Which of the following is NOT a function of blood?

• A. Protecting against infection through immune cells and antibodies
• B. Transporting respiratory gases (oxygen and carbon dioxide) between the lungs and body tissues
• C. Maintaining homeostasis by helping regulate pH and body temperature
• D. Producing hormones and secreting them into the bloodstream

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the primary functions of blood in the human body. Blood is a connective tissue that plays several critical roles including transportation, protection, and regulation.
2. Step 2: Identify the functions listed in the problem: (a) protecting against infection through immune cells and antibodies, (b) transporting respiratory gases between lungs and tissues, (c) maintaining homeostasis by regulating pH and body temperature, and (d) producing hormones and secreting them into the bloodstream.
3. Step 3: Recall that blood contains immune cells and antibodies, which are essential for protecting the body against infections, confirming that function (a) is a true function of blood.
4. Step 4: Recognize that blood transports oxygen and carbon dioxide between the lungs and body tissues, which is a fundamental transport function, confirming that function (b) is true.
5. Step 5: Understand that blood helps maintain homeostasis by regulating pH and body temperature through buffering systems and heat distribution, confirming that function (c) is true. However, blood does not produce hormones; hormone production is the role of endocrine glands. Therefore, function (d) is NOT a function of blood.