Question

Draw a labelled diagram of the pituitary gland and Describe the hormones secreted by Neurohypophysis.

Answer 1

Hormones of Neurohypophysis:

• The pars nervosa stores & releases two hormones which are secreted by supraoptic nucleus & paraventricular nucleus viz., oxytocin & vasopressin respectively. 
• Both the oxytocin & vasopressin are octapeptide & each has 8 amino acids. 

1. Oxytocin: 

• It is found only in females & it is also called as Pitocin. 
• It helps in parturition by stimulating contraction of the uterine muscles. 
• It also helps in the release of the milk from the mammary glands after parturition. 

2. Vasopressin: 

• It is also called an Antidiuretic hormone (ADH) or Pitressin.
• It controls reabsorption of water in the DCT. 
• Deficiency of ADH causes diabetes insipid us. Its main symptom is diuresis or polyurea.
• In this disease, the amount of urine is increased 15 to 25 litre per day from the normal.