needs
what do veins o
they carry blood toward the heart
what are the 3 wall layers found in arteries and veins
tunica intima
tunica media
tunica externa
what are capillaries lined with
endothelial cells
which layer in the artery or vein is slick and reduces friction
the tunica intima
which tunic influences blood flow and pressure
the tunica media
what are the tunica media made out of
smooth muscle and sheets of elastin
which of the 3 layers of arteries and veins controls vasconstriction
tunica media
what are the 3 kinds of arteries in the arterial system
elastic arteries
muscular arteries
arterioles
name the arterial system : large thick walled arteries with elastin in all 3 tunics .
large lumen
elastic arteries
names the arterial system : acts as pressure resavour , they expand and recoil as blood is injected into the heart
elastic arteries
name the arterial system : delivers blood to the body organs
muscular arteries
name the arterial system : active in vasoconstriction
muscular arteries
name the arterial system : smallest arteries
arterioeles
name the arterial system : controls flow into capillary beds via vasodiallation and vasoconstriction
muscular arteries
what are capillaries
they are microscopic blood vessels
what are the walls of capillaries made out of
thin tunica intima
name the structure that helps to stabilize the walls and control the permiability of capillaries
pericytes
is the diameter of capillary large or small? what can pass through
small , one red blood cell at a time
where are capillaries located
in all tissues except for cartilage , epithliea , cornea and lens of the eye
what are the functions of capillaries
exhcange of gases nutrients , waste, hormones between blood and interstial fluid
list the 3 structural types of capillaries
- continous capillaries
- fenestrated capillaries
- sinusoid capillaries
where are continous capillaries found
they are abundant in the skin and muscles
what does the interceullular cleft allow in continous capillaries
the passage of fluids and small solutes
are continous cappilaries found in the brain
yea
what forms a blood brain barrier
continous cappilaries
what is the function of fenestrated capillaries
the function in absorbtion or filtrate formation
where are sinsuoid capillaries found
liver , bone marrow spleen, adrenal medulla
what is microcirculation
interwoven networks of capillaries between aterioles and venules
what are the 2 types of vessels
vacular shunt and true capillaries
what is the funciton of precapillary spincter
they regulate blood flow into true capillaries
how are venules formed
formed when capillary beds unite
how are veins formed
when venules converge
do veins or arteries have thinner walls
veins
is the blood pressure lower or higher in arteries than in veins
higher arteries, lower in veins
name an adaptation of veins to allow blood to return to heart
they have a larger diameter lumen to allow for less resistance
what are venous valves,and where are they
they are on veins they prevent back flow of blood they are found on the limbs
how is blood flow measured
in ml/min
is blood flow constant when at rest or in motion
at rest
is blood flow the same for all organs
no it varies
define blood pressure
the force per unit area extered on wall of blood vessel
what keeps blood moving thorughout body
pressure gradient
what does resistance mean
opppostion to flow ,
measure of the amount of friction that blood encounters with vessel walls .
what are the sources of resistance
blood viscosity
total blood vessel length
blood vessel diameter
does a longer of shorter blood vessel have more resistance
longer = more resistance
what has the greatest influence on resistance
the blood vessel diamter
is the blood in arteries oxygenated
yes except for the pulmonary arteries and fetal umbillical arteries
which are the artieries that do not have oxygenated blood
the pulmonary arteries and the umbellical vessels of the fetus
what is the primary function of capillaries
- contact tissue cells
2. direct cellular needs
what are the smallest blood vessels
capillaries
in which blood vessel does the exchange of material happen
capillaries
what are the 3 main types of blood vessels
arteries, capilaries and veins
what are capillaries lined with
endothelial cells
which way do veins carry blood
Veins- carry blood toward the heart
is the blood in veins oxygenated or deoxygenated
. This blood is usually deoxenegated except in the pulmonary arteries.
what is lumen
Lumen- a space. this is the central space that contain the blood.
list the 3 layers that are found in blood vessels
tunica intima
tunica media
tunica externa
what is the blood vessels that does not have a 3 wall layer
capillaries
what is the function of endothelial cells
Endothelial cells- the function is to reduce friction
endothelial cells line what ?
