Question

the ______ is a system of ductless glands that manufacture hormones and secrete them into the bloodstream.

○ c) parasympathetic nervous system

○ a) endocrine system

○ b) sympathetic nervous system

○ d) somatic nervous system

Explanation:

The endocrine system consists of ductless glands (like the pituitary, thyroid, etc.) that produce and secrete hormones directly into the bloodstream. The parasympathetic, sympathetic, and somatic nervous systems are part of the nervous system, which uses neurotransmitters and nerve impulses, not hormones from ductless glands, to function. So the correct option is A.

Answer:

A) endocrine system