1 – both the nervous system and the endocrine system can be involved in homeostasis. e.g. hypothalamus in the brain detects a decrease in water level in the body. Pituitary gland secretes ADH to reabsorb more water to prevent dehydration
2 – chemicals in the nervous system could include noradrenaline. Endocrine system secretes hormones which are chemicals.
3 – pituitary gland is in the brain and receives information from the hypothalamus. Brain is part of the nervous system.
Statements 1, 2 and 3 are correct.