Lecture 22 CNS III: Higher Brain Functions, Protection, and Pathologies

Comprehensive vocabulary flashcards covering higher brain functions, memory consolidation, sleep stages, meningeal layers, cerebrospinal fluid dynamics, the blood-brain barrier, and common CNS pathologies from Lecture 22 (CNS III).

Broca's Area

A specialized brain region responsible for speech production.

Broca's Aphasia

A language deficit where a person can understand language but cannot produce speech.

Wernicke's Area

A specialized cortical region responsible for language comprehension.

Wernicke's Aphasia

A language condition where an individual can speak fluently but cannot speak coherently.

Left Cerebral Hemisphere (Language)

The hemisphere primarily responsible for language processing, concentrating specifically on what is being said.

Right Cerebral Hemisphere (Language)

The hemisphere that interprets nonverbal communication (body language), gesture interpretation, and the tone and emotion of speech, concentrating on how something is being said.

Short-Term Memory (STM / Working Memory)

The initial memory store formed prior to long-term memory; it is limited to $7\text{--}8$ chunks of information (e.g., digits of a phone number) and information is not permanently retained.

Declarative Long-Term Memory (LTM)

A memory formed from short-term memory through time-requiring consolidation; it possesses a virtually limitless capacity, undergoes changes over time, declines with age, and can be forgotten.

Emotional State (Memory Consolidation)

A factor promoting the transfer from STM to LTM where memories are formed most effectively when alert, motivated, surprised, or aroused, with norepinephrine aiding the retention of emotionally charged events.

Rehearsal

A factor promoting memory transfer from STM to LTM where repetition strengthens the memory trace.

Association

A factor promoting memory transfer where new data is consciously linked to old information already present in long-term memory.

Automatic Memory

The incidental learning and storage of information into long-term memory without conscious formation.

Hippocampus and Temporal Cortex

Brain regions critical for the consolidation of memories.

Occipital Cortex (Memory Function)

The brain region dedicated to the storage and retrieval of visual memories.

Temporal Cortex (Auditory/Musical Memory)

The brain region that assists in the storage and retrieval of musical memories.

Prefrontal Cortex (Memory Function)

The brain region responsible for concept recall.

Thalamus (Memory Function)

The brain structure associated with information relay during memory processing.

Consciousness

The combination of perception, voluntary movement, and higher mental functions arising from simultaneous, holistic, and interconnected neural activity across large areas of the cerebral cortex.

Syncope

Fainting; a brief, temporary loss of consciousness resulting from low blood pressure.

Coma

A state of prolonged unconsciousness that can be caused by head trauma, stroke, tumors, metabolic disorders (such as hypoglycemia), drug overdose, or liver and kidney failure.

Brain Death

A clinical state characterized as an irreversible coma, evidenced by a flat EEG.

Electroencephalogram (EEG)

A clinical recording of unique cortical electrical activity via scalp electrodes, used to diagnose sleep disorders, epilepsy, and brain death.

Alpha Waves

Brain waves with a frequency of $8\text{--}13\,\text{Hz}$ that are prominent in an awake, relaxed state.

Beta Waves

Brain waves with a frequency of $14\text{--}30\,\text{Hz}$ that are prominent when a person is alert and concentrating.

Theta Waves

Brain waves with a frequency of $4\text{--}7\,\text{Hz}$ that are common in children but rare in adults.

Delta Waves

High-amplitude brain waves with a frequency of $\le 4\,\text{Hz}$ that indicate deep sleep or brain damage.

Non-REM (nREM) Sleep

Sleep consisting of slow-wave stages (N1–N3) marked by slower, higher amplitude EEG patterns, present muscle tone, rare dreams, decreased brain oxygen use, and slowed heart rate and respiration.

REM Sleep

A sleep stage marked by irregular EEG activity similar to being awake, muscle paralysis (absent muscle tone), vivid story-like dreams, increased brain oxygen consumption, and increased heart and respiratory rates.

Suprachiasmatic Nucleus

A hypothalamic nucleus that establishes the circadian ($24\,\text{hr}$) rhythm and regulates sleep-wake cycles.

Preoptic Nucleus

A hypothalamic nucleus influenced by the suprachiasmatic nucleus to induce sleep.

Orexins

Peptides or wake-up chemicals released by the hypothalamus to maintain wakefulness.

Meninges

Three connective tissue membranes (dura mater, arachnoid mater, pia mater) that cover and protect the CNS, enclose venous sinuses, contain CSF, and form partitions within the skull.

Dura Mater

The superficial, strongest meninx consisting of an outer periosteal layer attached to the skull and an inner meningeal layer extending as the true external brain covering and spinal dura mater.

Falx Cerebri

A dural septum located in the longitudinal fissure between the right and left cerebral hemispheres that limits brain movement.

Falx Cerebelli

A vertical dural septum running along the cerebellar vermis.

Tentorium Cerebelli

A horizontal dural fold located between the cerebrum and the cerebellum.

Dural Venous Sinuses

Endothelial-lined channels enclosed by the dura mater that drain venous blood from the brain into the internal jugular veins.

Arachnoid Mater

The middle meninx that forms a loose covering over the brain without dipping into the cerebral sulci.

Subdural Space

A narrow serous cavity containing fluid located between the dura mater and the arachnoid mater.

Subarachnoid Space

The space beneath the arachnoid mater filled with cerebrospinal fluid, containing spiderweb-like extensions and large blood vessels.

Arachnoid Granulations

Knoblike projections of the arachnoid mater that protrude through the dura into the superior sagittal sinus to absorb CSF into venous blood.

Pia Mater

The delicate, vascularized deep meninx that clings tightly to every convolution of the brain and supports small arteries penetrating the nervous tissue.

Cerebrospinal Fluid (CSF)

A watery solution derived from blood plasma with lower protein and distinct ionic concentrations that cushions the CNS from trauma, reduces brain weight via buoyancy, and transports chemical signals and nutrients.

Choroid Plexuses

Frond-shaped capillary clusters found in each brain ventricle, enclosed by pia mater and ependymal cells with tight junctions, that filter blood and synthesize CSF.

Blood-Brain Barrier (BBB)

A specialized physiological barrier composed of continuous endothelial tight junctions, pericytes, and astrocyte end-feet that maintains a stable chemical environment for central neurons.

Concussion

A temporary disruption of neurological function following a blow to the head, typically presenting with dizziness or loss of consciousness, with cumulative damage from multiple occurrences.

Contusion

A severe brain injury characterized by bruising and permanent destruction of brain tissue, potentially causing prolonged coma if the brainstem is damaged.

Cerebrovascular Accident (CVA / Stroke)

A condition caused by ischemia (loss of blood supply and oxygen/nutrients) due to vascular occlusion or subarachnoid hemorrhage, leading to nervous tissue compression and cell death.

Glutamate Excitotoxicity

A secondary injury cascade in strokes where ischemic, damaged neurons release excessive glutamate, excessively stimulating neighboring cells and exciting them to death.

Beta-Amyloid Plaques

Extracellular protein aggregates that form outside neurons, serving as a primary pathological hallmark of Alzheimer's disease.

Neurofibrillary Tangles

Intracellular structural lesions composed of misfolded tau proteins, representing a key hallmark of Alzheimer's disease.

Parkinson's Disease

A neurodegenerative motor disorder caused by the degeneration of dopaminergic neurons in the substantia nigra, leading to loss of movement inhibition in the basal ganglia.

L-Dopa

A dopamine precursor used to temporarily alleviate movement symptoms in Parkinson's disease, which eventually loses efficacy and worsens symptoms over time.