Endocrine structures
A) are a type of nerve cell.
B) release their secretions onto an epithelial surface.
C) release their secretions directly into body fluids.
D) contain few vesicles.
E) are modified connective-tissue cells.

Question

Quizplus · Accepted Answer

Endocrine structures release their secretions directly into body fluids, such as blood, which then transports them to target cells.

Answer: E 
 Endocrine glands, such as the thyroid gland and adrenal gland, are modified connective-tissue cells that produce and release hormones into the bloodstream.

Endocrine Structures