1. CHAPTER 21 Blood Vessels & Circulation

2. 21.1: Blood Vessels Vessel types from heart & back Structure of Vessel Walls Tunica intima tunica media tunica externaTunica intima vs. tunica media vs. tunica externa Know differences in each vessel wall between arteries & veins (Figure 21-2)

3. Arteries Vasoconstriction vasodilationVasoconstriction vs. vasodilation elastic arteriesmuscular arteries arteriolesKnow differences in elastic arteries, muscular arteries & arterioles Arteriosclerosis—pg. 712 – 713 Capillaries Permit gas exchange Capillary beds join arterioles; empty into venules

4. Veins venules medium-sized veins large veinsKnow differences in venules, medium-sized veins & large veins valvesFunction of valves in veins Distribution of Blood Heart, arteries, capillaries: 30 – 35% of blood volume; venous system contains rest Capacitance vesselsCapacitance vessels accommodate changes in blood volumes

6. 21.2: Capillary Exchange Pressure & resistance Inc. pressure  inc. flow Inc. resistance  dec. flowPressure Blood pressure (BP) capillary hydrostatic pressure (CHP) venous pressureBlood pressure (BP) vs. capillary hydrostatic pressure (CHP) vs. venous pressure total peripheral resistanceFor circulation to occur, circulatory pressure must overcome total peripheral resistance

7. Total Peripheral Resistance Vascular resistanceVascular resistance Length vs. diameter; effects turbulenceHow blood viscosity & turbulence increase resistance Pressures in vessels (Figure 21-11) Arterial Blood Pressure Systolic diastolic pressuresSystolic vs. diastolic pressures Hypertension hypotensionHypertension vs. hypotension

9. Venous Pressure & Return Venous return has direct impact on cardiac output Muscular compression respiratory pumpMuscular compression & respiratory pump Capillary Pressure & Exchange diffusion filtrationDifferences & functions of diffusion & filtration out of intoHydrostatic pressure forces water out of solution; osmotic pressure draws water into solution

10. 21.3: Cardiovascular Regulation Autoregulation VasodilatorsVasodilators accelerate blood flow Know examples Neural Mechanisms Cardiac centers vasomotor centersCardiac centers & vasomotor centers of medulla oblongata Cardioacceleratory / -inhibitory; control of vasodilation / vasoconstriction

11. Baroreceptor reflexesBaroreceptor reflexes ↑ BP = ↓ CO, vasodilation ↓ BP = ↑ CO, vasoconstriction Chemoreceptor reflexesChemoreceptor reflexes ↑ CO 2 or↓ pH = ↑ CO, ↑ BP, vasoconstriction

14. 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

15. CVS Response to Hemorrhaging Short-term elevation of BP ↑ CO, vasoconstriction shockContinual 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

16. 21.5: Pulmonary & Systemic Circulation Pulmonary circuit systemic circuitPulmonary circuit vs. systemic circuit Patterns of blood vessel organization R & L sides generally identical Vessels have several names Several arteries & veins supply organs & tissues

17. 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!