Which hormones are classified as "direct" hormones according to the FLAT PEG mnemonic?

• A. FSH and LH
• B. Prolactin and Growth Hormone
• C. Adrenocorticotropic hormone and TSH
• D. All of the above

Answer: (B)

The hormones classified as "direct" hormones according to the FLAT PEG mnemonic are indeed represented by prolactin and growth hormone. Direct hormones are those that directly stimulate target tissues to elicit a response without the need for intermediary hormones. Prolactin directly stimulates mammary gland development and milk production in the breasts, while growth hormone has widespread effects, including stimulating growth and cell reproduction throughout the body.

The FLAT part of the mnemonic refers to hormones that are tropic, meaning they act on other endocrine glands to stimulate hormone release, which is why options involving FSH, LH, ACTH, and TSH do not fit under the "direct" classification. Tropic hormones typically regulate other hormonal functions rather than exert their effects directly on target tissues. Therefore, the classification of prolactin and growth hormone as direct hormones in this context is correct.