Practical/Exam 3 Muscle Structures, Movements, Parts, Clinical Application

Fascicle

A bundle of individual muscle fibers

Muscle Fiber

A single muscle cell composed of myofibrils that is enclosed in a specialized plasma membrane (sarcolemma).

oxidative phosphorylation

Aerobic Metabolism that takes place inside the mitochondria

Glycolysis

Anaerobic Metabolism that occurs outside the mitochondria

Abduction

Arm: Hand: Thigh: Digits:

Adduction

Arm: Hand: Thigh: Digits:

Lateral Rotation

Arm: Thigh:

Medial Rotation

Arm: Thigh:

Thick Filament

Contains myosin heads

Perimysium

Dense Irregular connective tissue surrounds fascicles

Epimysium

Dense irregular connective tissue that surrounds muscles

Opposition

Digits:

Dorsiflexion

Foot:

Eversion

Foot:

Inversion

Foot:

Plantar Flexion

Foot:

Muscle

Formed by groups of fascicles

Tendons

Formed from endomysium, perimysium, and epimysium that extend beyond each muscles fiber that attach the muscle to bone.

Pronation

Hand:

Supination

Hand:

Extension

Head: Arm: Forearm: Hand: Thigh: Leg:

Flexion

Head: Arm: Forearm: Hand: Thigh: Leg:

Synergist

Helps the agonist

Depression

Jaw:

Elevation

Jaw:

Protraction

Jaw:

Retraction

Jaw:

Endomysium

Layer of connective tissue surrounding individual muscle fibers

Circumduction

Leg: Arm:

Insertion

Moves toward the origin. The majority of tension developed when a muscles contracts is focused here

Rotation

Neck:

I Band

Only thin filament Decreases in size during contraction

Z Disc

Stabilizes proteins Size doesn't change during contraction

Fixator

Stabilizes the origin of the prime mover to increase efficiency

Triad

Two terminal cisternae on either side of a transverse tubule

Slow Oxidative FIbers

Type I Aerobic Respiration High fatigue resistance Slow rate of contraction High mitochondrial density High capillary density High myoglobin presence (dark red) 1st to be recruited

Fast Oxidative-Glycolytic Fibers

Type IIa Aerobic + Anaerobic Respiration Intermediate fatigue resistance Intermediate rate of contraction Intermediate mitochondrial density Intermediate capillary density Intermediate myoglobin presence (pinkish) 2nd to be recruited

Fast Glycolytic Fibers

Type IIx Anaerobic Respiration Low fatigue resistance Fast rate of contraction Low mitochondrial density Low capillary density Low myoglobin presence (white) 3rd to be recruited

Antagonist

Works against the agonist

Thin Filament

contains actin, troponin, tropomyosin

A Band

entire length of thick filament doesn't change during contraction

Transverse Tubules

extensions of the sarcolemma, contain large concentrations of ion channels, and permit rapid transmission of an AP into the cell

Maximal Voluntary Contraction

force and EMG amplitude decrease over time, BUT effort increases over time because all motor units are recruited at the start then drop off due to fatigue

Submaximal Contraction

force at onset and middle are 50% max then decrease at end, EMG Amplitude increase from middle to onset then decrease at end, effort increases over time due to submaximal number of motor units recruited which when they begin to fatigue more are recruited to take their place. After all are recruited they'll fatigue

Ramp Contraction

force, EMG amplitude, and effort increases over time as more motor units are recruited to increase force produced by the muscle

M Line

midline of sarcomere doesn't change during contraction

Isometric Contraction

no change in length but tension increases

Origin

nonmoving point of attachment when a muscle contracts

Motor Unit

one motor neuron and all the muscle fibers innervated by that motor neuron

H Zone

only thick filaments decreases in size during contraction

Botox side effects

pain, swelling, bruising, headaches/flu symptoms, eyelid drooping, crooked smile, and eye dryness/redness Can cause muscle weakness, vision/breathing problems, trouble swallowing or speaking

Agonist

prime mover

Botox

strain of a toxin produced by bacterium "Clostridium botulinum" created in the 1980s to treat double vision. 1 gram can kill a human, but in diluted solutions it can smooth wrinkles, reduce sweating, reduce muscle spasms, fix crossed eyes, help with migraines, and help with bladder control. Lasts 3-6 months

Electromyography (EMG)

technique used monitor the electrical activity of muscle cells by using electrodes that detect change in electrical charge due to current flow associated with muscle excitation helps determine muscle action to be ab/normal

Isotonic Contraction

tension is constant but length changes

Botox mechanism

weaken or paralyze muscles by inhibiting the ACH release from the presynaptic motor neuron to keep the signal from being sent.

Zone of overlap

where thick and thin filaments overlap increases in size during contraction

Terminal Cisternae

Store calcium, increase the SRs capacity to release