Which of the following glands secretes an oily substance into hair follicles in the armpits, and is probably responsible for the strong odor of armpits?
A apocrine sweat gland
B endocrine gland
C merocrine sweat gland
D sebaceous gland
The correct answer and explanation is:
The correct answer is A. Apocrine sweat gland.
Apocrine sweat glands are primarily responsible for secreting an oily substance into hair follicles, particularly in areas such as the armpits, groin, and around the nipples. These glands secrete a thicker, milky fluid that is high in proteins and lipids. The secretion from apocrine glands is odorless when it is first produced, but when it comes into contact with bacteria on the skin’s surface, the bacteria break down the components in the sweat, resulting in a strong odor.
Apocrine glands are different from eccrine (or merocrine) sweat glands, which are responsible for producing the watery sweat that helps regulate body temperature. Eccrine sweat glands are found all over the body and secrete a more fluid, clear substance directly onto the skin’s surface. This sweat evaporates, helping cool the body.
Endocrine glands (Option B) are not involved in sweat production. These glands secrete hormones directly into the bloodstream to regulate various bodily functions like metabolism, growth, and mood. Examples of endocrine glands include the thyroid, pancreas, and adrenal glands.
Sebaceous glands (Option D) secrete sebum, an oily substance that helps lubricate and waterproof the skin and hair. However, sebaceous glands are not responsible for the strong odor in the armpits; instead, they are more involved in maintaining skin and hair health.
In conclusion, the strong odor in the armpits is largely attributed to the secretion of apocrine sweat glands, which are activated during puberty and are influenced by hormones, especially during times of stress or emotional arousal.