histology notes

1. SKELETAL CARDIAC SMOOTH
MUSCLE CELL Muscle cell/ fiber
Fusion of myoblat
Shape Large elongated Short narrow fusiform
Diameter 10----- 100 um 10---- 15 um 0.2 ---2 um
Length Upto 100cm 80 ---- 100um 20 --- 200 um
Connective tissue Epimysium, Perimysium Sub epicardial, Endomysium, Sheaths &
component Endomysium subendocardial C.T. bundles
Endomysium
Fiber Single, skeletal muscle Linear branched Single smooth muscle
cell arrangement of several cell
cardiac muscle cells
Striations Present Present None
Nucleus Multinucleated Single central with clear Single central
peripheral juxta nuclear region Cock screw
Intercalated disc Absent Present Absent
Myofilaments arranged +ve +ve -ve
into Myofibrils
Sarcoplasmic reticulum Surrounds Myofibril Surrounds Myofibril -ve
AI----AI Z LINE---- ZLINE
Terminal cistern No Terminal cistern
T tubule AI JUNCTION Z LINE Larger with
invagination of external
lamina
Triad Diad
Mitosis Absent Absent Present
Response to demand Hypertrophy Hypertrophy Hypertrophy &
Hyperplasia
Innervation Somatic Autonomic Autonomic