Histology Flashcards
(27 cards)
What are the roles of the cardiovascular system?
- Transport of oxygen and nutrients to the tissues
- Transport of CO2 and other metabolic waste from the tissues.
- Temperature regulation.
- Distribution of hormones and immune cells.
- Reproductive function in males: penile erection
What is tunica intimate made of?
single layer of squamous epithelial cells termed endothelial cells supported by a basal lamina and a thin layer of connective tissue
What is tunica media made of?
smooth muscle.. thickness of tunica media varies dramatically
What is tunica adventitia made of?
supporting connective tissue
What separates the tunica intima and media?
elastic tissue called the internal elastic membrane
What separates the tunica media and adventitia?
elastic tissue called the external elastic membrane
How do elastic arteries get their nutrient supply?
vasa vasorum
What are the layers in an arteriole?
little smooth muscle, no adventitia
What are the layers in a capillary?
endothelial cells and a basal lamina
What are pericytes and where are thy found?
outside the basal lamina of capillaries
connective tissue cells that have contractile properties
What are the there types of capillaries?
Continuous capillaries: found in muscle, connective tissue, lung, skin and nerve
Fenestrated capillaries: found in mucosa of gut, endocrine glands and glomeruli of kidney
Sinusoidal or discontinuous capillaries: large gaps in walls, found in liver, spleen and bone marrow
What are post-capillary venues made of?
endothelial cell-lined and contain a thin layer of connective tissue and occasional pericytes
When does a post-capillary venue become a venule?
when they acquire intermittent smooth muscle cells in the tunica media layer
What are the layers in a vein?
thin tunica media with a few layers of smooth muscle, thick adventitia in large veins
What are the three layers of the heart?
- endocardium
- myocardium
- epicardium
What is the structure of the endocardium?
endothelium basal lamina thin layer of collagen fibres layer of dense connective tissue subendocardium containing loose connective tissue and impulse conducting parts
What is the structure of the myocardium?
bundles and layers of contractile carina muscle fibres, individual muscle fibres surrounded by connective tissue and rich network of capillaries
What do intercalated discs do?
attach cells and allow the spread of electrical activity
What is the structure of the epicardium?
single layer of flattened mesothelium, basal lamina and fibroelastic connective tissue and sometimes adipose tissue
What is the purpose of the fibrous skeleton on the heart?
support the valves
provides attachment for cardiac muscle fibres
electrically isolate the atria and the ventricles
What is the structure of heart valves?
endothelial layer with basal lamina over all surface
lamina fibrosa is extension of the fibrous skeleton
no blood vessels
tendinous cords and papillary muscles
What are the three types of cardiac muscle cells?
contractile
pacemaker
conducting
What is the structure of pacemaker cells?
smaller than normal myocytes pale few myofibrils little glycogen no T tubule system
What is the structure of the conducting cells in the Purkinje fibres?
larger than normal cells found in subendocardial layer deep to the endocardium lots of glycogen no T tubules and no intercalated discs pale
