Central Nervous System – Brain Structures and Functions

Vocabulary flashcards covering key brain structures, their functions, and related systems from CNS lecture notes.

Corpus Callosum

Large band of nerve fibers that connects the left and right cerebral hemispheres.

Brainstem

Collective name for the midbrain, pons, and medulla; passes information between spinal cord and brain and controls basic life functions and reflexes.

Medulla Oblongata

Lowest part of brainstem; relays signals between cerebrum and spinal cord, regulates heartbeat, respiration, blood pressure, and controls swallowing, vomiting, coughing; CN VIII–XII emerge here.

Pons

Brainstem region superior to medulla; relays information between cerebrum, spinal cord, and cerebellum; helps maintain normal breathing rhythm; CN V, VI, and VII emerge here.

Midbrain

Brainstem section above pons; relays information between cerebrum and spinal cord and houses visual and auditory reflex centers; CN III and IV emerge here.

Superior Colliculus

Midbrain reflex center that turns the head toward moving visual stimuli.

Inferior Colliculus

Midbrain reflex center that turns the head toward unexpected sounds.

Substantia Nigra

Midbrain structure whose dopamine-producing neurons degenerate in Parkinson’s disease.

Cerebellum

Brain region that receives muscle information, coordinates motor activity, and stores sequences of complex movements.

Motor Pattern

Cerebellum-stored template of a learned movement (e.g., riding a bike) that can be retrieved even years later.

Diencephalon

Brain region just above brainstem consisting of the thalamus, hypothalamus, and epithalamus.

Thalamus

Sensory ‘gateway’ that edits, sorts, and routes incoming sensory information before it reaches the cortex.

Hypothalamus

Brain area below the thalamus that connects to the pituitary and regulates thirst, hunger, GI movement, heart rate, blood pressure, sleep (hypocretin), sex drive, and pleasure/anger.

Pituitary Gland

Endocrine gland connected to and controlled by the hypothalamus to regulate body hormones.

Epithalamus

Dorsal part of the diencephalon that includes the pineal gland.

Pineal Gland

Epithalamic structure that secretes the hormone melatonin to initiate sleep.

Melatonin

Sleep-promoting hormone released by the pineal gland.

Reticular Activating System (RAS)

Network of brainstem cells that filters sensory input by importance and maintains alertness.

Limbic System

Primitive emotional brain circuitry surrounding thalamus and hypothalamus; includes amygdala, cingulate gyrus, hippocampus, and olfactory bulb.

Amygdala

Limbic structure for intuition and fear; recognizes angry or fearful faces, assesses danger, and triggers fear responses.

Cingulate Gyrus

Part of limbic system that expresses emotions through body language and gestures.

Hippocampus

Limbic region that decides where to store memories in the brain and dispatches them for long-term storage.

Olfactory Bulb

Limbic component that links odors with memories—both pleasant and unpleasant.

Cranial Nerves VIII–XII

Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, and Hypoglossal nerves that emerge from the medulla.

Cranial Nerves V–VII

Trigeminal, Abducens, and Facial nerves that emerge from the pons.

Cranial Nerves III & IV

Oculomotor and Trochlear nerves that emerge from the midbrain.