1. Control is the power of regulation by which something can be started, slowed down, expedited or stopped. Working together of various systems in a body to adjust the vital activities of life is called coordination.
2. Integration is the process which makes two or more organs to work as a functional unit in harmony.
3. The coordination and integration in animals is brought about by nervous and endocrine system. In plants it is brought about by certain chemicals known as phytohormones or plant hormones
4. Movement is an attempt by living organisms to bring about a change of position either due to growth or changes in their environment to their advantage.
5. Some movements like germination in seed, flowering etc., are caused due to growth.
6. Movements like running of a cat, children playing on swings, buffaloes chewing cud are growth independent movements.
7. When we touch a hot object, we detect the change in the environment and respond by immediately withdrawing our hand. This also helps us to protect ourselves.
8. The stimulus is an agent, factor, chemical or change in external or internal environment which brings about the reaction in the organism.
9. All information from the environment is detected by the specialised tips of some nerve cells present in tissues and organs. These are called receptors. They are located in our sense organs like nose, tongue, skin, eye and inner ear.
10. Sensory receptors are of different types. Photoreceptors, phonoreceptors, olfactoreceptors, gustatoreceptors, thermoreceptors and so on. They detect light, sound, smell, taste, heat and cold respectively.
11. The above mentioned receptors initiate electrical impulses to be picked up by sensory nerves. This impulse travels in a neuron from the dendrite to the cell body, and then along the axon to its end. Axon ending of one neuron is placed close to dendrites of the next neuron. This junction is called synapse or gap. As soon as the impulse reaches the end of neuron it sets off release of some chemicals (Neurotransmitters). These chemicals cross the gap or synapse and start a similar electrical impulse in dendrite of next neuron. Finally, the impulse reaches a muscle or a gland.
12. Effectors are muscles, glands, tissues or cells which act in response to a stimulus received by the nervous system.
13. Nervous system comprises of sense organs, nerves and neurons that form a network throughout the body for conducting information via electrical impulses. Nerve cell or neuron is the structural and functional unit of nervous system.
14. Human nervous system consists of three divisions : central nervous system (CNS), peripheral nervous system (PNS) and autonomic nervous system (ANS).
15. Brain and spinal cord constitute the central nervous system (CNS). The nerves arising from the brain (cranial nerves) and nerves arising from the spinal cord (spinal nerves) constitute the peripheral nervous system.
16. The human brain is protected by a bony skull, also called as cranium. Internal to the skull it is covered from outside by three membranes called meninges. In between the meninges, there is a fluid called as cerebrospinal fluid. Beneath the membranes brain is subdivided into three major parts namely forebrain, midbrain and hindbrain.
17. Fore-brain is the main thinking part of the brain. It has different regions or areas such as :
(i) Sensory area — It receives sensory impulses from various receptors.
(ii) Auditory area — It is concerned with hearing.
(iii) Olfactory area — It is concerned with the smell.
(iv) Gustatory area — It is concerned with taste.
(v) Optic area — It is concerned with sight.
(vi) Association area — This area interprets various sensory informations and makes a decision how to respond.
(vii) Motor area — Decisions made by association area are passed on to this area which controls the movement of voluntary muscles.
18. Midbrain comprises of four lobes. Actions of involuntary muscles are controlled by the mid-brain and hind-brain.