Question

What is the function of the Endocrine system?

Answer 1

Hint: Most of our body functions like reproduction, hunger, growth, behaviours and emotions are affected by hormones that are released by different endocrine glands. Nine endocrine glands are present in our body which work along with other organs and make up the endocrine system.

Complete answer:
Our body has two types of glands – Endocrine (which release their secretions directly into the bloodstream) and Exocrine (which release their secretion into the epithelial surface like skin with the help of a duct). Endocrine glands control our body by releasing different hormones which control functions of cells and tissues. Hormones are intercellular messengers which are produced in rare amounts.
Major endocrine glands include – Pineal gland, Thyroid, Pituitary, Parathyroid, Hypothalamus, Pancreas, Gonads (testes or ovary) and adrenal glands. Each of these glands secrete different hormones. Function of endocrine glands with respect to the glands and hormones are:

Gland	Hormone	Target Organ	Function
Pineal gland	Melatonin	Several	Biological clock
Pituitary gland	Growth hormone (GH),Prolactin,Thyroid stimulating hormone (TSH),Adrenocorticotropic hormone (ACTH),Follicle stimulating hormone (FSH),Luteinizing hormone (LH),Melanocyte stimulating hormone (MSH),Oxytocin, Vasopressin,Antidiuretic hormone (ADH)	GH - ManyFSH-LH - ovaries,ADH - kidney,Oxytocin - uterus,Prolactin - breast tissues.	ADH- osmoregulation,FSH/LH – Menstrual cycleGH – Growth and divisionOxytocin – Birth controlProlactin – Milk production
Thyroid gland	Thyroxin	Liver	Body’s metabolism
Adrenal glands	Cortisol and adrenaline	Many	Anti – stress, fight or flight
Ovaries	Estrogen and progesterone	Uterus	Menstrual cycle
Testes	Testosterone	Many	Development of male characteristics

Additional information:
Endocrine glands are also known as ductless glands.
Hormone has no nutritive values but their lack or overproduction causes serious problems.
Three regions of pituitary are involved in the secretion of hormones –
1. Pars distalis (anterior pituitary) release GH, prolactin, TSH, FSH, ACTH, LH
2. Pars intermedia secretes MSH
3. Neurohypophysis (posterior pituitary) releases oxytocin and vasopressin.

Note: All the hormones that are secreted do not come from endocrine glands only but some are also secreted by our body cells and tissues like our stomach secretes hunger inducing hormones called Ghrelin and Gastrin (stimulates the secretion of gastric acid in the stomach).