Download 21.1: Blood Vessels - Jordan High School

CHAPTER 21
Blood Vessels & Circulation
21.1: Blood Vessels
• Vessel types from heart & back
Structure of Vessel Walls
• Tunica intima vs. tunica media vs.
tunica externa
• Know differences in each vessel
wall between arteries & veins
(Figure 21-2)
Arteries
• Vasoconstriction vs. vasodilation
• Know differences in elastic
arteries, muscular arteries &
arterioles
• Arteriosclerosis—pg. 712 – 713
Capillaries
• Permit gas exchange
• Capillary beds join arterioles;
empty into venules
Veins
• Know differences in venules,
medium-sized veins & large veins
• Function of valves in veins
Distribution of Blood
• Heart, arteries, capillaries: 30 –
35% of blood volume; venous
system contains rest
• Capacitance vessels accommodate
changes in blood volumes
21.2: Capillary Exchange
• Pressure & resistance
• Inc. pressure  inc. flow
• Inc. resistance  dec. flow
Pressure
• Blood pressure (BP) vs. capillary
hydrostatic pressure (CHP) vs.
venous pressure
• For circulation to occur, circulatory
pressure must overcome total
peripheral resistance
Total Peripheral Resistance
• Vascular resistance
• Length vs. diameter; effects
• How blood viscosity & turbulence
increase resistance
• Pressures in vessels (Figure 21-11)
Arterial Blood Pressure
• Systolic vs. diastolic pressures
• Hypertension vs. hypotension
Venous Pressure & Return
• Venous return has direct impact
on cardiac output
• Muscular compression &
respiratory pump
Capillary Pressure & Exchange
• Differences & functions of
diffusion & filtration
• Hydrostatic pressure forces water
out of solution; osmotic pressure
draws water into solution
21.3: Cardiovascular
Regulation
Autoregulation
• Vasodilators accelerate blood flow
• Know examples
Neural Mechanisms
• Cardiac centers & vasomotor
centers of medulla oblongata
• Cardioacceleratory / -inhibitory;
control of vasodilation /
vasoconstriction
• Baroreceptor reflexes
• ↑ BP = ↓ CO, vasodilation
• ↓ BP = ↑ CO, vasoconstriction
• Chemoreceptor reflexes
• ↑ CO2 or↓ pH = ↑ CO, ↑ BP,
vasoconstriction
21.4: CVS Responses
CVS Response to Exercise
• How cardiovascular system & body
responds to light & heavy exercise
• More fit heart = ↑ SV, slower HR
• Know benefits of exercise in
reducing cardiovascular disease
CVS Response to Hemorrhaging
• Short-term elevation of BP
• ↑ CO, vasoconstriction
• Continual blood loss promotes shock
• Long-term restoration of blood
• Fluid retention, release of EPO
Vascular Supply to Special
Regions
• Blood transferred to brain, heart,
& lung tissues
21.5: Pulmonary &
Systemic Circulation
• Pulmonary circuit vs. systemic
circuit
• Patterns of blood vessel
organization
• R & L sides generally identical
• Vessels have several names
• Several arteries & veins supply
organs & tissues
21.6 – 21.7: Pulmonary &
Systemic Vessels
• Know major blood vessels of
pulmonary circuit; general
function
• Know major blood vessels of
systemic circuit; general function
• Think vessels learned during cat
dissection!