Unit 1: Biological Bases of Behavior - Flashcards

Vocabulary practice flashcards for AP Psychology Unit 1 covering Nature and Nurture, Divisions of the Nervous System, Neurons, Reflex Arcs, and Neural Communication.

Nature

An individual's genes, biological makeup, and inherited traits that shape who they are.

Nurture

An individual's environment, life experiences, and external influences that shape who they are.

Twin Studies

A research design comparing identical versus fraternal twins to investigate how genes and environment influence behavior.

Family Studies

A research design examining similarities among family members to observe genetic and environmental influences on traits.

Adoption Studies

A research design comparing adopted children to their biological family and adoptive family to isolate the effects of genes versus environment.

Evolutionary Psychology

A branch of psychology that explains human behavior as an adaptation shaped by evolutionary history.

Eugenics

A controversial and unethical historical movement that attempted to improve human populations through selective breeding.

Central Nervous System (CNS)

The core division of the nervous system consisting of the brain and spinal cord, responsible for thinking, learning, and behavior.

Peripheral Nervous System (PNS)

The branch of the nervous system consisting of all nerves outside the brain and spinal cord, transmitting sensory and motor information throughout the body.

Somatic Nervous System

A motor division of the PNS under conscious control that regulates voluntary movement of skeletal muscles.

Autonomic Nervous System

A motor division of the PNS operating automatically without conscious control to regulate smooth muscles, cardiac muscles, glands, and maintain homeostasis.

Parasympathetic Nervous System

The 'rest and digest' division of the autonomic nervous system that calms the body by constricting pupils, slowing heart rate, and stimulating digestion.

Sympathetic Nervous System

The 'fight or flight' division of the autonomic nervous system that alerts the body in high-stress situations by dilating pupils, increasing heart rate, and inhibiting digestion.

Neuron

A specialized cell designed to send and receive information throughout the nervous system.

Dendrites

Branching structures of a neuron that receive chemical and electrical signals from neighboring cells.

Axon

The elongated tube-like structure of a neuron that sends electrical signals away from the cell body toward other cells.

Myelin Sheath

A fatty coating wrapping around the axon that increases the speed of neural impulse transmission.

Axon Terminals

The endpoint branches of an axon that release neurotransmitters to transmit signals across the synapse.

Glial Cells

Non-neuronal cells in the nervous system that support, protect, nourish, and keep neurons functioning properly.

Reflex Arc

A quick, automatic, and protective neural response pathway that processes sensory information directly in the spinal cord without conscious brain involvement.

Sensory Neuron

A neuron that detects stimuli from receptors (such as the skin) and carries sensory signals to the spinal cord.

Interneuron

A neuron located within the spinal cord that integrates incoming sensory input and relays signals to motor neurons.

Motor Neuron

A neuron that transmits motor signals from the spinal cord to an effector muscle to produce movement.

Resting Potential

The stable electrical state of a neuron when it is at rest and ready to fire, typically measured at $-70\,\text{mV}$.

Excitatory Neurotransmitter

A chemical messenger (such as glutamate) that increases the likelihood that a receiving neuron will reach threshold and fire an action potential.

Inhibitory Neurotransmitter

A chemical messenger (such as GABA) that decreases the likelihood that a receiving neuron will fire an action potential.

Threshold

The minimum membrane potential level ($-55\,\text{mV}$) required to trigger an electrical action potential.

All-or-None Principle

The principle stating that a neuron fires completely if a signal reaches threshold voltage, or does not fire at all if the signal remains below threshold.

Depolarization

The rapid rise in membrane potential voltage during an action potential, climbing from threshold to a peak of approximately $+40\,\text{mV}$.

Refractory Period

A brief reset period following an action potential during which the neuron temporarily cannot fire another signal.

Multiple Sclerosis (MS)

An autoimmune disorder in which the immune system damages the myelin sheath of neurons, causing slower or disrupted neural signals.

Myasthenia Gravis (MG)

An autoimmune disorder in which antibodies block acetylcholine receptors at the neuromuscular junction, causing muscle weakness.

Dopamine

A neurotransmitter that plays a primary role in regulating reward, motivation, reinforcement, and pleasure.

Serotonin

A neurotransmitter that regulates mood, emotion, well-being, emotional stability, and sleep.

Norepinephrine

A neurotransmitter responsible for promoting alertness, attention, and physiological arousal.

Acetylcholine

A neurotransmitter essential for learning, memory processing, and triggering muscle movement.

Endorphins and Substance P

Neurotransmitters that jointly influence how the body senses, experiences, and modulates pain.

Leptin and Ghrelin

Chemical messengers that work together to regulate appetite, hunger signals, and energy balance.