Download Chapter 9 Circulatory system

Chapter 9
Circulatory system
---Closed tubular system
---Blood circulatory or cardiovascular S
---Lymph vascular S
The cardiovascular S
heart
artery
vein
capillary
Organs:
---cavity organ:
inner → outer
layers
---parenchymal organ:
capsule
parenchyma: -cortex
-medulla
interstitia
1.
Capillaries
1) LM:
endothelium:
basement membrane:
pericyte:
/flattened with processes
/function:
i. support
ii. undifferentiated cell
endothelial cell:
processes –microvilli-like, finger-liked
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)
Weibel-Palade body: rod-liked, 3um long, 0.10.3um in D, secrete factor VIII related antigen
microtubule and microfilament
EM: classification
①Continuous capillary:
---Structural feature:
endothelial cell:
-more plasmalemmal vesicles
-tight junction
basal lamina: complete
---Distribution: CT, MT, lung and CNS
② 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 renal glomerulus
③Sinusoid capillaries( enlarge capillary)
---Structural feature:
endothelium: gap, pore
basal lamina: incomplete or no( absent)
---Distribution: liver, spleen and bone
marrow
3) Function:
a. Selected permeability and exchange of
material
b. Synthesis(F VIII Rag, endothelin, ET
and PGI2) and metabolism(angiotensin
I→angiotensin II) activity
c. Anti-blood coagulate
2.
Artery
---large A: aorta, pulmonary trunk
---medium-sized A: all named A, the
diameter > 1mm(radial A,ulnar A)
---small A: 300um<D<1mm
1) Medium-sized A
– muscular A
---Tunica intima
endothelium
subendothelial layer: CT
-collagenous F
-elastic F
-smooth muscle
internal 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: produced
by SM
---Tunica adventitia:
LCT –with small BV-vasa
vasorum, NF and LV
external elastic M
2) Large A: elastic A
---Structural features:
a. Tunica intima is thick, and internal
elastic M is not prominant
b. Tunica media: consists of 40-70 layers
of elastic membrane, CF and SM
3) Small A:
---large SA:
internal EM
3-4 layers SM
no external M
---small SA:
no internal M
1-2 layers SM
2.
Veins
---three type
---correspond with A except for LV
---three layers
---structural features:
a. larger diameter, thinner walls- collapsed
b. no internal and external elastic membrane,
so the boundaries between three tunica are
not very clear
c. contains more CT, less smooth M, SM are
arranged in bundles
d. vein valve:
/infolding of tunica intima
/semilunar-liked
/prevent back flow of blood
4.
Heart
---atrium(right and left)
---ventricle (right and left)
1) The wall of heart
---endocardium:
endothelium
subendothelial layer: more dense CTcontain fibroblast, CF, EF, SM
subendocardial layer: LCT, with BV, N
and conducting S- Purkinje fiber
---myocardium:
cardiac M:
a. atrial muscle:
/thin, short, unbranch, 6-8um in D, 2030um long
/atrial granules: 0.3-0.4um in D, contain
atrial natriuretic factor, ANF or cardionatrin
b. ventricular M: thick, long, branches
LCT: rich in capillaries
*atrioventricular fibrous annulus: DCT
---epicardium: visceral
layerof pericardiumserous membrane:
mesothelium
LCT: more fat cellsubepicardial layer
---cardiac valve:
formed by infolding
of
endocardium:
endothelium + DCT
prevent the back
flow of blood
2) Conducting S
① components:
---sinoatriol node(SA node): located in
epicardium of right atrium
---atrioventricular node( AV node) and
bundles( AV bundles) : located in
subendocardial layer
---network of Purkinje fiber:
② three types of cells
a. pacemaker cell( P cell):
mainly distributed in SA and AV node
small, 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
The structure is between pacemaker
cell and cardiac M
thinner and shorter than CM
more myofibril than P cell
c. Purkinje cell:
mainly constitute AV bundle and
branches
shorter, boarder than CM, with 1-2
centrally located nuclei
rich in mitochondria, glycogen, less
myofibril
well-developed intercalated disks