Chapter 15: Coordination and Response : III Hormones and Endocrine Glands

%%Hormones%% are chemical substances ^^produced in endocrine glands^^, ^^transported by blood^^ and they alter the activity of one or more ^^target organ^^.

%%Endocrine Gland%%
- are ductless glands.
- which secrete hormones.

Glands and their secretion

Gland and Secretion	Cause of Secretion	Effect
Islets of Langerhans in pancreas produce the Insulin	Increase in blood glucose concentration	causing conversion of glucose to glycogen.
Adrenal medulla produces adrenaline	in conditions of fear, anger, anxiety and stress	increases blood glucose level - increases metabolic rate - increases rate of heartbeat and causes rise in blood pressure - constricts arteries - pupil dilates to enhance vision - contracts hair muscle producing goose pimples.
Testes produces testosterone	hormone from pituitary	involved in development of male characteristics - controls development of primary and secondary sexual characteristics in men - for sperm production.
Ovaries produce oestrogen	hormone from pituitary gland	controls development of female sex organs and sexual characteristics.
Ovaries produce progesterone	hormone from pituitary gland - pregnancy hormone	prepares uterus for implantation of embryo.