Biology and Behavior - Chapter 3 (Gazzaniga)

Vocabulary flashcards covering core terms, structures, and concepts from the chapter on biology and behavior.

Central nervous system (CNS)

The brain and spinal cord. Example: When you think or decide to move your arm, the CNS is processing that information.

Peripheral nervous system (PNS)

All nerve cells in the body that are not part of the CNS. Example: The nerves in your arm that allow you to feel touch or move your hand would be part of the PNS.

Somatic nervous system

Part of the PNS that transmits sensory signals and motor signals between the CNS and the skin, muscles, and joints. Example: Feeling a hot stove and quickly pulling your hand away involves the somatic nervous system.

Autonomic nervous system

Part of the PNS that transmits sensory signals and motor signals between the CNS and the body’s glands and internal organs. Example: Your heart rate increasing when you are scared, or your stomach digesting food, are functions of the autonomic nervous system.

Neuron

The basic unit of the nervous system; cells that receive, integrate, and transmit electrochemical information. Example: A single neuron transmitting a signal from your brain to your finger to type.

Glial cells

Support cells in the nervous system that do not transmit impulses like neurons. Example: Oligodendrocytes, a type of glial cell, form the myelin sheath in the CNS.

Dendrite

Branchlike extensions that receive information from other neurons. Example: A neuron's dendrites receiving neurotransmitters from a neighboring neuron.

Soma (cell body)

Receives information from other neurons; contains the cell nucleus. Example: The cell body integrates all the signals received by its dendrites.

Axon

Long, narrow outgrowth that sends electrical information (action potentials) to the terminal buttons. Example: The long 'wire' extending from a neuron's cell body that carries electrical signals away to other neurons.

Terminal buttons

Endings of the axon that release chemical signals into the synapse. Example: When an action potential reaches the terminal buttons, they release neurotransmitters into the synaptic gap.

Synapse

The gap between the sending neuron's axon and the receiving neuron's dendrites; site of chemical communication. Example: The space between two neurons where neurotransmitters travel to communicate.

Neurotransmitters

Chemical signals stored in vesicles and released into the synapse. Example: Dopamine, serotonin, and acetylcholine are common neurotransmitters.

Receptors

Proteins on the postsynaptic membrane that bind neurotransmitters. Example: A serotonin receptor on a dendrite binding to a serotonin molecule.

Reuptake

Neurotransmitter reabsorption into the presynaptic terminal buttons. Example: Serotonin being reabsorbed by the neuron that released it, clearing it from the synapse.

Enzyme deactivation

Enzymes destroy neurotransmitters in the synapse. Example: Acetylcholinesterase destroying acetylcholine in the synapse.

Auto-receptor

Presynaptic receptors that monitor and regulate neurotransmitter levels. Example: If auto-receptors detect high levels of a neurotransmitter, they can signal the presynaptic neuron to reduce its release.

Agonists

Drugs or substances that increase the actions of neurotransmitters. Example: SSRIs (Selective Serotonin Reuptake Inhibitors) are agonists for serotonin, as they block reuptake, increasing serotonin's presence in the synapse.

Antagonists

Drugs or substances that inhibit the actions of neurotransmitters. Example: Beta-blockers are antagonists that block norepinephrine receptors, slowing heart rate and reducing anxiety.

Acetylcholine (ACh)

Neurotransmitter responsible for motor control at neuromuscular junction; involved in learning and memory. Example: Essential for muscle contraction and plays a role in remembering new information.

Norepinephrine

Neurotransmitter involved in arousal and attention. Example: Helps you focus and become alert during stressful situations.

Serotonin

Neurotransmitter involved in mood, emotion, sleep, and dreaming. Example: Low levels are often associated with depression; many antidepressants target serotonin systems.

Dopamine

Neurotransmitter involved in reward, motivation, and motor control. Example: Important for feelings of pleasure and is deficient in Parkinson's disease, affecting movement.

GABA (gamma-aminobutyric acid)

Primary inhibitory transmitter in the nervous system. Example: Reduces neural excitability, often contributing to calming effects.

