Control and coordination
- Working together of various integrated body systems in response to changes in the surrounding for the maintenance of bodily functions is known as control and coordination
- Nervous system and endocrine system provide control and coordination in animals.
- Neurons -functional units of the nervous system, conduct messages in the form of electrical and chemical impulses
- Neuron composed of cell body and dendrite, axon and nerve endings.
- Types of neuron:-
- Sensory neuron
- Motor neuron
- Relaying or intermediate neuron
- Nerve: A nerve is a collection of nerve fibres (or axons) enclosed in a tubular medullary sheath. This sheath acts as an insulation and prevents mixing of impulses in the adjacent fibres.
- Transmission of nerve impulse:
Under normal conditions, the outer side of the nerve fibre consists of positive charge as more Na+ ions are present outside axon membrane. The neuron is then said to be in polarised state. On stimulation, the membrane becomes more permeable and Na+ ions move inside causing depolarisation. Such a region is known as excited region. The point of depolarisation behaves as stimulu…
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