Cscs Chapter - 2

Front 1

acetylcholine

Back 1

released on arrival of action potential at nerve terminal

diffuses across neuromuscular junction and excites sarcolemma

# when enough acetylCoa is generated, action potential generated across sarcolemma ----> then fiber contracts

Front 2

all-or-none principle

Back 2

all muscle fibres in a motor unit contract at the same time with the same power or not at all

Front 3

Type I fiber

Back 3

develop force and relax quickly
* Fatigue resistant
* high capacity for aerobic energy supply
* limited potential for rapid force development
o low actomyosin myofibril ATPase activity and low anerobic power

Front 4

Type II fiber

Back 4

# fatigueability
# low aerobic power
# rapid force development
# high actomyosin myofibril ATPase activity and high anerobic power

Front 5

Difference Between Type IIa and IIb fibers

Back 5

# Type IIa
* have greater capacity for aerobic metabolism and more capilaries surrounding them than type IIb
* therefore greater resistance to fatigue

# Type IIb
* less fatigue resistant than type IIa

Front 6

frequency of activation

Back 6

certain muscle vary frequency of fiber firing, thus limiting/increasing force production

Front 7

recruitment

Back 7

varying number of motor units activated

Front 8

proprioceptors

Back 8

# specialized sensory receptors locate in joints, muscles, tendons.

* sensitive to pressure and tension
* relay info regarding muscle dynamics to concious and subconcious parts of CNS
* brain get linesthetic sense, or conscious appreciation of body ind 3D space (spacial awareness)

Front 9

muscle spindles

Back 9

# proprioceptors that consist of several modified muscle fibres enclosed in a sheathe of CT
* called intrafusal fibers
# relay info on muscle length and rate of change in length
#detects and increases muscle activity in response to a stretch

Front 10

Golgi tendon organs

Back 10

# proprioceptors - located in tendons near myotendinous junction. in series (attached end to end) with extrafusal muscle fibers
# activated when tendon attached to a muscle is stretched
# as tension increases, activation of GTOs increases
# sensory neuron of GTO synapses with inhibitory interneuron in spinal cord

* interneuron synapses and inhibits a motor neuron that serves same muscle
* result is reduction in tension in muscle and tendon
* prohibits excess tension on muscle
* minimal activity at low force output, higher at high output

Front 11

adaptation to res ex

Back 11

hypertrophy - increase in x sectional area, not number of fibers

fast twitch seem to grow faster with res ex

Front 12

adaptations to aerobic ex

Back 12

increased aerobic capacity of muscle.
can compromise power gains