[基础医学]第三节 血管生理.ppt

年轻人正常值 SP : 100~120mmHg DP : 60~90mmHg PP : 30~40mmHg MAP : 100mmHg 平均动脉血压≈ 舒张压+1/3脉压 循环系统平均充盈压：7mmHg 生理差异：随年龄增长而升高，收缩压比舒 张压升高明显 血液从主动脉流向外周时，由于不断克服阻力，动脉血压逐渐降低。 a 主A （100mmHg ,13.3kPa) b 3mm 动脉（95mmHg,1Lb kPa) c 小动脉未（85mmHg,11.3kPa) d 微A （55mmHg,7.3kPa) e 毛细血管起始端（30mmHg, 4.0kPa) 血压降落的幅度和该段血管对血流的阻力大小成正比 Blood pressure in different blood vessels. 影响动脉血压的因素 The factors that affect arterial blood pressure （1）SV(搏出量）↑SP↑↑、DP↑PP↑ ↓SP↓↓、DP↓PP↓ Stroke volume (pumping function of the heart ) SBP ↑↑ DBP ↑ （2）HR（心率）↑ SP↑DP↑↑PP↓ ↓SP↓、DP↓↓PP↑ Heart Rate If heat beats fast than normal , both SBP and DBP rise , but DBP rises more because of shortening of diastolic period , less blood flows through the resistance vessels to the capillaries and more blood remains in the large arteries . (3）PR（外周阻力)↑ SP↑,DP↑↑↑,PP↓ ↓ DP↓,DP↓↓↓,PP↑ (r4,血液粘滞度增加），影响舒服张压大小的最主要因素 Total peripheral resistance (TPR) As the peripheral resistance to blood flow increases , more blood will remain in the large arteries during diastolic period , therefore , DBP rises markedly , SBP also rises slightly （4）大动脉，主A顺应性 Compliance of arteries 大动脉，主A顺应性下降 SP ↑ ↑ ↑ DP ↓ PP ↑↑ if the compliance of large arteries is decreased , systolic blood pressure rises greatly, and diastolic blood pressure falls (5）循环血量 / 血管容积之比 循环血量↑↓/血管容积不变 循环血量不变/血管容积改变 Ratio of blood volume to blood vessel capacity If blood volume remains constant , blood vessels dilates , or contracts , both SBP and DBP will fall or rise respectively If Blood vessels capacity remains constant , the blood volume is increased or decreased. * * 第三节 血管生理 Physiology of Blood Vessels 一、各类血管的功能特点 Functional characteristics of the blood vessels