基础医学各论I：Circulatory system

1、-Closed tubular system-Blood circulatory or cardiovascular S-Lymph vascular SThe cardiovascular S heart artery vein capillary1) LM: endothelium: basement membrane: pericyte: /flattened with processes/function: i. support ii. undifferentiated cellendothelial cell: processes microvilli-like, finger-li

2、ked plasmalemmal vesicle /60-70nm, constitute about 25-35% of total volume /transendothelial channel function: transport large molecules and storage of membrane (for enlarge, enlongated, pore-formed and microvilli)EM: classificationContinuous capillary: -Structural feature: endothelial cell: -more p

3、lasmalemmal vesicles -tight junction basal lamina: complete -Distribution: CT, MT, lung and CNS Fenestrated capillary-Structural feature: endothelial cell: -have fenestrae or pore (60-80nm in D, with 4-6 nm diaphragm) basal lamina: complete-Distribution: gastrointestinal tract, endocrine gland and r

4、enal glomerulusSinusoid capillaries (enlarge capillary)-Structural feature: endothelium: gap, pore basal lamina: incomplete or no (absent)-Distribution: liver, spleen and bone marrow-large A: aorta, pulmonary trunk-medium-sized A: all named A, the diameter 1mm (radial A, ulnar A)-small A: 300umD1mm1

5、) Medium-sized A muscular A-Tunica intimaendotheliumsubendothelial layer: CT -collagenous F -elastic F -smooth muscleinternal elastic membrane: wave-liked, pink-colored band- elastin-Tunica media: thickest layer smooth muscle: 10-40 layers of, circularly elastic F: produced by SM collagenous F: prod

6、uced by SM-Tunica adventitia: LCT with small BV-vasa vasorum, NF and LV external elastic M2) Large A: elastic A-Structural features: a. Tunica intima is thick, and internal elastic M is not prominantb. Tunica media: consists of 40-70 layers of elastic membrane, CF and SMelastic MSM3) Small A:-large

7、SA: internal EM 3-4 layers SM no external M-small SA: no internal M 1-2 layers SM-three type-correspond with A except for LV-three layers-structural features: a. larger diameter, thinner walls- collapsedb. no internal and external elastic membrane, so the boundaries between three tunica are not very

8、 clearc. contains more CT, less smooth M, SM are arranged in bundlesd. vein valve: /infolding of tunica intima /semilunar-liked /prevent back flow of blood-atrium(right and left)-ventricle (right and left) ESEsubendocardial layerendocardiummyocardiumepicardium1) The wall of heart-endocardium: endoth

9、elium subendothelial layer: more dense CT- contain fibroblast, CF, EF, SM subendocardial layer: LCT, with BV, N and conducting S- Purkinje fiber-myocardium: cardiac M: a. atrial muscle: /atrial granules: 0.3-0.4um in D, contain atrial natriuretic polypeptide or cardionatrin b. ventricular M: thick,

10、long, branches LCT: rich in capillaries*atrioventricular fibrous annulus: DCT-epicardium: visceral layer of pericardium- serous membrane: mesothelium LCT: more fat cell- subepicardial layer-cardiac valve: formed by infolding of endocardium: endothelium + DCT prevent the back flow of blood2) Conducti

11、ng S components: -sinoatriol node (SA n o d e ) : l o c a t e d i n epicardium of right atrium-atrioventricular node (AV node) and bundles (AV bundles): located in subendocardial layer-network of Purkinje fiber: three types of cells a. pacemaker cell ( P cell): mainly distributed in SA and AV node s

12、mall, fusiform or polygonal in shaped enclosed by DCT less organelle: myofibril, plasmalemmal vesicles and more glycogen b. transitional cell: mainly distributed in periphery of SAN or AVN and AV bundle T h e s t r u c t u r e i s b e t w e e n pacemaker cell and cardiac M thinner and shorter than CM more myofibril than P cell c. Purki