notesendocrine

The endocrine system is responsible for chemical regulation. Stimuli may cause certain glands to secrete chemical messengers known as hormones. These hormones cause other parts of the body to respond.

The endocrine system includes the ENDOCRINE GLANDS and their hormones. The glands of the endocrine system are called ductless glands. Ductless glands release hormones directly into the bloodstream. The bloodstream transports hormones throughout the body. Each hormone acts on a certain kind of tissue called its target tissue.

The endocrine glands, the hormones they secrete and their functions

GLAND AND

LOCATION

HORMONE

FUNCTION

OVERSECRETION OR

UNDERSECRETLON

Pituitary

Location: base of brain

Growth hormone

Stimulates the elongation of the long bones of the body. Also affects various metabolic activities, including the metabolism of glucose.

Oversecretion- in childhood, giantism. In adults, acromegaly (bones of face, hands, and feet enlarge).

Undersecretion-in childhood, dwarfism.

Thyroid

Location:

in the neck

 

Thyroxin

Regulates rate of metabolism in body. Essential for normal physical and mental development,

Oversercretion-(of thyroxin) nervousness, weight loss. Undersecretion-(of thyroxin) in childhood, cretinism (mental retardation, small size).

(Of iodine) results in goiter- an enlargement of the thyroid.

Parathyrold

embedded in back of thyroid gland

Parathormone

Controls the metabolism of calcium, necessary for normal nerve and muscle function, blood clotting, healthy bones and teeth.

Undersecretion-Nerve disorders, brittle bones, clotting problems

Adrenal

Location:

on top of each kidney.

Cortisone

 

 

 

Adrenaline

 

Regulates carbohydrate, protein, fat metabolism. Promotes conversion (change) of fats and proteins to glucose.

Raises blood sugar level and increases heartbeat and breathing rates.

 

Oversecretion-Cushing’s

disease(high blood glucose levels, excess fat). Undersecretion-Addison ‘s disease(low blood glucose level, weight loss).

Undersecretion-Inability to deal with stress.

Islets of Langerhans Location:

Pancreas

Insulin

Glucagon

 

Stimulates glucose uptake by cells.

Promotes conversion (change) of glycogen to glucose.

Oversecretion-low blood sugar Undersecretion-Diabetes (high blood sugar).

Oversecretion- High blood sugar.

endocrine system disorders.

Goiter: under secretion of iodine by thyroid gland

Diabetes: under secretion of insulin by Islets of Langerhans

Gigantism: over secretion in childhood of growth hormone by pituitary gland

Addison disease: under secretion of cortisone by adrenal gland

Acromegaly: over secretion of growth hormone in adults by pituitary gland