生理学——血管生理.ppt

Blood distribution Vascular classification according to the function Windkessel vessel (弹性贮器血管，大动脉) Distribution vessel (分配血管，中动脉) Resistance vessel (阻力血管，小动脉，微动脉) Precapillary sphincter (毛细血管前括约肌) Exchange vessel (交换血管, 毛细血管) Capacitance vessel (容量血管，静脉系统) Shunt vessel (短路血管，动静脉吻合支) Thinking: Why is total arteriolar resistance higher than total capillary resistance? Arteriolar radius capillary radius Number of arterioles number of capillaries Systemic and Pulmonary MAP Systemic MAP 80 + (120-80)/3 = 93.3 mmHg (~100 mmHg) Pulmonary MAP 8 + (22-8)/3 = 12.7 mmHg (~15 mmHg) In 1711 Hales began his studies on blood pressure. True to his mechanistic views, he carefully measured the blood pressure of three horses and produced the first recorded estimates of blood pressure. Furthermore, he studied the pulse rates of various-sized animals and measured the hearts capacity to pump blood through the pulmonary veins. Hales also studied the effects of heat, cold, and various drugs on the blood vessels and experimented with animal reflex. 2.毛细血管的数量和交换面积 全身400亿根毛细血管。 毛细血管的密度与其代谢率或机能有关 心肌、脑、肝、肾，2500～3000根/mm3 骨骼肌 100～400根/mm3 骨、脂肪 密度较低 总的有效交换面积 1000m2。 The night before Easter Sunday of that year I awoke, turned on the light, and jotted down a few notes on a tiny slip of thin paper. Then I felt asleep again. It occurred to me at six oclock in the morning that I had written down something most important, but I was unable to decipher the scrawl. The next night, at three oclock, the idea returned. It was the design of an experiment to determine whether or not the hypothesis of chemical transmission that I had uttered seventeen years ago was correct. I got up immediately, went to the laboratory, and performed a simple experiment on a frog heart according to the nocturnal design. [...] Discovery of neurotransmitters These results unequivocally proved that the nerves do not influence the heart directly but liberate from