A very large molecule (as of a protein, nucleic acid, or carbohydrate) built up from smaller chemical structures.

A natural feature or phenomenon that enhances the quality of human life.

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in the cell.

Synthetic, energy-requiring reactions whereby small molecules are built up into larger ones.

The rate at which heat is given off by an organism at complete rest.

A measure of body fat that is the ratio of the weight of the body in kilograms to the square of its height in meters.

A soft mass of chewed food.

The amount of heat energy required to raise the temperature of 1 g of water by 1 degree C. 

Chemical reactions that break down complex organic compounds into simple ones, with the net release of energy.

A substance that enables a chemical reaction to proceed under different conditions (as at a lower temperature) than otherwise possible.

The process of making food absorb-able by mechanically and enzymatic-ally breaking it down into simpler chemical compounds in the alimentary canal.

A protein serving as a catalyst, a chemical agent that changes the rate of reaction without being consumed by the reaction.

A muscular tube that in adult humans is about nine inches (23 centimeters) long and passes from the pharynx down the neck between the trachea and the spinal column and behind the left bronchus where it pierces the diaphragm slightly to the left of the middle line and joins the cardiac end of the stomach.

A membranous muscular sac in which bile from the liver is stored.

The stomach and intestine as a functional unit.

The more terminal division of the vertebrate intestine that is wider and shorter than the small intestine, typically divided into cecum, colon, and rectum, and concerned especially with the resorption of water and the formation of feces.

The largest internal organ in the vertebrate body; performs diverse functions such as producing bile, preparing nitrogenous wastes for disposal, and detoxifying poisonous chemicals in the blood.

The totality of an organism's chemical reactions, consisting of catabolic and anabolic pathways.

A molecule that can combine with others to form a polymer.

The part of the mouth behind the gums and teeth that is bounded above by the hard and soft palates and below by the tongue and by the mucous membrane connecting it with the inner part of the mandible.

A gland with dual functions: The non-endocrine portion secretes digestive enzymes and an alkaline solution into the small intestine via a duct; the endocrine portion secretes the hormones insulin and glucagon into the blood.

Successive muscular contractions along the wall of a hollow muscular structure.

An area in the vertebrate throat where air and food passages cross.

A large molecule composed of repeating structural units or monomers.

A salivary gland enzyme that hydrolyzes starch.

Exocrine glands associated with the oral cavity. The secretions of salivary glands contain substances to lubricate food, adhere together chewed pieces into a bolus, and begin the process of chemical digestion.

The part of the intestine that lies between the stomach and colon, consists of duodenum, jejunum, and ileum, secretes digestive enzymes, and is the chief site of the absorption of digested nutrients.

A sac-like expansion of the alimentary canal of a vertebrate communicating anteriorly with the esophagus and posteriorly with the duodenum and being typically a simple often curved sac with an outer serous coat, a strong complex muscular wall that contracts rhythmically, and a mucous lining membrane that contains gastric glands.

A substance acted upon by an enzyme.

The body cavity in mammals that primarily houses parts of the digestive, excretory, and reproductive systems. It is separated from the thoracic cavity by the diaphragm.

Terminal air sacs that constitute the gas exchange surface of the lungs.

Pair of breathing tubes that branch from the trachea into the lungs.

A sheet of muscle that forms the bottom wall of the thoracic cavity in mammals; active in ventilating the lungs.

Muscle located between the ribs.

The volume of air breathed in one minute without conscious effort. Minute volume = Tidal Volume x (breaths/minute)

The volume of air remaining in lungs after maximum exhalation.

A brief written account of personal, educational, and professional qualifications and experience, as that prepared by an applicant for a job.

An instrument for measuring the air entering and leaving the lungs.

The body cavity in mammals that houses the lungs and heart. It is surrounded in part by ribs and separated from the lower abdominal cavity by the diaphragm.

The volume of air breathed in and out without conscious effort.

The total volume of air that can be exhaled after maximal inhalation.

Hormone-producing glands located superior to the kidneys; each consists of a medulla and a cortex.

A mineralcortocoid produced by the adrenal cortex that promotes sodium and water reabsorption by the kidneys and potassium excretion in urine.

Hormone produced by the neurosecretory cells in the hypothalamus that stimulates water reabsorption from kidney tubule cells into the blood and vasoconstriction of arterioles.

The disposal of nitrogen-containing waste products of metabolism.

In the vertebrate kidney, the extraction of water and small solutes, including metabolic wastes, from the blood by the nephrons.

The first step in urine formation in which substances in blood pass through the filtration membrane and the filtrate enters the proximal convoluted tubule of the nephron.

A ball of capillaries surrounded by Bowmans capsule in the nephron and serving as the site of filtration in the vertebrate kidney.

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in humans are bean-shaped organs about 4 inches (11 centimeters) long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into the pelvis of the kidney whence it is conveyed by the ureter to the bladder.

The tubular excretory unit of the vertebrate kidney.

A duct leading from the kidney to the urinary bladder.

A tube that releases urine from the body near the vagina in females or through the penis in males; also serves in males as the exit tube for the reproductive system.

Chemical analysis of urine.

The pouch where urine is stored prior to elimination.

The organs of the urinary tract comprising the kidneys, ureters, urinary bladder, and urethra.

Waste material that is secreted by the kidney, that forms a clear amber and usually slightly acid fluid.