Bio 150 Ch11v

A form of physical exercise, such as running or swimming, that promotes cariopulmonary efficiency and fatigue resistance more than muscular strength. Compare resistance exercise.

A neurotransmitter released by somatic motor fibers, parasympathetic fibers, and some other neurons, composed of choline and an acetyl group

A muscle contraction in which the muscle shortens and moves a load while its internal tension remains constant

A stable voltage across the plasma membrane of an unstimulated cell

In skeletal and cardiac muscle, the portion of a myofibril from one Z disc to the next, constituting one contractile unit

An intracellular protein that binds calcium ions and mediates many of the second messenger effects of calcium

A microscope that uses an electron beam in place of light to form high-resolution, three-dimensional images of the surfaces of objects; capable of much higher magnification than a light microscope

Nonstriated invoulantary muscle found in the walls of the blood vessels, many of the viscera, and other places

A junction at the end of an axon where it stimulates another cell

The tendency of a stretched structure to return to its original dimensions when tension is released

A rapid voltage change in which a plasma membrane briefly reverses electrical polarity; has a self-propagating effect that produces a traveling wave of excitation in nerve and muscle cells

A motor protein that constitues the thick myofilaments of muscle and has globular, mobile heads of atpase that bind to actin molecules

The smooth endoplasmic reticulum of a muscle cell, serving as a calcium reservoir

The swollen tips of the distal branches of an axon; the site of synaptic vesicles and neurotransmitter release

A protein found in smooth endoplasmic reticulum that reversibly binds and stores calcium ions, rendering calcium chemically unreactive until needed for such processes as muscle contraction

A spheroid organelle in a synaptic knob containing neurotransmitter

A tissue composed of elongated, electrically excitable cells specialized for contractio; the three types are skeletal, cardiac, and smooth muscle

A red oxygen-storage pigment of muscle; supplements hemoglobin in providing oxygen for aerobic muscle metabolism

A narrow space between the synaptic knob of an axon and the adjacent cell, across which a neurotransmitter diffuses

The minimum voltage to which the plasma membrane of a nerve or muscle cell must be depolarized before it produces an action potential

A bundle of myofilaments forming an internal subdivision of a cardiac or skeletal muscle cell

An energy storage molecule in muscle tissue that donates a phosphate group to ADP and thus regenerates ATP in periods of hypoxia

A catecholamine that functions as a neurotransmitter and adrenal hormone, especially in the sympathetic nervous system

Events that link the synaptic stimulation of a muscle cell to the onset of contraction

A tubular extension of the plasma membrane of a muscle cell that conducts action potentials into the sarcoplasm and excites the sarcoplasmic reticulum

An enzyme that hydrolyzes acetylcholine, thus halting signal transmission at a cholinergic synapse

The ability of a cell to respond to a stimulus, especially the ability of nerve and muscle cells to produce membrane voltage changes in response to stimuli; irritability

A law that relates the tension generated by muscle contraction to the length of the muscle fiber prior to stimulation; it shows that the greatest tension is generated when the fiber exhibits an intermediate degree of stretch before stimulation

A diffrence in ion concentration from one point to another, resulting in a gradient of both chemical concentration and electrical charge

Having the same osmotic pressure as human cells or some other reference solution

The interval between a stimulus and response, especially in the action of nerve muscle cells

A muscle contraction in which internal tension rises but the mucsle does not shorten

A depression in a muscle fiber where it has synaptic contact with a nerve fiber and has a high density of neurotransmitter receptors

One motor neuron and all the skeletal muscle fibers innervated by it

A state of continual, partial contraction of resting skeletal or smooth muscle

A protein microfilament responsible for the contraction of a muscle cell, composed mainly of myosin or actin

A statement pertaining to action potentials and the contraction of muscle fibers that a cell either produces its maximum response or no response at all, depending on whether the stimulus is above or below threshold.

A synapse between a nerve fiber and a muscle fiber

A wave of constriction traveling along a tubular organ such as the esophagus or ureter, serving to propel its contents

A perriod of time after a nerve or musle cell has responded to a stimulus in which it cannot be reexcited by a threshold stimulus