it14spr201.20bc12t1,2.txt

The synapse where a motor neuron axon and a skeletal muscle fiber meet

The functional connection between the axon of one neuron and the dendrite or cell body of another or membrane of another cell

A narrow extracellular space between the cells at a synapse

Neurons that conduct impulses from the CNS to an effector

A specialized part of a muscle fiber membrane at a neuromuscular junction

A type of neurotransmitter which is a biochemical secreted at the axon end of neurons which acts on post-synaptic cell

Motor neurons that originate in motor region of the cerebral cortex or brain stem and carry motor information down to the final common pathway – any motor neurons that are not directly responsible for stimulating the target muscle

The motor neurons connecting the brain stem and spinal cord to muscle fibers, bringing the nerve impulses from the upper motor neurons out to the muscles – axon terminates on an effector

Wave of excitation along a muscle fiber initiated neuromuscular endplate, accompanied by chemical and electrical changes at the surface of the muscle fiber and by activation of contractile elements of muscle fiber

Depolarization of skeletal muscle fibers caused by neurotransmitters binding to post synaptic membrane in neuromuscular junction

Enzymes catalyze the breakdown of acetylcholine

Highly organized bundles of contractile and elastic proteins that carry out the work of the contraction; consist of two types of protein filaments (thick/myosin and thin/actin); the main intra-cellular structure in striated muscles

The cells that comprise muscle tissue; a muscle cell

Motor protein with the ability to create movement; combine to form thick filaments

A protein that makes up the thin filaments

The striations (repeating patterns of light and dark bands) created by the thick (myocin) and thin (actin) filaments – one repeat of patter forms one unit; functionional unit of skeletal muscle

Accessory protein that attaches myosin filaments to Z links

Calcium binding complex of 3 proteins – controls positioning of tropomyosin (associated with actin filaments)

Rod-shaped molecules that occupy the longitudinal grooves of the actin helix – held in place by troponin molecule – blocks myosin from binding in resting skeletal mode

A form of modified ER that wraps around each myofibril like a piece of lace – consists of longitudinal tubules with enlarged end regions called cisternae

A set of membrane channels, each between two cisternae (forming a triad) that extend into the sarcoplasm and contain ECF. Allow action potentials to move rapidly from cell surface to interior of muscle fiber

Enlarged portions of sarcoplasmic reticulum (longitudinal tubules – two join transverse tubules to form triad)

An aggregatin of myosin in muscle; About 250 myosin molecules join to create

Filaments made of actin

More motor units are activated due to the intensity of stimulation to increase the force of contraction in a muscle