Human Body: An Orientation - Life Functions and Survival Needs

A set of vocabulary flashcards covering the necessary life functions, survival needs, and organ system roles described in the lecture notes.

Metabolism

A broad term referring to all chemical reactions that occur within the body and all of its cells.

Adenosine triphosphate (ATP)

The energy-rich molecules that power cellular activities, produced using nutrients and oxygen.

Excretion

The process of removing excreta, or wastes, from the body.

Cellular reproduction

Process where an original cell divides to produce two identical daughter cells, used for body growth or repair.

Organismal reproduction

The production of offspring by the union of a sperm and an egg to form a fertilized egg.

Growth

An increase in cell size or body size, usually accomplished by an increase in the number of cells.

Survival needs

The factors required to maintain life, including nutrients, oxygen, water, and appropriate temperature and atmospheric pressure.

Carbohydrates

The major energy-providing fuel for body cells.

Proteins

Nutrients essential for building cell structures.

Fats

Chemicals that cushion body organs, provide reserve fuel, and help build cell structures.

Minerals and vitamins

Required chemicals for the reactions that occur in cells and for oxygen transport in the blood.

Water

The most abundant chemical substance in the body, accounting for $60$ to $80\,\%$ of body weight.

Normal body temperature

The thermal state of the body which must be maintained at $37\,^{\circ}\text{C}$ ($98.6\,^{\circ}\text{F}$) for chemical reactions to continue.

Atmospheric pressure

The force exerted on the surface of the body by the weight of air, necessary for breathing and gas exchange.

Maintaining boundaries

The principle that every living organism must keep its "inside" distinct from its "outside," facilitated by cell membranes and the integumentary system.

Interstitial fluid

The fluid located between cells.

Movement

Includes activities promoted by the muscular system and the internal propulsion of substances like blood, food, and urine.

Responsiveness (irritability)

The ability to sense changes (stimuli) in the environment and then to react to them.

Digestion

The process of breaking down ingested food into simple molecules that can be absorbed into the blood.

Urinary system

Also known as the excretory system, it consists of the kidneys, ureters, bladder, and urethra and removes nitrogen-containing wastes.

Nitrogenous wastes

Substances such as urea and uric acid that result from the breakdown of proteins and nucleic acids.

Liver

A digestive organ that produces bile to help break down fats.

Pancreas

An organ that has both endocrine and digestive functions, delivering enzymes to the small intestine.