566 GlossaryHyperglycemia (HIGH-per-gligh-SEE-mee-ah) A high
blood glucose level (Chapter 10).
Hyperkalemia (HIGH-per-kuh-LEE-mee-ah) A high
blood potassium level (Chapter 19).
Hypernatremia(HIGH-per-nuh-TREE-mee-ah) A high
blood sodium level (Chapter 19).
Hyperopia (HIGH-per-OH-pee-ah) Farsightedness; an
error of refraction in which only distant objects are seen
clearly (Chapter 9).
Hypertension (HIGH-per-TEN-shun) An abnormally
high blood pressure, consistently above 130/85 mmHg
(Chapter 13).
Hypertonic(HIGH-per-TAHN-ik) Having a greater con-
centration of dissolved materials than the solution used as
a comparison (Chapter 3).
Hypertrophy(high-PER-troh-fee) Increase in size of a
body part, especially of a muscle following long-term
exercise or overuse (Chapter 7).
Hypocalcemia(HIGH-poh-kal-SEE-mee-ah) A low blood
calcium level (Chapter 10).
Hypoglossal nerves (HIGH-poh-GLAH-suhl) Cranial
nerve pair XII; motor to the tongue (Chapter 8).
Hypoglycemia(HIGH-poh-gligh-SEE-mee-ah) A low
blood glucose level (Chapter 10).
Hypokalemia(HIGH-poh-kuh-LEE-mee-ah) A low blood
potassium level (Chapter 19).
Hyponatremia(HIGH-poh-nuh-TREE-mee-ah) A low
blood sodium level (Chapter 19).
Hypophyseal portal system(high-POFF-e-SEE-al POR-
tuhl) The pathway of circulation in which releasing hor-
mones from the hypothalamus circulate directly to the
anterior pituitary gland (Chapter 10).
Hypophysis (high-POFF-e-sis) The pituitary gland
(Chapter 10).
Hypotension(HIGH-poh-TEN-shun) An abnormally low
blood pressure, consistently below 90/60 mmHg
(Chapter 13).
Hypothalamus(HIGH-poh-THAL-uh-muss) The part of
the brain superior to the pituitary gland and inferior to
the thalamus; its many functions include regulation of
body temperature and regulation of the secretions of the
pituitary gland (Chapter 8).
Hypothermia(HIGH-poh-THER-mee-ah) 1. The condi-
tion in which the body temperature is abnormally low
due to excessive exposure to cold. 2. A procedure used
during some types of surgery to lower body temperature
to reduce the patient’s need for oxygen (Chapter 17).
Hypotonic(HIGH-po-TAHN-ik) Having a lower concen-
tration of dissolved materials than the solution used as a
comparison (Chapter 3).
Hypovolemic shock(HIGH-poh-voh-LEEM-ik SHAHK)
A type of circulatory shock caused by a decrease in blood
volume (Chapter 13).
Hypoxia(high-PAHK-see-ah) A deficiency or lack of oxy-
gen (Chapter 2).—I—
Idiopathic(ID-ee-oh-PATH-ik) A disease or disorder of
unknown cause (Chapter 11).
Ileocecal valve(ILL-ee-oh-SEE-kuhl VALV) The tissue of
the ileum that extends into the cecum and acts as a
sphincter; prevents the backup of fecal material into the
small intestine (Chapter 16).
Ileum(ILL-ee-um) The third and last portion of the small
intestine, about 11 feet long (Chapter 16).
Ilium(ILL-ee-um) The upper, flared portion of the hip
bone (Chapter 6).
Immunity(im-YOO-ni-tee) The state of being protected
from an infectious disease, usually by having been
exposed to the infectious agent or a vaccine; human
immunity has two major components: innate and adap-
tive. Innate immunity is nonspecific, has no memory, and
consists of anatomic barriers, defensive cells, and chemi-
cals; adaptive immunity is specific, has memory, and may
involve antibodies (Chapter 11).
Impetigo(IM-pe-TYE-go) A bacterial infection of the skin
that occurs most often in children (Chapter 5).
Implantation (IM-plan-TAY-shun) Embedding of the
embryonic blastocyst in the endometrium of the uterus 5
to 8 days after fertilization (Chapter 21).
In vitrofertilization(IN VEE-troh FER-ti-li-ZAY-shun)
Fertilization outside the body, in which sperm and ova
are mixed in laboratory glassware; early embryos may
then be introduced into the uterus for implantation
(Chapter 20).
Inactivator(in-AK-ti-vay-tur) A chemical that inactivates a
neurotransmitter to prevent continuous impulses (Chap-
ter 8).
Inapparent infection(IN-uh-PAR-ent) An infection with-
out symptoms (Syn.—subclinical, asymptomatic)
(Chapter 22).
Incubation period(IN-kew-BAY-shun) In the course of an
infectious disease, the time between the entry of the
pathogen and the onset of symptoms (Chapter 22).
Incus(ING-kuss) The second of the three auditory bones
in the middle ear; transmits vibrations from the malleus
to the stapes (Chapter 9).
Infarct(IN-farkt) An area of tissue that has died due to lack
of a blood supply (Chapter 12).
Infection(in-FEK-shun) A disease process caused by the
invasion and multiplication of a microorganism (Chapter
22).
Inferior(in-FEER-ee-your) Below or lower (Chapter 1).
Inferior vena cava(VEE-nah KAY-vah) The vein that
returns blood from the lower body to the right atrium
(Chapter 12).
Infestation(in-fess-TAY-shun) The harboring of parasites,
especially worms or arthropods (Chapter 22).
Inflammation(in-fluh-MAY-shun) The reactions of tissue
to injury (Chapter 5).30Scanlon(p3) Glossary 8/17/06 11:08 AM Page 566