醫(yī)學(xué)教學(xué)課件：心臟之后的 血管生理

1、Regulation of Cardiovascular Activities Nervous Regulation Innervation of the heart Cardiac sympathetic nerve Cardiac vagus nerve 1. 起源origin 2. 節(jié)前纖維preganglionic fiber 3. 外周神經(jīng)節(jié)ganglion 4. 節(jié)后纖維postganglionic fiber 5. 支配distribution 6. 遞質(zhì)neurotransmitter Cardiac sympathetic actions Positive chronotro

2、pic effect正性變時(shí)作用 Positive dromotropic effect正性變傳導(dǎo)作用 Positive inotropic effect正性變力作用 Cardiac mechanisms of norepinephrine Mechanisms of norepinephrine increase Na+ the CVCC determines autonomic output to the heart. i.e., MAP is above homeostatic set point i.e., reduce cardiac output Reflex pathway Ty

3、pical carotid sinus reflex Maintaining relatively constant arterial pressure, reducing the variation in arterial pressure Physiological Significance Humoral Regulation Vasoconstrictor agents Vasodilator agents Renin-angiotensin system Juxtaglomerular cell Renin Constricts resistance vessels Acts upo

4、n the adrenal cortex to release aldosterone Stimulates the release of vasopressin Facilitates norepinephrine release from sympathetic nerve endings Stimulates thirst centers within the brain Physiological effects of angiotensin II Epinephrine this increases the rate of flow through the lumen. From:

5、http:/www.umm.uni-heidelberg.de/inst/cbtm/kphys/research-schubert.html Universitt Heidelberg Fakultten Medizinische Fakultt Mannheim CBTM: Kardiovaskulre Physiologie From: AJP - Heart October 2008 vol. 295 no. 4 H1505-H1513 Metabolic mechanism Any intervention that results in an inadequate oxygen (n

6、utrient) supply for the metabolic requirements of the tissues results in the formation of vasodilator substances which increase blood flow to the tissues Metabolic mechanism Lack of oxygen? Formation of vasodilators? Combination of both? Metarteriole Precapillary Sphincter Capillary Relaxation of sm

7、ooth muscle Increased Blood Flow Metabolic mechanism Hypoxia Tissue metabolites and ions Adenosine Potassium ions Carbon dioxide Hydrogen ion Lactic acid Inorganic phosphate Mary rose quickly from her bed to answer the door. This change in body position resulted in: A. Increased dilation of peripher

8、al blood vessels B. Decreased firing of the carotid baroreceptors C. Increased parasympathetic stimulation of the SA node D. Unchanged venous return Total peripheral resistance decreases in a runner during strenuous exercise due to: A. increased parasympathetic nervous stimulation of the working ske

9、letal muscle B. increased vasoconstriction of the large veins of the body C. increased metabolites in the IS surrounding the muscle If two liters of blood are lost from the body, arterial hypotension occurs. This can lead to the movement of fluid from the tissues into the capillaries in response to: A. Higher capillary hydrostatic pressure B. Lower capillary hydrostatic pressure C. Higher capillary oncotic pressure D. Lower capillary oncotic pressure Does