Exam 2 Neuroscience

Arachnoid Mater

middle meningeal layer located just below the subdural space. Has the appearance of a spider web

Ascending spinal cord tracts

the axons of the sensory tracts that are part of the CNS and carry sensory information into the brain

Broca's areas

programs the sequencing of mucles used in speech. damage here can result in aphasia

Descending spinal cord tracts

The axons of the UNM that are part of the CNS carry motor information to the ventral horn of the spinal cord. They may or may not connect with interneurons

Dorsal horn

part of the CNS that receives the sensory information. This is where the sensory axon meets the sensory tract in the spinal cord. May or may not connect with interneurons

Dorsal root/rootlets

made up of the axons of the sensory neuron that enter the dorsal horn of the spinal cord

dorsal ganglia (aka dorsal root ganglia)

cluster of sensory neuron cell bodies located in the dorsal root of the spinal nerve

Dura Mater

outermost meningeal layer, it has 2 projections into the brain: falx cerebri & tentorium

Frontal eye fields

Produces voluntary eye movements. and supports conjugate eye movements (eyes move together as a pair)

Multimodal sensory procesing

relating to more than one sensory modality. the combined effect enhances our perception and action

Pia Mater

deepest meningeal layer, located on the surface of the gyri and sucli of the brain and on the surface of the spinal cord

Primary motor cortex

produces motor commands for skilledd movement of voluntary muscles through the motor humunculus

Pre-motor cortex

controls axial and proximal limb muscles, involved in motor planning

Secondary motor cortex:

has a bilateral homunculus but specific functions are unknown

Skeletal muscles

highly organized tissues composed of budles of muscle fibers that support and move the skeletal system

Spinal Nerve.

individual nerve fibers that carries afferent and/or efferent messages connecting the CNS and PNS

Subarachnoid Space

area beneath the arachnoid mater and above the pia mater. contains CSF

Supplementary motor cortex

active when we watch others move and prepares our motor system to move. involed in imitation of motor movements

Unimodal sensory processing

relating to a single sensory modality

Ventral horn

part of the CNS that contains cell bodies (somas) of the LMN. Delivers motor messages to the LMN. This is where UMN and LMN meet in the spinal cord

Ventral root/rootlets

are made up of the axons of the LMN in the PNS that leave the ventral horn of the spinal cord. they innervate the skeletal muscles

Voluntary movements:

in contrast to reflexes, voluntary movements are purposefully initiated to accomplish a specific goal. These movements can vary, can be improved with practice, and can be corrected in real time as we are moving

Adaptation rate

how quickly or slowly the receptor accommodates to the sensation

Anterior lobe of cerebellum

Coordinates and fine-tunes body and limb movements in real time through comparison; helps maintain posture and regulate tone. (aka paleocerebellum, spinocerebellum)

Bundle

a collection of axons that run together but do not necessarity have the same origin or destination

Decussate

Occurs when a tract crosses from one side to the other. Decussation is the point at which this crossing happens

Funiculi

columns of white matter that contain the spinal cord tracts (may also be referred to as lateral columns)

flocculunodular lobe

works with the estibular nuclei to integrate vestibular information; controls balance and equilibrium reactions; coordinates head and eye movements; contributes to motor coordination between the two sides of the body (such as jumping jacks) aka: vestibulocerebellum

Itch

an unpleasant or uncomfortable sensationthat signals the need to scratch

Lemniscus

A band of nerve fibers that carries sensory information from the PNS to the CNS. Example: medial lemniscus

Nerve

a bundle of axons in the PNS. There is only one collection of CNS axons called a nerve, that is the optic nerve

posterior lobe of the cerebellum

crucial for planning complex movements and supports procedural learning. receives input from M1 and works with the thalamus as part of a motor feedback loop to facilitate smoothe execution of planned movements. aka: neocerebellum, cerebrocerebellum

Reflex

involuntary coordinated patterns of mucle contraction and relaxation that are elicited by peripheral stimuli

Repetative rhythmic motor patterns

Alternating patterns of flexor and extensor muscle actions controlled by circuits located in the spinal cord and brainstem. Examples include swallowing, chewing, and crawling in quadruped

Sensory receptors

specialized cells thatdetect specific stimuli such as light, sound, or heat, and act as transducers by converting these stimuli into electrical signals (action potentials) that the nervous system can process

Spinal arteries

carry oxygenated blood from the heart to the spinal cord

Spinal veins

carry deoxygenated blood from the spinal cord to the heart

Stereognosis

the ability to identify the shape and form of a three-dimensional object and give it meaning

Tract

a collection of CNS axons having a common site of origin and a common destination (ex: corticospinal tract, which originates in the cerebral cortex and ends in the spinal cord)

Dysarthria

difficulty articulating words clearly, slurring words

Dysphagia

difficulty swallowing

Dysphonia

difficulty projecting ones voice audibly

Nystagmus

involuntary back and forth movements of the eye in quick, jerky, oscillating fashion

Ptosis

drooping of a body region

Strabismus

deviation of the eyeball laterally (lateral strabismus or exotropia) or medially (medial strabismus/ esotropia)

Tenodesis

a grasp and release pattern used by individuals with a C6-7 SCI; uses active wrist extension, and the passice finger and thumb flexion enabled by tendon shortening