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Endocrine system

Table 3.1: The major endocrine glands, their locations, hormones they secrete,
functions of each hormone and disorders associated with hormonal excess or deficiency

Endocrine Position Hormone produced Role of the hormone Effects of Effect of excess
gland deficiency production
Pituitary Below the Somatotropic growth Controls growth Dwarfism Gigantism
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gland hypothalamus hormones (GH)
Thyrotropic hormone Controls production of Low thyroxine More thyroxine
or thyroid stimulating thyroxine hormone from hormone produced hormone produced
hormone (TSH) the thyroid gland (Hypothyroidism) (Hyperthyroidism)
Adrenocorticotropic Stimulates activities of the Less water More water
hormone (ACTH) adrenal cortex reabsorbed reabsorbed
Follicle-stimulating Causes development of Poor ovarian func- Ovarian failure
hormone (FSH) the follicle in the ovary tion Testicular failure
Luteinising hormone Causes ovulation Infertility in both Infertility in both
(LH) men and women men and women
Antidiuretic Regulates the amount of Less water More water
hormone (ADH) water reabsorbed in the reabsorbed reabsorbed
kidney tubules
Oxytocin Controls the contraction Delaying of birth Premature birth
and relaxation of the
uterus muscles during Poor milk secretion
birth
Causes milk secretion
from the mammalian
gland
Thyroid Below larynx Thyroxine Regulates metabolic rate Retardation of Exophthalmic goitre
gland in the neck in mammals physical and mental
region development
(cretinism)
Parathyroid Associated Parathyroid hormone Regulate Calcium Causes Calcium/ Bone thinning due
gland with thyroid (PTH) concentration in the Phosphorus to low availability of
gland bloodstream imbalance in the Calcium
body leading to
muscle pains
Pancreas In the Insulin Regulates sugar levels, High blood sugar Low blood sugar
abdominal causing conversion of (diabetes mellitus) (hypoglycaemia)
( Islets of cavity glucose to glycogen Hyperglycaemia
Langerhans)
Glucagon Regulates sugar levels, Low blood sugar High blood sugar
causing conversion of
glycogen to glucose (Hypoglycaemia) (Hyperglycaemia)
Adrenal Above kidney Adrenaline Causes increased Slow response to an Over reaction on the
glands heartbeat, conversion emergency emergency
of glycogen to glucose,
dilation of pupils and
increased blood flow to
skeletal muscles.
Prepares the body to
cope with a dangerous
situations

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