582 Glossarythat is a consequence of a bacterial infection (Chap-
ter 13).
Septicemia(SEP-tih-SEE-mee-ah) The presence of bacte-
ria in the blood (Chapter 5).
Septum(SEP-tum) A wall that separates two cavities, such
as the nasal septum between the nasal cavities or the
interventricular septum between the two ventricles of the
heart (Chapter 12).
Serous fluid(SEER-us FLOO-id) A fluid that prevents
friction between the two layers of a serous membrane
(Chapter 4).
Serous membrane(SEER-us MEM-brayn) An epithelial
membrane that lines a closed body cavity and covers the
organs in that cavity (Chapter 4).
Sex chromosomes(SEKS KROH-muh-sohms) The pair
of chromosomes that determines the gender of an indi-
vidual; designated XX in females and XY in males
(Chapter 21).
Sex-linked trait (SEKS-LINKED TRAYT) A genetic
characteristic in which the gene is located on the X chro-
mosome (Chapter 7).
Simple(SIM-puhl) Having only one layer, used especially
to describe certain types of epithelial tissue (Chapter 4).
Sinoatrial (SA) node(SIGH-noh-AY-tree-al NOHD) The
first part of the cardiac conduction pathway, located in
the wall of the right atrium; initiates each heartbeat
(Chapter 12).
Sinusoid(SIGH-nuh-soyd) A large, very permeable capil-
lary; permits proteins or blood cells to enter or leave the
blood (Chapter 13).
Skeletal muscle pump(SKEL-e-tuhl MUSS-uhl) A mech-
anism that increases venous return; contractions of the
skeletal muscles compress the deep veins, especially those
of the legs (Chapter 13).
Skeletal system(SKEL-e-tuhl) The organ system that con-
sists of the bones, ligaments, and cartilage; supports the
body and is a framework for muscle attachment (Chap-
ter 6).
Skin(SKIN) An organ that is part of the integumentary sys-
tem; consists of the outer epidermis and the inner dermis
(Chapter 5).
Sliding filament mechanism(SLY-ding FILL-ah-ment)
The sequence of events that occurs within sarcomeres
when a muscle fiber contracts (Chapter 7).
Small intestine(SMAWL in-TESS-tin) The organ of the
alimentary tube between the stomach and the large intes-
tine; secretes enzymes that complete the digestive
process and absorbs the end products of digestion
(Chapter 16).
Smooth muscle(SMOOTH MUSS-uhl) The muscle tis-
sue that forms the walls of hollow internal organs. Also
called visceral or involuntary muscle (Chapter 4).
Sneeze reflex(SNEEZ) A reflex integrated by the medulla
that expels irritating substances from the nasal cavities by
means of an explosive exhalation (Chapter 15).Sodium-potassium pumps(SEW-dee-um pa-TASS-ee-
um) The active transport mechanisms that maintain a
high sodium ion concentration outside the cell and a high
potassium ion concentration inside the cell (Chapter 7).
Soft palate(SAWFT PAL-uht) The posterior portion of
the palate that is elevated during swallowing to block the
nasopharynx (Chapter 15).
Solute(SAH-loot) The substance that is dissolved in a solu-
tion (Chapter 2).
Solution(suh-LOO-shun) The dispersion of one or more
compounds (solutes) in a liquid (solvent) (Chapter 2).
Solvent(SAHL-vent) A liquid in which substances (solutes)
will dissolve (Chapter 2).
Somatic(soh-MA-tik) Pertaining to structures of the body
wall, such as skeletal muscles and the skin (Chapter 8).
Somatostatin (SOH-mat-oh-STAT-in) 1. Growth hor-
mone inhibiting hormone (GHIH); produced by the
hypothalamus. 2. The hormone produced by the delta
cells of the pancreas (Chapter 10).
Somatotropin (SOH-mat-oh-TROH-pin) Growth hor-
mone (Chapter 10).
Specialized fluids(SPEH-shul-eyezd FLOO-ids) Specific
compartments of extracellular fluid; include cere-
brospinal fluid, synovial fluid, and aqueous humor in the
eye (Chapter 2).
Spermatic cord(sper-MAT-ik KORD) The cord that sus-
pends the testis; composed of the ductus deferens, blood
vessels, and nerves (Chapter 20).
Spermatogenesis(SPER-ma-toh-JEN-e-sis) The process
of meiosis in the testes to produce sperm cells (Chap-
ter 3).
Spermatozoa(sper-MAT-oh-ZOH-ah) (Sing.—spermato-
zoon) Sperm cells; produced by the testes (Chapter 20).
Sphenoid bone(SFEE-noyd) The flat bone that forms part
of the anterior floor of the cranial cavity and encloses the
pituitary gland (Chapter 6).
Sphincter(SFINK-ter) A circular muscle that regulates the
size of an opening (Chapter 7).
Spina bifida(SPY-nuh BIF-i-duh) A congenital malforma-
tion of the backbone in which the spinal cord and
meninges may protrude; there are many variations and
degrees of impairment (Chapter 17).
Spinal cavity(SPY-nuhl KAV-i-tee) The cavity within the
vertebral column that contains the spinal cord and men-
inges; part of the dorsal cavity (Syn.—vertebral canal or
cavity) (Chapter 1).
Spinal cord(SPY-nuhl KORD) The part of the central
nervous system within the vertebral canal; transmits
impulses to and from the brain (Chapter 8).
Spinal cord reflex(SPY-nuhl KORD REE-fleks) A reflex
integrated in the spinal cord, in which the brain is not
directly involved (Chapter 8).
Spinal nerves(SPY-nuhl NERVS) The 31 pairs of nerves
that emerge from the spinal cord (Chapter 8).
Spinal shock (SPY-nuhl SHAHK) The temporary or30Scanlon(p3) Glossary 8/17/06 11:08 AM Page 582