Glutamate

Primary excitatory transmitter in the nervous system. Example: Crucial for learning and memory formation, but excessive levels can be toxic to neurons.

Endorphins

Neurotransmitters involved in natural pain reduction and reward. Example: The 'runner's high' is often attributed to the release of endorphins.

Myelin sheath

Fatty layer around some axons that speeds electrical transmission. Example: Like insulation on an electrical wire, it helps electrical signals travel faster along the axon.

Node of Ranvier

Gaps in the myelin sheath where action potentials occur. Example: The action potential 'jumps' from one node to the next, speeding up transmission.

Action potential (AP)

Rapid depolarization that travels along the axon, caused by Na+ influx. Example: The electrical 'spark' that travels down a neuron's axon to transmit information.

Resting membrane potential

Electrical charge of a neuron at rest, typically about -70 \text{ mV}. Example: The neuron's baseline electrical state before it fires an action potential.

Depolarization

Change in a neuron's potential that makes the inside more positive, triggering an AP. Example: When sodium ions rush into the neuron, making the inside less negative.

Repolarization

Return of the neuron to its resting negative state after an AP. Example: When potassium ions flow out, restoring the negative charge inside the neuron.

Threshold of excitation

The level of stimulus intensity needed to trigger an action potential. Example: The minimum amount of electrical input required for a neuron to 'fire'.

All-or-None Principle

An action potential either occurs fully or not at all; size is constant. Example: A neuron either fires completely or it doesn't; there's no 'half-fire' or 'stronger fire'.

Rate law

Variations in stimulus intensity are represented by changes in firing rate. Example: A strong stimulus causes a neuron to fire more rapidly than a weak stimulus.

Broca’s area

Left frontal region crucial for language production. Example: Damage to this area can lead to difficulty forming words, even if understanding is intact.

Thalamus

Gateway to the cortex; relays sensory information to the cortical areas. Example: All sensory information (except smell) passes through the thalamus before reaching the cerebral cortex.

Hypothalamus

Regulates bodily functions and motivated behaviors; controls pituitary gland. Example: Controls hunger, thirst, and body temperature.

Hippocampus

Involved in formation of new memories and spatial learning; supports memory consolidation. Example: Damage to this area might prevent someone from forming new long-term memories.

Amygdala

Processes emotional information and emotional significance of stimuli; involved in fear. Example: Essential for recognizing fear in others and experiencing fear yourself.

Basal ganglia

Group of structures important for planning and producing movement; includes the dopamine pathway. Example: Involved in initiating and coordinating voluntary movements.

Cerebral cortex

Outer layer of brain tissue; site of thought, perception, and complex behaviors. Example: The wrinkled outer surface of the brain responsible for higher-level functions.

Frontal lobe

Region involved in movement, planning, decision-making, and impulse control. Example: Essential for executive functions like planning a complex task or resisting an urge.

Parietal lobe

Region important for touch and spatial relations; contains primary somatosensory cortex. Example: Allows you to feel pressure, pain, and temperature and understand where your body is in space.

Occipital lobe

Region important for vision; contains primary visual cortex. Example: Processes what you see, allowing you to recognize objects and perceive colors.

Temporal lobe

Region important for hearing and memory; contains primary auditory cortex and areas for object/face perception. Example: Processes sounds, recognizes faces, and helps form long-term memories.

Prefrontal cortex

Part of the frontal lobe involved in planning, decision-making, and executive functions. Example: Helps you set goals, make rational choices, and control impulses.

Primary motor cortex

Area in the frontal lobe controlling voluntary movement. Example: When you decide to lift your arm, this area sends signals to your muscles.

Primary somatosensory cortex

Area in the parietal lobe processing somatosensory information. Example: Receives input from your skin regarding touch, temperature, and pain.

Primary visual cortex

Area in the occipital lobe processing visual information. Example: The initial processing center for all visual input from your eyes.

Primary auditory cortex

Area in the temporal lobe processing auditory information. Example: Processes the sounds you hear, distinguishing between speech and music.

Fusiform face area

Region in the temporal lobe specialized for face perception. Example: Damage to this area can lead to prosopagnosia, the inability to recognize faces.

