Lec 21 Flashcards
Each side of heart function as
Independent pump
Elastic systemic arteries are
Pressure reservoir
Systematic veins are
Volume reservoir
In arterioles
Adjustable screws=variable resistance
Lower resistance = higher diameter= lower BP
screw=sympathetic effect
In venules, BP
Is low
Artery tissues
High smooth
High elastic
Medium fibrous
Low epithelium
Arteriole tissues
High smooth
Low epithelium
Capillaries tissue
One layer epithelium
Venule tissue
Medium fibrous
Low epithelium
Vein tissue
Medium fibrous
Medium elastic
Medium smooth
Low epithelium
Cardiac output at rest vs exercise
5.8 L//min
Vs
25.6 L/min
During exercise less blood goes to
Brain/kidney/GI
Most of blood goes to
88% to skeletal muscle
Resistance to blood flow increase as
Radius decrease
Vasodilation
Decrease resistance
Vasoconstriction
Increased resistance
Larger tube
Slower blood flow
Veloctiy of blood flow will
Increase as blood flow rate increase
Decrease as tubes get larger
Blood pressure through circulation,
loose pressure
losing pressure in circulation called
pressure gradient
Pressure lost through circulation is due to
Friction
Friction in circulation is between
blood And vessel walls
friction in vessel walls increase as their diameter
decrease
flow is proportional to
pressure gradient
flow is inversely proportional to
resistance
F(flow) formula is
dP/R
veins selectively —- to increase flow to skeletal muscle
Vasodilate
Mean systematic blood pressure is caqlculated via
avg btw systolic and diastolic pressure
Mean systematic pressure when 120/80
93
Pressure gradient of blood is generated by
Cardiac contractions
Thick, elastic arteries are
pressure reservoir
thin, expandable veins are
volume reservoir
Venous return
flow of blood into right atrium from peripheral vessels
valves ensure — flow
one-way
how valves ensure of one-way flow
1- valves in veins prevent backflow
2- when skeletal muscle compresses the veins, they pushes the blood toward heart skeletal muscle pump
capillaries has —- individual diameter but —- total cross sectional diameter
smallest
largest
what determine velocity of blood flow
TOTAL cross sectional area of vessels
higher total cross sectional will lead to —- blood flow
slower
CApillary bed is available all the time in every region?
No
Precapillary sphincters open/close capillaries in response to
metabolic condition
Metarteriols
divert blood flow if sphincters are closed
Metarterioles can act as
Bypass channels
Capillaries are —- to some degree
leaky
non leaky capillaries in –
brain tissue
capillary density is related to
metabolic activity cellls
capillaries tissue is
single layer flattened epithelial tissue
leak in capillaries is from —- to —-
blood to interstitial cells
what leaks from blood?
-gases
-water
-ions
-rarely protein
how much filtered out of capillaries
3L/day
excess tisuue fluid is picked up by
lymphatic vessels
lymph returns excess tissue fluid to
venous circulation at subclaivian vein
During ventricular ejection, blood presuure
will cause arteries to stretch and expand and store pressure in elastic walls
During isovolumc ventricular relaxation, how blood goes forward
the pressure that was stored in elastic walls, will recoil to maintain pressure
