Pyschology Vocab

Nervous System

The body’s command center, a complex network of nerves and specialized cells that transmits messages between the brain, spinal cord, and all the parts of the body. Controls everything from breathing and walking to thinking and feeling.

Central Nervous System (CNS)

The body's primary control and processing center, consisting of the brain and spinal cord. Receives and interprets sensory information from all over the body before sending out signals that control the body’s response.

Peripheral Nervous System (PNS)

A network of nerves extending from the central nervous system (CNS) (brain and spinal cord) that carries messages to and from all parts of the body. It is divided into the somatic nervous system, which controls voluntary movements, and the autonomic nervous system, which manages involuntary functions like heartbeat and digestion.

Autonomic Nervous System

The part of the nervous system that controls involuntary bodily functions, such as heart rate, blood pressure, digestion, and sweating.

Sympathetic Nervous System

A part of the autonomic nervous system that prepares the body for "fight or flight" by increasing heart rate, dilating pupils, and diverting blood flow to muscles.

Parasympathetic Nervous System

Part of the autonomic nervous system that promotes "rest and digest" functions, which counteracts the "fight or flight" response of the sympathetic nervous system.

Somatic Nervous System

The part of the peripheral nervous system that controls voluntary movements and transmits sensory information from the body to the central nervous system.

Endocrine System

Uses hormones to regulate body functions like growth, development, metabolism, and reproduction. It does this by releasing hormones into the bloodstream, which then travel to target cells to control processes such as mood, stress response, blood sugar levels, and heart rate.

Hormones

Chemical messengers produced by specialized cells in the body that travel through the bloodstream to target organs and tissues, where they regulate various physiological processes and functions.

Homeostasis

The process by which living organisms maintain a stable, constant internal environment. This includes regulating factors like body temperature, blood sugar, and blood pressure, despite external changes.

Neuron

A basic cell of the nervous system that receives and sends messages throughout the body. Messages are sent using electrical and chemical signals, allowing for functions like movement, thought, and sensation.

Axon

The long, thread-like projection of a nerve cell (neuron) that transmits electrical impulses away from the neuron's cell body. It acts like a cable, carrying signals to other neurons, muscles, or glands through its terminals at the end.

Dendrites

The branched, tree-like extensions of a nerve cell that receive signals from other neurons and transmit them to the cell body. They act as the primary receivers for communication within the nervous system, collecting impulses from other nerve cells to process information.

Myelin Sheath

A fatty, insulating layer that wraps around the axons (nerve fibers) of neurons in the central and peripheral nervous systems.

Action Potential

A rapid, transient electrical impulse that travels along a neuron's axon, allowing it to transmit information throughout the nervous system.

Resting Potential

The electrical charge difference between the inside and outside of a neuron when it is not actively transmitting signals.

Refractory Period

A brief time interval after a neuron or muscle cell has fired an action potential, during which it is temporarily unresponsive to further stimulation.

Synapse

A specialized junction between two neurons (nerve cells) where information is transmitted from one neuron to the next.

Neurotransmitter

Chemical messengers that transmit signals between neurons (nerve cells) and other cells in the body.

Reuptake

Process in neuroscience and psychology where neurotransmitters, chemical messengers in the brain, are reabsorbed by the presynaptic neuron (the neuron that released them) after they have completed their function