Chapter 4 Flashcards
neuron
a nerve cell; the basic component of the nervous system
dendrites
receive neural impulses from other neurons;
neuron may have none or as many as thousands of dendrites
axons
extensions from neuron’s cell body that transmit neural impulses to other neurons, structures in the CNS, or muscles; a neuron has only one axon, although most axons branch into many branches
sensory neurons
afferent
nerve cells that send neural impulses to the CNS
motor neurons
efferent
nerve cells that send neural impulses from the CNS to skeletal muscle fibers
interneurons
specialized nerve cells that originate and terminate in the brain or spinal cord; they function between axons descending from the brain and synapse on motor neurons, and between the axons from sensory nerves and the spinal nerves ascending to the brain
cerebrum
a brain structure in the forebrain the consists of 2 halves, known as right and left cerebral hemispheres
Alpha motor neurons
in spinal cord, axons synapse on skeletal muscles
gamma motor neurons
in intrafusal fibers of skeletal muscles
cerebral cortex
the undulating, wrinkly, gray-colored surface of the cerebrum; it is a thin tissue of nerve cell bodies (2-5 mm thick) called gray matter
sensory cortex
cerebral cortex area located posterior to the central sulcus; it includes several specific regions that receive sentry info transmitted via the sensory nerves specific to that type of info
4 structures that are directly involved in the control of voluntary movement
cerebrum, diencephalon, cerebellum, brainstem
primary motor cortex
a cerebral cortex area located in the frontal lobe just anterior to the central sulcus; it contains motor neurons that send axons to specific skeletal muscles throughout the body
lower limb, trunk, upper limb, head
pre-motor area
cerebral cortex are located in the frontal lobe just anterior to the primary motor cortex
supplementary motor area (SMA)
a cerebral cortex area located on the medial surface of the frontal lobe adjacent to portions of the primary motor cortex
gyrus
ridges, within the lobes
sulcus
groove, separate the loves
4 lobes
frontal, parietal, temporal, occipital
Central Sulcus
separates movement portion of brain (forebrain) and sensory brain (posterior)
sits behind primary motor, infant of pre-motor
parietal lobe
an area of the cerebral cortex that plays an important role in the control of voluntary movement, such as the integration of movement preparation and execution processes by interacting with the premotor cortex, primary motor cortex, and SMA before and during movement
basal ganglia
subcortical collection of nuclei, buried within the cerebral hemispheres;
receives info from cerebral cortex and brainstem. sends info to brainstem via thalamus & cerebral cortex
parkinson’s disease
basal ganglia disorder caused by the lack of production of the neurotransmitter dopamine by the substantial nigra;
the disease is characterized by slow movements (bradykinesia), a reduced amount of movement (akinesia), tremor and muscular rigidity (aka BART Bradykinesia Akinesia rigidity tremor)
diencephalon
a component of the forebrain located between the cerebrum and the brainstem;
it contains the thalamus and hypothalamus
cerebellum
a brain structure located behind the cerebral hemispheres and attached to the brainstem; it is covered by the cerebellar cortex and is divided into 2 hemispheres;
it plays a key role in the execution of smooth and accurate movements, eye-hand coordination,
movement error correction system
involved in learning motor skills
brainstem
a brain structure located directly under the cerebral hemispheres and connected to the spinal cord;
it contains 3 areas that are significantly involved in motor control: the pons, medulla, and reticular formation
primary motor cortex function
initiate and coordinate movements for fine motor control, postural coordination
limbic system
a group of brain structures consisting of parts of the frontal and temporal lobes of the cerebral cortex, the thalamus and hypothalamus, and the nerve fibers that interconnect these parts and other CNS structures; it is involved in the learning of motor skills
Premotor Area function
organization of movements before they are initiated
rhythmic coordination during movement
control of movement based on observing another person performing a skill
ascending tracts
sensory neural pathways in the spinal cord and brainstem that connect with the various sensory areas of the cerebral cortex and cerebellum
descending tracts
motor neural pathways that descend from the brain through the spinal cord
supplementary motor area function
sequential movements
preparation and organization of movement
motor unit
the alpha motor neuron and all the muscle fibers it innervates; it serves as the functional unit of motor control for the innervation of the muscles involved in a movement
motor unit recruitment
the process of increasing the # of motor units needed to increase the number of muscle fibers active at any one time and thereby increase the amount of force the muscle can exert
parietal lobe function
interacts with pre-motor cortex, primary motor cortex, and SMA before and during movement
basal ganglia function
movement initiation
antagonist muscles during movements
force
pons
involved in control of various body functions (ex chewing) and balance
medulla
regulatory center for internal physiologic processes (ex breathing)
reticular formation
integrator of sensory and motor info; inhibits/activates neural signals to skeletal muscles
2 important sensory tracts for motor control
dorsal column
anterolateral system
-cross from left to right at brainstem
spinocerebellar tract
primary pathway for proprioceptive information
pyramidal tracts
(descending-corticospinal tracts)
60% are motor neurons
most fibers cross to other side of body
involved in control of fine motor skill performance
non-pyramidnal tracts
(descending - brainstem pathways)
fibers do not cross to other side of body
involved in postural control and control of hand and finger flexion-extension
research carson and kelso (2004)
Participants performed finger-flexion movement to a metronome
On the beat (synchronize) Between beats (syncopate)
Task involved exactly the same movement but two different cognitive intentions
