What are the 4 main characteristics of muscle
- excitability: receive and respond
- contractility: shorten
- extensibility: stretch
- elasticity: recoil to resting length
what are the 3 types of muscle tissue
- skeletal
- cardiac
- smooth
how is skeletal tissue connected to bones
through tendons
key characteristics of skeletal muscle
skeletal
voluntary
striated
what is epimysium
surronding the entire muscle
what is perimysium
fibrous connective tissue surrounding fascia’s
what is endomysium
fine connective tissue surrounding each muscle fiber
what is tendon
fused sheathes that connects periosteum to bone
what is aponeurosis/fascia
broad sheet-like tendon
what is T tubule
tube formed by fold of sarcolemma
allows electrical nerve transmissions
what is sarcoplasmic reticulum
stores and releases calcium
what is the sarcomere
functional unit of muscle cell
Parts of thin filaments
actin: extends across I band and A band
Troponin&Tropomyosin: surround actin
Parts of thick filament
Myosin: all of A band
Connect at M line
what is neuromuscular junction (nmj)
site where motor neuron meets muscle fiber
Parts/ functions of nmj
axon: travels from central nervous system to skeletal muscle fiber
axon terminal: releases neural transmitter
Crosses synaptic cleft
Binds to ach receptors on muscle sarcolemma
what is synapse or a nmj
connection between axon terminal and muscle fiber
What is muscle tone
tension in a resting muscle
what is isotonic contraction
muscle changes length
what is concentric
muscle shortens
what is eccentric
muscle lengthens
what is isometric contraction
no shortening; muscle tension but doesn’t change length
key words of cardiac muscle
striated, involuntary, cardiac
connected by intercalated discs (connections of gap junctions)
key words of smooth muscle
hollow organs, non-striated, involuntary
lack troponin
examples: stomach, urinary bladder, blood vessels
