Organisation of the Nervous System

• The Nervous system uses electrical impulse to rapidly transfer information along cells called neurones
• Sensory Neurons carry messages from receptors to the CNS
• There are three types of neuron, sensory (afferent), motor (efferent) and interneurons.
• Motor Neurons carry messages from the CNS to effectors (muscles or glands)
• Information is transferred between receptors, CNS, and Effectors
• The Nervous is Divided into two category; CNS (Central Nervous System) and PNS (Peripheral Nervous System)
• CNS is compose of the brain and the spinal cord
• The CNS receives information and coordinates response
• PNS is composed of the nerve tissue that connects the CNS to the rest of the body
• PNS id divided into Motor and Sensory
• Motor is divided into Autonomic and Somatic
• Autonomic is divided into sympathetic and parasympathetic
• Sympathetic response is fight or flight
• Parasympathetic response is rest and digest
• the role of sympathetic is to prepare the body for physical activity
• The role of parasympathetic is to conserve energy during periods of low activity
• example of action in sympathetic is pupils dilate, heart rate accelerates, and bronchi in lungs dilate
• example of parasympathetic action is pupils constrict, heart rate decelerates, and bronchi in lungs constrict.
• The autonomic nervous system controls involuntary actions such as breathing, blood pressure, and digestion.
• The somatic nervous system controls voluntary movements like walking and talking.
• give two functions of the sympathetic nervous system

  • dilates pupils
  • Increases heart rate
• Explain two functions of the parasympathetic nervous system

  • Constrict pupils to prevent damage to the retina
  • Breathing rate back to normal for less demand of oxygen