Endocrine Glands

Secrete hormones directly into blood; act at receptors (often on other endocrine glands)

Multiple endocrine glands throughout body, including:

-Pancreas
-Pituitary
-Thryoid/Parathyroid
-Adrenal
-Ovary and Testes (reproductive pathology lecture)

Hormones control many functions, such as:
-Metabolism
-Reproduction
-Fluid and electrolyte balance
-Growth

Patterns of hormone secretion:

1. Constant (thyroid axis)


2. Episodic
(i)On demand (after a meal; during stress), i.e. Insulin; ACTH
(ii)Pulsatile (most hormones)
(iii)Diurnal (many hormones)
(iv)Light entrained (ACTH/cortisol)
(v)Sleep entrained (GH, testosterone)

(vi)Infradien,

-Ovarian hormones during the menstrual cycle, Gonadal hormones in seasonally reproducing species

Endocrine Disorders:

Too much produced and/or released Too little hormone produced and/or released
  • Often involves tumour
  • May be ectopic (organ diplaced from common location)

Treatment:

  • Inhibitory drug therapy
    Ex. Bromocryptine for hyperprolactinemia
    Ex. Androgen antagonist for hirsutism (excess hair)
  • Ablation therapy
    Ex. Surgical removal of lesion, leaving gland intact
  • Target cell resistance due to:
    -Genetic defect (lack receptor)
    -Autoimmune response
    -Overworked (no longer responds adequately)

Treatment:

Hormone replacement
Ex. Insulin for diabetes mellitus





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