Question at position 3 Which components of the endocrine system directly responds to the hypothalamus by secreting tropic hormones such as TSH, ACTH, FSH, and LH?Thyroid glandGonadsAdrenal glandsPituitary glandHypothalamic-hypophyseal portal system单项选择题
A
Thyroid gland
B
Gonads
C
Adrenal glands
D
Pituitary gland
E
Hypothalamic-hypophyseal portal system

Question

Question at position 3 Which components of the endocrine system directly responds to the hypothalamus by secreting tropic hormones such as TSH, ACTH, FSH, and LH?Thyroid glandGonadsAdrenal glandsPituitary glandHypothalamic-hypophyseal portal system单项选择题

A

Thyroid gland

B

Gonads

C

Adrenal glands

D

Pituitary gland

E

Hypothalamic-hypophyseal portal system

BlackTom AI · Accepted Answer

Rephrasing the question: You’re being asked which component of the endocrine system directly responds to the hypothalamus by secreting the tropic hormones TSH, ACTH, FSH, and LH.
Option 1: Thyroid gland. The thyroid produces thyroid hormones (T3/T4) but these are not tropic hormones that regulate other endocrine organs; they are effector hormones acting on target tissues. This makes the thyroid gland an unlikely candidate for secreting the listed tropic hormones in response to hypothalamic signaling.
Option 2: Gonads. The gonads (ovaries and testes) secrete sex steroids and gametes, not TSH, ACTH, FSH, or LH. They respond to tropic signals from the pituitary, but they are not the source of these pituitary tropic hormones themselves.
Option 3: Adrenal glands. The adrenal cortex and medulla produce corticosteroids and catecholamines, respectively. They are targets of ACTH but do not secrete ACTH, TSH, FSH, or LH in response to the hypothalamus; thus this option misplaces the location of the secretion.
Option 4: Pituitary gland. The anterior pituitary receives releasing and inhibiting hormones from the hypothalamus via the hypothalamic-hypophyseal portal system and, in response, secretes several tropic hormones, including TSH, ACTH, FSH, and LH. This reflects the direct hypothalamic control over these hormones and their role in regulating other endocrine glands.
Option 5: Hypothalamic-hypophyseal portal system. This vascular link carries hypothalamic releasing/inhibiting hormones to the anterior pituitary but does not itself secrete hormones. It functions as a conduit for signaling rather than as the source of the tropic hormones listed.
In summary, the statements that incorrectly identify the source either place the hormones in a non-endocrine or non-source role (thyroid, gonads, adrenal glands) or describe the portal system’s transport function rather than its hormonal secretion. The hormone-secreting structure in response to hypothalamic signals for these particular tropic hormones is the pituitary gland, specifically the anterior pituitary, which releases TSH, ACTH, FSH, and LH upon stimulation by hypothalamic releasing factors.