GROUP IPituitary

“The master gland”

Main points :-1-Name & location.2-Structure.3-pituitary in vertebrates.4-How does it work?5-The glands’ hormones & their function.6-Disorders of pituitary.

1-Name & location.-Pituitary gland is also called the hypophysis.It lies in a small cavity in the skull called

hypophysial fossa below the brain as shown:

2-Structure.Pituitary is divided into 2 parts : 1- Anterior one which is glandular or

adenohypophysis located toward the front of the head

2- Posterior one which is neural or neurohypophysis located toward the back of the head.

3-pituitary in vertebrates.In lower vertebrates there is an intermediate lobe

between the anterior & the posterior ones , this lobe has an endocrine function.

In higher vertebrates there is no intermediate lobe but cells with no endocrine function.

4-How does it work?Scan this diagram then tell me what did you understand.

As shown, the anterior pituitary secretion is under the control of hypothalamus through the following hormones: GRH , GIH , TRH , CRH , GnRH , PRH & PIH .

THE FUNCTION OF THESE HORMONES

THE FUNCTION OF THESE HORMONES

Diagram showing the work of ADH

Pituitary disorders

As compared with the hand of a typical person (left), the hand of a patient with acromegaly (right) is enlarged, the fingers are widened, thickened and stubby, and the soft tissue is thickened

Teeth showing classic teeth gapping due to acromegaly on lower jaw

 

Figure 1 A 22-year-old man with gigantism due to excess growth hormone is shown to the left of his identical twin. The increased height (Panel A) and enlarged hand (Panel B) and foot (Panel C) of the affected twin are apparent. Their height and features began to diverge at the age of approximately 13 years.

Have a look for more information & figures : http://www.tjhsst.edu/~jleaf/disability/jweb/JWEB.HTM

With our best wishes

Jihad , Asmaa & Hanan