Download Nervous coordination

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