Part 1:

• Sensory input -> integration -> motor output
• CNS And PNS
• PNS
  • Sensory or affrent division picks up stimuli
  • Motor or effernt division responds to stimuli
    • Somatic nervous system (Voluntary) rules skeletal muscle movement
    • Autonomic nervous system (Involuntary) rules heart beat, breath and stomach chruning
      • Sympathetic Division fires up the body
      • Parasympathetic Division relaxes the body
• Neurons
• Glial Cells
  • CNS
    • Astrocytes surround, support and regulate ions
    • Microglial Cells defend the neurons and perform immune operations
    • Ependymal Cells line cavities and create, secrete and circulate cerebrospiral fluid
    • Oligodendrocytes wrap, insulate and help in forming myelin sheath
  • PNS
    • Satellite Cells surround neuron cell bodies
    • Schwann Cells insulate and help in forming myelin sheath
• Longest lived cells in body
• Irreplacable
• Huge appetites
• Soma
• Process is a projecting part of an organic structure
• Polarity of neurons
  • Multipolar
  • Bipolar
  • Unipolar
• Anatomical Separation
  • Sensory neurons are usually unipolar and transmit info from body to CNS
  • Motor neurons are usually multipolar and transmit info from CNS to body
  • Interneurons or association neurons are usually multipolar, live in CNS and transmit impulses between sensory and motor neurons

Part 2:

• Neurons can send only one signal and transmission is done at uniform strength and speed
• Voltage is the measure of potential energy generated by separated charges
• Current is the flow of electricity from one point to another
• Resistance is the whatever gets in the way of current.
• Action Potential
• Resting neuron is more negative on the inside and the resting potential is -70mV.
  • Na K Pump
  • Electrochemical gradient

Part 3:

• 70% of all sensory receptors are in eyes
• Eyes look at electromagnetic radiation travelling in waves
  • Frequency determine hue
  • Amplitude determine brightness
• Eye’s photorecptors convert eye’s light energy into nerve impulses
• Lacrimal Glands, Eyebrows, Eyelids and Eyelashes are protective equipments
• Globe luxation
• Layers of eye
  • Fibrous
    • Sclera made of white connective tissue
    • Cornea
  • Vascular
    • Choroid supplies blood to all layers
    • Ciliary body
    • Iris
    • Pupil
  • Inner
    • Retina
      • Pigmented Layer
      • Neural Layer
        • Photoreceptors
          • Rods
            • Numerous and light sensitive
            • Grayscale of black and white
            • Tell about general shape and features not details
          • Cones
            • Find fine detail and color
            • Red, blue and green sensitive types
        • Ganglion Neurons
        • Bipolar Neurons
• Optic nerve
• Photoreceptors can make us see after images
• Cones can get tired and hence many illusions