CNS, PNS & ANS1

• Nervous system


  Central nervous system, peripheral nervous system, autonomic nervous system, sensory and motor divisions

  
• Neurons and nerves


  Microscopic anatomy and corresponding function

  
• Generation and transmission of nerve action potential

  1. Role of sodium, potassium, and calcium ion movement

  2. Role of voltage-gated and chemically gated ion channels
• Synapse


  Events associated with synaptic transmission
• Autonomic nervous system


  Sympathetic and parasympathetic nervous systems and their structural organisation

  
• Eye


  Key structures and their role in vision
• Ear


  Key structures and their role in hearing
• The special senses (Smell, Taste, Sight and Hearing+-Equilibrium or balance) have distinct receptors rather than general receptors
• The receptors are localised to the head and are LOCALISED within either sensory organs (like eye and ear) or in specialised epithelia (taste & smell)
• Like all receptors, special senses DETECT CHANGE and they translate this message into an action potential
• Receptors


  Transduce physical stimuli into action potentials
• Transduction of auditory stimuli or SOUNDS to Action potentials

  1. Sound passes through external auditory meatus

  2. Contacts tympanic membrane

  3. Vibration passes through middle ear bones

  4. Vibrates oval window to inner ear
• Ear wax (cerumen)


  • Acts as waste disposal system
• Eustachian tube


  Equilibrates air pressure on inside versus outside of tympanic membrane
• Inner ear


  • For sound transduction AND balance
• Middle ear


  • Transmits sound from outer ear to inner ear
• Otitis media


  Common middle ear infection resulting in fluid accumulating and not draining from middle ear
• Eye


  • Protection: eyelashes, lacrimal fluid, eye lids, sclera/cornea, fat pad
  • Lacrimal fluid/tears rinse cornea and drain into nose, contain antibacterial agents
  • Movement: Extraocular muscles, cranial nerve control
  • Pupil size is controlled by smooth muscle in the Iris which in turn is controlled by the autonomic nervous system
• Sclera


  The visible white part of the eye
• Cornea


  The clear part of the eye, has nerve ends for pain reception
• Anterior chamber


  Contains aqueous humor (fluid)
• Posterior chamber


  Contains vitreous humor (gel)
• Choroid


  Pigmented to absorb light
• Ciliary muscles


  Attached to lens via suspensory ligaments, they adjust lens shape
• Iris


  The coloured part of the eye
• Pupil


  The viewing hole, controlled by the autonomic nervous system
• Autonomic Nervous System


  Has two divisions: Sympathetic and Parasympathetic, has a significant Homeostatic role, under involuntary control, provides dual innervation to effectors

  
• Diencephalon


  Includes thalamus, hypothalamus, epithalamus
• Thalamus


  Sorts and edits sensory information
• Hypothalamus


  Connects directly to pituitary, involved in homeostasis, endocrine control, autonomic control, emotional perception
• Epithalamus


  Includes pineal gland which secretes melatonin, and choroid plexus which forms CSF
• Sympathetic system


  Fight or Flight, EXCITATORY, leaves spinal cord in thoracic and lumbar regions to enter sympathetic chain of ganglia
• Parasympathetic system


  Features are the opposite to sympathetic