The endocrine system..
A- affects only the reproductive system
B- releases substances into the bloodstream
C- competes with the nervous system to send signals
D- fights with the antibodies preoduced by the immune system
A is wrong. C depends on what "compete" means. D is wrong.
So B. Usually true, but not always. Sometimes substances are released just to stimulate adjacent cells.
So B is the best answer.
The correct answer is B- releases substances into the bloodstream.
To arrive at this answer, let's go through the options one by one:
A- The endocrine system does not only affect the reproductive system. It affects several systems in the body, including the reproductive system, metabolism, growth and development, and the regulation of body functions.
B- This is the correct answer. The endocrine system is a collection of glands that produce and release chemical substances called hormones. These hormones are released directly into the bloodstream. From there, they are carried to target tissues or organs throughout the body to regulate various physiological processes.
C- While both the endocrine system and the nervous system are involved in communication and signal transmission within the body, they do not compete with each other. They work in coordination to maintain homeostasis and regulate bodily functions. The nervous system primarily uses electrical signals and neurotransmitters to send rapid signals, while the endocrine system uses hormones to send slower, long-lasting signals.
D- The endocrine system does not fight with the antibodies produced by the immune system. The immune system is responsible for defending the body against infections and diseases, while the endocrine system regulates various physiological processes. Although both systems are involved in maintaining overall health, they operate independently and have different functions.
So, the correct answer is B- releases substances into the bloodstream.