parts of the brain

Hindbrain

• Location: Base of brain, connects to spinal cord.

• Function: Controls basic survival functions (breathing, heartbeat, balance).

• Includes: Medulla, pons, cerebellum.

Midbrain

• Location: Above hindbrain, below forebrain.

• Function: Coordinates simple movement and integrates sensory information; contains part of the reticular formation (arousal/attention).

Forebrain

• Location: Largest, most complex part—upper/front areas.

• Function: Higher-order thought, emotions, decision-making.

• Includes: Thalamus, hypothalamus, limbic system, cerebral cortex.

Brainstem

• Location: Stem-like base of brain (hindbrain + midbrain).

• Function: Automatic survival functions; a pathway connecting spinal cord and higher brain.

Medulla

• Location: Base of brainstem.

• Function: Regulates heartbeat, breathing, blood pressure.

• Damage = death (because vital functions stop).

Thalamus

• Location: Top of brainstem.

• Function: Sensory “switchboard”—relays all senses except smell to the cortex.

Reticular Formation

• Location: Runs through brainstem and midbrain.

• Function: Arousal, attention, alertness.

• Damage = coma.

Cerebellum

• Location: “Little brain” at back of brainstem.

• Function: Balance, coordination, fine motor control, implicit memory (skills like riding a bike).

Limbic System

• Location: Border between brainstem and cerebral hemispheres (forebrain).

• Function: Emotion, motivation, and memory.

• Includes: Amygdala, hippocampus, hypothalamus.

Amygdala

• Location: Almond-shaped, deep in temporal lobe (part of limbic system).

• Function: Emotions, especially fear and aggression.

• Damage = reduced fear response.

Hypothalamus

• Location: Below thalamus.

• Function: Regulates drives (hunger, thirst, sex, body temp). Links nervous system to endocrine system via pituitary gland.

• Hunger: Contains the lateral hypothalamus (LH) = hunger center and ventromedial hypothalamus (VMH) = satiety (fullness) center. Damage to LH → never eat; damage to VMH → never stop eating.

Hippocampus

• Location: Temporal lobe (limbic system).

• Function: Forms new explicit (declarative) memories.

• Damage = anterograde amnesia (can’t form new memories).

Frontal Lobe

• Location: Front of brain.

• Function: Planning, judgment, personality, voluntary movement, speech production (Broca’s area).

• Contains: Motor cortex, Broca’s area.

Parietal Lobe

• Location: Top/back of brain.

• Function: Processes touch sensations (pressure, temperature, pain).

• Contains: Somatosensory cortex.

Occipital Lobe

• Location: Back of brain.

• Function: Visual processing.

• Damage = vision problems.

Temporal Lobe

• Location: Sides of brain near temples.

• Function: Auditory processing, language comprehension (Wernicke’s area), memory.

Motor Cortex

• Location: Rear of frontal lobe.

• Function: Controls voluntary movements (contralateral—right side controls left body).

• Mnemonic: “Motor = movement.”

Somatosensory Cortex

• Location: Front of parietal lobe (just behind motor cortex).

• Function: Processes sensations of touch.

• Homunculus map shows more cortex devoted to sensitive areas (hands, lips).

Association Areas

• Location: Found throughout cortex (especially frontal lobes).

• Function: Higher-order thinking, integrating information, problem-solving.

• Damage = difficulty with judgment and planning.

Neurogenesis

• Definition: The brain’s ability to form new neurons.

• Most active in: Hippocampus.

• Importance: Basis of plasticity (brain can adapt and recover after damage).

Corpus Callosum

• Location: Band of neural fibers connecting left and right hemispheres.

• Function: Enables communication between hemispheres.

• Split-brain studies (Sperry & Gazzaniga): Showed lateralization (left = language, right = spatial/visual tasks).

Broca’s Area

• Location: Left frontal lobe.

• Function: Speech production.

• Damage = Broca’s aphasia (can understand speech, but speech is broken/halting).

Wernicke’s Area

• Location: Left temporal lobe.

• Function: Language comprehension.

• Damage = Wernicke’s aphasia (fluent but nonsensical speech, can’t understand others).