IB SEHS - not created by me

1. Neuromuscular Function
Disclaimer – Mrs. Rowe did NOT
create this – but I am sharing it.

2. Movement Analysis

3. Neuromuscular Function:
I. The Motor Unit:

5. II. The Structure of Muscle Tissue:

7. III. The Role of Neurotransmitters in stimulating
skeletal muscle contraction:
A. Acetylcholine (Ach):
increases the post-
synaptic membrane’s
permeability to sodium
and potassium ions
spreading the impulse
over the entire muscle
fiber.

9. B. Cholinesterase: enzyme that breaks down Ach repolarizing
the muscle fiber to await another nerve impulse.

10. IV. Skeletal Muscle Contraction:

13. A. The sliding filament theory:
Steps of a muscle
contraction:
*Ca++ are released by the
sarcoplasmic reticulum.
*Ca++ binds to troponin
preventing the blocking
action of tropomyosin.

14. Sliding filament cont.
*myosin heads can now
attach to active sites on
the actin filament.
*myosin heads pulls on
the actin filament,
decreasing the width of
the sarcomere.
*myosin head releases the
actin when a new ATP is

17. V. Types of Muscle Fibers:
A. Slow Twitch: (type 1)
*smaller in diameter
*reddish color
*use aerobic resp. for ATP
supply
*contain more mitochondria
*fire slowly, but take long to
fatigue.

18. B. Fast Twitch: used for short explosive movements,
stop and go sports.
Type IIA:
*large diameter
*white in color
*less mitochondria
*uses both anaerobic and
aerobic energy transfer
Type IIB:
*same physical
characteristics as Type
IIA, but strictly uses the
glycolytic anaerobic
system.