Blood vessels capillaries and arteries are lined with this
what is the largest of the arteries
Elastic Artery- the largest of the arteries
what is the most common artery that we have
Muscular Arteries- most the arteries in our body are muscular. These are smaller than the elastic arteries
which arteries feed into the capiliaries
Arterial- these feed the capilaries
what are venules
Venule - small veins.
name the largest of the arteries of the arteries leaving the heart
.Elastic Arteries
these arteries act as pressure resavours
elastic arteries
these arteriesdeliver blood to organs
muscular arteries
these artieries are active in vasoconstrictions
musclular arteries
these arteries are the smallest of the arteries
arterials
these arteries are the most responsive in local regulation
arterials
which arteries have laumen , and what does this offer
elastic, low resistance
which arterial system controls blood flow into capillary beds
arterioles
what are the 2 mechanisms that control blood flow
vasodialation
vasoconstriction
what are capillaries
they are microscopic blood vessels
what is the primary function of capillaries
these are for microcirculation.
are capillaries wide or narrow
the capillaries are very narrow, it is so small that only one red blood cell can go through
what are pericytes
pericytes are cells that help to stabilize the walls of the capillaries , and help to control their permeability
what helps to control the permiability of capillaries
pericytes
whar are the 3 types of muscle
smooth cardiac skeletal
where are capillaries found
capilaries are found in all tissues of the body except for cartilage, lens of the eye and cornea and epithelial
what are capillary beds
Capillary beds allow for access and exchange of materials with just about every cell in the body.
blood enters capillary system, and then exchange happens through simple diffusion
what kind of diffusion happens in capillary beds
simple diffusion
what are the function of capillaries
The function of the capillaries are to help in the exchange of gases nutrients waste and hormones
list the 3 types of capillareis
- continuous capillaries (least permeable )
- fenestrated capillaries
- sinusoid capillaries (most permeable)
They have similarities but they differ in respect to their permeability.
where are continous capillaries found
abundant in our skin and muscles
what does it mean to say that something is a tight junction
there are tight junctions - they connect to other
These capillaries are the most common and least permeable
Continuous Capillaries
where are fenestrated capillaries found
they are found in kidneys
what are fenestration s
fenestrations are pores
what is the function of a fenestration
the function of the pores is to increase the permeability
where are sinousoid capillaries found
They are only found in liver,
what is an arterial
arterials = arteries that connect with capillary beds
list the 2 kinds of vessels that are found in capillary beds
within the capillary beds there are 2 types of vessels:vascular shunt or true capillaries
what is a metaarterial
metaarterial - not quite an capillary or an artery
what is capillary sphincter
within capillary beds there are true capillary sphincters.
The sphincters open and close. If they are opens, blood flows through the capillary beds, where it flows into a vein.
If they are closed, it does not flow into the capillary beds
this thing regulates blood flow into true capillaries
precapillary sphincter
after blood flows thorugh the capillary system where does it go
it flows into the venoles
what are venules
Venules are small veins
veins have…walls and …lumen compared to …
veins have thinner walls and larger lumen compared to to ateries
which has lower blood pressure, veins or arteries
blood pressure is lower in veins
name 2 adaptations to help blood flow in veins
The body has adaptations to help flow blood: larger diameter lumen , they also have venous valves which prevents backflow of blood. Venous valves are found in the veins of the limbs.
why do vercose veins happen
Verecose veins - happens because of backflow of blood in the arteries. being on your feet a lot can cause these. Not having a high fiber diet, or having a baby can cause hemmroids which are vercous veins in the butt.
what is the name of the valve that prevents backflow of blood in veins
venous valves
what does blood flow mean
Bloodflow- the volume of blood flowing through an organ or vessel. It is measured as ml per minute. It is a measure of cardiac output. blood flow can vary based on what you are doing.
define blood pressure
blood pressure - force per unit area that exerted on wall of a blood vessel. It is expressed in ml off mercury. we measure it as large arteries near the heart. Blood pressure is what keeps blood pumping through the heart. As blood moves further away through the heart there is less pressure, but as long as there is a gradient it will flow.
