NSCI 2101 Exam 3

Doesn't include the labs, but has everything else!

Somatomotor System

System that controls striated skeletal muscles (i.e. movement)

Autonomic Motor System

System that controls the heart, blood vessels, and digestive tract

Primary Motor Cortex

Somatotopically organized region of the frontal lobe responsible for voluntary movement

Premotor Cortex

Region of the frontal lobe responsible for planning and organizing movement

Upper Motor Neurons

Motor neurons that start in layer V of the cerebral neocortex and travel to the brainstem

Lower Motor Neurons

Motor neurons that start in the brainstem and have somas in the ventral root of the spinal cord and cranial nerve motor nuclei in the brainstem

Neuromuscular Junction

Synapse between a lower motor neuron and muscle fibers

Acetylcholine

Neurotransmitter released by lower motor neurons

Acetylcholine Receptors

Ligand-gated ion channels in muscle fibers

Myosin Molecules

Thick muscle filaments which require ATP to produce muscle contractions

Actin Molecules

Thin muscle filaments that slide across thick filaments to produce muscle contractions

Muscle Fibers

Muscle cells

Muscle Fascicles

Bundles of muscle fibers

Type I Muscle Fibers

Thin low-force muscle fibers utilized in slow and sustained exercise

Type IIa Muscle Fibers

Thick mid-force muscle fibers utilized in short and intense exercise

Type IIb Muscle Fibers

Thick high-force muscle fibers utilized in short and intense exercise

Motor Unit

Lower motor neuron and the specific muscle fibers it innervates

Fine Control Motor Units

Small motor units found in the hands and face

Course Control Motor Units

Large motor units found in the thigh and back

Pyramidal Tracts

Tracts that originate in the cerebral cortex and descend through the pyramids of the medulla

Corticobulbar Tract Function

Tract that controls voluntary movements of the eyes, face, mouth, larynx, and neck

Corticospinal Tract Function

Tracts that control voluntary movements of the trunk and limbs

Lateral Corticospinal Tract Function

Tract that controls voluntary movements of the limbs

Ventral Corticospinal Tract Function

Tract that controls voluntary movements of the trunk

Corticobulbar Tract Pathway

Tract that descends from the motor cortex through the internal capsule and cerebral peduncle and projects bilaterally to the cranial nerve lower motor nuclei in the brainstem

Corticospinal Tract Pathway

Tract that descends from the motor cortex and premotor cortex through the internal capsule, cerebral peduncle, pons, and pyramids before descending through two different pathways at the lower medulla

Lateral Corticospinal Tract Pathway

Corticospinal tract that descends contralaterally after the lower medulla and projects laterally to the lateral ventral horn of the spinal cord

Ventral Corticospinal Tract Pathway

Corticospinal tract that descends ipsilaterally after the lower medulla and projects bilaterally to the medial ventral horn of the spinal cord

Reflex Circuit

Circuit from a sensory neuron to a motor neuron through an interneuron in the spinal cord that produces an involuntary muscle response

Rubrospinal Tract

Tract from red nucleus to spinal cord that coordinates fine limb movements

Vestibulospinal Tract

Tract from vestibular nucleus to spinal cord that controls balance and head position adjustments

Reticulospinal Tract

Tract from reticular formation to spinal cord that controls posture and learned limb movements

Tectospinal Tract

Tract from superior colliculus to cervical spinal cord that coordinates head and eye movements

Amyotrophic Lateral Sclerosis

Progressive loss of motor control due to degeneration of motor neurons

Primary Lateral Sclerosis

Progressive loss of motor control due to degeneration of upper motor neurons

Progressive Muscle Atrophy

Progressive loss of motor control due to degeneration of lower motor neurons

Paralytic Polio

Loss of motor control due to the death of motor neurons caused by a virus

Basal Ganglia

Subcortical nuclei critical for information processing related to decision making and movement selection

Striatum

Basal ganglia structure in the telencephalon consisting of the caudate nucleus, putamen, and nucleus accumbens

