Disorders of the Endocrine System

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Gigantism

 Overproduction of growth hormone in infants - adolescents

 Acromegaly

 Gigantism in adults (enlargement of mandible, growth of hands and feet)

 Goiter
Enlargement of the thyroid gland

Cretinism

Congenital hypothyroidism (underproduction of thyroid hormone) which occurs in infants (protruding tongue, delayed puberty)

Aldosteronism

 Overproduction of aldosterone (from zona glomerulosa)

Myxoedema

Hypothyroidism in adults (decreased mental ability, sparse, dry hair, puffy body areas)

Grave's disease

Hyperthyroidism (protrusion of eyeballs, heat intolerance, fatigue and weakness)

Hypocalcaemia

Too little parathyroid hormone (excitability of muscle tone, e.g. Chvostek's and Trousseau's sign)

Hypercalcaemia

Too much parathyroid hormone (depression of neuromuscular activity, softening of bones)

Rickets

Vitamin D3 deficiency with reduced bone density

Cushing's Syndrome

Increased ACTH or glucocorticoids causing hyperglycaemia (leading to oedema and moon face)

Diabetes

Hypo secretion or hyperactivity of insulin causing use of glucose stored in triglycerides (leading to ketosis). Symptoms and consequences:
  • Polyuria
  • Polydipsia (thirst)
  • Polyphagia (hunger)
  • Retinopathy
  • Neuropathy
  • Nephropathy
  • Peripheral vascular disease
Type 1: autoimmune destruction of beta cells, which produce insulin (genetic, requires insulin supplement)
Type 2: developed insulin-resistant tissues (often diet caused)

Functions of insulin:

  1. Increased glucose uptake by cells
  2. Increased production of glycogen
  3. Increased production of triglyceride stores
  4. Increased glucose use for ATP in cellular metabolism
  5. Increased amino acid absorption and protein synthesis
Functions of glucagon:
  1. Increased glycogen breakdown to glucose
  2. Increased glucose production at liver
  3. Increased breakdown of triglyceride stores

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