LAB EXERCISE 11 CRANIAL NERVES * * * Cranial Nerves The

1
LAB EXERCISE11

• CRANIAL NERVES

2
Cranial Nerves

• Twelve pairs of cranial nerves
• That arise from the brain
• Each nerve is identified by a Roman number
• I through XII
• and a name

3
Cranial Nerves

• Four Classifications of Cranial Nerves
• Sensory nerves
• Carry somatic sensory information, including
  touch, pressure, vibration, temperature, and pain
• Special sensory nerves
• Carry sensations such as smell, sight, hearing,
  balance
• Motor nerves
• Axons of somatic motor neurons
• Mixed nerves
• Mixture of motor and sensory fibers

4
Summary of Function of Cranial Nerves
Figure 13.5b
5
Cranial Nerves

• Four cranial nerves carry parasympathetic fibers
  that serve muscles and glands
• Occulomotor (III)
• Facial (VII)
• Glossopharyngeal (IX)
• Vagus (X)

6
Cranial Nerves

• Cranial Nerves
• The 12 cranial nerve groups are identified by
• Primary function
• Origin
• Pathway
• Destination

7
Cranial Nerves

• Olfactory Nerves (I)
• Primary function
• Special sensory (smell)
• Origin
• Receptors of olfactory epithelium

8
Cranial Nerves

• Olfactory Nerves (I)
• Pathway
• Olfactory foramina in cribriform plate of ethmoid
  bone
• Destination
• Olfactory bulbs
• To the olfactory tract

9
Cranial Nerve I - Olfactory Nerve

• Assesment
• Have patient smell different items
• Damage to the ethmoid bone
• Can cause anosmia
• Loss of smell

10
Cranial Nerves

• Optic Nerves (II)
• Primary function
• Special sensory (vision)
• Origin
• Retina of eyes

11
Cranial Nerves

• Optic Nerves (II)
• Pathway
• Optic Canal of sphenoid bone

12
Cranial Nerves

• Optic Nerves (II)
• Destination
• Diencephalon via optic chiasm
• Optic tracts
• Leading to lateral geniculate nuclei
• Olfactory Lobe

13
Cranial Nerve II - Optic Nerve

• Assessment
• Test visual Acuity one eye at a time
• Snellen eye chart
• Test peripheral vision one eye at a time
• Cover one eye and have the patient look at your
  nose.
• Move your finger to check superior and inferior
  fields
• Damage to the orbits or diseases in the nervous
  system can cause a loss of vision.
• Anopia
• Ipsilateral blindness due to sensory loss in the
  nerve

14
Cranial Nerves

• Oculomotor Nerves (III)
• Primary function
• Motor (eye movements)
• Controls four of six eye-movement muscles
• Origin
• Midbrain
• Pathway
• Superior orbital fissures of sphenoid

15
Cranial Nerves

• Oculomotor Nerves (III)
• Destination
• Somatic motor
• Superior, inferior, and medial rectus muscles
• Inferior oblique muscle
• Levator palpebrae superioris muscle

16
Cranial Nerves

• Oculomotor Nerves (III)
• Visceral motor
• Parasympathetic Function
• Ciliary ganglion

17
Cranial Nerves

• Oculomotor Nerves (III)
• Destination
• Visceral motor (Parasympathetic)
• Intrinsic eye muscles
• Cilliary Muscle
• Accommodation
• of the lens
• Circular Muscles
• Constriction of iris
• Radial Muscles
• Dilation of iris

18
Cranial Nerve III - Oculomotor
Assessment - To test the patients pupils Use
a penlight and mm ruler - Check to see where
eyelid falls on the pupil
Damages Causes Ptosis Drooping of
eyelid Causes diplopia Double vision
Trouble with eye movements
19
Cranial Nerves

• The Trochlear Nerves (IV)
• Primary function
• Motor (eye movements)
• Origin
• Midbrain

