non-striated small, spindle-shaped muscle cells, usually with one nucleus per cell

- cytoplasm of a muscle fiber - contains many bundles of protein filaments

- bundles of protein filaments - consist of the myofilaments, actin and myosin

an increase in muscle tension, but no change in length

Na+ channels close change back to resting potential

have a resting membrane potential, but can also perform action potentials

- the ability to be stretched beyond it normal resting length and still be able to contract

ony striated, usebranching, with usually striated as a result of the sarcomere arrangement

- a vesicle in the presynaptic terminal that stores and releases neurotransmitter chemicals

refers to the cell-to-cell junction between a nerve cell and either another nerve cell

the time during which the muscle relaxes

- chemicals that stimulate or inhibit postsynaptic cells

- attached to bones - striated - voluntarily controlled

- muscle group subdivisions of skeletal muscles

a group of muscle fibers that a motor neuron stimulates

the increase in positive charge inside the cell membrane

the muscle fiber membrane (sarcolemma)

a temporary state of reduced work capacity

a connective tissue sheath that surrounds skeletal muscle

- dark staining bands - extend the length of the myosin myofilaments

- located in blood vessels, hollow organs - non-striated - involuntarily controlled

the electrical charge difference across the cell membrane of an unstimulated cell

the neurotransmitter that stimulates skeletal muscles

a single contraction of a muscle fiber in response to a stimulus - three phases: latent phase, contraction phase, and relaxation phase

resemble bundles of tiny golf clubs

specialized structures that include desmosomes and gap junctions

the ability of the muscle to recoil to its original resting length after it has been stretched

the basic structural and functional unit of a skeletal muscle

the ability of muscle to shorten forcefully, or contract

the end of the muscle attached to the bone undergoing the greatest movement

o a change in muscle length with no change in tension

- the constant tension produced by body muscles over long periods of time - responsible for keeping the back and legs straight, the head in an upright position, and the abdomen from bulging

has many tubelike inward folds called transverse tubules, or tubules

slide past each other, causing the sarcomeres to shorten

a single cylindrical cell, with several nuclei located at its periphery

contain several nuclei that are located at the periphery of the fiber

- band of connective tissue that holds down the tendons at each wrist and ankle

- a value where the depolarization changes - an action potential is triggered

- located in the heart - striated - involuntarily controlled

- occur at regular intervals along the muscle fiber and extend into the center of the muscle fiber -connect the sarcolemma to the terminal cisternae to form a muscle triad

- a nerve cell stimulates muscle cells

a synapse where a the fiber of a nerve connects with a muscle fiber

cause for action potential in muscle fibers

the end of a neuron cell axon fiber

group of muscles working together

the time between the application of a stimulus and the beginning of contraction

form a network of protein fibers that both serve as an anchor for actin myofilaments

connective tissue covering that surrounds each fascicle

light bands that consist only of actin - extends toward the center of the sarcomere to the ends of the myosin myofilaments

broad, sheetlike tendons

the space between the presynaptic terminal and postsynaptic membrane

- has a blend of types, with one type dominating - humans have both types of fibers - the distribution of fibers is genetically determined

muscle or group of muscles that oppose muscle actions

a rapid change in charge across the cell membrane

made up of three components: actin, troponin, and tropomyosin

connects skeletal muscle to bone

connective tissue covering that surrounds each skeletal muscle cell fiber

very energy-demanding cells whether at rest or during any form of exercise

the time during which the muscle contracts

- the capacity of muscle to respond to a stimulus

plays a major role in muscle contraction

due to the membrane having gated channels