Chapter 2: The Role of Biology in Psychology

Vocabulary flashcards covering key terms and concepts from Chapter 2: The Role of Biology in Psychology, including neural communication, brain structures, neurotransmitters, nervous system divisions, genetics, and neuroplasticity.

Central Nervous System (CNS)

The division of the nervous system consisting of the brain and spinal cord that processes information and sends signals to the peripheral nervous system.

Peripheral Nervous System (PNS)

All nerves and nerve cells located outside of the brain and spinal cord that process information in the body and transmit signals to and from the CNS.

Neurons

The basic units of the nervous system; nerve cells that receive, integrate, and transmit information.

Dendrites

Branchlike extensions of a neuron's cell body that receive chemical signals from other neurons.

Axon

A long narrow outgrowth of a neuron along which electrical signals travel, sometimes coated in a fatty myelin sheath that increases communication speed.

Terminal Buttons

Knoblike structures at the end of the axon that release chemical signals called neurotransmitters into the synapse.

Synapse

The microscopic gap between the terminal buttons of a sending neuron and the dendrites of a receiving neuron, where neurotransmitters are released.

Presynaptic Neuron

The sending neuron that releases chemical information across the synaptic gap.

Postsynaptic Neuron

The receiving neuron that collects chemical information via receptors after the synaptic gap.

Receptors

Structures located on the postsynaptic neuron's dendrites that specifically fit certain types of neurotransmitters like a lock and key.

Reuptake

The process by which neurotransmitters in the synapse are reabsorbed back into the presynaptic neuron.

Enzyme Degradation

The process by which neurotransmitters in the synapse are broken down and destroyed by enzymes.

Excitatory Signal

A signal sent by a neurotransmitter that increases the likelihood that a receiving neuron will fire an action potential.

Inhibitory Signal

A signal sent by a neurotransmitter that decreases the likelihood that a receiving neuron will fire an action potential.

Action Potential

An electrical impulse created in the cell body by the movement of ions across the neuron's membrane, which travels down the axon to trigger neurotransmitter release.

"All or Nothing" Principle

The rule stating that a neuron either reaches its threshold of electrical charge and fires an action potential completely, or it does not fire at all.

Refractory Period

The phase following an action potential during which the neuron returns to its resting state and is temporarily less responsive and less likely to fire.

Agonist

A drug or substance that mimics and enhances the action of a neurotransmitter.

Antagonist

A drug or substance that blocks and inhibits the action of a neurotransmitter.

Acetylcholine

A neurotransmitter that regulates motor control, attention, memory, learning, and sleeping.

Norepinephrine

A neurotransmitter involved in arousal and alertness, known as epinephrine (adrenaline) when active in the rest of the body.

Serotonin

A neurotransmitter important for emotional states, impulse control, and dreaming; low levels are associated with depression.

Dopamine

A neurotransmitter involved in reward, motivation, and voluntary motor control; severe loss of dopamine is associated with Parkinson's disease.

GABA

The primary inhibitory neurotransmitter in the nervous system, which helps reduce anxiety.

Glutamate

The primary excitatory neurotransmitter in the nervous system, which facilitates learning and memory.

Endorphins

Neurotransmitters involved in pain reduction and the feelings of pleasure experienced during rewarding activities.

Phrenology

An early nineteenth-century theory developed by Franz Gall and Johann Spurzheim asserting that specific brain functions are localized in distinct areas of the brain.

Broca's Area

A region located in the left frontal lobe of the brain, identified by Paul Broca in 1861, that is crucial for speech production.

Electroencephalograph (EEG)

A device used to record and measure the electrical activity of the brain.

Functional Magnetic Resonance Imaging (fMRI)

A neuroimaging technique that maps brain activity during mental tasks by measuring changes in blood flow and blood oxygen levels.

Transcranial Magnetic Stimulation (TMS)

A research technique that uses magnetic fields to momentarily disrupt neural activity in a specific brain region to assess its necessary role in cognitive functions.

Medulla

A hindbrain structure that controls vital survival functions including heart rate, breathing, and swallowing.

