●●●●● Human Heart ●●0 ●●● ●●●● This is a common carotid artery总颈动脉 ventral (front 头售 brachiocephalic eft subclavian arter在锁骨下动 n humans superior iew of the aorta heart. The ght pulmonary right side [in arteries blue left pulmonary arteries receives and right pulmonary pulmonary trunk pumps left pulmonary veins deoxygenate left atrium blood. Th right atrium semilunar left side [in valves red receives atrioventricular (tricuspid ) valve atrioventricular oxygenated mitral) valve blood f chordae the lungs nd pumps it to the interior vena cava systemic circuit. the g chambers
左总颈动脉 左锁骨下动脉 头臂动脉
(1)心脏肌 ●●●●● ●●●● ●●0 ●●● ●●●● Circulatory Cardiac Cardiac Organ system Organ Tissue FIGURE 46.4 Levels of organization within the body. Similar cell types operate together and form tissues. T issues functioning together form organs. Several organs working together to carry out a function for the body are called an organ system. The circulatory system is an example of an organ system
（1）心脏肌
(2)心搏和心脏传导糸统 心搏( Heart beat):心腔有节律的收缩和舒张产生了心跳或名心搏。 心搏来自心肌的收缩,心肌的特点是自主性和节律性。 心脏传导亲统: 窦房结(S- A node):静脉窦发畏而来,位于右心房大静脉入口附近, 是一块特化的心肌组织。是心搏的启搏器pace- maker) °房室结(A-node):心搏的启搏器 °房室束即希斯束( bundle of his) 浦肯野氏纤维( Purkinje fibers
（2）心搏和心脏传导系统 心搏(Heart beat)：心脏有节律的收缩和舒张产生了心跳或名心搏。 心搏来自心肌的收缩，心肌的特点是自主性和节律性。 心脏传导系统： 窦房结(S-A node): 静脉窦发展而来，位于右心房大静脉入口附近， 是一块特化的心肌组织。是心搏的启搏器pace-maker) • 房室结(A-V node)：心搏的启搏器 • 房室束即希斯束（bundle of His) • 浦肯野氏纤维(Purkinje fibers
心动周期 ●●●●● ●●●● ●●0 ●●● ●●●● 心脏一次收缩和舒张,称为一个心动周期。通常的心 动周期是指心室的活动周期而言。在一个心动周期中, 两心房先收缩,继而舒张,心房舒张后不久,心室开 始收缩,随后舒张。两心房的活动和两心室的活动各 自同步。心脏收缩期比舒张期短。心率增快时,收缩 期和舒张期均缩短,但舒张期缩短更显著,心肌工作 时间相对延长,休息期相对缩短,这对心脏的持久活 动是不利的
心动周期 心脏一次收缩和舒张，称为一个心动周期。通常的心 动周期是指心室的活动周期而言。在一个心动周期中， 两心房先收缩，继而舒张，心房舒张后不久，心室开 始收缩，随后舒张。两心房的活动和两心室的活动各 自同步。心脏收缩期比舒张期短。心率增快时，收缩 期和舒张期均缩短，但舒张期缩短更显著，心肌工作 时间相对延长，休息期相对缩短，这对心脏的持久活 动是不利的
●●●● ●●● ●●●● 心动周期 Heart cycle ●●● ●●● 次心搏就是一个心动周期,分为 缩 systole和心张 diastole西个肘期 分别代表心蜜的收缩和心室的舒张。 心搏的次数就是心动周期的次数。 04 sec Figure 38.6 Heart cycle. Each heart cycle consists of two phases of roughly equal duration, systole and diastole. During the first 0. 1 second of the cycle, the atria contract and force blood into the ventricles. The ventricles contract for about 0. 3 second and push the blood out of the heart ompleting systole. During diastole, the heart relaxes and blood fiows into the atria and ventricles. Blood also fows into the atria during the second part of systole
心动周期 Heart cycle 一次心搏就是一个心动周期，分为心 缩systole 和心张diastole两个时期， 分别代表心室的收缩和心室的舒张。 心搏的次数就是心动周期的次数