ENDOCRINOLOGY (by Rodriguez, M.T.
, RMT, MAEd, MSMT)
Hormones – chemical signals produced by specialized cells Hypothyroidism
secreted into the blood stream and carried to a target issue o 1˚, 2˚ and/or 3˚
o Hashimoto’s Dse. (with goiter)
Classification accdg. to Composition/Structure: o Congenital Hypothyroidism/Cretinism
1. Peptides & Proteins Thyroid Function Tests:
a. Glycoproteins (FSH, HCG, TSH, EPO)
b. Polypeptides (ACTH, ADH, GH, Ins, Gluc) 1. TSH Test
2. Steroids (Aldo, Cortisol, Progesterone, Testosterone, 2. Thyroglobulin Assay
Vit. D) 3. Serum T3 & T4
3. Amines (Catecholamines & Thyroid Hormones)
PARATHYROID GLAND – smallest endoc. gland in the body;
HYPOTHALAMUS – the link between the nervous system & secretes PTH (hypercalcemic)
the endocrine system
ADRENAL GLAND – pyramid-like shape
PITUITARY GLAND – the “Master Gland”
1. Adrenal Cortex
a. Adenohypophysis – the “true pituitary gland”; a. Zona glomerulosa: Mineralocorticoids
produces & secretes GH, Prolactin, Aldosterone
Gonadotropins, TSH, ACTH Hyperaldosteronism: Conn’s Disease
b. Neurohypophysis – releases ADH & Oxytocin b. Zona fasiculata: Glucocorticoids
Cortisol
Hormones of the Pituitary Gland: Hypercortisolism: Cushing’s Syndrome
(with “buffalo hump”, hirsutism
1. GROWTH HORMONE/SOMATOTROPIN (<7 ng/mL)
Screening Tests: 24hr urinary free cortisol
Stimulus: deep sleep
test, overnight dexamethasone suppression
Inhibitor: Somatostatin
test, midnight salivary cortisol test
GH Deficiency: Idiopathic (children), Pituitary
Confirmatory Tests: Low-dose
adenoma (adults)
dexamethasone test, midnight plasma
GHD Screening Test: Exercise test
cortisol, CRH stimulation test
GHD Confirmatory Test: Insulin Tolerance Test
Hypocortisolism: Addison’s Dse.
and Arginine Stimulation Test
Screening Test: ACTH Stimulation Test
Acromegaly: (>50 ng/mL)
Confirmatory Test: Insulin Tolerance Test
Acro. Screening Test: Somatomedin C/IGF-I
Congenital Adrenal Hyperplasia:
Acro. Confirmatory Test: Glucose Suppression Test-
- 21-hydroxylase def: CYP21 gene defect
OGTT (75g)
- 11 β-hydroxylase def: CYP11B1 gd
2. GONADOTROPINS
- 3β-hydroxysteroid dehydrogenase-
FSH: For spermatogenesis (males)
isomerase def: HSD3B2 gene defect
LH: For production of testosterone (males), for
- 17-hydroxylase def: CYP17 gene defect
ovulation (females)
c. Zona reticularis: Androgens
3. TSH/THYROTROPIN
DHEA & Androstenedione
The main stimulus for the uptake of iodide by
thyroid gland; unique β subunit
2. Adrenal Medulla
4. ACTH
a. Catecholamines (Norepi/Epi)
Peaks at 6am-8am
Metabolite: VMA
Best collected at 8am-10am
Pheochromocytoma: Hypertension,
Blood should be collected into polysterene/plastic
tachycardia, headache, tightness of chest,
EDTA tubes.
sweating
5. PRL
Neuroblastoma: high Norepi in children
For lactation
Spx: 24hr urine, plasma (EDTA), fasting px
Inhibitor: Dopamine
Methods: Chromatography, RIA (sensitive)
6. Oxytocin
b. Dopamine
Stimulates contraction of the gravid uterus, termed
Metabolite: HVA
“Fergusson reflex”
7. Vasopressin/ADH
REPRODUCTIVE HORMONES:
Maintains osmotic homeostasis
1. Testosterone, DHEA, Estrogen, Progesterone
THYROID GLAND – “butterfly-shaped gland”, connected by
PANCREAS:
isthmus
1. Glucagon, Insulin, Somatostatin
Hormones of the thyroid gland:
MISCELLANEOUS HORMONES:
1. T3/TRIIODOTHYRONINE (active) & T4 1. HCG, HPL, Gastrin, Serotonin, Inhibin A
By follicular cells
Transporters: TBG, Transthyretin, Albumin Samples for Hormonal Assay:
2. CALCITONIN 1. Whole blood (LH, Testosterone)
By parafollicular/C cells 2. Plasma (EDTA – ACTH, ADH, PTH), (Heparin –
Disorders: Catecholamines, Cortisol, Dopa, FSH)
Hyperthyroidism 3. Serum (Aldo, androgens, FSH, GH, Progesterone)
o Thyrotoxicosis 4. Urine – Estriol)
o Grave’s Dse. (with exophthalmos)
