Let’s make a muscle!
SUPPLIES
1 blue cut into 4 strips
1 white cut into 2 strips
1 yellow cut into 2 strips
3 half sheets of pink
1 full red sheet
Small strips of pink, blue
yellow, light green, dark
green, orange
Small piece of yarn
Glue stick
Scissors
Hole punch
2 colored markers
MYOFILAMENT
Groups of
myofilaments
make
myofibrils
MYOFIBRIL
Groups of myofibrils make a
muscle fiber
MYOFIBRIL
SR
T-tubule
SR
Triade
Crossbridge
MYOFIBRIL
SR
Sarcoplasmic reticulum. Type of organelle. Similar to Smooth ER in
other cells that form channels in the cytoplasm.
T-tubule A groove between the SRs
Triade
Group of 3: SR- T tubule - SR
Crossbridge Link filaments together during
contraction.
MUSCLE FIBER
The muscle
fiber is simply
the group of
myofilaments
and myofibrils
Covered
with an
endomysium
FASSICLE
The muscle fibers form a fassicle.
It is covered with the perimysium
The Muscle!
The entire muscle is covered
with the epimysium
Muscle Contraction and Relaxation
Myosin: pink
Actin:
blue
Tropomyosin: teal
Troponin:
orange
Calcium:
light green
Acetylcholine: yellow
Muscle Contraction and Relaxation
Myosin
Actin
Tropomyosin
Troponin
Calcium
Acetycholine
The Love Story
Completed Muscle
Major Events of Muscle
Contraction and Relaxation
Excitation and Contraction: put in the correct order:
5
3
SR releases Ca
6
1
Muscle fiber contracts
2
Contact is made btw muscle and neuron (neuromuscular
junction
4
Electrical charge travels over sacrolemma into T-tubules
into SR
Acetycholine is released causing an electrical change
(action potential)
Stimulus transmitted by neuron
Major Events of Muscle
Contraction and Relaxation
Relaxation: put in the correct order:
3
1
Muscle fiber returns to resting length
2
Cross bridge are prevented
SR actively pumps Ca back into sacs