Brain Organization, Functions, and Imaging Methods

Hormones: Chemical messengers produced by endocrine glands that travel through the bloodstream to influence target tissues and organs.
Pituitary Gland: Regarded as the "master gland," situated in the brain and regulated by the hypothalamus; controls other endocrine glands and directs growth.
Adrenaline (Epinephrine): Secreted by the adrenal glands during stress; elevates heart rate, blood pressure, and available energy.
Leptin: Protein hormone released by fat cells that signals satiety to inhibit appetite.
Ghrelin: Released primarily by an empty stomach to signal hunger to the brain.
Melatonin: Secreted by the pineal gland to control circadian rhythms (sleep-wake cycles) based on environmental light and darkness.
Oxytocin: Facilitates social bonding, trust, maternal behaviors, and contractions during labor and lactation.

Limbic System: A donut-shaped group of neural structures bordering the brainstem and cerebral hemispheres; coordinates emotion, basic drives, and memory.
Thalamus: The sensory relay center directing all incoming sensory signals (excluding olfaction/smell) to appropriate cortical areas.
Hypothalamus: Sits beneath the thalamus; regulates body temperature, hunger, and thirst, and directs the endocrine system via the pituitary gland.
Hippocampus: Limbic structure vital for converting and processing explicit memories (facts and events) into long-term storage.
Amygdala: Two lima-bean-sized neural clusters associated with emotional processing, especially aggression and fear.
Corpus Callosum: Broad band of neural fibers bridging the left and right cerebral hemispheres to allow interhemispheric communication.

Prefrontal Cortex: The anterior portion of the frontal lobes responsible for personality expression, decision-making, social behavior, and executive functions.
Motor Cortex: Located at the rear boundary of the frontal lobes; directs voluntary muscular movement.
Executive Functioning: Prefrontal cortex-driven abilities, including impulse control, mental flexibility, working memory, and goal-directed action.
Higher-Order Thinking: Advanced cognitive tasks such as critical thinking, problem-solving, abstract reasoning, and synthesis.
Linguistic Processing: The cognitive and neural procedures required to understand, interpret, and generate spoken or written language.

Hemispheric Specialization (Lateralization): Distinct cognitive functional distribution between the hemispheres (e.g., left hemisphere specializes in logic and language; right hemisphere specializes in spatial and facial recognition).
Contralateral Hemispheric Organization: Structural principle where each cerebral hemisphere directs motor and sensory processing for the opposing side of the body.
Split-Brain Research: Studies involving patients with a surgically severed corpus callosum, illustrating independent and specialized hemispheric functions.
Epilepsy: Neurological disorder marked by recurrent, unprovoked seizures caused by abnormal, excessive electrical brain discharges.
Plasticity: The brain's structural capacity to reorganize and create new neural pathways in response to experience, learning, or injury.
Broca's Area & Broca's Aphasia: Left frontal lobe region managing motor aspects of speech articulation; damage causes expressive aphasia (difficulty producing fluent speech despite retained comprehension).
Wernicke's Area & Wernicke's Aphasia: Left temporal lobe region managing language comprehension; damage causes receptive aphasia (fluent yet nonsensical speech with impaired comprehension).
Aphasia: Language impairment resulting from brain damage.

EEG (Electroencephalogram): Scalp-mounted electrodes that measure and amplify electrical activity waves moving across the brain's surface.
fMRI (Functional Magnetic Resonance Imaging): Neuroimaging method tracking blood oxygenation and flow to detect active brain regions during tasks.
Lesioning: Surgical or experimental ablation or destruction of brain tissue to evaluate subsequent functional and behavioral deficits.