Nervous System: Special Senses, Sleep, Cortical Functions, and Cranial Nerves

Comprehensive vocabulary flashcards reviewing sensory brain areas, sleep stages, language processing, memory mechanisms, cerebral lateralization, neurodegenerative disorders, and the twelve cranial nerves.

Olfactory association area

The specialized region of the brain that interprets the sense of smell.

Primary gustatory complex

The brain region responsible for handling the sensation and interpretation of taste.

Visual association area

The cortical area that interprets visual information acquired through the primary visual cortex, enabling the recognition of familiar objects.

Primary visual cortex

The brain region responsible for sight that governs the recognition of size, color, light, motion, and dimension.

Auditory association area

The cortical area that gives individuals the ability to recognize familiar sounds, such as a person's voice or a piece of music.

Primary auditory complex

The specialized brain region directly responsible for hearing.

Stage N1 sleep

A light sleep state (formerly stage 1) characterized by drowsiness and easy arousal, accounting for $2\%-5\%$ of total sleep in young adults.

Stage N2 sleep

A light sleep state (formerly stage 2) marked by loss of environmental awareness, regular breathing and heart rate, and decreased body temperature, making up $45\%-55\%$ of total sleep in young adults.

Stage N3 sleep

Deep, restorative sleep (formerly stages 3 and 4) where muscles relax, heart rate slows, blood pressure drops, growth hormones are released, and tissue repair occurs; accounts for $12\%-23\%$ of sleep in young adults.

Stage R (REM sleep)

A metabolically active sleep state characterized by rapid eye movements and active dreaming, first appearing $90\,\text{minutes}$ into the sleep cycle and constituting $20\%-25\%$ of total sleep in young adults.

Broca's area

A region in the left frontal lobe that plans the muscle movements of the larynx, tongue, cheeks, and lips required to form words and sends impulses to the primary motor cortex.

Broca's aphasia

A condition caused by damage to Broca's area in which comprehension remains intact, but the patient finds speaking difficult or impossible.

Wernicke's area

A region housed in the temporal lobe that regulates language comprehension and formulates words into phrases complying with learned grammatical rules.

Wernicke's aphasia

A condition resulting from damage to Wernicke's area characterized by impaired language comprehension and the production of speech that makes no sense.

Angular gyrus

The cerebral cortex structure that translates written words into an auditory or spoken form.

Encoding

The process by which the mind attaches meaning or factual knowledge to an initial sensory experience as memory formation begins.

Neuroplasticity

The ability of the brain to alter its physical structure by modifying existing synaptic connections or creating new neuronal pathways to adapt to experiences or compensate for injury.

Hippocampus

A component of the limbic system essential for forming new memories; it is one of the earliest brain structures damaged in Alzheimer's disease.

Corpus callosum

The nerve fiber bundle through which the two cerebral hemispheres communicate, enabling the integration of information across both sides.

Categorical hemisphere

The designation usually given to the left hemisphere due to its specialization in language, sequential processing, analytical thought, and math and science.

Substantia nigra

A region of the brainstem containing dopamine-producing cells that degenerate in Parkinson's disease, precipitating motor deficits.

Bradykinesia

Slowness of movement, a hallmark physical symptom of Parkinson's disease caused by the loss of dopamine.

Beta amyloid

An abnormal protein that aggregates into extracellular plaques between neurons in Alzheimer's disease, impairing cell function.

Tau

A neuronal protein that detaches from its supporting role on microtubules to form intracellular neurofibrillary tangles in Alzheimer's disease.

Olfactory nerve (Cranial Nerve I)

A sensory cranial nerve responsible for smell that terminates in the olfactory bulbs within the cribriform plate just above the nasal cavity.

Optic nerve (Cranial Nerve II)

A sensory cranial nerve dedicated to vision that connects the retina directly to the primary visual cortex of the brain.

Oculomotor nerve (Cranial Nerve III)

A mainly motor cranial nerve that regulates voluntary movements of the eyeball and eyelid, as well as pupil constriction.

Trigeminal nerve (Cranial Nerve V)

A cranial nerve comprising two sensory branches (ophthalmic and maxillary) that sense facial touch, pain, temperature, and the corneal reflex, and one mixed branch (mandibular) controlling chewing.

Facial nerve (Cranial Nerve VII)

A mixed cranial nerve whose sensory division handles taste on the anterior two-thirds of the tongue and whose motor division controls facial expression and secretion of tears and saliva.

Vestibulocochlear nerve (Cranial Nerve VIII)

A sensory cranial nerve responsible for the senses of hearing and equilibrium/balance.

Glossopharyngeal nerve (Cranial Nerve IX)

A mixed cranial nerve whose motor fibers govern swallowing, gagging, and tongue movements, and whose sensory fibers handle blood pressure regulation and taste on the posterior one-third of the tongue.

Vagus nerve (Cranial Nerve X)

The longest and most widely distributed cranial nerve; it supplies structures in the head and neck, thorax, and abdomen, playing vital roles in cardiac, pulmonary, digestive, and urinary functions.

Spinal accessory nerve (Cranial Nerve XI)

A predominantly motor cranial nerve that innervates muscles governing movement of the head, neck, and shoulders.

Hypoglossal nerve (Cranial Nerve XII)

A predominantly motor cranial nerve responsible for tongue movements during speech and swallowing.