CH7 Flashcards
control the digestive system and other organs
Smooth muscles
control movement of the body in relation to the environment
Skeletal muscles/striated muscles
heart muscles that have properties of skeletal and smooth muscles
Cardiac muscles
a synapse between a motor neuron axon and a muscle fiber
neuromuscular junction
causes the muscle to contract
Release of acetylcholine
fibers produce fast contractions but fatigue rapidly
are anaerobic and use reactions that do not require oxygen, resulting in fatigue
Fast-twitch
fibers produce less vigorous contraction without fatigue
are aerobic and require oxygen during movement and therefore do not fatigue
Slow-twitch
receptors that detect the position or movement of a part of the body
Proprioceptors
are proprioceptors parallel to the muscle that respond to a stretch: cause a contraction of the muscle
Muscle spindles
occurs when muscle proprioceptors detect the stretch and tension of a muscle and send messages to the spinal cord to contract it
stretch reflex
refers to a fixed sequence of movements that is either learned or built into the nervous system
motor program
located in the precentral gyrus located in the frontal lobe
“orders” an outcome
active when people intend a movement
primary motor cortex
keeps track of the position of the body relative to the world
Damage to this area causes difficulty in coordinating visual stimuli with movement
Important for planning movement
Posterior parietal cortex
Active during preparation for movement
Receives information about a target
Integrates information about position and posture of the body; organizes the direction of the movement in space
Premotor cortex
Organizes rapid sequence of movements in a specific order; inhibitory if necessary
Active seconds before the movement
Active following an error in movement so you can inhibit the incorrect movement the next time
Supplementary motor cortex
Active during a delay before movement
Stores sensory information relative to a movement
Necessary for you to consider the probable outcomes of a movement
Prefrontal cortex
inhibits a saccade, a voluntary eye movement from one target to another
Antisaccade task
Neurons that are active during both preparation of a movement and while watching someone else perform the same or similar movement
May be important for understanding, identifying, and imitating other people
May be involved in social behaviors
Unknown whether they cause or result from social behavior
Mirror Neurons
are paths from the cerebral cortex to the spinal cord
Corticospinal tracts
a midbrain area with output mainly to the arm muscles
Red nucleus
a brain area that receives information from the vestibular system
Vestibular nucleus
controls the muscles of the neck, shoulders, and trunk
Responsible for bilateral movements like walking, turning, bending, standing up, and sitting down
Medial Corticospinal Tract
Inability for voluntary movement in part of the body
Cause: Damage to motor neurons or their axons in the spinal cord
Paralysis
Loss of sensation and voluntary muscle control in the legs (Despite the lack of sensations from the genitals, stimulation of the genitals can produce orgasm.)
Cause: A cut through the spinal cord in the thoracic region or Lower
Paraplegia
Loss of sensation and voluntary muscle control in both arms and legs
Cause: Cut through the spinal cord in the cervical (neck) region (or cortical damage)
Quadriplegia (or tetraplegia)
Loss of sensation and voluntary muscle control in the arm and leg of either the right or left side
Cause: Cut halfway through the spinal cord or damage to one hemisphere of the cerebral cortex
Hemiplegia
Impaired sensations and muscle control in the legs and pelvic region, including bowel and bladder control
Cause: Damage to the dorsal roots of the spinal cord from the late stage of syphilis
Tabes dorsalis
Paralysis.
Cause: A virus that damages motor neurons in the spinal cord
Poliomyelitis
Gradual weakness and paralysis, starting with the arms and spreading to the legs
Cause: Unknown. Traced to genetic mutations in some cases, and to exposure to toxins in other cases
Amyotrophic lateral sclerosis
A structure in the brain often associated with balance and coordination
Important for the establishment of new motor programs that allow the execution of a sequence of actions as a whole, for example, tasks that require timing
Also critical for certain aspects of attention, such as the ability to shift attention and attend to visual stimuli
The Cerebellum
is the surface of the cerebellum
cerebellar cortex
flat parallel cells in sequential planes
transmit inhibitory messages to the cells in the nuclei of the cerebellum (clusters of cell bodies in the interior of the cerebellum) and the vestibular nuclei in the brain stem
Purkinje cells
axons parallel to one another; perpendicular to planes of Purkinje cells
Parallel fibers
_____ excite ____
parallel fibers, purkinje cells
a group of large subcortical structures in the forebrain
critical for learning motor skills, organizing sequences of movement, “automatic” behaviors, and new habits
basal ganglia
a particular type of activity in the motor cortex that occurs before any type of voluntary movement
readiness potential
A movement disorder characterized by muscle tremors, rigidity, slow movements, and difficulty initiating physical and mental activity
Caused by gradual and progressive death of neurons, especially in the substantia nigra
Parkinson’s Disease
A neurological disorder characterized by various motors symptoms
Associated with gradual and extensive brain damage especially in the basal ganglia but also in the cerebral cortex
Motors symptoms progress to tremors and writhing that affect the person’s walking, speech, and other voluntary movements
Huntington’s Disease
