AIIMS 201926 May
- Exam
- AIIMS
- Year
- 2019
- Date
- 26 May
- Subject
- Zoology
- Chapter
- Chemical Coordination and Integration
AIIMS 2019 · 26 May · Zoology · Chemical Coordination and Integration
Assertion : Posterior pituitary gland releases a hormone which is...
Assertion : Posterior pituitary gland releases a hormone which is helpful in childbirth.
Reason : Pituitary gland releases vasopressin which helps in child birth.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
C. If assertion is true but reason is false.
Step-by-step solution
The secretion of the posterior lobe of pituitary is known as pituitrin and it contains two hormones. (i) Oxytocin or pitocin. (ii) Antidiuretic hormone (ADH) or vasopressin. The posterior lobe of the pituitary gland does not secrete any hormone. Its hormones are secreted in the hypothalamus. Oxytocin (OT) promotes contraction of the uterine muscle and contraction of the myoepithelial cells of the lactating breast, squeezing milk into the large ducts behind the nipple. In late pregnancy the uterus becomes very sensitive to oxytocin. The amount secreted is increased just before and during labour and by sucking of the baby. Because of its role, oxytocin is called "birth hormone" and "milk ejecting hormone."