what does resistance mean
Resistance- it is a measure of the amount of friction that blood is going to encounter in vessel walls.
what 3 things effect resistance
length ( the longer it is, the more resistance) diameter ( this offers the greatest amount of resistance the larger the diameter, the greater the velocity of the flow) and viscosity (increased viscosity = increased resistance) are factors that affect resistance
as resistance increases , what happens to blood flow
Resistance increases, blood flow decreases.
what causes blood flow
the pumping action of our heart is what causes blood flow
what does blood viscosity refer to
the stickiness of blood
what can make blood very sticky
plasma proteins
what does a longer blood vessel mean in terms of resistance
longer vessel = greater resistance
what has the greatest influence on resistance
blood vessel diameter
if lamaniar flow is disrupted what kind of flow will occur
turbulant flow
is there more pressure in arteries or veins
There is a lot more pressure in the arteries in the veins!!!!
what kind of relationship does blood flow and blood pressure have
blood flow is directly proportional to blood pressure gradient
what kind of relationship does blood flow and peripheral resistance have
blood flow is inversely proportional to peripheral resistance
is resistance increases ,what happens to blood flow
blood flow decreases
how is pressure formed
when flow is opposed by resistance
where is systemic pressure the highest
in the aorta
what factors affect arterial blood pressure
- how much eleastic arteries close to the heart can stretch
- the volume of blood forced into them at any one time
what is the diostolic pressure
the lowest level of arotic pressure
what is pulse pressure
the differene between systolic and diastolic pressure
what is mean arterial pressure
pressure that propels blood tissues
how do you calculates MAP
Diastolic pressure + 1/3 pulse pressure
do pulse pressure and MAP increase or decrease with distance from the heart
decrease
what is the standard range for capillary blood pressure
17 to 35 mmhg
do we want low or high capillary blood pressure
low
why is high capillary blood pressure bad
high capillary blood pressure is bad because it would rupture thin walled capillaries
are capilaries usually permiable or impermiable
permeable
does venous blood pressure change a lot during the cardiac cycle
no
is venous presssure usally high
no , due to the cumulative effects of resistance
list the 3 factors aiding in venous returns
- muscular pump
- respiratory pump
- venoconstriction
describe the muscular pump interms of venous retuens.. what does it do
muscular pump: the contraction of skeletal muscles contracts the and it “milks” blood towards the heart
describe how the repiratory pump works interms of venous returns
pressure changes during breathing move blood toward the heart by squeezing abdomincal veins
explpalin venoconstriction in terms of venous return
it pushes blood toward the heart
what 4 things are involved in maintaining blood pressure
cooperation of the heart , blood vessels, kidneys and supervsion of the brain
list the 3 main factors influencing blood pressure
cardiac output
periipheral resistance
blood volume
where is the radial pulse taken
at the wrist
what method do we use to measure blood pressure
the auscultory method
what instrument do we use to measure blood pressure
spyhmomonameter
what is the name of the sound that we listen for when taken blood pressure
sounds of korotokoff
what number should your systolic pressure be at
less than 120
what sould your didstolic pressure be
80
is the artery restricted when you are hearing the distoic pressure
no , the artery is not free and blood is flowing freely
list some thing that can cause blood presrue to vary
sex, age, race, weight
what is hypertension
high blood pressure
what numbers do you have to have to be considered highblood pressure
sustained values of 140/90
why is hypertension bad
heart works harder, myocardium enlarges, weakens and becomes flabby.
what are some factors that contribute to primary hypertension
heredity , diet, obeiesity, stress , smoking
can primary hyptension be cutred
no , but it can be controlled
what is hypotension
low blood pressure
wha tis the average for hypotension
90/60
is hypotension a concern
no
what 5 things is tissue perfusion involved in
delivery of o2 removal of waste gas exchange absorbtion of nutrients urine formation
where is blood flow the fastest
in the aorta
where is blood flow the slowest
in the capillaries
name a reason why blood flow is slow in the capillaries
it allows for adequte time for exchange between blood and tissues
do blood flow at the same rate for all skeletal muscles
no