20
Cranial Nerves

• The Trochlear Nerves (IV)
• Pathway
• Superior orbital fissure of sphenoid
• Destination
• Superior oblique muscle

21
Cranial Nerve IV - Trochlear Nerve
Assessment -Have patient follow your finger
while moving it to the nose Damages
Causes ? Diplopia ? Paralysis ?
Strabismus Lazy Eye
22
Cranial Nerves

• The Trigeminal Nerves (V)
• Primary function
• Mixed Nerve
• Sensory
• Functions in touch, pain, temperature receptors
  of the face
• Motor
• Innervates the muscles of mastication

23
Cranial Nerves

• The Trigeminal Nerves (V)
• Largest cranial nerves
• With three major branches
• Ophthalmic
• Maxillary
• Mandibular

24
Cranial Nerves

• The Trigeminal Nerves (V)
• Sensory Innervation
• Semilunar ganglion
• Contains cell bodies of sensory neurons

25
Cranial Nerves

• The Trigeminal Nerves (V)
• Ophthalmic Branch (V1)
• Sensory innervation to
• Orbital structures
• Nasal cavity
• Skin of forehead
• Upper eyelid
• Eyebrow
• Part of nose

26
Cranial Nerves

• The Trigeminal Nerves (V)
• Pathway
• Ophthalmic Branch (V1)
• Superior Orbital Fissure

27
Cranial Nerves

• The Trigeminal Nerves (V)
• Origin
• Maxillary Branch (V2)
• Sensory innervation to
• Lower eyelid
• Upper
• Lip
• Gums
• Teeth
• Cheek and nose
• Palate and part of pharynx

28
Cranial Nerves

• The Trigeminal Nerves (V)
• Pathway
• Maxillary branch (V2)
• Foramen Rotundum

29
Cranial Nerves

• The Trigeminal Nerves (V)
• Mandibular Branch (V3)
• Sensory
• innervation to
• Lower
• ?Gums
• ?Teeth
• ?Lips
• Palate
• Part of tongue
• ?Lingual Nerve

30
Cranial Nerves

• The Trigeminal Nerves (V)
• Origin
• Mandibular branch (V3)
• Motor innervation From
• Motor nuclei of pons

31
Cranial Nerves

• The Trigeminal Nerves (V)
• Destination
• Motor nerves of Mandibular Branch
• Muscles of mastication
• Chewing

32
Cranial Nerves

• The Trigeminal Nerves (V)
• Pathway
• Mandibular branch
• Foramen Ovale

33
Cranial Nerve V - Trigeminal
Assessment To test for pain, touch
tempersture -Safety pin hot and cold
objects Corneal reflex - Cotton wisk
To test motor function -Clench teeth and
move jaw side to side
34
Cranial Nerve V - Trigeminal
Damages Cause problems in chewing Loss of
sensations of pain and temperature
Tic Douloureux ? Trigeminal
Neuralgia Severe pain from damage
of maxillary and
mandibular nerves
35
Cranial Nerves

• The Abducens Nerves (VI)
• Primary function
• Motor (eye movements)
• Origin
• Pons

36
Cranial Nerves

• The Abducens Nerves (VI)
• Pathway
• Superior orbital fissures of sphenoid
• Destination
• Lateral rectus muscle
• Moves eye laterally

37
Cranial Nerve VI - Abducens
Assessment Make a big x in the air and draw a
line through it. Observe
for twitching or
nystagmus Damages Cannot move eyeball
laterally Nystagmus Dancing Eyes
38
Cranial Nerves

• The Facial Nerves (VII)
• Mixed
• Sensory
• Motor
• Origin
• Sensory
• Taste receptors on anterior 2/3 of tongue
• Destination
• Sensory
• Sensory nuclei of pons

39
Cranial Nerves

• The Facial Nerves (VII)
• Sensory Innervation
• Geniculate Ganglion
• Contains cell bodies of sensory neurons

