Download Cardiovascular System

Cardiovascular System
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【Objectives】
1. To identify and describe:
A. Structure of the heart wall-- endocardium, myocardium, epicardium
and Purkinje fibers.
B. Structure of the different arteries-tunica intima, tunica media, tunica adventitia, internal and external elastic lamina.
2. To understand and describe the common features of veins and three layers in
their walls; differentiate these from those in the arteries.
3. To understand and describe the main histological structure of the capillaries.
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Heart
Veins
Arteries
Capillaries
Lymphatic vascular
Interstitial
fluid
Cells , tissues
Lymph Capillariers
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The structure of the Heart wall
Endocardium
*
Myocardium
*
Epicardium
What is the principal component in
the wall of the heart?
Cardiac muscle cells
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Endocardium
endothelium
Subendothelial layer
subendocardial layer
(contain Purkinje fibers)
Cardiac conduction system
Myocardium
Question
How to distinguish endocardium
and epicardium?
Epicardium
loose connective tissue
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mesothelium
General Structure of blood vessels
endothelium
subendothelium
Tunica intima
internal elastic
lamina
Tunica media
smooth muscle
cells
elastic elastic laminae
Tunica adventitia
external elastic
lamina
connective tissue
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Comparison of large, medium small arteries and arterioles
Tunica
intima
Large A
（elastic A）
(＞10mm)
Tunica media
Tunica
adenvential
smooth muscle
making the blood
flux uniform .
numerous elastic lamellae
prominent internal numerous smooth muscle prominent
Medium A
relatively little
external
(Muscular artery) elastic lamina
elastic tissue
elastic lamina
(2-10mm)
Small A
prominent internal
(Muscular artery) elastic membrane
(0.1-0.3mm)
Arterioles
(10-100um)
smooth muscle
(8-10 cell layers)
smooth muscle
(1-2 cell layers)
Function
control the
affluence of
blood to the
organs
help control and
modulate blood pressure
responsible for the regulating
of blood pressure 7
Medium Artery
Tunica media
Tunica media
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Tunica adventitia
Small artery
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artery
artery
vein
Larger lumen and thinner wall compared with the same grade of artery,
usually shows an irregular shape when sectioned. The boundaries between
3 layers are obscure.
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Arterioles:
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Vein:
Larger lumen and thinner wall compared with the same grade of
artery, usually shows an irregular shape when sectioned. The
boundaries between 3 layers are obscure.
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The tunica adventitia is relatively thick. In tunica adventitia of
some large veins, longitudinally arranged smooth muscle fibers
can be found.
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Medium Artery
Medium vein
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Small artery and small vein
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Arterioles
capillary
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Homework
Compare the structure of elastic and Muscular artery
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THANK YOU
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