Pons

A hindbrain structure involved in sleep, arousal, and coordinating movements between the left and right sides of the body.

Cerebellum

A large hindbrain structure essential for coordinating smooth physical movements and maintaining balance.

Substantia Nigra

A midbrain structure key for producing dopamine and initiating voluntary movements; cell death in this area causes Parkinson's disease.

Limbic System

A group of subcortical forebrain structures (thalamus, hypothalamus, hippocampus, amygdala) involved in motivations, emotions, and memory.

Thalamus

A subcortical forebrain structure that acts as a sensory relay station, receiving almost all incoming sensory input except smell before routing it to the cortex.

Hypothalamus

A subcortical structure that regulates internal organ functions, body temperature, blood sugar, sleep rhythms, and basic drives like hunger, thirst, and sex.

Hippocampus

A subcortical forebrain structure critical for the formation of new memories and spatial navigation.

Amygdala

A subcortical forebrain structure responsible for processing emotional information (especially fear) and enhancing memory during emotional arousal.

Cerebral Cortex

The convoluted, outer layer of forebrain tissue divided into two hemispheres that processes complex mental activity.

Corpus Callosum

A thick band of nerve fibers connecting the left and right cerebral hemispheres, allowing communication and information transfer between them.

Occipital Lobes

Regions of the cerebral cortex located at the back of the brain, responsible for visual processing and housing the primary visual cortex.

Parietal Lobes

Regions of the cerebral cortex responsible for processing touch sensations and spatial information, housing the primary somatosensory cortex.

Temporal Lobes

Regions of the cerebral cortex responsible for hearing, memory, and facial/object recognition, containing the primary auditory cortex and fusiform face area.

Frontal Lobes

Regions of the cerebral cortex responsible for complex thought, planning, attention, inhibition, decision making, and movement.

Prefrontal Cortex

The frontmost portion of the frontal lobes critical for rational thought, social connection, attention, and personality identity.

Split Brain

A condition resulting from surgical cutting of the corpus callosum, isolating the two cerebral hemispheres so they can no longer communicate directly.

Somatic Nervous System

A subdivision of the PNS that carries sensory signals from the skin, muscles, and joints to the CNS and motor signals from the CNS to initiate voluntary movement.

Autonomic Nervous System

A subdivision of the PNS that automatically regulates the internal environment by transmitting signals between the CNS and glands/internal organs.

Sympathetic Nervous System

A division of the autonomic nervous system that prepares the body for action by increasing arousal and energy expenditure.

Parasympathetic Nervous System

A division of the autonomic nervous system that calms the body and returns it to a resting state.

Endocrine System

A communication network that uses glands to secrete hormones into the bloodstream to influence body functions, mental activity, and behavior.

Hormones

Chemical substances produced and released by endocrine glands that travel through the bloodstream to target organs and tissues.

Gonads

The primary reproductive glands (testes in males, ovaries in females) that secrete sex hormones such as androgens and estrogens.

Natural Selection

The evolutionary principle that organisms inheriting traits beneficial for survival and adaptation are more likely to reproduce and pass on those traits.

Genotype

An organism's complete genetic makeup, which is established at fertilization and remains unchanged throughout life.

Phenotype

An organism's observable physical and psychological characteristics, produced by the interaction of its genotype and environmental factors.

Gene Expression

The process determining whether a gene's genetic instructions are active and observable in the phenotype, influenced by environmental factors.

Behavioral Genetics

The field of study examining how biological genes and environmental influences interact to shape behavior and mental processes.

Monozygotic Twins

Identical twins resulting from a single fertilized egg splitting into two identical embryos with identical genetic material.

Dizygotic Twins

Fraternal or nonidentical twins resulting from two separate eggs fertilized by two different sperm at the same time.

Epigenetics

The study of environmental influences on gene expression that occur without altering the underlying DNA sequence.

Plasticity

The brain's ability to adapt, grow, and reorganize its structure and functional connections in response to experience, learning, or injury.

Neurogenesis

The biological process of growing and producing new neurons in the brain.

Neural Pruning

The process of systematically eliminating inactive or unnecessary neural connections to make the brain operate more efficiently.