AP Psych Unit 1 Biology Vocab

Neuron

A nerve cell that sends and receives information.

Dendrites

Branches of a neuron that receive messages from other neurons.

Axon

The part of a neuron that carries messages away from the cell body.

Myelin Sheath

A fatty covering around the axon that speeds up neural messages.

Action Potential

A neural impulse that travels down the axon.

Threshold

The minimum stimulation needed to trigger an action potential.

Synapse

A tiny gap between neurons where messages are passed.

Refractory Period

A short period when a neuron cannot fire again immediately.

All or None Principle

A neuron either fires completely or does not fire at all.

Neurotransmitters

Chemicals that carry messages between neurons.

Acetylcholine (ACh)

A neurotransmitter involved in movement, learning, and memory.

Endorphins

Neurotransmitters that reduce pain and can produce feelings of pleasure.

Nervous System

The body’s system for communicating using electrical and chemical signals.

Central Nervous System

The brain and spinal cord.

Peripheral Nervous System (PNS)

All nerves outside the brain and spinal cord.

Nerves

Bundles of axons that carry information throughout the body.

Sensory Neurons

Neurons that carry information from the senses toward the brain and spinal cord.

Interneurons

Neurons that connect sensory and motor neurons within the CNS.

Motor Neurons

Neurons that carry commands from the CNS to muscles and glands.

Somatic Nervous System

Controls voluntary movements of skeletal muscles.

Autonomic Nervous System (ANS)

Controls automatic body functions such as heartbeat and digestion.

Sympathetic Nervous System

Activates the body during stress; the “fight-or-flight” response.

Parasympathetic Nervous System

Calms the body after stress; the “rest-and-digest” response.

Reflex

A quick, automatic response to a stimulus.

Neural Networks

Groups of connected neurons that work together to process information.

Endocrine System

A system of glands that releases hormones into the bloodstream.

Hormones

Chemical messengers released by endocrine glands.

Adrenal Glands

Glands that release hormones involved in stress and arousal.

Pituitary Gland

A gland that controls many other endocrine glands; often called the “master gland.”

Lesion

Damage to a specific area of the brain used to study its function.

EEG

A test that records the brain’s electrical activity.

PET scan

A brain scan that shows areas of brain activity by tracking radioactive glucose.

MRI

A scan that creates detailed pictures of brain structures.

fMRI

A scan that shows brain activity by measuring changes in blood flow.

Brain Stem

The part of the brain that controls basic survival functions.

Medulla

Controls vital functions such as breathing and heartbeat.

Reticular Formation

A network involved in alertness, attention, and arousal.

Thalamus

The brain’s sensory relay station, sending most sensory information to the cortex.

Cerebellum

Controls balance, coordination, and fine motor movements.

Limbic System

A group of structures involved in emotion, motivation, and memory.

Amygdala

Helps process emotions, especially fear and aggression.

Hypothalamus

Regulates basic needs such as hunger, thirst, body temperature, and sex drive.

Cerebral Cortex

The brain’s outer layer responsible for higher-level thinking and processing.

Glial Cells

Cells in the nervous system that support, protect, and nourish nerve cells.

Frontal Lobes

Involved in planning, decision-making, personality, and voluntary movement.

Parietal Lobes

Process touch and other body sensations and help with spatial awareness.

Occipital Lobes

Process visual information.

Temporal Lobes

Process hearing, language, memory, and some aspects of emotion.

Motor Cortex

Controls voluntary muscle movements.

Sensory Cortex

Processes information from touch and other body sensations.

Association Areas

Areas of the cortex involved in higher-level thinking, such as interpreting and combining information.

Aphasia

Difficulty with speaking or understanding language caused by brain damage.

Broca’s Area

Brain area involved in producing speech.

Wernicke’s Area

Brain area involved in understanding language.

Plasticity

The brain’s ability to change and reorganize itself.

Brain Plasticity

The brain’s ability to form new connections or adapt after experience or damage.

Corpus Callosum

A bundle of nerve fibers connecting the brain’s two hemispheres.

Phrenology

The outdated belief that personality traits can be determined by the shape of the skull.