Caudate Nucleus

Upper dorsal section of the striatum

Putamen

Lateral ventral section of the striatum

Nucleus Accumbens

Medial ventral section of the rostral striatum

Globus Pallidus

Basal ganglia in the telencephalon medial to the putamen

External Globus Pallidus

Lateral globus pallidus

Internal Globus Pallidus

Medial globus pallidus

Substantia Nigra

Basal ganglia structure in the midbrain caudal to the thalamus

Pars Compacta

Dorsal substantia nigra

Pars Reticulata

Ventral substantia nigra

Subthalamic Nucleus

Basal ganglia structure in the diencephalon caudal to the thalamus

Medium Spiny Neurons

Inhibitory projection neurons of the striatum

Nigrostriatal Neurons

Neurons that project dopamine to the striatum

Corticostriatal Neurons

Neurons that project glutamate to the striatum

Cortex Circuitry

Structure that receives glutamate from the thalamus and projects glutamate to the striatum

Thalamus Circuitry

Structure that receives GABA from the internal globus pallidus and pars reticulata and projects glutamate to the cortex

Striatum Circuitry

Structure that receives glutamate from the cortex and projects glutamate to the globus pallidus and substantia nigra

External Globus Pallidus Circuitry

Structure that receives GABA from the striatum and projects GABA to the internal globus pallidus

Internal Globus Pallidus / Pars Reticulata Circuitry

Structure that receives GABA from the striatum and external globus pallidus and glutamate from the subthalamic nucleus and projects GABA to the ventral anterior and ventral lateral thalamus

Pars Compacta Circuitry

Structure that receives GABA from the striatum and projects dopamine to the striatum

Subthalamic Nucleus Circuitry

Structure that receives GABA from the external globus pallidus and projects glutamate to the internal globus pallidus and pars reticulata

Hypokinesia

Reduced movements

Akinesia

Impaired initiation of movements

Bradykinesia

Slowed movements

Rigidity

Stiff movements

Hyperkinesia

Increased movements

Chorea

Jerky movements

Athetosis

Slow twisting movements

Ballism

Flailing movements

Basal Ganglia Dysfunction

Cause of many motor diseases

Deep Brain Stimulation

Electrode stimulation in the internal globus pallidus and subthalamic nucleus

Parkinson’s Cause

Degeneration of dopamine neurons in the pars compacta

Parkinson’s Symptoms

Hypokinesia and tremors

Huntington’s Cause

Degeneration of medium spiny neurons in the striatum

Huntington’s Symptoms

Hyperkinesia

Tourette’s Cause

Dysfunction in striatal and frontal cortical circuits

Tourette’s Symptoms

Uncontrollable movements and vocalizations

Cerebellum

Brain structure that facilitates movement, coordination, balance, and some cognition

Cerebellar Cortex

External surface of the cerebellum

Cerebellar Folia

Ridges in the cerebellar cortex

Cerebellar Vermis

Medial cerebellum

Cerebellar Hemispheres

Lateral cerebellum

Superior Cerebellar Peduncles

Cerebellar peduncle that connects to the midbrain

Inferior Cerebellar Peduncles

Cerebellar peduncle that connects to the pons

Middle Cerebellar Peduncles

Cerebellar peduncle that connects to the medulla

Cerebellar Anterior Lobe

Cerebellar lobe rostral to the primary fissure

Cerebellar Posterior Lobe

Cerebellar lobe caudal to the primary fissure

Cerebellar Flocculonodular Lobe

Smallest cerebellar lobe

Molecular Cerebellar Cortex

Outer layer of the cerebellar cortex

Purkinje Cerebellar Cortex

Middle layer of the cerebellar cortex

Granular Cerebellar Cortex

Inner layer of the cerebellar cortex

Arbor Vitae

White matter tracts of the cerebellum

Granule Cells

Cerebellar cortex neurons that send axons to the molecular layer

Purkinje Cells

Cerebellar cortex neurons that have large dendrite trees and spread in a plane perpendicular to the cerebellar folia at the molecular level

Climbing Fibers

Cells from the olivary nucleus of the medulla that contact purkinje cells

Mossy Fibers

Cells from many places in the brain that contact granule cells

Deep Cerebellar Nuclei

Output nuclei of the cerebellum that connect with purkinje cells

Fastigial Nuclei

Medial deep cerebellar nuclei that receives information from the vestibulocerebellum

Red Nucleus

Structure in the midbrain that projects to the spinal cord and cranial nerve nuclei

Interposed Nuclei

Middle deep cerebellar nuclei that project information to the red nucleus

Ventrolateral Thalamic Nucleus

Structure in the diencephalon that projects information from the cerebrocerebellum to the cerebral cortex

Dentate Nuclei

Lateral deep cerebellar nuclei that project to the ventrolateral thalamic nucleus