568 GlossaryIsotonic exercise(EYE-so-TAHN-ik) Contraction of
muscles with movement of a body part (Chapter 7).—J—
Jaundice(JAWN-diss) A condition characterized by a yel-
low color in the whites of the eyes and in light skin;
caused by an elevated blood level of bilirubin. May be
hepatic, prehepatic, or posthepatic in origin (Chapter 11).
Jejunum(je-JOO-num) The second portion of the small
intestine, about 8 feet long (Chapter 16).
Joint capsule(JOYNT KAP-suhl) The fibrous connective
tissue sheath that encloses a joint (Chapter 6).
Juxtaglomerular cells (JUKS-tah-gloh-MER-yoo-ler
SELLS) Cells in the wall of the afferent arteriole that
secrete renin when blood pressure decreases (Chapter
18).—K—
Keratin(KER-uh-tin) A protein produced by epidermal
cells; found in the epidermis, hair, and nails (from the
Greek “horn”) (Chapter 5).
Keratinocyte(KER-uh-TIN-oh-sight) A cell of the epider-
mis, produces keratin before dying (Chapter 5).
Ketoacidosis(KEY-toh-ass-i-DOH-sis) A metabolic acido-
sis that results from the accumulation of ketones in the
blood when fats and proteins are used for energy pro-
duction (Chapter 10).
Ketones (KEY-tohns) Organic acid molecules that are
formed from fats or amino acids when these nutrients are
used for energy production; include acetone and ace-
toacetic acid (Chapter 10).
Ketonuria (KEY-ton-YOO-ree-ah) The presence of
ketones in urine (Chapter 18).
Kidneys(KID-nees) The two organs on either side of the
vertebral column in the upper abdomen that produce
urine to eliminate waste products and to regulate the vol-
ume, pH, and fluid–electrolyte balance of the blood
(Chapter 5).
Kilocalorie(KILL-oh-KAL-oh-ree) A Calorie, which is
1000 calories; used to indicate the energy content of
foods or the energy expended in activity (See: Calorie)
(Chapter 17).
Kinesthetic sense (KIN-ess-THET-ik) Muscle sense
(Chapter 9).
Krebs cycle(KREBS SIGH-kuhl) The stage of cell respi-
ration comprising a series of reactions in which pyruvic
acid or acetyl CoA is broken down to carbon dioxide and
ATP is formed; aerobic; takes place in the mitochondria
of cells (Syn.—citric acid cycle) (Chapter 17).
Kupffer cells(KUP-fer SELLS) The macrophages of the
liver; phagocytize pathogens and old red blood cells
(Chapter 16).Kyphosis(kye-FOH-sis) An exaggerated thoracic curvature
of the vertebral column (Chapter 6).—L—
Labia majora(LAY-bee-uh muh-JOR-ah) The outer folds
of skin of the vulva; enclose the labia minora and the
vestibule (Chapter 20).
Labia minora(LAY-bee-uh min-OR-ah) The inner folds of
the vulva; enclose the vestibule (Chapter 20).
Labor(LAY-ber) The process by which a fetus is expelled
from the uterus through the vagina to the exterior of the
body (Chapter 21).
Labyrinth(LAB-i-rinth) 1. A maze; an interconnected
series of passageways. 2. In the inner ear, the bony
labyrinth is a series of tunnels in the temporal bone lined
with membrane called the membranous labyrinth
(Chapter 9).
Lacrimal glands(LAK-ri-muhl) The glands that secrete
tears, located at the upper, outer corner of each eyeball
(Chapter 9).
Lactase(LAK-tays) A digestive enzyme that breaks down
lactose to glucose and galactose; secreted by the small
intestine (Chapter 16).
Lacteals(lak-TEELS) The lymph capillaries in the villi of
the small intestine, which absorb the fat-soluble end
products of digestion (Chapter 14).
Lactic acid(LAK-tik ASS-id) The chemical end product of
anaerobic cell respiration; contributes to fatigue in mus-
cle cells (Chapter 7).
Lactose(LAK-tohs) A disaccharide made of one glucose and
one galactose molecule (Syn.—milk sugar) (Chapter 2).
Lactose intolerance(LAK-tohs in-TAHL-er-ense) The
inability to digest lactose due to a deficiency of the
enzyme lactase; may be congenital or acquired (Chapter
16).
Langerhans cell (LAHNG-er-hanz SELL) A mobile,
phagocytic cell of the epidermis (Syn.—dendritic cell)
(Chapter 5).
Large intestine(LARJ in-TESS-tin) The organ of the ali-
mentary tube that extends from the small intestine to the
anus; absorbs water, minerals, and vitamins and elimi-
nates undigested materials (Syn.—colon) (Chapter 16).
Laryngopharynx(la-RIN-goh-FA-rinks) The lower por-
tion of the pharynx that opens into the larynx and
the esophagus; a passageway for both air and food
(Chapter 15).
Larynx(LA-rinks) The organ that is an airway between the
pharynx and the trachea; contains the vocal cords for
speech (Syn.—voice box) (Chapter 15).
Lateral(LAT-er-uhl) Away from the midline, or at the side
(Chapter 1).
Lens(LENZ) The oval structure of the eye posterior to the
pupil, made of transparent protein; the only adjustable30Scanlon(p3) Glossary 8/17/06 11:08 AM Page 568