Thyroid
Thyroxine (hormone containing iodine)
Hormone from pituitary gland
Regulate metabolic rate of body, ensuring normal growth and mental development
Severe deficiency in childhood, cretinism occurs-child becomes idiotic dwarf, usually with bow legs, coarse leathery skin and enlarged tongue.
In adolescents and adults -- low metabolic rate; individual becomes bald, fat, sluggish and feeble-minded. Simple goitre also occurs.
-Simple Goitre
Abnormally high metabolic rate. Individual becomes irritable, restless, nervous and often thin.
Eye commonly protrude, gland also enlarge.
Islets of Langerhans in pancreas
Insulin
- Cell secreting Insulin
Increase in concentration of blood glucose
Causes the conversion of glucose to glycogen for storage in liver and muscles
Enables tissue cells to oxidise glucose to produce energy in tissue respiration
Blood glucose concentration rises. And some is lost in the urine- diabetes mellitus.
Body weakness follows. Continuous loss of weight.
Production of poisonous substances. Ketones, which are excreted in urine. Death can occur.
Abnormal decrease in blood-sugar concentration.
Shock results.
Coma and death may follow.
Adrenal (a) Medulla (inner part of adrenal gland)
Adrenaline
Conditions of fear, anger, anxiety
Increase in metabolic rate means more energy is release in tissue respiration.
Increase in rate of heart beat and rises in blood pressure so that oxygen and glucose are carried faster to the muscles.
Constriction of arteries in skin causes pallor and more blood is sent to the muscles.
Coagulation rate of blood increases.
Conversion of glycogen to glucose.
Pupils dilate.
Hair muscles might contract, producing "goose pimples".
These reactions prepare the body for states of emergency.
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Gonads (a)Testes
Testosterone
Hormone from pituitary
Controls development of male sex organs and secondary sexual characteristics.
Adult-male sexual characteristics do not develop.
Hyper-masculinity
(b) Ovaries
Oestrogen
Hormone from pituitary
Controls development of female sex organs and secondary sexual characteristics.
Adult-female sexual characteristics do not develop.
Hyper-femininity
(b) Ovaries
Progesterone
Hormone from pituitary
Causes enlargement of wall of uterus for implantation of the embryo.
Enlargement of memory glands during pregnancy.
Prevents ovulation
Abortion
Failure of parturition at proper time
Pituitary
(a) Anterior lobe
Somatotrophic hormone (growth-stimulating hormone)
-pituitary gland
Other hormones
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Controls growth, esp. of long bones.
Stimulate thyroid glands, parathyroid glands, adrenal glands and gonads to produce their respective hormones.
"Dwarfism" with disproportionate limbs and body.
These glands fail to produce their hormones.
"Gigantism" results from excessive lengthening of long bones.
Ends of limb bones enlarge; facial bones become abnormally broad and long- these are symptoms of the disease acromegaly.
As for respective glands shown above.
(b) Posterior lobe
Vasopressin (Anti-diuretic hormone or ADH)
Oxytocin
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Prevents excessive loss of water from kidneys by stimulating re-absorption of water by kidney tubules.
Production of milk in memory glands of lactating mother.
Stimulates contraction of uterine muscles which may help in childbirth
Diabetes insipidus- excessive amounts of urine excreted, resulting in excessive thirst.
Oedema due to excessive amounts of water stored.
Abortion
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