Part 1

 Endocrine System

The endocrine system maintain the stability of internal environment. The endocrine system consists of glands . Glands are the group of epithelial cells. They produce specialised secretion.  Gland are two types:----

1. Exocrine glands

They discharge their secretion  on to the epithelial surface of an organ ,  either directly or through a duct and are called if the exocrine gland.

They vary in shape,size and complexity.

Endocrine gland

Endocrine gland are type of gland which secret hormone into the blood and lymph . Endocrine gland is a ductless  gland.

Hormones

It is a chemical substance , i.e. secreted into the body fluids by one cell or a group of cell. It regulate the body's activity. It is also called as chemical Messengers.

Pituitary Gland and Hypothalamus

* The pituitary gland and Hypothalamus work together.

* The pituitary gland also called hypophysis.

* Their secretion control the function of other gland.

* It is also called master endocrine gland.

* It about 1.2 to 1.5 cm in length it's weight is about 0.5gram.

* The gland has  a stem like stalk called the infundibulum, which connects it to the hypothalamus of the brain. 

* It secretes a different hormones.

* The pituitary look like one gland, but is consist of 2 glands. That are as follows .....

A) Anterior pituitary gland     7 hormones

B) Posterior pituitary gland     2 hormones

Anterior pituitary gland is also known as adenohypophysis.

Growth Hormones (gh)

It is also known as Somatotrophin hormones.

It is synthesis by anterior pituitary gland.

It helps in the growth of muscles and other tissues.

The hypothalamus secretes the growth hormone releasing inhibition hormone(GHRIH ).

2. Thyroid stimulating hormone (TSH)

This hormone synthesized by the anterior pituitary gland.

It is also called thyrotropin

It helped in the growth and development of target glands.

Thyroid stimulating hormone secrete 2 harmons..

Triiodothyronine ( T3 ) and thyroxin (T4)