1.3 Requirements for Life - Necessary Life Functions

Vocabulary flashcards covering the eight necessary life functions and related physiological terms from Section 1.3 Requirements for Life.

Maintaining boundaries

A necessary life function where separation between internal and external environments must exist, such as plasma membranes separating cells and skin separating the organism from the environment.

Movement

A necessary life function allowed by the muscular system, involving movement of body parts via skeletal muscle and movement of substances via cardiac muscle (blood) and smooth muscle (digestion, urination).

Contractility

Refers to movement at the cellular level when muscles contract.

Metabolism

All chemical reactions that occur in body cells, defined as the sum of all catabolism (breakdown of molecules) and anabolism (synthesis of molecules).

Catabolism

The breakdown of molecules within body cells.

Anabolism

The synthesis of molecules within body cells.

Responsiveness

The ability to sense and respond to stimuli, regulated by the nervous system (e.g., withdrawal reflex preventing injury and control of breathing rate during different activities).

Reproduction

The division of cells for growth or repair at the cellular level, and the production of offspring at the organismal level.

Motor nerves

Nerves that control muscle function.

Excretion

The removal of waste from metabolism and digestion—including urea (from breakdown of proteins), carbon dioxide (from metabolism), and feces (unabsorbed foods)—involving the urinary, digestive, and integumentary systems.

Urea

A waste product generated from the breakdown of proteins, excreted by the body.

Digestion

The breakdown of ingested foodstuff, followed by the absorption of simple molecules into the blood.

Growth

An increase in size of a body part or of an organism.