16 CONTROL AND COORDINATION Homeostasis The nervous system

16. CONTROL AND CO-ORDINATION • • Homeostasis The nervous system Afferent nerves Efferent nerves Reflex action Endocrine system Control and co-ordination in plants

• Life processes-respiration , digestion, circulation, excretion. • At any season our body temperatureis maintained at about 370 c. • Optimum the level of the body in the given conditions is maintained in all circumstances. This continuous process of adjustment is called homeostasis.

The Nervous System • CNS-brain, spinal cord. (regulates all actions of the body). • PNS-nerves(connects various parts of the body to CNS)

TYPES OF NERVES • Afferent nervesbring information about different parts of the body to the. CNS. • Efferent nervescarry the commands given by the CNS to the various parts of the body.

Reflex Action • Sometimes actions take place even without messages reaching the brain. in such cases the messages reach only spinal cord and the actions of the specific organs take place. these are called reflex actions. • E. g. your mouth waters at the ssight of tamarinds. • You cover your ears with your hands when someone light a cracker.

Endocrine system • Consists of various glands. these glands are ductless. they secrete hormones, which control various life processes and movements. • The pituitary, thyroid, ad renal, pineal, thymus.

Stages of growth • 1. Production • 2. Growth • 3. Differentiation

The control and regulation of growth in animals • Genes –are genetic factors. • When the limit of growth as determined by genes is reached , growth stops. • The nervous system and hormones control and regulate the growth animals.