2.3 Homeostasis and the Stimulus–Response Model

This set of vocabulary flashcards covers the fundamental components of homeostasis, the stimulus-response model, and the functional differences between the nervous and endocrine systems.

Homeostasis

The maintenance of a constant internal environment, such as temperature, pH, and concentrations of ions, glucose, water, and carbon dioxide, within a particular range.

Stimuli

Changes or variations in the internal or external environment that need to be detected and, if necessary, responded to by the body.

Receptors

Special types of nerve cells, often located in sense organs like the eyes, ears, nose, tongue, and skin, that identify changes inside and outside the body.

Control centre/modulator

The brain and spinal cord, where nerve impulses are processed to determine which response is appropriate before sending a message to an effector.

Effectors

Muscles or glands that receive messages from the central nervous system to respond in a particular way based on the original stimulus.

Stimulus–response model

A major functioning system involving the nervous and endocrine systems that allows for a change to be detected and a response to occur to return conditions to normal.

Negative feedback

A homeostatic mechanism that occurs when the response is in an opposite direction to the stimulus, allowing for the maintenance of variables within a set range.

Nervous system

A system that uses electrical impulses and neurotransmitters to send fast, immediate, and short-lasting messages across synapses.

Endocrine system

A system that uses glands and hormones to send messages through the bloodstream that are usually slow to respond but long lasting.

Hormones

Chemical signaling molecules used by the endocrine system to communicate messages throughout the body.

Neurotransmitters

Chemicals used by the nervous system, along with electrical impulses, to transmit messages along nerves and across synapses.

Central nervous system

The processing unit of the body, consisting of the brain and spinal cord, that coordinates responses to stimuli.