A milkman is very upset one morning as his cow refuses to give any milk. The milkman's wife gets the calf from the shed. On fondling by the calf, the cow gave sufficient milk. Describe the role of endocrine gland and the pathway associated with this response?
Ans. Milk secretion in mammals is provoked by the hormone known as oxytocin which works on positive feedback mechanisms.
(a) When the calf suckles on the cow's udder; it stimulates the nerve impulses.
(b) Nerve impulses in order to send signals to the hypothalamus, which starts producing oxytocin in the body.
(c) Therefore, Oxytocin results in the contraction of the smooth muscles around the alveoli (in the cow's udder) and hence milk is released.
Udder (suckling stimulus) Hypothalamus Posterior lobe of pituitary Oxytocin (in the blood) Udder (Smooth muscles) Milk flow.