Cardiovascular and limfe histology

Heart

• Heart Walls layer– ENDOCARDIUM

– MYOCARDIUM

– EPIKARDIUM

• PERIKARDIUM

Endothelium cell:

POLIGONAL

Sub endothelium layer:

Loose thin connective tissue layer

Compact tight connective tissue layer

Sub endocardial layer:

Loose connective tissue

Contain vascular, nervous, and hearts conduction.

Myocardium

The tightest layer: heart muscular

Contractile cell

Conductive cell

The webbing of elastin fibers between muscular heart cells

Ventricle wall is tighter than atrium wall

Papillaris muscular in ventricle

Pericardium

PEMBUNGKUS SEROSA BERBENTUK KANTONG

Free surface of pericardium is covered by mesothel

Contains liquid

There are 2 layers:

LAMINA PARIETALIS

LAMINA VISCERALIS (EPICARDIUM)

Blood vessels

Histologically, blood vessels consist of concentric layers or "tunics" of different tissue types.

The tunica intima is the inner lining, consisting of endothelium and a relatively thin layer of supporting connective tissue. 

The tunica media is the middle muscular and/or elastic layer, containing smooth muscle and elastic tissue in varying proportions. 

The tunica adventitia is the outer, fibrous connective tissue layer.

Arteries

The largest arteries, such as the aorta and its larger branches, have a tunica media dominated by elastic tissue.  The elasticity conferred by elastin allows these elastic arteries to smooth out the sharp changes in blood pressure resulting from the pumping heart.

Most arteries are muscular arteries, with a media dominated by smooth muscle.  But elastin is also a substantial component (for a good view of elastin in vessel walls, see Virtual Slidebox, Artery and Vein).

 Arterioles are the smallest arteries.  Note that gross anatomists and surgeons may use the term arteriole for any very small artery.  Histologists tend to use the term arterioles only for terminal arterial vessels (i.e., those immediately preceding a capillary bed) which are characterized by having only a single layer of smooth muscle cells. 

EM image of artery (longitudinal section, from Elektronenmikroskopischer Atlas im Internet).

Most arteries have continuous layer of elastin, called the internal elastic lamina, at the boundary between the media with the intima.

In routine histological sections, the internal elastic lamina of transversely-sectioned arteries typically displays a distinctive sinusoidal appearance, resulting from postmortem contraction of the artery's smooth muscle in the absence of normal blood pressure.

The thickness of arterial walls is typically not much less than the diameter of the lumen.  With such relatively thick walls, arteries tend to retain a round cross-section in postmortem histological preparations (in contrast to veins, which tend to appear more flattened).

Note that arteries of pulmonary circulation (which convey blood of lower pressure than systemic circulation) have relatively thinner walls, similar to systemic veins.

Veins

Veins have a wall similar to that of arteries but with a thinner tunica media.

The walls of the smallest veins (sometimes called "venules") do not include smooth muscle.

The thickness of vein walls is typically much less than the diameter of the lumen (i.e., proportionately much thinner than arteries carrying a similar volume). With such relatively thin walls, veins tend to appear flattened or collapsed in cross-section in postmortem histological preparations (in contrast to arteries, which tend to appear more round).

Note that vessels of pulmonary circulation (which convey blood of lower pressure than systemic circulation) have relatively thinner walls than systemic vessels of comparable diameter.

LIMFE

- PEMBULUH LIMFEDIMULAI DENGAN KAPILER LIMFE BUNTU

MENAMPUNG DARI CAIRAN JARINGAN

- LYMPHONODUSMENAMPUNG KAPILER PADA PERMUKAAN CEMBUNG

- PEMBULUH LIMFE LEBIH BESARMENAMPUNG DARI VASA EFERENTIA N. LYMPHATICUS

- PEMBULUH LIMFE BESAR MENUJU KE JANTUNGDIAMETER PEMBULUH LIMFE SEMAKIN BESAR

DUCTUS THORACICUS V. SUBCLAVIA SINISTRA

DUCTUS LYMPHATICUS DEXTER V. SUBCLAVIA DEXTRA

Lymphatic vessels

Lymphatic vessels (often just called lymphatics) are channels which drain excess fluid ("lymph") from tissues.

In most peripheral tissues, some plasma seeps out of capillaries. A portion of this is taken back up in venules while the rest drains into terminal lymphatic channels, also called lymphatic capillaries. A shift in the balance between fluid entering and leaving tissues (e.g., increased vascular permeability due to inflammation) can result in accumulation of tissue fluid, or edema.

All lymphatic vessels eventually lead "downstream" to the thoracic duct, which empties into the vena cava (a point where blood pressure is quite low; higher pressure would impede drainage).

Lymphatic vessels resemble blood vessels with exceptionally delicate walls (and, of course, without red blood cells). Smaller lymphatic vessels consist of little more endothelium.

If, while examining a histological specimen, you encounter a flattened, endothelially-lined passage that seems too delicate to be a vein but too large to be a capillary, it is probably a lymphatic.