Muscle Histology Flashcards
What makes up thin tissue?
actin
What makes up thick tissue?
myosin
Where are the nuclei located in the muscle cells?
Peripherally
Endomysium
surrounds individual muscle fibers with small blood vessels. Surround perimysium
perimysium
thicker, form fasicle with larger blood vesselse
epimysium
dense, surrounds fasciles with major blood vessels
What are muscle fibers classified as? (What 3 types)
Red, white, intermediate
A band
ansiotropic, dark, stays same in contraction. Encompass all thick filament (myosin)
I band
istropic, light, shortens in contraction, encompass all actin
H band
bright, middle of A bind, shorten in contraction, made of myosin
M line
middle of sarcomere, made of myosin
Z disc
between and middle of I band, shorten in contraction, in between I band, doesn’t contain myosin
What does troponin do?
facilitate/inhibit contraction through detection of Ca
Calcium regulate contraction
Stimulate AP
Sarcoplasmic reticulum
from A-I junction
Terminal Cisterna
resevoirs of Ca, has cell membrane
Transverse tubular system
invaginations of sarcolemma at A-I band, have T-Tubules with electrical currents
Triad
one T tubule, 2 adjacent terminal cisternae only works on skeletal muscle
Skeletal Ca blocker
Leads to what?
What structure produces Ca
leads to paralysis, sarcoplasmic reticulum produces Ca
Presynaptic Vesicle Contents
acetylcholine
Innervation
need to maintain structural integrity, each neuron/motor unit brings contraction
muscle spindles
encapsulate sensory receptors, with stretch receptor, degree muscle tension
spindle cells
modified muscle fibers
Morphological appearance of elongated cells
sensory nerve fib ers
back to CNS
motor nerve gamma fibers
sensitivity of muscle spindle
Muscular Dystrophy
destroy own muscles
Duchenne Muscular dystrophy
Xlink recessive, most common muscular dystrophy
