Nervous System

• The Nervous system is a complex t of nerves that allow the brain and spinal cord to communicate with different parts of the body
• Nervous System

  1. Central Nervous System - 1a. Brain 1b. Spinal Cord
  2. Peripheral Nervous System - 2a. Somatic NS 2b. Automatic NS
  3. Automatic NS - 3a. Sympathetic Nervous System 3b. Parasympathetic Nervous System
• The Central Nervous System is made up of the brain and spinal cord.
• The spinal cord sends info from the brain to the PNS and then back to the brain
• The PNS takes info from the outer world to the CNS and from the CNS to the muscles and glands
• The SNS is in control of conscious movements of the body, it has sensory neurons to detect and motor neurons to effect
• The ANS is in control of involuntary movements in the body such as breathing or the heart rate, it only has motor neurons
• The endocrine system is glands throughout the body that create and secretes (chemical messengers) hormones
• The function of the endocrine system is to provide a chemical system of communication via the bloodstream - secreting hormones that are needed for bodily functions
• Pituitary gland - releases oxytocin during birth
• Pineal gland - releases melatonin for sleep
• Thyroid - releases thyroxin which creates energy
• Adrenal gland - releases adrenaline to the SNS
• Ovaries/testes - release sex hormones such as estrogen, progesterone, testosterone
• The Sympathetic Nervous System (fight or flight) and Parasympathetic Nervous System (rest and digest) work in opposite of eachother
• Fight or flight effects on body;

  1. Heart rate increases
  2. Breathing rate increases
  3. Saliva production hi it’s
  4. Digestion inhibited
  5. Pupils dilate
• Rest and digest effects on body;

  1. Heart rate decreases
  2. Breathing rate decreases
  3. Saliva production resumes
  4. Digestion resumes
  5. Pupils return to normal
• Stages of flight or Fight response -

  1. Automatic Nervous System detects on changes in environment and goes from normal to state of psychical arousal
  2. Sympathetic Nervous System prepares body for rapid actions
  3. Endocrine System, adrenal gland releases adrenaline —> Flight or Fight changes occur
  4. Parasympathetic Nervous System - Rest and Digest returns body to normal state