Nervous and Endocrine Systems

• Top two branches of the nervous system

  • Central nervous system
  • Peripheral nervous system
• Two parts of the central nervous system

  Brain & Spinal cord
• What is the brain?

  • Centre of all conscious awareness and where all decision making takes place
  • It is split in two hemispheres
• What covers the brain?

  cerebral cortex
• What is the cerebral cortex?

  3mm thick and It is only found in mammals
• How does the brain control the body?

  Contralaterally, The left hemisphere controls the right side of the body and vice versa
• Where is the brain stem?

  At the base of the brain/top of the spinal cord
• What does the brain stem do?


  Controls basic functions
• What does the brain stem connect to?

  The spinal cord
• What is the spinal cord?

  • Extension of the brain
  • It carries incoming and outgoing messages between the brain and the body
  • Responsible for reflex actions
• What are reflex actions?

  • Automatic muscle movements in response to a sensory stimulusNo conscious awareness required
• Examples of reflex actions


  Touching a hot plate, closing eyes due to bright light
• What is the peripheral nervous system?

  Around the outside Sends and receives messages from the central nervous system
• How does the peripheral nervous system send messages?


  Through millions of nerve cells called neurons
• What sections does the peripheral nervous system split into?

  • Somatic nervous system
  • Autonomic nervous system
• What is the somatic nervous system?


  • Controls voluntary movements
  • Takes in sensory information
  • Also controls some reflexes
• What is the autonomic nervous system?

  controls automatic functions of the bodyInvolved in the response to stress
• What are the two parts of the autonomic system?

  Sympathetic nervous systemParasympathetic nervous system
• What does the sympathetic nervous system do?

  Fight or flight Prepares body:Breathing quickensHeart rate increasesSweating beginsPupils dilate Saliva production is inhibitedDigestion is stopped
• What does the parasympathetic nervous system do?

  Rest and digestBrings the body back to normal state:Breathing slowsHeart rate decreases Sweating ceases Pupils constrict Saliva production is stimulatedDigestion is restarted
• Why do we have fight or flight?


  To prepare to save yourself from a threatBody's response to stressors
• How does the nervous system transmit messages?

  Fast electric signals
• What is the endocrine system?


  One of the body's major information systems
• How does the endocrine system send messages?

  HormonesGlands produces hormonesHormones are released into bloodstreamHormones tell the body to do specific functions
• Is the nervous system faster or slower at sending messages than the endocrine system?

  Faster
• Where is the pituitary gland?

  In the brain
• What is the pituitary gland?

  Master glandSecretes hormones which regulate functions of other endocrine glands
• Where is the thyroid gland?


  Throat
• What is the thyroid gland?


  Produces hormones like Thyroxine which affect metabolism and cells in the heart increasing heart rate
• Where are the adrenal glands?

  On top of the kidneys
• What are the adrenal glands?

  Produce adrenaline for triggering fight or flight
• Where is the pancreas?

  Middle of the body
• What is the pancreas?

  Secretes insulin which regulates blood sugar levels
• Where are the ovaries?

  lower abdomen
• What are the ovaries?


  Secrete female sex hormonesoestrogen and progesterone
• Where are the testes?

  Lower body
• What are the testes?


  Secrete male sex hormonesTestosterone
• Stage one of fight or flight

  Hypothalamus in the brain detects the threat which activates the pituitary gland
• Stage two of fight or flight


  Stage one triggers sympathetic nervous system
• Stage three of fight or flight


  Adrenaline is released from the adrenal glands into the blood stream