MOD F

synapse

The upper motor neuron will ___ with the α-motor neuron before reaching the muscle.

NMJ

A _______ is a synapse between a motor neuron and a muscle fiber

Axon terminal

this is the end of the motor neuron

the synaptic knob or the terminal bouton

Another term for axon terminal

Pre-synaptic membrane

the membrane of the axon terminal

 Synaptic vesicles:

: are filled with a _neurotransmitter___, which is a chemical messenger.

acetylcholine.

 The neurotransmitter found in synaptic vesicles is called

Synaptic cleft

this is an open space where the neurotransmitter diffuses across.

motor end plate

this is the area of the muscle fiber that the α-motor neuron synapses with.

Sarcolemma:

 the muscle cell membrane

Chemical (or ligand)-gated ___sodium_ ion channels

 open in response to neurotransmitter; these are also referred to as acetylcholine receptors

contraction

Excitation-contraction coupling is the process by which the activation of a skeletal muscle fiber leads to

troponin

 The calcium travels through the sarcoplasm/cytosol until it binds to___ on the sarcomere’s thin filament

cross-bridge cycling

 Once actin and myosin are able to connect with one another, _____can occur.

contraction AND skeletal muscle relaxation

ATP is required for:  skeletal muscle _____ and _____

cross bridge cycling, myosin filaments, actin filaments

 When your muscles are activated,____ occurs and your ____ pull your ___ filaments towards the center of the sarcomere.

Concentric action

 during this type of muscle action, the skeletal muscle is__shortened_

 Eccentric action

: during this type of muscle action, the skeletal muscle is_lengthened_

Isometric action

during this type of muscle action, the skeletal muscle length__ does not move

an eccentric action

are the most likely type of muscle action to cause delayed-onset muscle soreness.

alpha-motor neuron ,force-frequency relationship

You can change the force output of skeletal muscle in several ways: Changing how quickly the_____ fires; this is referred to as the _ __ 

motor units

You can change the force output of skeletal muscle in several ways: Changing how many ____ are recruited; this is related to changing the strength of stimulation.

length , length-tension relationship

You can change the force output of skeletal muscle in several ways:Changing the ___ of the muscle before it is stimulated; this is referred to as the __.

highest

When the length of the muscle is optimal (i.e., ideal actin and myosin overlap), force output is

speed, force-velocity relationship.

You can change the force output of skeletal muscle in several ways:  Changing the ___ of a concentric action; this is referred to as the__

increases

Decreasing the speed of a concentric action ___ the amount of force you can generate.and vis versa

50-50

 The muscles of a sedentary individual are

are primarily made of__fast fibers __type II.

The muscles of successful power athletes

 slow fibers_ type I

The muscles of successful endurance athletes are

growth & repair.

Satellite cells are undifferentiated cells that play a role in skeletal muscle______

sarcolemma & basal lamina

Satellite cells are located between the _______ of the endomysium (i.e., just outside the skeletal muscle cell membrane).

resistance training

In response to ___ satellite cells divide and become new nuclei

muscle cramp

a painful, spasmodic, involuntary muscle contraction.

spinal reflex activity

 Under most conditions, muscle cramps are most likely caused by a fatigue-related change in _____________

muscle spindles, golgi tendon organs

This means that. __ _____ will start to fire too much, leading to inappropriate motor unit activation, AND ____ will fire less than they should,

passive stretching

is the best way to relieve a muscle cramp because it activates the

golgi tendon organ, which leads to relaxation