40
Cranial Nerves

• The Facial Nerves (VII)
• Origin
• Motor
• Motor nuclei of pons
• Destination
• Somatic Motor
• Muscles of facial expression

41
Cranial Nerves

• Somatic Motor
• Facial nerve branches
• Temporal
• Zygomatic
• Buccal
• Mandibular
• Cervical branches

42
Cranial Nerves

• The Facial Nerves (VII)
• Destination
• Visceral motor
• Parasympathetic Function
• Pterygopalatine Ganglion
• ? Lacrimal gland
• ? Mucous Glands
• Submandibular Ganglion
• ?Submandibular Glands
• ?Sublingual Glands

43
SUBLINGUAL
SUBMANDIBULAR
44
Cranial Nerves

• The Facial Nerves (VII)
• Pathway
• Internal acoustic meatus to facial canals
• Then through the stylomastoid foramina

45
Cranial Nerve VII - Facial Nerve
Assessment -- To test for taste Place
sugar(sweet) salt, vinegar(sour)
quinine(bitter) on anterior 2/3 of
tounge -- To test for tearing Place
ammonia near the eyes -- To test for facial
symmetry Have patient close eyes, smile,
whistle and blow
46
Cranial Nerve VII - Facial Nerve
Damages Shingles Lyme disease Loss of
taste Decreased saliva Bells
Palsy.
47
Cranial Nerves

• The Vestibulocochlear Nerves (VIII)
• Primary function
• Special sensory
• Vestibular branch
• Balance and equilibrium
• Originates at receptors of vestibule (balance)
• Connects to vestibular nuclei of pons and medulla
  oblongata

48
Cranial Nerves

• The Vestibulocochlear Nerves (VIII)
• Primary function
• Special sensory
• Cochlear branch
• Hearing
• Originates at sensors of cochlea (hearing)
• Connects with cochlear nuclei of pons and medulla
  oblongata

49
Cranial Nerves

• The Vestibulocochlear Nerves (VIII)
• Origin
• Receptors of inner ear
• Pathway
• Internal acoustic meatus of temporal bones

50
Cranial Nerve VIII - Vestibulocochlear
Assessment Tuning Fork Damages Vertigo
? Rotating Ataxia ? Lack of coordination
Tinnitus ? Ringing of ears
51
Cranial Nerves

• The Glossopharyngeal Nerves (IX)
• Primary function
• Mixed to head and neck
• Origins
• Motor
• From motor nuclei of medulla oblongata
• Sensory
• Posterior 1/3 of tongue
• Part of pharynx and palate
• Carotid arteries

52
Cranial Nerves

• Superior and inferior ganglion
• Sensory neurons of tongue and pharynx

FIGURE 14-25
53
Cranial Nerves

• The Glossopharyngeal Nerves (IX)
• Pathway
• Jugular foramina
• Between occipital and temporal bones

54
Cranial Nerves

• The Glossopharyngeal Nerves (IX)
• Destination
• Sensory
• Sensory nuclei of medulla oblongata
• Somatic motor
• Nerves involved in swallowing

55
Cranial Nerves

• The Glossopharyngeal Nerves (IX)
• Destination
• Visceral motor
• Parasympathetic Function
• Otic Ganglion
• Parotid salivary gland

56
Cranial Nerve - IX Glossophary-ngeal

• Assessment
• Test for taste on posterior 2/3
• Test position of uvula
• Test swallowing and gag reflex
• Damages
• Difficulty in
• Swallowing
• Digestion
• Loss of taste
• Loss of sensation in throat
• Reduced saliva production

57
Cranial Nerves

• The Vagus Nerves (X)
• The Vagabond
• The only cranial nerve that extends beyond the
  head and neck
• Primary function
• Mixed
• 90 of parasympathetic function
• Thorax and abdomen

58
Cranial Nerves

• The Vagus Nerves (X)
• Origins
• Sensory
• Part of pharynx
• Auricle and external acoustic meatus
• Diaphragm
• Visceral organs of thoracic and abdominopelvic
  cavities
• Motor
• Motor nuclei in medulla oblongata

