Heart and vessel histology Flashcards
What are the layers of the endocardium?
Simple squamous epithelium
Subendothelial CT
Subendocardial layer - conducting system
What junctions are contained in the intercalated discs?
Fascia adherents
Desmosomes
Gap junctions
Where are secretory cardiomyocytes found?
Atria
What are the two polypeptide hormones secreted by secretory cardomyocytes?
Atrial natriuretic factor (ANF/ANP)
Brain natriuretic factor (BNF)
What secretes the pericardial fluid in the epicardium?
Mesothelium
What are the functions of the fibrous skeleton of the heart?
Keeps the AV orifices and semilunar valves patent
Provides attachment to leaflets and cusps of valves
Provides attachment to myocardium
Form electrical insulator separating atria and ventricles
What are the 3 layers of AV valves?
Fibrosa - dense irregular CT
Spongiosa - loose CT
Ventricularis/atrialis - dense CT/elastic
What are the layers of the vascular wall?
Tunica intima
Tunica media
Tunica adventitia
What are the histological characteristics of the tunica intima?
Endothelium
Basal lamina
Subendothelial layer
Internal elastic membrane
What are the histological characteristics of the tunica media?
Circular layer of smooth muscle
Elastin
Reticular fibers
Proteoglycans
External elastic membrane
What are the histological characteristics of the tunica adventitia?
CT with collagen and elastic
Small vessels and nerves
Where is tunica adventitia thicker?
In venules and veins
Where is the tunica media thicker?
Arteries
What are the characteristic of large/elastic arteries?
Contain multiple sheets of elastic lamellae
No fibroblasts in tunica media
Thin adventitia
What are the characteristic of medium/muscular arteries?
More smooth muscle in the tunica media
Prominent internal elastic lamina
No fibroblasts in media
Thick adventitia with recognizable external elastic lamina
