Unit 1: Brain Structure and Function

A comprehensive vocabulary review of Unit 1: Brain Structure and Function, detailing the anatomy of the brainstem, cerebral cortex, limbic system, split-brain phenomena, neural plasticity, and brain research methodologies.

Brainstem

The oldest part of the brain that connects the brain to the spinal cord; handles life-support functions such as breathing, heart rate, and blood pressure, and relays messages between the body and the opposite cerebral hemisphere.

Medulla oblongata

The first large swelling at the top of the spinal cord forming the lowest part of the brain; responsible for vital autonomic functions such as heartbeat, breathing, swallowing, digestion, and sneezing.

Pons

A large swelling of nerve fibers above the medulla that serves as a bridge or relay station sending information from the brainstem to the cerebellum and cortex; helps coordinate movement and control sleep and dreaming.

Midbrain

Brain structure located above the pons that connects sensory inputs to motor outputs and bridges the hindbrain to the forebrain; assists with vision, hearing, movement, and muscle coordination.

Reticular formation

A network of neurons running through the brainstem from the medulla to the midbrain; helps regulate pain intensity and filters out unnecessary stimuli to focus on useful sensory input.

Reticular Activating System (RAS)

A component of the reticular formation extending into the thalamus that controls alertness, arousal, attention, and sleep-wake transitions, playing a fundamental role in maintaining consciousness.

Reward center

A collection of brain structures essential for the experience of pleasure, motivation, and reinforcement learning.

Dopamine

A neurotransmitter involved in motivation, reward, pleasure, motor control, and forming learning associations.

Cerebellum

A structure located at the back of the brain (often termed the 'little brain') that coordinates muscle activity, maintains balance and posture, and contributes to procedural and motor learning.

Cerebral cortex

The wrinkled outer layer of the brain composed of densely packed neurons; responsible for higher cognitive functions including thinking, memory, language, planning, and sensory interpretation.

Cerebrum

The upper part of the brain consisting of the two cerebral hemispheres and the structures that connect them.

Association Areas

Cortical areas within each lobe responsible for higher mental processing and linking sensory inputs with motor outputs to give meaning to sensations, rather than receiving primary input directly.

Corpus callosum

A large tract of nerve fibers running across the longitudinal fissure that connects the right and left cerebral hemispheres, allowing them to communicate and coordinate actions.

Frontal lobes

Cortical regions located at the front and top of the brain; responsible for higher mental processes, decision-making, planning, reasoning, emotional control, and fluent speech production.

Motor cortex

The rear band of the frontal lobe responsible for sending motor commands to the muscles of the somatic nervous system to control voluntary movements.

Broca's area

A specialized region situated in the left frontal lobe responsible for speech formulation and fluent language production.

Broca's Aphasia

A language disorder caused by damage to Broca's area characterized by halting, effortful, and dysfluent speech and writing impairments, while comprehension remains relatively intact.

Parietal lobes

Brain sections located behind the frontal lobes responsible for processing bodily sensory signals such as touch, pressure, temperature, pain, and body position.

Somatosensory cortex

A strip of cortex located at the anterior edge of the parietal lobes that registers sensory inputs from the skin and internal body receptors, with the face occupying the largest area.

Occipital lobes

Cortical lobes located at the rear and bottom of each cerebral hemisphere containing the primary visual centers of the brain.

Visual association cortex

An area within the occipital lobe that identifies, integrates, and makes sense of incoming visual information.

Temporal lobes

Cortical regions positioned near the ears responsible for auditory processing, speech comprehension, and auditory memory.

Wernicke's area

A region located in the left temporal lobe primarily responsible for language comprehension and understanding spoken or written words.

Wernicke's Aphasia

A condition caused by damage to Wernicke's area resulting in an inability to comprehend language, leading to fluent but nonsensical speech often referred to as 'word salad.'

Limbic System

A group of subcortical brain structures (including the amygdala, hippocampus, hypothalamus, and thalamus) involved in emotion, motivation, memory, and learning.

Amygdala

An almond-shaped limbic structure that processes strong emotions, particularly fear, aggression, and anxiety; key for threat detection, triggering fight-or-flight, and forming emotional memories.

Hippocampus

A seahorse-shaped structure in the limbic system responsible for the consolidation, formation, and storage of new declarative/explicit memories (facts and events) as well as navigation.

Hypothalamus

A limbic structure regulating the autonomic nervous system and directing the pituitary gland; maintains homeostasis by controlling body temperature, hunger, thirst, sleep, and sexual behavior.

Lateral hypothalamus (LH)

A hypothalamic nucleus responsible for triggering sensations of hunger ('Let\'s eat').

Ventromedial hypothalamus (VMH)

A hypothalamic nucleus that signals satiety or fullness to inhibit eating ('I\'m full').

Pituitary gland

A pea-sized endocrine 'master gland' situated below the hypothalamus that secretes hormones (e.g., oxytocin, growth hormone) controlling other endocrine glands; not part of the limbic system.

Thalamus

The central relay station ('post office') of the brain that processes and redirects incoming sensory information for hearing, sight, touch, and taste (all senses except smell) to the cortex.

Split-Brain Research

The study of patients with a surgically severed corpus callosum, demonstrating that the two cerebral hemispheres function independently and specialize in distinct cognitive tasks.

Contralateral hemispheric organization

The principle that each hemisphere of the brain receives sensory inputs from and controls motor functions of the opposite side of the body.

Plasticity

The brain's ability to adapt, reorganize neural pathways, and allow undamaged areas to assume lost functions as a result of experience, learning, or injury.

Lesioning

An experimental research method (also called ablation) in which an insulated wire electrode is inserted into brain tissue to deliver an electric current that destroys specific cells at its tip.

Electroencephalogram (EEG)

A non-invasive technique that records the electrical activity (brainwaves) of large groups of cortical neurons just below the skull using electrodes affixed to the scalp.

Functional MRI (fMRI)

A neuroimaging method that tracks changes in blood oxygen levels to visualize both brain structure and active brain function simultaneously during mental tasks.