Question

1) in reproduction, is the female considered the default system?

2) during pregnancy, the alveoli if the breast begin to grow under the contril of what? oxytocin, progesterone, estrogen? or both or all of the above?

3) during pregnancy what inhibits milk production?

4) after parturition, the hormone that causes production of milk is ? which is produced by the ?

5) contraction of smooth muscle around the ducts of the breast is under control of ? which is produced by the ?

Answer 1

1)in reproduction , female is considered as the default , because the female contain two similar copies of X chromosome. During the gametogenesis female can only produce gamete with X chromosome , No gamete with Y chromosome.

so, the sex of the offsprings are decided by the male because they contain both X and Y chromosome, the gamete coming from the male can be with X chromosome (female offspring) or with Y chromosome (male offspring)

2)Estrogen and progesterone

During the period of pregnancy teh breast undergo some developement for the production of milk

Hormones estrogen and progesterone are high in the blood during the pregnancy period.

Breast duct system will undergo some modification to form milk storing space called alveoli.

This alveoli are produced by the action of the estrogen and progesterone.

3)Estrogen and progesterone

Although the estrogen and progesterone is essential for the developement of breast during the pregnancy , they inhibit the milk production by inhibiting the prolactin hormone from the anterior pituitary.

4)After the parturition PROLACTIN HORMONE help in the milk production and it is produced from the ANTERIOR PITUITARY GLAND

After the parturition , the level of teh progesterone and estrogen get low, because of theis the inhibition on the prolactin hormone get released and the prolactin hormone produce milk

5)OXYTOCIN HORMONE help in the contraction of the smooth muscle and the releas of the milk

it is produced from Hypothalamus and stored in the posterior pituitary gland