Neural Structures, CNS/PNS, and Memory – Vocabulary Flashcards

Vocabulary flashcards covering key brain structures, the nervous system divisions, and memory processes from the lecture.

Afferent neurons (sensory neurons)

Carry sensory information from receptors toward the CNS (brain/spinal cord); ascending pathways.

Efferent neurons (motor neurons)

Carry motor commands from the CNS to muscles and glands; responsible for initiating movement.

Central nervous system (CNS)

Brain and spinal cord; processes information and coordinates responses.

Peripheral nervous system (PNS)

Nerves outside the CNS; connects the CNS to the body and contains afferent and efferent pathways.

Brainstem (hindbrain / old brain)

Base of the brain; governs basic life-sustaining functions; includes medulla, reticular formation, and pons.

Medulla

Controls basic life-support functions such as heart rate and respiration.

Reticular formation

Network in the brainstem with ascending (sensory) and descending (motor) pathways; modulates arousal.

Pons

Part of the brainstem; involved in sleep regulation and arousal; extension of the reticular formation.

Cerebellum

Coordinates voluntary movements and balance; integrates sensory inputs to produce smooth actions.

Primary motor cortex

Initiates voluntary movements; located in the frontal lobe.

Cerebral cortex

Outer gray matter where conscious perception, thought, and language occur; high-level processing.

Gray matter

Outer brain layer of neuron cell bodies; site of processing in the cortex.

White matter

Myelinated axons connecting brain regions; enables communication between areas.

Corpus callosum

Dense bundle of axons connecting the left and right hemispheres; facilitates interhemispheric communication.

Ventricles

Fluid-filled cavities with cerebrospinal fluid; cushion the brain and transport nutrients.

Limbic system

Midline brain network involved in emotion and memory; includes thalamus, hypothalamus, hippocampus, amygdala.

Thalamus

Relay station that routes sensory information to appropriate cortical areas (the brain's post office).

Olfactory bulb

Direct pathway for smell; olfactory information bypasses the thalamus and goes to this structure first.

Hippocampus

Key structure for memory encoding; damage can cause amnesia; memories are stored across the cortex.

Amygdala

Processes basic emotions (e.g., fear, anger); influences memory encoding and interacts with the hippocampus.

Hypothalamus

Regulates basic drives and hormones; controls motivational states like hunger, thirst, and temperature.

Pituitary gland

Master gland of the endocrine system; releases hormones controlled by the hypothalamus.

Interneurons

Neurons in the CNS that connect other neurons; enable communication within the CNS and reflexes.

Reflex arc

Spinal cord reflex pathway: afferent input → interneuron → efferent output causing rapid movement.

Retrograde amnesia

Loss of memory for events prior to injury; storage or retrieval is impaired.

Anterograde amnesia

Inability to form new memories after injury; past memories may remain intact but new encoding fails.

Gyrification

Folding of the cerebral cortex (gyri and sulci) to increase surface area without enlarging the skull.

Olfactory pathway exception

Smell information goes directly to the olfactory bulb, not routed first through the thalamus.

Memory encoding, storage, retrieval

Encoding: getting information into memory; Storage: maintaining it; Retrieval: accessing it later.

Cerebral cortex vs. other regions

Conscious experience and higher-order processing primarily occur in the cortex; subcortical regions support basic functions.