Why Doesn't Every Cell in the Body Respond to Every

question 23

Multiple Choice

Why doesn't every cell in the body respond to every hormone circulating in the bloodstream?

• A) Each cell has a limited number of protein channels that shuttle hormones through its membrane.
• B) Not all hormones can diffuse through all cell membranes.
• C) The concentration of some hormones is too low to stimulate every cell.
• D) Each cell has specific surface receptors, which interact only with hormones that they recognize.
• E) Although all hormones bind to all cell surfaces, some cells lack second messengers for expression.