chapter 1.1 human nervous system

• The nervous sytem is responsible for transmitting impulses throughout our body.
• A fully functioning body is primarily supported by the nervous system.
• Without nervous sytem,body will not be able to control muscles and the tissues and organs will no longer be able to function.
• Organisms are always exposed to various stimuli.
• Stimulus are any triggers that received by the organims' body with the aid of the sensory organs.
• Stimuli includes sound,light intensity,touch and chemicals.
• Upon receiving stimulus,organisms will respond.
• Response is the action made by the organims due to receiving stimulus.
• The nervous system coordinates response in organisms.
• List 4 Peripheral nerves system

  A) Cranial nerve

  B) Spinal nerve

  C) Brain

  D) Spinal cord

  
• Human nervous sytem consist of:Brain,Spinal cord,Periphernal nerves system.
• The cranium protects the brain.
• The spine protects the spinal cord.
• The perpheral nerves consist of all the nerve branches that brach out and exend out from the spinal cord.
• Figure shows the pathway of nerve impulse in human nervous system to give out response:

  Stimmulus ---> Receptor ---> Central nervous system ---> Effector ---> Response
• Stimulus:Trigger from the enviroment eg.Temperature,pressure ,sound and taste.
• Receptor:Special cells in the sensory organ that produces nerve impulses.Also known as affector.
• Central nervous system:Consists of brain and spinal cord.Nerve impulse will be received and interpreted.
• Effector:An organ/cell that acts in response to the nerve impulse sent by central nervous system.
• Response:Action done by parts of the body. eg.Movement of hand/leg,blinking,sneezing
• Helmet and seat belts are designed to prevent nervous system injuries during high impact accidents.
• Over comsumption of drugs,alcohol and glue sniffing could damage the health of the nervous system.
• Stimulus detected by the nervous system produces two types of responses:Voluntary action,Involuntary action
• Voluntary action:

  -Action made in consciousness and under control of the person's will.

  -This action involves control by the brain

  -Example of voluntary actions:

  --->Writing,dancing,speaking,riding a bike,kicking a ball and swimming