| Hormones | Informations |
| Glands – Hypothalamus |
Releasing Hormones
- TRH – regulates production of TSH and prolactin
- GnRH – regulates production of LH and FSH
- GHRH – regulates production of GH
- CRH – regulates production of ACTH
Somatostatin - Inhibitor of GH and TSH production
Dopamine - Prolactin release inhibitor
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| Anterior pituitary Glands |
Growth Hormone - Most abundant pituitary hormone
- Gigantism: increase (excess) in GH before the closure of epiphyseal plate
- Acromegaly: increase (excess) in GH after the closure of epiphyseal plate
- Dwarfism: a deficiency of GH
Prolactin - Initiates and maintains lactation
- Highest levels at 4am, 8am, 8pm and 10pm
- Prolactinoma: most common type of functional pituitary tumor
TSH - Stimulation for the production of T3 and T4
LH - For secretion of progesterone; for ovulation
ACTH - Stimulation for the production of adrenocortical steroid formation and secretion
FSH - For secretion of estrogen
- For development of seminiferous tubules; spermatogenesis
|
| Posterior pituitary ~ only releases hormones (doesn’t produce) |
Oxytocin - Stimulates contraction of the uterine “Fergusson reflex”
- Also acts in parturition and in transport of sperm
- Also for milk ejection (suckling as stimulator)
ADH - Aka vasopressin
- For water balance and blood pressure elevation
- Deficiency: diabetes insipid
|
| Thyroid gland |
T3 and T4: - produced by follicular cells
- For metabolism
- There are more T4 than T3
- T3 is more biologically active
Primary hyperthyroidism (Graves’ disease) - increased T3 and T4 but decreased TSH
- presence of anti-TSH receptor antibody
Secondary hyperthyroidism - both FT4 and TSH are increased
Primary hypothyroidism (Hashimoto’s thyroiditis) - increased TSH but decreased T3 and T4
- presence of anti-TPO antibody
Myxedema: manifestation of Hashimoto’s disease |
| Parathyroid gland: smallest gland in the body |
Calcitonin: - produced by parafollicular cells
- produced by parafollicular cells
PTH - Produced and secreted by chief cells of parathyroid gland
- For bone resorption
- Primary hyperparathyroidism: increased ionized calcium
- Secondary hyperparathyroidism: decreased ionized calcium
|
| Adrenal gland |
Cortisol - Secreted by zona fasciculate
- Highest levels in: 6am-9am
- Lowest levels: 11pm-3am
- Cushing’s syndrome:
- increased levels of cortisol and ACTH but decreased levels of aldosterone and renin are notable
- screening test: 24hr urine free cortisol test
- Confirmatory: low dose dexamethasone suppression test and CRH stimulation test
- Cushing’s disease:
- increased levels of ACTH due to tumor on the pituitary gland
- Methods:
- Porter-Silber reaction (corticosteroids); + reaction = yellow pigment
- Zimmerman reaction (ketosteroids) + reaction = reddish purple color
Aldosterone - Secreted by zona glomerulosa
- Most important mineralocorticoid
- Responsible to Na+ and K+ retention
- Barterr’s syndrome: there is a defect in the kidney’s ability to reabsorb sodium
- Conn’s syndrome (1’ hyperaldosteronism): there is hypokalemia and hypernatremia
- Liddle’s syndrome: there is an excess sodium reabsorption and excretion of potassium due to defect in the DCT
Catecholamine - Secreted in medulla
- 80% epinephrine, 20% norepinephrine
- Pheochromocytoma: tumor that results to overproduction of catecholaminess
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| Reproductive glands |
Testosterone - Principal androgen in the blood
- Most potent male androgen
- Synthesized by the Leydig cells
Estrogen - Estrone: most abundant in menopausal women
- Estradiol: most potent; most abundant in pre-menopausal women
- Estriol: major estrogen detected during pregnancy; produced by placenta; marker for down syndrome
- Kober reaction: used to analyze estrogens
Progesterone - Single best hormone to evaluate if ovulation has occurred
|
| Pancreas |
Insulin Glucagon |
