Histology Flashcards
Where is the most blood in the body?
Peripheral veins
What is the inner, middle and outer layers of blood vessels?
- Tunica intima
- Tunica media
- Tinica adventitia
Describe the tunica intima?
Made up of single layer of squamosu epithelial cells termed endothelial cells (collectivly endothelium) supported by a basal lamina and thin layer of connective tissue.
Describe the tunica media?
Made up of predominantly muscle (some areas elastic tissue). It varies and sometimes disapears.
What is the tunica adventitia made from?
Supporting connective tissue
What are the very largest arteries termed?
Elastic arteries
What do elastic arteries have that provides elastic recoild?
Sheets of elastic fibres
What are the elastic arteries own vascular supply called?
Vaso vasorum
What does Verhoeff’s/Masson trichrome stain do to elastic fibres, collagen and smooth muscle?
Elastic fibres - black
Collagen - green
Smooth muscle cells - red
What does the tunica intima extend to?
An internal elastic membrane
What seperates the tunica media nad tunica adventitia?
External elastic membrane
What does Modified van Gieson’s stain do to collagen, cytoplasm and elastin?
Collagen - red
Cytoplasm - yellow
Elastin - black
What are capillaries essentially composed of?
Endothelial cells and a basal lamina
What do capilarries often have ar intervals just outside the basal lamina?
Pericytes
What are the three types of capillary?
- Continuous capillaries
- Fenestrated capillaries
- Sinusoidal or discontinuous capillaries
What types of capillaries are found in muscle, connective tissue, lung, skin and nerves?
Continuous capillaries
What capillaries are found in mucosa of gut, endocrine glands and glomeruli of the kidney?
Fenestrated capillaries
What capillaries lack basal lamina and have large gaps through which macromolecules, and in some cases even cells can pass. Found in liver, spleen and bone marrow?
Sinusoidal or discontinuous
What are important sites for exchange e.g. cells moving into the tissue in inflammation?
Postcapillary venule