Sections Of The Heart And Blood Vessels Histology

Sections of the heart and blood vessels

Tunica intima: Layer of the endothelial cells, underneath basal lamina Subendothelial layer: loose connective tissue with some smooth muscle Tunica media: Smooth muscle cells and elastic and reticular fibers, collagen type I, proteoglycans no characteristic or absent in veins Tunica adventitia: mainly consists of connective tissue (longitudinally arranged collagen and elastic fibers, collagen type III) well-developed in veins (smooth muscle cells can be found) Vasa vasorum, vascular nerves In muscular arteries internal elastic lamina (I. E. L.) separates the t. media from t. intima. Between the t. media and t. adventitia, the external elastic lamina (E. E. L.) is found.

T. intima: endothelial cells, basal lamina subendothelium: loose connective tissue, collagen and elastic fibers. T. media: 30-70 concentrically arranged elastic laminae smooth muscle, some collagen fibers and fibrocytes. T. adventitia: poorly developed, longitudinal collagen fibers, reticular fibers, fibrocytes. vasa vasorum, vascular nerves

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Increasing number of muscle cells, decreasing amount of fibers

T. intima: endothelial layer, basal lamina, subendothelial layer I. E. L.: between t. intima and media, irregular, wavy lines (orcein and resorcin-fuchsin stain the lamina) T. media: concentrically oriented smooth muscle cells intermingled with some elastic and collagen fibers and fibrocytes

T. adventitia: E. E. L.: in larger arteries, longitudinal elastic fibers poorly developed, collagen fibers, fibrocytes, fat cells vasa vasorum, vascular nerves

1. Continuous / somatic capillaries basal lamina is continuous Skeletal muscle, lungs, connective tissue, brain 2.a Fenestrated / visceral capillaries with diaphragm large feneastrae in the wall of endothelial cells their diamater is between 60-70 nm Diaphragm (macromolecular filter) Intense interchange of substances: resorptive epithelium of small intestine, epihtelium of renal tubuli, epihtelium of the endocrine organs 2.b Fenestrated capillaries without diaphragm Basal lamina is thick Renal glomeruli 3. Discontinuous sinusoidal capillaries Enlarged diameter, irregular shape maybe with pores Liver, lymph node, spleen

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They have thinner wall, bigger lumen than the arteries have

T. intima: - endothel layer, basal lamina subendothelial layer - at the border of the t. media, there is an increasing number of the elastic fibers T. media: - thin layer - the smooth muscle cells are loosely situated, - collagen fibers and fibrocytes T. adventitia: - the widest layer of the veins, rich of elastic fibers - longitudinal smooth muscle cells in the large veins - vasa vasorum (vessels of the vessels)

To study the structure of the wall of the different blood vessels

20. Aorta (HE), 4X

Subendothelium Intima

Media

Adventitia Vasa vasorum

Endothelial cells Intima

Media

20. Aorta (HE), 20X

21. Aorta (resorcin-fuchsin), 4X Intima

Media

Adventitia

21. Aorta (resorcin-fuchsin), 20X Intima

Media Elastic laminas

22. Artery-vein (HE), 4X

Artery

Vein

22. Artery-vein (HE), 20X Subendothelium

I. E. L.

Intima

Smooth muscle cells Media

E. E. L. Adventitia

22. Artery-vein (HE), 20X

Lumen of a vein Intima

Media

Adventitia

Vasa Vasorum

23. Artery-vein (orcein), 4X

Artery Vein

Intima I. E.M. Media

E. E. M.

Adventitia

23. Artery-vein (orcein), 20X

Lumen of an artery

Intima

Media

Adventitia

23. Artery-vein (orcein), 40X

Less prominent striation Morphological unit: branching / Y-shape muscle cells (junctional complexes: gap junction, intercalated disc / Eberth s line) Types: working muscle propagating system

To study of the morphological unit of cardiac muscle

15. Cardiac muscle (HE), 40X Eberth s lines

capillary

16. Cardiac muscle (iron-hematoxilin), 40X

Eberth s lines

capillary