posterior lobe does not itself synthesize any hor-
mones. The hypothalamus regulates the posterior
lobe primarily through neurologic signals (notably
via the NEUROTRANSMITTERacetylcholine) that stim-
ulate it to release its hormones into the blood cir-
culation.
HORMONES OF THE POSTERIOR PITUITARY LOBEANTIDIURETIC HORMONE(ADH) OXYTOCIN
For further discussion of the pituitary gland
within the context of the endocrine system’s
structure and function please see the overview
section “The Endocrine System.”
See also ACROMEGALY; ADENOMA; ANABOLIC
STEROIDS AND STEROID PRECURSORS; CORTICOTROPIN-
RELEASING HORMONE(CRH); GONADOTROPIN-RELEASING
HORMONE(GNRH); GROWTH HORMONE–RELEASING HOR-
MONE(GHRH); HYPERPROLACTINEMIA; HYPOPITUITARISM;
THYROTROPIN-RELEASING HORMONE(TRH).
polyglandular deficiency syndrome An autoim-
mune disorder in which the IMMUNE SYSTEMpro-
duces antibodies that attack various endocrine
glands and structures, resulting in deficiencies of
the hormones the structures produce. The
endocrine glands most commonly affected are the
ADRENAL GLANDS, theTHYROID GLAND, thePARATHY-
ROID GLANDS, and the PITUITARY GLAND. When one
autoimmune deficiency condition develops in an
endocrine structure, others are likely to follow.
The three types of polyglandular deficiency syn-
drome are
- type 1 polyglandular deficiency syndrome,
which affects children under the age of 12 and
typically affects the parathyroid glands, causing
HYPOPARATHYROIDISM, and the adrenal glands,
causing ADRENAL INSUFFICIENCYor ADDISON’S DIS-
EASE - type 2 polyglandular deficiency syndrome,
which affects adults over the age of 30 and
includes type 1 DIABETES, adrenal insufficiency
or Addison’s disease, and HYPOTHYROIDISM - type 3 polyglandular deficiency syndrome,
which affects women age 40 to 50 and includes
THYROIDITIS, early MENOPAUSE, Addison’s disease,
and VITILIGO
Symptoms correlate to the endocrine glands
affected and the endocrine disorders that result
from damage to those glands. As well, symptoms
may also affect functions such as FERTILITY, particu-
larly when the thyroid gland is among the
involved endocrine glands. Fertility requires a
fairly precise endocrine balance throughout the
body. The diagnostic path combines clinical evi-
dence, history of symptoms, and laboratory tests
that measure various HORMONElevels. All forms of
polyglandular deficiency syndrome are chronic
and require appropriate, lifelong HORMONE THERAPY
to supplement or replace deficient hormones.
See also ANTIBODY; AUTOIMMUNE DISORDERS;
ENDOCRINE GLAND; HYPERTHYROIDISM; INSULIN RESIST-
ANCE; MULTIPLE ENDOCRINE NEOPLASIA(MEN).progesterone A steroid HORMONE the adrenal
cortex of the ADRENAL GLANDS, the OVARIES, and the
TESTESsynthesize from a base of cholesterol. Adi-
pose cells (fat cells) also synthesize small amounts
of progesterone. Progesterone is a precursor hor-
mone from which men and women synthesize
TESTOSTERONE. The HYPOTHALAMUSinitiates the hor-
monal cascade that results in progesterone synthe-
sis with the release of GONADOTROPIN-RELEASING
HORMONE (GNRH), which stimulates the anterior
lobe of the PITUITARY GLANDto produce LUTEINIZING
HORMONE (LH) and FOLLICLE-STIMULATING HORMONE
(FSH). LH and FSH act on the gonads (sex glands),
stimulating their hormone productions.
Women have significantly higher levels of prog-
esterone, which vary cyclically with MENSTRUATION,
than men. In women the primary role of proges-
terone is to prepare the UTERUS for PREGNANCY.
Progesterone levels spike with OVULATION and
remain elevated for about 10 days. If pregnancy
occurs, the corpus luteum continues to secrete
progesterone to maintain the uterine environ-
ment. Progesterone also stimulates growth of the
mammary glands in the breasts. If pregnancy does
not occur the corpus luteum deteriorates, ceases
progesterone production, and MENSTRUATION
begins. The primary role of progesterone in men is
to testosterone production.
For further discussion of progesterone within
the context of the endocrine system’s structure
and function please see the overview section “The
Endocrine System.”156 The Endocrine System