Question:easy
In the breast, lactiferous ducts are formed under the influence of which hormone?
In the breast, lactiferous ducts are formed under the influence of which hormone?
Show Hint
Ducts versus lobules - one steroid grows the ducts, the other the alveoli.
Updated On: Jun 24, 2026
- Estrogen
- Progesterone
- LH
- FSH
Show Solution
The Correct Option is A
Solution and Explanation
Step 1: Recall the simple rule for mammary morphogenesis: ducts equal estrogen, lobules equal progesterone.
Step 2: Under rising estrogen at puberty, the primitive duct buds elongate and branch to build the lactiferous duct tree that converges toward the nipple. This makes estrogen the duct-forming hormone.
Step 3: Progesterone then works on the estrogen-primed tissue to expand the lobuloalveolar units, which is a separate step from duct formation.
Step 4: The gonadotropins FSH and LH act on ovarian follicles and the corpus luteum, so their effect on the breast is only secondary. The direct answer to duct formation is therefore estrogen.
\[\boxed{\text{Estrogen}}\]
Step 2: Under rising estrogen at puberty, the primitive duct buds elongate and branch to build the lactiferous duct tree that converges toward the nipple. This makes estrogen the duct-forming hormone.
Step 3: Progesterone then works on the estrogen-primed tissue to expand the lobuloalveolar units, which is a separate step from duct formation.
Step 4: The gonadotropins FSH and LH act on ovarian follicles and the corpus luteum, so their effect on the breast is only secondary. The direct answer to duct formation is therefore estrogen.
\[\boxed{\text{Estrogen}}\]
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