A and B are the two systems of control and coordination in the human body. The messages in system A are trasmitted in the form of chemical substances C which travel comparatively slowly through the blood stream. The substances C are made in tissues D present in the head and trunk of human body. The messages in system B are transmitted by system B usually lasts for a much shorter time as compared to those transmitted by system A.
(a) Name the system A. What does system A consist of?
(b) Name the chemical substance C.
(c) What is tissue D? Name any five such tissues in the human body.
(d) Name the system B. What does system B consist of?
(E) Name the fibres E.
(f) State whether system A controls the working of system B or system B controls the working of system A.

Answer

(a) Endocrine system; Glands (b) Hormones (c) Endocrine glands; Pituitary, Thyroid, Pancreas, Adrenals, Testes (d) Nervous system; Brain, Spinal cord and Nerves (e) Nerve fibres (F) System B (Nervous system) controls the working of system A (Endocrine system)