Nerve impulse for muscle contraction

thru neuromuscular junction

1) Electrical signal

2)Neurotransmitters r realeased from the Synaptic Nob into the Synaptic cleft

3) Neurotransmitters attach to the motor end plate and send motor impulse/signal

4)to Muscle fibers

5) reaches the Triad (terminal cisternae & the T-tubules), which tells the 

6) thus initiates the Sarcoplasmic reticulum to release calcium

7) actin and myosin react

Actin myofilaments(I band)

sides toward the center of

Myosin myofilaments(H band)

& the Sarcomere shortens

Actin myofilaments (I-band)

r pulled into the H zone, which then disapears

I-band narrows

A-band remains unchanged

basic fully contracted muscle 

____________ happens

A-band = stays the same

I-band = shrinks, shortens, narrows

H-zone = disapears

Sarcomere = shortens

Z-disk = stays the same

M-line = stays the same

Muscle tissue organization & cells

from superficial to deep 

Epimyseum

Muscle

Perimyseum

Fasicles

(bundle of muscle fibers)

Endomyseum

Muscle fibers

Myofibrils

(bundle of myofilaments)

Myofilaments

Perimyseum

tissue

Dense irrg CT sheath

surrounds fasciles

Middle layer

Dense irr CT

surrounds whole skeletal muscle

outer layer(superficial)

Areolar CT

surrounds each muscle fiber

Deep layer

Superficial fascia

(muscle)

tissue

separates muscle from skin

Areolar & Adipose CT

Separates indiv muscles, connects neighboring muscles

Dense irr CT

Slow, Fast & Intermediate 

Muscle fibers