1. Ch 14 & 15 Overview of Circulation Flashcards
start at slide 31
Blood flow is inversely proportional to ____
peripheral resistance ( R)
_____: ability of a blood vessel to become stretched
distensability
What vessel on the arteriol side has the more distensability
arteries
- V.’s are actually more distensable than the art.’s
blood vessels are able to dilate bc of layers of ___ btw the smooth M
elastin
Which has more distensability?: art. or V.
veins
_____: ability of the vessel to stretch & the total quantity of blood that can be stored in a given vessel
compliance
high compliance: can stretch and hold alot of blood
Low compliance: can stretch but not hold a lot of blood
compliance = ______ x______
compliance = distensability x vol
_____ collapses the artery so blood flow stops during taking BP
Systolic BP
_____sounds heard when taking BP
horotkoff
____: calc as the differ btw SBP & DBP
pulse pressure
What are the two factors that go into Pulse pressure
- how much the art. close to the heart can stretch
2. vol of blood forces into them at one time which is SV
_______: the pressure that propels the blood into the tiss
Mean arterial Pressure (MAP)
at rest more time is spent in systolic or diastolic?
diastolic
MAP = ______+ ______/3
MAP = DBP + pulse pressure/ 3
during low to moderate exercise, MAP is the ____ btw SBP and DBP
midpoint
- during rest it is more in DBP
at high intensity exercise, MAP is closer to ___ BP
systolic
_______ is why during resting conditions, 64% of all blood vol is in the venous side of circulation
blood reservoir
during rest most blood is in the ___ side of circulation
venous
c.c____: occurs when the valves in the venous system become incompetent
varicose veins
- V.s are overstretched by excessive venous pressure
during varicose veins: the ____ area of the vein increases but the ____ do not increase in size
cross-sectional area
valves
- the valves do not close completely
vessels walls have ___ layers referred to as ___
3 layers
referred to as tunics
(except in caps)
____ is the inner channel within the blood vessels
lumen
name the three vessel layers
- tunica intima
- tunica media
- tunica externa
_____: contains endothelium that lines the lumen. Forms a slick surface that minimizes friction
tunica intima
____: circularly arranged SM and layers of elastic fiBers
tunica media
- regulates vasoconstriction & vasodilation
___ is usually the thickest layer of the vessel
tunica media
____ layer regulars vasoconstriction & dilation
tunica media
_____ is composed mainly of collagen fibers
tunica externa
What three studctures does the tunica externa contain
Nerve fibers
lymphatic vessels
tiny blood vessels
_____ nurish the external tiss of the vessels. It is contained in the tunica externa
vasa vasorum
blood circulation is divided into : (2)
peripheral (systemic ) circulation
pulmonary circulation
name the series of vessels that carry blood from heart back to heart
arteries–> arterioles–> capillaries –> venules–> veins
arteries are _____ vessels for high pressure
elastic
What occurs when arteries branch into arterioles
blood pressure decreases rapidly
_____ are the narrowest vessels
capillaries
Veins have larger _____
lumen
At rest the majority of blood is in the _____
veins
The majority of blood is in the ____ system
systemic system
The heart is the \_\_\_\_\_ arteries are \_\_\_\_ arterioles control \_\_\_\_\_\_ capillaries are \_\_\_\_\_ venules and veins are \_\_\_\_
heart- pump arteries- pressure reservoirs arterioles- control blood distribution cap- exchange site V- blood reservoirs
what is the driving force to move blood through the circulatory system
difference in pressure
______: is moving from an area of higher pressure to an area of lower pressure
pressure gradient
C.O = ____x____
CO= SV x HR
What organs get most of the blood at rest
GUT , liver, kindeys
_____: when blood flows at a steady stream through Smooth vessels. Ea layer of blood remains the same distance from vessel wall
laminar flow
- blood in the center flows faster than outer layer
Laminar flow: blood in the center flows ____ than outer layers
faster
= parabolic profile
What is parabolic profile
when the laminar flow occurs, the blood in the center flows faster than outer layers
_____: when blood flow is fast and blood passes over a rough surface or obstruction
turbulent flow
_____: force per unit area exerted on the vessel wall by the contained blood
blood pressure
aterial pressure ranges from ___ to ___
120 to 80
Capillary pressure ranges from ____ on the arterial side and drops to ___ on the venule side
35 on artery
15 on venule side
_____: oopposition to flow. Measure of the friction blood encounters as it passes through the vessels
resistance
most friction is encountered as ____ resistance
peripheral resistance
_______: resistance of the entire systemic circulation (arteries- veins)
total peripheral resistance
The longer the vessels the ____ the resistance
greater
1:4 ratio length to resistance
if the diameter of the vessel doubles, flow increases by the power of ___
four
“fourth power law”
blood flows from larger ___ vessels (art) to smaller ___ vessels (capillaries)
larger series vessels
smaller parallel vessels (resistance is lower)
Name 4 sources of resistance
- blood vessel length
- blood vessel diameter
- series vs. parallel blood vessels
- blood viscosity
