| A | B |
|---|
| abdomen | Portion of the body b/n the diaphragm & the pelvis |
| abdominal | Pertaining to the abdomen |
| abdominal cavity | The space b/n the diaphragm & the pelvic inlet that contains the abdominal viscera |
| abdominopelvic cavity | The space b/n the diaphragm & the lower portion of the trunk of the body |
| abduction | Movement of a body part away from the midline |
| absorption | The taking in of substances by cells or membranes |
| accessory organs | Organs that supplement the functions of other organs |
| accommodation | Adjustment of the lens for close vision |
| acetone | One of the ketone bodies produced as a result of the oxidation of fats |
| acetylcholine | A type of neurotransmitter |
| acetyl coenzyme A | An intermediate compound produced during the oxidation of carbohydrates & fats |
| acid | A substance that ionizes in water to release hydrogen ions |
| acid-base buffer system | A pair of chemicals, 1 a weak acid, the other a weak base, that resists pH changes |
| acidosis | A relative increase in the acidity of body fluids |
| acromial | Pertaining to the shoulder |
| ACTH | Adrenocorticotropic hormone |
| actin | A protein in a muscle fiber that, together w/ myosin, is responsible for contraction & relaxation |
| action potential | The sequence of electrical changes occurring when a nerve cell membrane is exposed to a stimulus that exceeds its threshold |
| activation energy | Energy required to initiate a chemical reaction |
| active site | Region of an enzyme molecule that combines temporarily w/ a substrate |
| active transport | Process that requires an expenditure of energy to move a substance across a cell membrane;usually moved against the concentration gradient |
| acupuncture | Procedure in which needles are inserted into various veins to control pain sensations |
| adaptation | Adjustment to environmental conditions |
| adduction | Movement of a body part toward the midline |
| adenoids | The pharyngeal tonsils located in the nasopharynx |
| adenosine diphosphate | ADP; molecule produced when the terminal phosphate is lost from a molecule of adenosine triphosphate |
| adenosine triphosphate | An organic molecule that stores energy & releases energy for cellular processes |
| adenylate cyclase | An enzyme that is activated when certain hormones combine w/ receptors on cell membranes,causing ATP to release 2 phosphates and circularize, forming cyclic AMP |
| ADH | Antidiruetic hormone |
| adipose tissue | Fat-storing tissue |
| adolescence | Period of life b/n puberty & adulthood |
| ADP | Adenosine diphosphate |
| adrenal cortex | The outer portion of the adrenal gland |
| adrenal glands | Endocrine glands located on the superior portions of the kidneys |
| adrenaline | A hormone produced by the adrenal glands |
| adrenal medulla | The inner portion of the adrenal gland |
| adrenergic fiber | A nerve fiber that secretes norepinephrine at the axon terminal |
| adrenocorticotropic hormone | ACTH: hormone secreted by the anterior lobe of the pituitary gland that stimulates activity in the adrenal cortex |
| aerobic respiration | Phase of cellular respiration that requires oxygen |
| afferent | Conducting toward a center. For example, an _arteriole conveys blood to the glomerulus of a nephron w/in the kidney |
| agglutination | Clumping of blood cells in response to a reaction b/n an antibody & an antigen |
| agranulocyte | A nongranular leukocyte |
| albumin | A plasma protein that helps regulate the osmotic concentration of blood |
| aldosterone | A hormone, secreted by the adrenal cortex, that regulates sodium & potassium ion concentrations and water balance |
| alimentary canal | The tubular portion of the digestive tract that leads from the mouth to the anus |
| alkaline | Pertaining to or having the properties of a base or alkali; basic |
| alkaline tide | An increase in the blood concentration of bicarbonate ions following a meal |
| alkaloid | A group of organic substances that are usually bitter in taste and have toxic effects |
| alkalosis | A relative increase in the alkalinity of body fluids |
| allantosis | A structure that appears during embryonic development & functions in the formation of umbilical blood vessels |
| allele | Different forms of a gene |
| allergen | A foreign substance capable of stimulating an allergic reaction |
| all-or-none response | Phenomenon in which a muscle fiber contracts completely when it is exposed to a stimulus of threshold strength |
| alpha receptor | Receptor on effector cell membrane that combines w/ epinephrine or norepinephrine |
| alpha-tocopherol | Vitamin E |
| alveolar ducts | Fine tubes that carry air to the air sacs of the lungs |
| alveolar pores | Minute openings in the walls of air sacs, which permit air to pass from 1 alveolus to another |
| alveolar process | Projection on the border of the jaw in which the bony sockets of the teeth are located |
| alveolus | An air sac of a lung; a saclike structure |
| alveoli | plural of alveolus |
| amacrine cell | A retinal neuron whose fibers pass laterally b/n other retinal cells |
| amine | A type of nitrogen-containing organic compound, including the hormones secreted by the adrenal medulla |
| amino acid | An organic compound of relatively small molecular size that contains an amino group and a carboxyl group; the structural unit of a protein molecule |
| the structure of an amino group | -NH2 |
| the structure of a carboxyl group | -COOH |
| amniocentesis | A procedure in which a sample of amniotic flud is removed thru the abdominal wall of a pregnant woman. Fetal cells in it are cultured & examined to check for chromosome complement |
| amnion | An extra embryonic membrane that encircles a developing fetus & contains amniotic fluid |
| amniotic cavity | Fluid-filled space enclosed by the amnion |
| amniotic fluid | Fluid w/in the amniotic cavity that surrounds the developing fetus |
| ampulla | An expansion of the end of each semicircular canal that contains a crista ampullaris |
