Chapter 7 Brain and Behavior

smooth muscles

control the digestive system and other organs,

skeletal muscle

Control the body in relation to the environment

Cardiac muscles

Control the heart

neuromuscular junction

a synapse between a motor neuron axon and a muscle fiber.

antagonistic muscles

opposing sets of muscles that are required to move a leg or arm back and forth

flexor

muscle brings your hand toward your shoulder

extensor

muscle straightens the arm

fast twitch fibers

muscle fibers that contract rapidly and forcefully but fatigue quickly

slow twitch fibers

muscle fibers that contract at a slow rate and have very good endurance

aerobic

use oxygen during movements

anaerobic

using reactions that do not require oxygen at the time but need oxygen for recovery

proprioceptor

a receptor that detects the position or movement of a part of the body—in these cases, a muscle.

stretch reflex

muscle contraction in response to stretching within the muscle

muscle spindle

a receptor parallel to the muscle that responds to a stretch.

Golgi tendon organs

Receptors sensitive to change in tension of the muscle and the rate of that change

Reflexes

consistent automatic responses to stimuli in- sensitive to reinforcements, punishments, and motivations

ballistic movement

motion that proceeds as a single organized unit that cannot be redirected once it begins

central pattern generators

neural mechanisms in the spinal cord that generate rhythmic patterns of motor output.

motor program

a fixed sequence of movements

primary motor cortex

the section of the frontal lobe responsible for voluntary movement

posterior parietal cortex

monitors the position of the body relative to the world

supplementary motor cortex

important for planning and organizing a rapid sequence of movements

premotor cortex

area of the frontal cortex, active during the planning of a movement

Prefrontal cortex

also active during a delay before a movement, stores sensory information relevant to a movement

antisaccade task

a voluntary eye movement away from the normal direction

mirror neurons

Neurons that are active both during preparation for a movement and while watching someone else perform the same or a similar movement

corticospinal tracts.

Paths from the cerebral cortex to the spinal cord

lateral corticospinal tract

a set of axons from the primary motor cortex, surrounding areas, and midbrain area that is primarily responsible for controlling the peripheral muscles

red nucleus

A large nucleus of the midbrain that receives inputs from the cerebellum and motor cortex and sends axons to motor neurons in the spinal cord.

medial corticospinal tract

set of axons from many parts of the cerebral cortex, midbrain, and medulla; responsible for control of bilateral muscles of the neck, shoulders, and trunk

Vestibular nucleus

a brain area that receives input from the vestibular system

cerebellar cortex

the cortex that covers the surface of the cerebellum

Purkinje cells

are flat (two- dimensional) cells in sequential planes, parallel to one another

parallel fibers

axons parallel to one another and perpendicular to the planes of the Purkinje cells.

nuclei of the cerebellum

clusters of neurons in the interior of the cerebellum that send axons to motor-controlling areas outside the cerebellum

basal ganglia

a set of subcortical structures that directs intentional movements

caudate nucleus

one of the major nuclei that make up the basal ganglia

Putamen

large subcortical structure, part of the basal ganglia

globus pallidus

component of the basal ganglia that connects to the thalamus which relays information to the motor areas and the prefrontal cortex

dorsal striatum

caudate nucleus and putamen. Receives input from the cerebral cortex and substantia nigra and sends its output to the globus pallidus, which then sends output to the thalamus and frontal cortex.

readiness potential

the increased motor cortex activity prior to the start of the movement

Parkinson's disease

a progressive disease that destroys brain cells and is identified by muscular tremors, slowing of movement, and partial facial paralysis

MPTP

chemical that the body converts to MPP+ which accumulates in and then destroys neurons that release dopamine - substance responsible for the symptoms of Parkinsons - in herbicides and pesticides and can damage cells of substantia nigra

L-Dopa

A drug for Parkinson's disease that contains the precursors to dopamine so that once it is in the brain, it will be converted to dopamine.

Stem cells

unspecialized cells that are able to renew themselves for long periods of time by cell division

Huntington's disease

Genetic disorder that causes progressive deterioration of brain cells. caused by a dominant allele. symptoms do not appear until about the age of 30.

huntingtin