Exocrine glands differ from endocrine glands in that exocrine glands:
A.
Only secrete salts.
B.
Secrete only local hormones.
C.
Secrete only into the bloodstream.
D.
Secrete through ducts or tubes to the body’s exterior.
The correct answer and Explanation is :
The correct answer is:
D. Secrete through ducts or tubes to the body’s exterior.
Explanation:
Exocrine and endocrine glands are both part of the body’s glandular system, but they differ significantly in how they release their secretions and their functions.
- Exocrine Glands:
- Function: Exocrine glands release their secretions into ducts or tubes that lead to the body’s surfaces, such as the skin or the lumen of the digestive tract.
- Secretions: These secretions can be enzymes, sweat, saliva, mucus, or other substances. Examples include sweat glands, salivary glands, and the pancreas (which functions as both an endocrine and exocrine gland).
- Ducts: The key feature is the presence of ducts or tubes that carry the secretion to a specific target area. For example, sweat glands secrete sweat through ducts that open onto the skin surface, while salivary glands release saliva into the mouth.
- Endocrine Glands:
- Function: Endocrine glands, in contrast, do not have ducts. They secrete hormones directly into the bloodstream.
- Secretions: The secretions of endocrine glands are hormones, which act as chemical messengers to regulate various physiological processes. Examples include the thyroid gland, adrenal glands, and pituitary gland.
- Target: These hormones travel through the blood to distant organs or tissues, where they exert their effects on processes such as metabolism, growth, and reproduction.
Key Differences:
- Exocrine glands use ducts to release their products outside the body or into the digestive system, while endocrine glands release hormones directly into the bloodstream.
- Exocrine secretions often perform local functions, such as digestion or skin lubrication, whereas endocrine hormones generally have systemic effects, influencing organs far from the gland itself.
Thus, exocrine glands secrete through ducts or tubes to the body’s exterior or into internal body cavities like the digestive system, which makes D the correct choice.