Chapter 4

a neuron that conducts impulses from the periphery to the central nervous system; also known as sensory neuron

a motor neuron that transmits impulses from the central nervous system to the extrafusal skeletal muscle fibers

the branch of the nervous system that regulates involuntary functions, including the activity of the cardiac muscle, smooth muscle, and glands

the portion of a neuron that conducts impulses away from the cell body

paired masses of gray matter in each cerebral hemisphere

large pyramidal cells in the motor area of the precentral gyrus of the cerebral cortex; also known as Bevan–Lewis cells

the brain and spinal cord

reflex extension of the contralateral (opposite) limb

the portion of a neuron that receives impulses

a neuron that conducts impulses from the central nervous system to the muscles and other effectors; also known as motor neuron

the recording of muscle action potentials (or their currents)

a tool that finds the average amplitude of summated muscle action potentials

the fluid in the semicircular canals of the inner ear

a typical skeletal muscle fiber

the portion of the brainstem and spinal pathways that do not pass through the pyramids and are concerned with postural control

an involuntary flexion of a muscle in response to a stimulus; allows for the removal of the body part from the stimulus; a simple reflex

the domain of the EMG signal that is the rate at which a wave form fluctuates above and below the baseline

a motor neuron that transmits impulses from the central nervous system to the intrafusal fibers of a muscle spindle

a sensory receptor in the tendon of a muscle; it is sensitive to stretch and serves as a detector of tendon tension

the mathematical process of determining the area under a curve; used to find the mean amplitude of summated muscle action potentials

a neuron that lies in the gray matter of the spinal cord, between a sensory and a motor neuron

a small fiber located within the capsule of a muscle spindle

The sense of movement and position of body parts in space

a neuron whose cell body is in the spinal cord

the precentral gyrus of the frontal lobe of the cerebrum; contains nerve cell bodies whose axons form the descending pyramidal motor tracts

a neuron that conducts impulses from the central nervous system to the muscles and other effectors; also known as efferent neuron

the electrical charge that accompanies the contraction of muscle tissue

a sensory receptor within skeletal muscle, containing intrafusal muscle fibers enclosed in a fibrous sheath; it is sensitive to stretch and serves as a detector of muscle length

a simple, two-neuron reflex in which the tapping (or stretching) of a tendon results in the contraction of that tendon’s muscle

a nerve cell

the division of the autonomic nervous system that originates in the brain and the sacral region of the spinal cord and is activated during times of inactivity and digestion of nutrients

the nerves that lie outside the brain and spinal cord

the use of an engineering instrument to trace a curve and find the area under it

spectrum that describes the amount of power that exists in the EMG at each given frequency

the portion of the brain that is rostral to the motor area and contains the nerve cell bodies of the extrapyramidal system

feedback of sensory information regarding movement and body position

the corticospinal pathways that originate in large nerve cells that are shaped like pyramids and have axons that synapse with the motor neurons in the ventral horn of the spinal cord

descending motor pathways that originate in cell bodies of the motor cortex and synapse with motor neurons in the ventral horn of the spinal cord

electromyography concerned with the wave form of the muscle action potential from single discrete motor units

electromyography concerned with the amount of electrical activity that is present in a given muscle under varying conditions

the neuromuscular function that serves to turn off one of a pair of muscles when its opponent is activated

an involuntary motor response to a sensory stimulus

a series of reflex movements that cause a person or animal placed upside down to change to an upright position

a neuron that conducts impulses from the periphery to the central nervous system; also known as afferent neuron

the branch of the nervous system that regulates voluntary functions

a two-neuron reflex in which a sensory neuron receives a stimulus and carries an impulse to the spinal cord, and the impulse is transmitted to another neuron, which carries the impulse to a muscle or gland

the division of the autonomic nervous system that originates in the thoracic and lumbar regions of the spinal cord and is activated in emergency or stressful situations

the domain of the EMG signal that involves determining the amplitude (voltage) of electrical current that exists during a specific period of time

a neuron whose cell body is in the brain

the portion of the inner ear that functions to provide a sense of equilibrium