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• Control and coordination: Identification of situation and performing suitable action on it.
• Sense organs:
• Nose, Ear, Eyes, Tongue, and Skin are sense organs. Helps to identify situation.
• Sense organs contains specialized cells called receptors, which detect specific type of information. Eg. Nose have olfactory receptors that detects smell.
• Neuron: [Refer the video to understand in detail]

• Dendrites of neuron receives stimulus. Electrical impulses are produced by conversion of chemical energy to electrical energy. These electrical impulses travel through body of nerve cell and reaches to end of cell through axon. At nerve ending, electrical energy is converted to chemical energy, which is passed to dendrite of another neuron. With network of neuron information received from stimulus is transferred to all body parts.
• Reflex Actions: Sudden response to a stimulus without our knowledge. E.g. accidently touching hot object moving hand back.
• What happens during Reflex Action? :

• On receiving stimulus, signals are passed to spinal cord and from there it is again passed to nerves that moves muscle, without involving brain, which causes quick response. This is possible with reflex arc.
• Nervous System :
• Central nervous system (Brain and Spinal Cord) : Receives signal from body part and send response to appropriate muscle.
• Peripheral nervous system (Cranial nerves and Spinal nerves) : Communication between central nervous system and other body parts.
• Human Brain : Brain consist of three major region-

Forebrain	Midbrain	Hindbrain
Thinking process Receives sensory impulse from receptors (olfactory receptor, gustatory receptors) Has separate areas for analysing signals(hearing, smell,etc) Compares incoming signals with other receptor and stored information Decision are made on incoming signal and appropriate signal are passed.	Handles involuntary actions like vision, hearing, sleep/awake, alertness, temperature regulation , etc.	Medulla controls involuntary actions like blood pressure, salivation, vomiting, heartbeat, breathing Cerebellum in the hindbrain is responsible for precision in voluntary actions such as walking  in a straight line, balancing a bicycle

• Protection of tissues in nervous system :
• Brain : Brain is present in fluid filled balloon inside the skull, skull protects brain from severe injury while fluid protects it from shock.
• Spinal Cord : Vertebral column or backbone protects spinal cord.
• Movement of muscle fibre : Muscle cells have special proteins which help to change their shape according nerve impulse. The new arrangement is contraction or relaxation of muscle.
• Coordination in plants :
• Growth dependent movement : Changes direction of growth according to environmental stimulus.
1. Phototropism : Movement of plant in response to light. E.g. growth of stem towards light.
2. Geotropism : Movement of plant in response to gravity. E.g. stem grows away from gravity while root grows towards the gravity.
3. Hydrotropism : Movement of plant in response to water. E.g. roots grows in direction of water.
4. Chemotropism : Movement of plant in response to chemicals. E.g roots grows towards minerals and away from harmful chemicals.  
• Growth independent movements :

Touch me not plant closes leaves on touch, does not cause plant growth. Such moments are growth independent movements.  

• Plant hormones :
1. Plant Hormones : Chemical compounds helps in movement of plants.
2. Plant cell when experiences stimulus, it release hormone that reaches to adjacent cell. Cell surfaces have molecules, which helps to identify these hormones and accordingly changes the content of the cell facilitating plant movement.
3. Example of plant hormones :

Harmone	Function
Auxin	Growth of plant towards light
Gibberellins	Promote stem growth
Cytokinins	Promotes cell division
Abscisic acid	Causes wilting of leaves.

• Hormones in animals :

 

• Endocrine glands consist of  Hypothalamus gland, Pineal gland, Pituitary gland, Thyroid gland, Parathyroid glands, Thymus, Pancreas, Adrenal gland, Testes in males and ovary in females.

 

• Hormones :

Hormone	Secreted by	Function and Effects
Adrenaline	Adrenal gland	Secreted under scary situation. Causes faster heartbeat, contraction of muscles around small arteries, increased breathing
Thyroxine	Thyroid gland	Regulates carbohydrate,fats and proteins metabolism Deficiency causes goiter.
Growth hormone	Pituitary gland	Regulates growth and development of body Deficiency causes dwarfism (short height) In excess causes extreme tallness (giants)
Testosterone and estrogen	Testosterone secreted in males Estrogen secreted in females	Results in the significant changes in like faster growth, change in body shape, lack of sleep, hair growth, face and skin changes during puberty phase.
Insulin	Pancreas	Regulates blood sugar level Imbalance causes diabetes. So external insulin is injected into body