Cerebellum

Large structure at the back of the brain; essential for coordinated movement and balance; motor learning. Example: Allows you to walk smoothly, play a musical instrument, and maintain balance.

Brain stem

Lower part of the brain that governs survival functions; includes medulla, pons, and reticular formation. Example: Controls basic life support like breathing and heart rate.

Medulla oblongata

Brainstem structure essential for heart rate, respiration, and reflexes. Example: Automatically regulates your breathing and heartbeat without conscious effort.

Pons

Brainstem structure important for REM sleep and arousal. Example: Plays a role in generating dreams during REM sleep.

Reticular formation

Network in the brainstem involved in sleep and arousal. Example: Helps regulate your sleep-wake cycle and alerts you to important sensory information.

Spinal cord

Cord that transmits signals between the brain and the body; coordinates reflexes. Example: When you touch something hot, your spinal cord can trigger a withdrawal reflex before the signal even reaches your brain.

Gray matter

Tissue dominated by neuron cell bodies in the CNS. Example: The outer layer of the cerebral cortex, where most neuronal processing occurs.

White matter

CNS tissue largely composed of myelinated axons. Example: Connects different areas of gray matter, allowing for rapid communication between brain regions.

Plasticity

Brain's ability to change and adapt as a result of experience or injury. Example: After a stroke, the brain can reorganize itself to compensate for lost functions.

Brain-derived neurotrophic factor (BDNF)

Protein that supports neuron growth and synaptic plasticity. Example: Promotes the survival and growth of new neurons and synapses, important for learning.

Neurogenesis

Production of new neurons. Example: New neurons forming in the hippocampus, which may contribute to learning and memory.

Epigenetics

Study of how environmental factors influence gene expression without changing DNA sequence. Example: Diet or stress can influence how certain genes are turned on or off, affecting traits without altering the underlying DNA.

Twin studies

Behavioral genetics method comparing monozygotic and dizygotic twins to estimate heritability. Example: Comparing intelligence scores of identical vs. fraternal twins to see how much genetics contribute.

Adoption studies

Research comparing biological and adoptive relatives to separate environment and genes. Example: If an adopted child's personality is more similar to their biological parents, it suggests a genetic influence.

Minnesota Twin Project

Study of identical twins raised together or apart to assess genetic influence on traits. Example: Research showing striking similarities in personality traits between identical twins separated at birth.

Gene expression

Turning genes on or off and producing the proteins encoded by genes. Example: A gene for eye color being 'expressed' to produce brown pigment.

Genes

Units of heredity that influence traits. Example: The gene for hair color or a gene affecting susceptibility to certain diseases.

Zygote

Fertilized egg that eventually divides to form a fetus. Example: The single cell formed by the fusion of a sperm and an egg.

Event-related potential (ERP)

EEG response that is time-locked to a specific stimulus. Example: A researcher observing a specific brain wave pattern (ERP) occurring consistently 300 milliseconds after a participant sees an unexpected image.

Electroencephalograph (EEG)

Device that measures electrical activity of the brain. Example: Used to diagnose sleep disorders or epilepsy by recording brain waves.

Positron emission tomography (PET)

Imaging technique that assesses metabolic activity using radioactive glucose. Example: Used to identify active brain regions by showing which areas are consuming the most glucose.

Magnetic resonance imaging (MRI)

Imaging technique that produces high-quality structural images of the brain using magnetic fields. Example: Used to detect brain tumors or structural abnormalities in the brain.

Functional magnetic resonance imaging (fMRI)

Imaging technique measuring brain activity by detecting changes in blood oxygenation. Example: While a person performs a cognitive task, fMRI can show which brain areas 'light up' due to increased blood flow.

Transcranial magnetic stimulation (TMS)

Technique using magnets to briefly interrupt or stimulate brain activity. Example: Used to temporarily 'turn off' a brain region to study its function or treat depression.

Phantom limb pain

Sensation that a missing limb still exists and can be painful. Example: A person who has had an amputation reporting pain that feels like it's coming from their missing arm or leg.