Topic 4 Flashcards
Label a diagram of a motor
unit
Limit to:
7 marks
* dendrite
* cell body
* nucleus
* axon
* motor end plate
* synapse
* muscle
Explain the role of
neurotransmitters in
stimulating skeletal muscle
contraction
Limit to acetylcholine and cholinesterase.
When a nerve action potential arrives at a motor end plate, Acetylcholine (Ach) is released from the synaptic knobs and diffuses across the synaptic cleft to bind with post-synaptic receptors. This takes approximately 0.5 milliseconds to complete and is followed by a muscle action potential which is required to initiate muscular contraction.
Once the nerve action potential is completed, Cholinesterase is released.
This enzyme is responsible for the hydrolysis of acetylcholine into choline and acetic acid, clearing the synaptic cleft in readiness for the next impulse.
This is necessary in order to avoid continuous synaptic transmission.
Explain how skeletal muscle
contracts by the sliding
filament theory
Include the terms:
* myofibril
* myofilament
* sarcomere
* actin
* myosin
* H zone
* A band
* Z line
* tropomyosin
* troponin
* sarcoplasmic reticulum
* calcium ions
* ATP.
Aim 7: Various online muscle contraction
simulations are available
Explain how slow and fast
twitch fibre types differ in
structure and function
Limit fibre types to slow twitch (type I) and fast
twitch (type IIa and type IIb).
Type IIa and IIb are high in glycogen content
depending on training status.
Aim 8: Implications of invasive techniques for
taking samples, such as muscle biopsies.
Aim 9: Implications of drawing conclusions from
indirect measurements.
Outline the types of
movement of synovial joints
Outline the types of muscle
contraction
Isotonic: Muscle changes length under constant tension (e.g., bicep curl).
Isometric: Muscle contracts without changing length (e.g., plank).
Isokinetic: Muscle moves at a constant speed with variable resistance (e.g., rehab machines).
Concentric: Muscle shortens while contracting (e.g., lifting a weight).
Eccentric: Muscle lengthens while contracting (e.g., lowering a weight).
Explain the concept of
reciprocal inhibition
Analyse movements in
relation to joint action and
muscle contraction
Explain delayed onset
muscle soreness (DOMS)
in relation to eccentric
and concentric muscle
contractions
Define the terms force,
speed, velocity, displacement,
acceleration, momentum and
impulse
Analyse velocity–time,
distance–time and force–
time graphs of sporting
actions
Define the term centre of
mass
Explain that a change
in body position during
sporting activities can
change the position of the
centre of mass
Distinguish between first,
second and third class levers
Label anatomical
representations of levers
Define Newton’s three laws
of motion.
Explain how Newton’s three
laws of motion apply to
sporting activities
State the relationship
between angular
momentum, moment of
inertia and angular velocity
Explain the concept of
angular momentum in
relation to sporting activities
Explain the factors that
affect projectile motion at
take-off or release
Outline the Bernoulli
principle with respect to
projectile motion in sporting
activities
