Nervous coordination nervous system and brain Nervous system
Nervous coordination ~ nervous system and brain
Nervous system 1) Central nervous system(CNS) • a) spinal cord • b) brain 2) Peripheral nervous system(PNS) • a) cranial nerves • b) spinal nerves
General pathway: stimuli => receptor => CNS(Central nervous system) => effector => response
Basic structure of neurone: • Nervous system compose of many nerve cells called neurons. • Neuron have a cell body and nerve fibres. • Cell body contain of cytoplasm with a nucleus. • Nerve fibers contain dendron(transmits nerve impulses towards the cell body) and axon(transmits nerve impulse away form the cell body).
Basic structure of neurone:
Basic structure of spinal cord: • Spinal cord enclosed in the neural canal and arises form the medulla oblongata. • Outer cortex is made up of white matter. • Inner cortex is made up of grey matter. • Spinal cord is the reflex centre for controlling involuntary actions(spinal reflex arc).
Spinal reflex arc • Simple reflex arc is a quick, inborn and automatic response to a stimulus. • This reflex actions are protective. • Same stimulus initiates the same response. • Example: knee jerk reflex, blinking reflex, coughing reflex.
Position of brain:
Main function of brain: A) Cerebrum • Thinking • Voluntary movement • Reasoning • Language • Memory • Imagination
B) Cerebellum • Movement • Balance • Posture
C ) Medulla • Vision • Audition • Eye Movement • Body Movement
Difference between reflex and voluntary action: Reflex action (involuntary) • Quick • Inborn • Cerebrum does not take part • Same stimulus cause same response Voluntary action • Slow • Need to learn • Cerebrum takes parts • Same stimulus cause different responses
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