Science chapter 2

• Human Nervous System


  • All of the processes that take place in the human body must be coordinated
  • The brain and the spinal cord together make up the central nervous system
  • Millions of nerves branch off from the central nervous system to all parts of the body
• Brain


  Protected by the skull
• Spinal cord


  Runs down the middle of the backbone
• Parts of the forebrain

  • Cerebrum
  • Hypothalamus
  • Thalamus
• Cerebrum


  Largest part of the brain, dealing with conscious thought, reasoning, memory, emotions, and the control of body movements using voluntary muscles
• Thalamus


  Small structure located above the brain stem, responsible for relaying sensory information and transmitting information for movement and coordination
• Hypothalamus


  Located at the base of the brain, regulates body temperature to keep it at a constant 37°C
• Midbrain


  • Smallest and central part of the brain, connects the forebrain and hindbrain, associated with vision, hearing, temperature, and alertness
• Parts of the hindbrain

  • Cerebellum
  • Medulla
  • Pons
• Cerebellum


  Located at the back of the brain beneath the cerebrum, deals with balance and coordinated movement, can learn movements with practice
• Medulla (Brain stem)


  Located where the brain connects to the spinal cord, controls involuntary actions that keep the body alive such as breathing, heartbeat and peristalsis
• Pons


  Structure that links the brain to the spinal cord
• Pituitary gland


  Attached to the base of the brain, produces hormones that regulate the amount of water and sugar in the body and the body's growth rate
• The brain is a wrinkly, grey organ located inside the skull, protected by a layer of fluid between it and the hard bone surrounding it
• The brain is like a very powerful computer, it stores memories, makes judgements, and analyses and controls how we think and respond to things happening around us, while also automatically controlling things like heartbeat and breathing
• Cerebrum


  The large outer layer of the cerebrum has lots of folds and creases which give the brain its characteristic wrinkly appearance
• Cerebral cortex


  The outer surface of the cerebrum
• Cerebral cortex


  • Different areas receive information from sense organs and deal with the movement of body parts
• The cerebrum is made up of two halves called cerebral hemispheres
• Right cerebral hemisphere


  Processes information from the left side of the body
• Left cerebral hemisphere


  Processes information from the right side of the body
• The cerebral hemispheres are connected, each has its own specialised functions
• Functions of the cerebral hemispheres

  • Analytical skill
  • Calculations and Science
  • Language/speech
  • Logical thinking
  • Reasoning
  • Writing
  • Muscles on the left side of the body
• There is some scientific evidence to suggest that one cerebral hemisphere may dominate the other and this determines whether you are left or right-handed
• Stimulus


  The change you feel
• Response


  The body's reaction to a stimulus
• Responses

  • Shivering when the body gets cold
• Reflex action when you accidentally sit on a drawing pin

  1. Pain receptors in skin stimulated

  2. Impulses travel to spinal cord

  3. Relay nerve cell in spinal cord passes message on

  4. Impulses travel back to muscles

  5. Muscles contract to pull leg away
• Synapse

  The special link where impulses travel from one nerve to another
• Synapse


  Nerve endings lie close to another nerve cell, but don't touch. A chemical is released that diffuses across and stimulates the other nerve cell.
• You have many responses to one stimulus because the body has many receptors and effectors connected to the nervous system
• Reflex actions protect the body from harm
• Picking up a cup of tea and drinking it is not a reflex action, it is a voluntary action that requires thinking
• Games that require more thinking use the brain more than games that are just reflexes
• Left Hemisphere


  Analytical skill, calculations and science, language/speech, logical thinking, reasoning, writing, controls right side of the body
• Right Hemisphere


  Spatial ability, artistic and musical abilities, creativity, intuition, controls left side of the body
• Left Hemisphere - Language

  Responsible for language processing and speech production in most people
• Right Hemisphere - Creativity


  Important for creativity and imaginative thinking