16.7: Key Terms

Example and Directions

Words (or words that have the same definition)	The definition is case sensitive	(Optional) Image to display with the definition [Not displayed in Glossary, only in pop-up on pages]	(Optional) Caption for Image	(Optional) External or Internal Link	(Optional) Source for Definition
(Eg. "Genetic, Hereditary, DNA ...")	(Eg. "Relating to genes or heredity")		The infamous double helix	https://bio.libretexts.org/	CC-BY-SA; Delmar Larsen

Glossary Entries

Word(s)	Definition	Image	Caption	Link	Source
accommodation	in vision, a change in the ability of the eye to focus on objects at different distances
accommodation–convergence reflex	coordination of somatic control of the medial rectus muscles of either eye with the parasympathetic control of the ciliary bodies to maintain focus while the eyes converge on visual stimuli near to the face
anterograde amnesia	inability to form new memories from a particular time forward
aphasia	loss of language function
ataxia	movement disorder related to damage of the cerebellum characterized by loss of coordination in voluntary movements
Babinski sign	dorsiflexion of the foot with extension and splaying of the toes in response to the plantar reflex, normally suppressed by corticospinal input
cerebrocerebellum	lateral regions of the cerebellum; named for the significant input from the cerebral cortex
check reflex	response to a release in resistance so that the contractions stop, or check, movement
clasp-knife response	sign of UMN disease when a patient initially resists passive movement of a muscle but will quickly release to a lower state of resistance
conduction aphasia	loss of language function related to connecting the understanding of speech with the production of speech, without either specific function being lost
conductive hearing	hearing dependent on the conduction of vibrations of the tympanic membrane through the ossicles of the middle ear
conjugate gaze	coordinated movement of the two eyes simultaneously in the same direction
convergence	in vision, the movement of the eyes so that they are both pointed at the same point in space, which increases for stimuli that are closer to the subject
coordination exam	major section of the neurological exam that assesses complex, coordinated motor functions of the cerebellum and associated motor pathways
cortico-ponto-cerebellar pathway	projection from the cerebral cortex to the cerebellum by way of the gray matter of the pons
cranial nerve exam	major section of the neurological exam that assesses sensory and motor functions of the cranial nerves and their associated central and peripheral structures
cytoarchitecture	study of a tissue based on the structure and organization of its cellular components; related to the broader term, histology
deep tendon reflex	another term for stretch reflex, based on the elicitation through deep stimulation of the tendon at the insertion
diplopia	double vision resulting from a failure in conjugate gaze
edema	fluid accumulation in tissue; often associated with circulatory deficits
embolus	obstruction in a blood vessel such as a blood clot, fatty mass, air bubble, or other foreign matter that interrupts the flow of blood to an organ or some part of the body
episodic memory	memory of specific events in an autobiographical sense
expressive aphasia	loss of the ability to produce language; usually associated with damage to Broca’s area in the frontal lobe
extrinsic muscles of the tongue	muscles that are connected to other structures, such as the hyoid bone or the mandible, and control the position of the tongue
fasciculation	small muscle twitch as a result of spontaneous activity from an LMN
fauces	opening from the oral cavity into the pharynx
fibrillation	in motor responses, a spontaneous muscle action potential that occurs in the absence of neuromuscular input, resulting from LMN lesions
flaccid paralysis	loss of voluntary muscle control and muscle tone, as the result of LMN disease
flaccidity	presentation of a loss of muscle tone, observed as floppy limbs or a lack of resistance to passive movement
flocculonodular lobe	lobe of the cerebellum that receives input from the vestibular system to help with balance and posture
gait	rhythmic pattern of alternating movements of the lower limbs during locomotion
gait exam	major section of the neurological exam that assesses the cerebellum and descending pathways in the spinal cord through the coordinated motor functions of walking; a portion of the coordination exam
gnosis	in a neurological exam, intuitive experiential knowledge tested by interacting with common objects or symbols
graphesthesia	perception of symbols, such as letters or numbers, traced in the palm of the hand
hemisection	cut through half of a structure, such as the spinal cord
hemorrhagic stroke	disruption of blood flow to the brain caused by bleeding within the cranial vault
hyperflexia	overly flexed joints
hypotonicity	low muscle tone, a sign of LMN disease
hypovolemia	decrease in blood volume
inferior cerebellar peduncle (ICP)	input to the cerebellum, largely from the inferior olive, that represents sensory feedback from the periphery
