1. Circulatory system

2. General outline Heart Arteries Capillaries veins Blood vascular system
Lymphatic capillaries
Lymphatic vessel
Lymphatic ducts
Lymphatic vascular system

3. Capillaries A single layer of endothelial cells basement membrane
A few connective tissue (pericytes) LM
Continuous capillary
Fenestrated capillary
Sinusoid EM

4. Capillaries
Continuous C.
Fenestrated C.
Sinusoid

5. Continuous capillary:
distributed in muscle tissue, brain, lung and
connective tissue, etc.
endothelial cell: large number of pinocytotic
vesicles, no pores, exist cell junctions
between the endothelia
basement membrane: integrity

7. Continuous capillary

8. Fenestrated capillary:
distributed in the kidney glomerulus, mucosa
of gastrointestine, some endocrine glands
endothelial cells: present abundant pores, have
or haven’t diaphragm on them
basement membrane: continuous

9. Fenestrated capillary

10. Sinusoid: distributed in liver, spleen, and some endocrine glands
a greatly enlarged diameter
endothelial cell: intercellular clefts are large
between cells, many pores without diaphragm
absence of a continuous basement membrane

11. Sinusoid

12. Artery transport blood from heart to capillaries
according to their size, structure
and function
Large artery
Medium-sized artery
Small artery
arteriole
are classified

13. Medium-sized artery: muscular artery Endothelium
Subendothelial layer: LCT
Internal elastic lamina: clear
Tunica intima
Tunica media: contain 10~40 layers of circular
smooth muscle
External elastic lamina
LCT: contain vasa vasorum
Tunica adventitia

15. Medium-sized artery

16. Large artery: elastic artery
subendothelial layer is thicker with a few
smooth muscles
tunica media is thick, contains a lot of circular
elastic membrane
internal and external elastic lamina are not
distinguished
tunica adventitia are thiner

17. Large artery

18. Small artery: muscular artery and peripheral resistance vessel
internal elastic lamina is clear, while
external elastic lamina is not distinguished
the media contains 3~9 layers of smooth
muscles

19. Vein large lumen, thin wall, irregular
internal and external elastic lamina are not clear
tunica media is thin, with a few elastic fibers and
smooth muscles
tunica adventitia is thick
some veins have valves

20. Heart a muscular organ that contracts rhythmically
pump blood through the circulatory
system

21. The wall of heart Endothelium Subendothelial layer
Subendocardial layer
endocardium
myocardium: thickest layer, consists of
cardiac muscle
LCT: contain adipose tissue
Methothelium
epicardium

22. Impulse generating and conducting system of the heart:
Pacemaker cells: heartbeat generating
Purkinje cells (bundle cell):
distributed in subendocardial layer, larger than cardiac muscle cells
Transitional cells: transmit impulse

23. Purkinje cell
Cardiac cell