59
Cranial Nerves

• The Vagus Nerves (X)
• Pathway
• Jugular foramina
• Between occipital and temporal bones

60
Cranial Nerves

• Sensory Neurons located in
• Superior Ganglion
• Jugular ganglion
• Inferior Ganglion
• Nodose ganglion

61
Cranial Nerves

• The Vagus Nerves (X)
• Destination
• Sensory
• Sensory nuclei and autonomic centers of medulla
  oblongata
• Visceral motor
• Parasympathetic
• Muscles of the palate and pharynx
• Muscles of the digestive, respiratory, and
  cardiovascular systems in thoracic and abdominal
  cavities

62
Cranial Nerve X - Vagus

• Assessment
• Same as IX
• Damages
• Loss of sensations to organs
• Interfere with swallowing, digestion and vocal
  cords
• Increase blood pressure

63
Cranial Nerves

• The Accessory Nerves (XI)
• Primary function
• Motor to muscles of neck and upper back
• Origin
• Motor nuclei of spinal cord and medulla oblongata

64
Cranial Nerves

• Accessory Nerve Structures
• Spinal root
• Motor fibers that originate in anterior gray
  horns of first five cervical segments of spinal
  cord
• Cranial root
• Motor fibers that originate in medulla oblongata

65
Cranial Nerves

• The Accessory Nerves (XI)
• Pathway
• Jugular foramina between occipital and temporal
  bones

66
Cranial Nerves

• The Accessory Nerves (XI)
• Destination
• Internal branch
• Voluntary muscles of palate, pharynx, and larynx

Figure 14-27
67
Cranial Nerves

• The Accessory Nerves (XI)
• Destination
• External branch
• Sternocleidomastoid and trapezius muscles

68
Cranial Nerve XI - Accessory

• Assessment
• Have patient rotate head
• Have patient cough
• Damages
• Ipsilateral paralysis of sternocleidimastoid and
  trapezius
• So you cant raise your shoulders or turn your
  head
• Difficulty in swallowing

69
Cranial Nerves

• The Hypoglossal Nerves (XII)
• Primary function
• Motor (tongue movements)
• Origin
• Motor nuclei of medulla oblongata

70
Cranial Nerves

• The Hypoglossal Nerves (XII)
• Pathway
• Hypoglossal canals of occipital bone
• Destination
• Muscles of tongue

71
Cranial Nerve XII - Hypoglossal

• Assessment
• Have patient protrude and retract
• tongue
• Damages
• Atrophy of ipsilateral tongue
• Difficulty
• Swallowing
• Chewing
• Speaking

72
(No Transcript)
73
(No Transcript)
74
Cranial Reflexes

• Cranial Reflexes
• Monosynaptic and polysynaptic reflex arcs
• Involve sensory and motor fibers of cranial
  nerves
• Clinically useful to check cranial nerve for
  brain damage

75
(No Transcript)
76
CEREBRUM - I - Olfactory smelll - II -
Optic - vision

• BRAINSTEM
• MIDBRAIN
• III - Oculomoter - movement of eye
• IV - Trochlear movement of eye
• PONS
• V - Trigeminal chewing, touch, pain
  temperature receptors
• VI - Abducens movement of eyeball
• VII - Facial facial expressions, tears, saliva
  taste
• VIII - Vestibulocochlear (vestibular branch
  only). - equilibrium
• Medulla Oblongata
• VIII Vestibulocohlear hearing equilibrium
• IX - Glossopharyngeal swallowing, taste,
  saliva production, blood pressure and
  monitor breathing
• X - Vagus swallowing, coughing, voice, blood
  pressure, monitor breathing,
  control digestive secretions organs of
• heart,
  stomachand G, I tract
• XI - Accessory swallowing, movement of head
  and shoulders
• XII - Hypoglossal swallowing, chewing
  speaking

77
(No Transcript)
78
(No Transcript)