inferior olive	large nucleus in the medulla that receives input from sensory systems and projects into the cerebellar cortex
internuclear ophthalmoplegia	deficit of conjugate lateral gaze because the lateral rectus muscle of one eye does not contract resulting from damage to the abducens nerve or the MLF
intorsion	medial rotation of the eye around its axis
intrinsic muscles of the tongue	muscles that originate out of, and insert into, other tissues within the tongue and control the shape of the tongue
ischemic stroke	disruption of blood flow to the brain because blood cannot flow through blood vessels as a result of a blockage or narrowing of the vessel
jaw-jerk reflex	stretch reflex of the masseter muscle
localization of function	principle that circumscribed anatomical locations are responsible for specific functions in an organ system
medial longitudinal fasciculus (MLF)	fiber pathway that connects structures involved in the control of eye and head position, from the superior colliculus to the vestibular nuclei and cerebellum
mental status exam	major section of the neurological exam that assesses cognitive functions of the cerebrum
middle cerebellar peduncle (MCP)	large, white-matter bridge from the pons that constitutes the major input to the cerebellar cortex
motor exam	major section of the neurological exam that assesses motor functions of the spinal cord and spinal nerves
neurological exam	clinical assessment tool that can be used to quickly evaluate neurological function and determine if specific parts of the nervous system have been affected by damage or disease
paramedian pontine reticular formation (PPRF)	region of the brain stem adjacent to the motor nuclei for gaze control that coordinates rapid, conjugate eye movements
paresis	partial loss of, or impaired, voluntary muscle control
plantar reflex	superficial reflex initiated by gentle stimulation of the sole of the foot
praxis	in a neurological exam, the act of doing something using ready knowledge or skills in response to verbal instruction
procedural memory	memory of how to perform a specific task
pronator drift	sign of contralateral corticospinal lesion when the one arm will drift into a pronated position when held straight out with the palms facing upward
receptive aphasia	loss of the ability to understand received language, such as what is spoken to the subject or given in written form
red nucleus	nucleus in the midbrain that receives output from the cerebellum and projects onto the spinal cord in the rubrospinal tract
retrograde amnesia	loss of memories before a particular event
Rinne test	use of a tuning fork to test conductive hearing loss versus sensorineural hearing loss
Romberg test	test of equilibrium that requires the patient to maintain a straight, upright posture without visual feedback of position
rubrospinal tract	descending tract from the red nucleus of the midbrain that results in modification of ongoing motor programs
saccade	small, rapid movement of the eyes used to locate and direct the fovea onto visual stimuli
sensorineural hearing	hearing dependent on the transduction and propagation of auditory information through the neural components of the peripheral auditory structures
sensory exam	major section of the neurological exam that assesses sensory functions of the spinal cord and spinal nerves
short-term memory	capacity to retain information actively in the brain for a brief period of time
Snellen chart	standardized arrangement of letters in decreasing size presented to a subject at a distance of 20 feet to test visual acuity
spasticity	increased contraction of a muscle in response to resistance, often resulting in hyperflexia
spinocerebellar tract	ascending fibers that carry proprioceptive input to the cerebellum used in maintaining balance and coordinated movement
spinocerebellum	midline region of the cerebellum known as the vermis that receives proprioceptive input from the spinal cord
stereognosis	perception of common objects placed in the hand solely on the basis of manipulation of that object in the hand
stroke	(also, cerebrovascular accident (CVA)) loss of neurological function caused by an interruption of blood flow to a region of the central nervous system
superficial reflex	reflexive contraction initiated by gentle stimulation of the skin
superior cerebellar peduncle (SCP)	white-matter tract representing output of the cerebellum to the red nucleus of the midbrain
transient ischemic attack (TIA)	temporary disruption of blood flow to the brain in which symptoms occur rapidly but last only a short time
vermis	prominent ridge along the midline of the cerebellum that is referred to as the spinocerebellum
vestibulo-ocular reflex (VOR)	reflex based on connections between the vestibular system and the cranial nerves of eye movements that ensures that images are stabilized on the retina as the head and body move
vestibulocerebellum	flocculonodular lobe of the cerebellum named for the vestibular input from the eighth cranial nerve
Weber test	use of a tuning fork to test the laterality of hearing loss by placing it at several locations on the midline of the skull
Wernicke’s area	region at the posterior end of the lateral sulcus in which speech comprehension is localized