 General paralysis  Severe damage to spinal cord  Loss feeling from injury down  Quadriplegia—lose control of both arms and legs

 Paraplegia  Lose control of just the legs  Repair  Impossible naturally  No cell division of neurons  Trying artificial division  Uses stem cells

 About 35 billion neurons  About 3 pounds  Cerebrospinal fluid (CSF)  Brain floats in this  Makes brain light  Transports nutrients, neurotransmitters, and wastes  Lumbar puncture—useful in determining CNS disease  Replaced every 8 hours

 Largest part of the brain  Conscious Thought  Intelligence  Gray matter—superficial layer  White matter—deep layer  Contains axons  Gyri—grooves that increase the surface area  Left and Right Lobes  Control opposite sides of the body

 Parietal Lobe  Primary motor cortex  Directs voluntary movements  Primary sensory cortex  Receives somatic sensory information  Ex: Touch, pressure, pain, temperature

 Occipital Lobe  Visual cortex  All visual information

 Frontal Lobe  Gustatory cortex  Taste sensations

 Temporal Lobe  Auditory cortex—hearing  Olfactory cortex—smell