Biology and Behavior

Neuroscience

The field that deals with the structure and functioning of the brain and the nervous system, focusing on their relationship to behavior and learning.

Neuron

Specialized cells that transmit information throughout the nervous system.

Afferent neurons

Sensory neurons that relay information from the sense organs and receptors to the brain or spinal cord.

Efferent neurons

Motor neurons that convey signals from the brain and spinal cord to the glands and muscles.

Interneurons

Neurons that carry information between neurons in the brain and spinal cord.

Dendrites

Parts of a neuron that receive messages from other neurons.

Axon

The long part of a neuron that carries messages to other cells.

Myelin sheath

A protective coating around the axon that increases the velocity of electrical impulses.

Action Potential

An electrical nerve impulse that travels through a neuron, changing the cell’s charge from negative to positive.

Synapse

A chemical connection that bridges the gap between two neurons.

Neurotransmitters

Chemicals that carry messages across the synapse to the receiving neuron.

Acetylcholine (ACh)

A neurotransmitter that is excitatory and involved in skeletal muscle contraction and cognitive functioning.

Dopamine

A neurotransmitter that plays a role in movement, learning, attention, and emotional responses.

Norepinephrine

A neurotransmitter and hormone that speeds up heartbeat and is involved in arousal and memory.

Serotonin

A neurotransmitter that regulates mood, sleep, and appetite.

Gamma-aminobutyric Acid (GABA)

The main inhibitory neurotransmitter in the brain that controls anxiety.

Endorphins

Neurotransmitters involved in pain suppression, pleasure, and the placebo effect.

Central nervous system

The part of the nervous system that includes the brain and spinal cord.

Peripheral nervous system

The part of the nervous system that includes the autonomic and somatic subdivisions.

Autonomic nervous system

Controls involuntary movements and functions, usually without conscious effort.

Somatic nervous system

Specializes in voluntary movements and communicates sensory information.

Sympathetic nervous system

Prepares the body for fight-or-flight responses during emergencies.

Parasympathetic nervous system

Returns the body to a relaxed state and is involved in digestion.

Frontal lobes

The part of the brain associated with decision making and voluntary muscle movement.

Broca’s area

A region in the frontal lobe that controls speech production.

Wernicke’s area

A region involved in comprehending spoken language and formulating coherent language.

Hemispheres

The two halves of the brain that control opposite sides of the body.

Neuroplasticity

The brain's ability to adapt and reorganize itself, especially after injury.

Pituitary gland

The master gland of the endocrine system, controlled by the hypothalamus.

Thyroid gland

Produces hormones that regulate metabolism.

Adrenal glands

Glands that release hormones related to stress response and body regulation.

Pancreas

Regulates blood sugar levels by releasing insulin and glucagon.

Gonads

Sex glands (ovaries in females and testes in males) that release sex hormones.