week 3

• nerves - cablelike organs in the PNS
• nerves - consists of numerous axons wrapped in connective tissue
• endoneurium - layer of delicate connective tissue surrounding the axon
• perineurium - connective tissue wrapping surroundinga nerve fascicle
• nerve fascicles - groups of axons bound into bundles
• epineurium - whole nerve is surrounded by tough fibrous sheath
• axon is surrounded by schwann cells
• cranial nerves - attach to the brain and pass through foramina of the skull
• cranial nerves - numbered from I-XII
• cranial nerves - I AND II attach to the forebrain . the rest is attach to the brain stem
• cranial nerves - primarily serve head and neck structures
• cranial nerves - the vagus nerve ( X , 10 )extends into the abdomen
• nerves

  A) axon

  B) myelin sheath

  C) endoneurium

  D) perineurium

  E) epineurium

  F) fascicle

  G) blood vessel

  
• 12 pairs of cranial nerves

  A) frontal lobe

  B) temporal lobe

  C) infundibulum

  D) vestibulocochlear nerve ( VIII , 8 )

  E) facial nerve ( VII , 7 )

  F) glossopharyngeal nerve ( IX , 9 )

  G) vagus nerve ( X , 10 )

  H) accessory nevre ( XI , 11 )

  I) hypoglossal nerve ( XII , 12 )

  J) cerebellum

  K) medulla

  L) filaments of OLFACTORY NERVE ( I , 1 )

  M) olfactory bulb

  N) olfactory tract

  O) optic nerve ( II , 2 )

  P) optic chiasma

  Q) optic tract

  R) oculomotor nerve ( III , 3 )

  S) trochlear nerve ( IV , 4 )

  T) trigeminal nerve ( V , 5 )

  U) abducens nerve ( VI , 6 )

  
• olfactory nerves 1 - sensory nerves of smell
• optic nerve 2 - sensory nerve of vision
• oculomotor nerve 3 - helps to adjust and coordinate eye position during movement
• trochlear nerve 4 - innervates ( stimulate ) the superior oblique muscle ( an extrinsic eye muscle )
• trigeminal nerve 5 V - provides sensory innervation to the face. Motor innervation to chewing muscle
• abducens nerve 6 VI - abducts the eyeball - innervates lateral rectus muscle
• facial nerve 7 VII - innervates muscle of facial expression
• vestibulocochlear nerve 8 VIII - sensory nerve of hearing and balance
• glossopharyngeal nerve 9 IX - innervates structure of the tongue and pharynx
• vagus nerve 10 X - a mixed sensory and motor nerve - "wanders" into thorax and abdomen
• accessory nerve 11 X1 - an accessory part of vagus nerve - innervates trapezius muscle
• hypoglossal nerve 12 XII - runs inferior to the tongue - innervates the tongue muscle. allows us to speak
• spinal nerves - 31 pairs - contain thousands of nerve fibers
• spinal nerves - connect to the spinal cord
• spinal nerves - named for point of tissue from the spinal cord
• spinal nerves

  • 8 pairs of cervical nerves
  • 12 pairs of thoracic nerves
  • 5 pairs of sacral nerves
  • 1 pair of coccygeal nerves ( co1)
• spinal nerves

  A) cervical nerves

  B) c1 - c8

  C) thoracic neves

  D) t1 - t12

  E) lumbar nerves

  F) L1 - L5

  G) sacral nerves

  H) s1 - s5

  I) coccygeal nerve

  J) co1

  K) cervical plexus

  L) brachial plexus

  M) cervical enlargement

  N) intercostal nerves

  O) lumbar enlargement

  P) lumbar plexus

  Q) sacral plexus

  R) cauda equina

  
• cervical nerves - they stimulate muscle movement in your neck, shoulder, arm, and hand, and provide sensation
• cervical nervs - c1, c2, and c3 control your forward, backward, and side head and neck movements
• cervical nerves - c2 nerve provides sensation to the upper area of your head
• cervical nerves - c3 gives sensation to the side of your face and back of your head
• cervical nerves -c4 controls your upward shoulder motion and is one of the nerves that controls your diaphragm ( muscle at the bottom of your rib cage that helps you breathe )
• cervical nerves - c4 provide sensation for parts of your neck, shoulders, and upper arms
• cervical nerves - c5 controls the deltoid muscle of your shoulders and biceps
• cervical nerves - c5 provides sensation to the upper part of your upper arm down to elbow
• cervical nerves - c6 controls the extensor muscles of you wrist and is involved in the control of your biceps