anatomy of NS

• Infection in meninges leads to condition known as meningitis, causing headache, stiff neck, incoherence, drowsiness, coma, and death
• Old CSF is reabsorbed into the blood supply at the top of the head
• Cerebrospinal Fluid (CSF)


  Protective fluid around the brain and spinal cord
• Tumors in the meninx's tissues are referred to as meningiomas
• CSF circulates through subarachnoid space, central canal, and cerebral ventricles
• CSF has similar composition as blood plasma
• CSF is produced by choroid plexus and made three times a day
• Protecting and Supplying of the Nervous System

  • Meninges
  • Cerebrospinal Fluid
  • Blood Supply
• Meninges


  Layers of membranes that cover the CNS and PNS
• Anatomical Directions and Planes of Section

  • Coronal – A plane that shows brain structures as seen from the front
  • Sagittal – A plane that shows brain structures as seen from the side
  • Horizontal/Transverse – A plane that shows brain structures as seen from above
  • Dorsal – Toward the back, away from the ventral (stomach) side
  • Ventral – Toward the stomach, away from dorsal (back) side
  • Anterior – Toward the front end
  • Posterior – Toward the rear end
  • Superior – Above another part
  • Inferior – Below another part
  • Lateral – Toward the side, away from the midline
  • Medial – Toward the midline, away from the side
  • Proximal – Located close (approx.) to the point of origin or attachment
  • Distal – Located more distant from the point of origin or attachment
  • Ipsilateral – on the same side of the body
  • Contralateral – On the opposite side of the body
• CSF cushions the brain and prevents maladaptive responses due to pressure
• Hydrocephalus is caused by a blockage of CSF flow and can lead to brain expansion
• Brain death is the working definition of death
• Blood supply to the brain flows through carotid arteries and vertebral arteries
• Significant damage occurs less than 3 minutes after the heart stops
• Parts of the brain without BBB include the Pituitary gland
• Brain cannot store energy and interruptions of blood supply could lead to damages
• Parts of brain without BBB

  • Pituitary gland
  • Median eminence
  • Area postrema
  • Preoptic recess
  • Paraphysis
  • Pineal gland
  • Endothelium of choroid plexus
• Peripheral Nervous System (PNS)

  • All nerves exiting the brain and spinal cord – carrying sensory and motor messages to and from other parts of the body
  • Tissues not encased in bone
  • Covered in 2 layers
  • Cells regenerate (With recovery)
  • Without Cerebrospinal Fluid
• Nerve - a set of actions in the periphery, either from the CNS to a muscle or gland or from a sensory organ to the CNS
• Central Nervous System (CNS)

  • Brain and Spinal Cord
  • Tissues encased in bone
  • Covered in 3 layers of membrane
  • Cells do not regenerate (Permanent damage)
  • With Cerebrospinal Fluid
• Nervous System

  1. Central Nervous System (CNS)

  2. Brain

  3. Spinal Cord

  4. Peripheral Nervous System (PNS)

  5. Somatic Nervous System (SNS)

  6. Autonomic Nervous System (ANS)

  7. Sympathetic

  8. Parasympathetic
• Hemorrhagic - bleeding
• Ischemia - lack of oxygen
• The cord is shorter than the vertebral column
• The spinal cord communicates with all the sense organs and muscles except those in the head
• Nucleus (pl. nuclei)


  A cluster of neuron cell bodies with shared functions within the CNS
• The spinal cord is part of the CNS within the vertebral column. It extends from medulla to the first lumbar vertebra
• Ganglion (pl. ganglia)


  A cluster of neuron cell bodies, usually outside the CNS (as in the sympathetic nervous system)
• The central canal runs down in the center of the spinal cord
• Damage to the spinal cord results in loss of sensation and voluntary movement in parts of the body served by nerves located below the damaged area
• Spinal cord has 8 cervical nerves, 12 thoracic nerves, 5 lumbar nerves, 5 sacral nerves, and 1 coccygeal nerve
• Quadriplegic (quad meaning four) – Cervical damage that leads to loss of sensation and inability to move the arms, legs, and torso
• Spinal cord has 31 segments
• Paraplegic – Lumbar-level damage
• Spinal cord has white matter composed of myelinated axons and grey matter densely packed with cell bodies and dendrites
• Axons from sensory neurons are found in the dorsal roots and carry information about touch, position, pain, and temperature
• Spinal cord has dorsal horns and ventral horns
• Spinal nerves are attached to the spinal cord at 31 different levels
• Axons from motor neurons are found in the ventral roots and are responsible for movement