Histology of Muscle and the Circulatory System Flashcards
Type of muscle cell:
- elongated with blunted ends
- multinucleated
- peripheral nuclei
- sorted in bundles or fascicles
Skeletal myocyte
Type of muscle cell:
- elongated with branching ends
- mononucleated or binucleated
- central nucleus/nuclei
- sorted in bundles or fascicles
- with intercalated discs (zonula adherens)
Cardiac myocyte
Type of muscle cell:
- elongated with tapered ends, spindle-shaped
- mononucleated
- central nucleus
- non-striated
- sorted in layers
Smooth myocyte
Layers of the cardiac wall
- epicardium
- myocardium
- endocardium
Cardiac wall layer:
- thin layer connective tissue and fat (fat deposits seen at the sulci)
- serves as an additional layer of protection for the heart
- the continuation of the serous pericardium
Epicardium
Cardiac wall layer:
- contains the muscle tissue of the heart
- composed of the cardiomyocytes that receive nervous stimulation from the sinoatrial (SA) and atrioventricular (AV) nodes via the Purkinje fibers
Myocardium
Cardiac wall layer:
- composed of endothelial cells that provide a smooth, non-adherent surface for blood collection and pumping and may help regulate contractility
- thin serous membrane
- lines the interior of the heart and valves
Endocardium
Type of artery responsible for DISTRIBUTION of blood to different organ
Muscular artery (or medium artery)
Type of artery responsible for CONDUCTING responses of pulse - to stretch in response to each pulse
Elastic artery (or conduit artery, or large artery)
Layer of blood vessel entirely made of connective tissue
- thickest in veins
- contains nerves that supply the vessel
- contains nutrient capillaries (vasa vasorum) in the larger blood vessels
Tunica adventitia
Layer of blood vessel made up of circularly arranged elastic fiber, connective tissue, polysaccharide substances:
- thickest in arteries
- layered, in which the second and third layer are separated by another thick elastic band called external elastic lamina
- may (especially in arteries) be rich in vascular smooth muscle, which controls the caliber of the vessel
- veins lack the external elastic lamina, but only an internal one
Tunica media
Layer of blood vessel made up of a single layer of simple squamous endothelial cells glued by a polysaccharide intercellular matrix:
- thinnest layer
- surrounded by a thin layer of subendothelial connective tissue
- with interlacing circularly arranged elastic bands called the internal elastic lamina
Tunica intima
Type of large vessel:
- small lumen
- thick wall
- tunica media thickest
- rigid
- with internal elastic membrane
- no valves
- more abundant muscles and elastic tissue
- vasa vasorum extended up to tunica media
Artery
Type of large vessel:
- large lumen
- thinner wall
- tunica adventitia thickest
- non-rigid
- without internal elastic membrane
- with valves (extension of tunica intima)
- less abundant muscles and elastic tissue
- vasa vasorum extended up to tunica intima
Vein
Type of vessel:
- no smooth muscle
- large amount of connective tissue at its periphery
Venule
