1. Cranial Nerves and Soft Tissues of the Skull
Biology 323
Human Anatomy for Biology Majors
Week 10; Lecture 1; Tuesday
Dr. Stuart S. Sumida
Cranial Nerves and Soft Tissues of the Skull

2. FOREBRAIN
MIDBRAIN
HINDBRAIN

4. Midbrain (Mesencephalon)
Forebrain:
Cerebrum – Perception, movement of somatopleure,
sensoro-motor integration, emotion, memory, learning.
Diencephalon – Homeostasis, behavioral drives in
hypothalamus; sensory relay and modification in thalamus;
melatonin secretion in pineal gland.
Midbrain (Mesencephalon)
Control of eye movement.
Hindbrain
Cerebellum and Pons – control of movement,
proprioreceptive input; relays visual and auditory reflexes in
pons.
Medulla Oblongata – Involuntry functions: blood pressure,
sleep, breathing, vomiting.

5. Development
Special Sense organs = nose, eyes and ears, begin as small outcrops of ectoderm called placodes

6. Development
Placode 1 = nose
Placode 2 = eye
Placode 3 = ear

7. Development
In the nose, the ectoderm become nerve cells that send their fibres through the cribriform plate of the ethmoid, back to the brain
This is Cranial Nerve I = the Olfactory Nerve

8. Development

9. Development

10. Development The second placode becomes the lens of the eye.
It sinks below the surface of the skin, and an outgrowth of the brain wraps around it.
The outgrowth is the retina, and the stalk connecting it is Cranial Nerve II = The Optic Nerve

11. Development

12. Development
The Inner ear starts out as a lens, but turns into a fluid filled sac
Receptor organs of hearing and balance.
Cranial Nerve VIII = Auditory or Vestibulocochlear Nerve

13. Development

14. Development
Head somites can be divided into 2 sets. Pre-otic and post-otic

15. Development
The sklerotomes of the post otic somites help form the floor of the brain case

16. Development
….and their myotomes develop into muscles of the tongue

17. Development
The myotomes of the pre-otic somites form the muscles that move the eyeballs.

18. Development
Each is supplied by a different cranial nerve:

19. Development
Cranial Nerve III =
Occulomotor Nerve

20. Development
Cranial Nerve IV =
Trochlear Nerve

21. Development
Cranial Nerve VI = Abducens Nerve

22. Development
Gill Arch Derivatives

23. Development
Mandibular arch

24. Cranial Nerve V: The Trigeminal Nerve (3 branches) V1 Opthalmic ,
V2 Maxillary,
V3 Mandibular

25. Development
Hyoid arch

26. Cranial Nerve VII:
Facial nerve

27. Development
Next arch

28. Cranial nerve IX:
Glossopharyngeal Nerve

29. Development
Remaining arches

30. Cranial nerve X:
The Vagus Nerve

31. Summary of Cranial Nerves
The Cranial Nerves
Summary of Cranial Nerves

32. Is there a “#0” nerve?
The Nervus Terminalis (Nerve Zero) has been suggested as a primitive vertebrate structure serving the vomeraonasal organ.

33. Special Sensory Nerves

34. I

35. Cranial Nerve I The Olfactory Nerve Sensory Smell
Cribriform plate of ethmoid

37. II

39. Introduction to eye proper

40. Cranial Nerve II
The Optic Nerve
Sensory
Vision
Optic foramen

41. Ventral Root Cranial Nerves

42. III

43. Cranial Nerve III
The Occulomotor Nerve
Mainly motor
Eye Movement
Superior orbital fissure

44. Cranial Nerve III
The Occulomotor Nerve
Mainly motor
Eye Movement
Superior orbital fissure

45. Detail on Occulomotor (III) Function:
Motor to all extra-ocular muscles except lateral rectus and superior oblique.
Parasympathetic innervation to sphincter pupillae and ciliaris muscles (synapse in ciliary ganglion).
Sympathetic innervation to sphincter pupillae and ciliaris muscles. Fibers originate in upper thoracic levels, synapse in cervical ganglia, get to orbit via associated arteries.

46. Opthalmic nerve pathways

47. IV

48. Cranial Nerve IV
The Trochlear Nerve
Mainly motor
Superior oblique
Superior orbital fissure

49. Cranial Nerve IV
Superior oblique

50. VI

51. Cranial Nerve VI
The Abducens Nerve
Mainly motor
Lateral rectus
Superior orbital fissure

52. Cranial Nerve VI
Lateral rectus

53. SUPERIOR ORBITAL FISSURE AND STRUCTURES PASSING THROUGH IT.V1
III 1
Opth. a. IV VI V2
Opthalmic v.
Sphenoid/ anterior view of orbital surface and sutures with frontal, ethmoid and palatine bones/ cranial nerves indicated

54. XII

55. Cranial Nerve XII
The Hypoglossal Nerve
Mainly Motor
Tongue
Hypoglossal Canal

56. Dorsal Root Cranial Nerves

57. V

58. Cranial Nerve V
The Trigeminal Nerve
Both
V1= ophthalmic
V2 = maxillary
V3 = mandibular

59. Cranial Nerve V1
Ophthalmic division
Sensory
Superior orbital fissure

60. Opthalmic and maxillary nerve pathways/lateral view

61. Opthalmic and maxillary nerve pathways/medial view of lateral cut away orbit
Lateral path of efferent parsympathetics from VII to lacrimal gland following zygomatico-temporal n. V2 to lacrimal n. V3

62. Cranial Nerve V1
Ophthalmic division
Sensory
Superior orbital fissure

63. Detail on Ophthalmic (V-1) Function:
Almost wholly sensory: eyeball, lacrimal gland, conjunctiva, part of nasal mucosa, from brow ridge superiorly.
Carrys a bit of sympathetic fibers for dilator pupillae. From upper thoracic levels, synapsing in in upper cervical ganglion. Reaches via branches of internal carotid artery.

64. Cranial Nerve V2
Maxillary division
Sensory
Foramen rotundum

65. Cranial Nerve V2
Maxillary division
Sensory
Foramen rotundum

66. Cranial Nerve V3
Mandibular division
Both
Foramen ovale

67. Cranial Nerve V3 Mandibular division Both Foramen ovale
Sensory Component

68. Detail on Mandibular (V-3) Function:
Sensory to lower jaw region, including teeth.
Motor nerve to muscles of the mandibular arch: masseter, temporalis, anterior and posterior pterygoids, mylohyoid, tensor tympani, anterior digastric, and tensor veli palatini.
The auriculotemporal branch contains secretomotor fibers to the parotid gland via the parotid branches.

69. Cranial Nerve V

70. VII

71. Cranial Nerve VII
The Facial Nerve
Both
Motor and sensory

72. Cranial Nerve VII
The Facial Nerve
Both motor and sensory
Muscles of facial expression
Parasympathetic:
Lacrimal ducts, taste, salivary glands

73. VIIa Temporal VIIb Zygomatic VIIc Buccal VIId Mandibular VIIe Cervical
Cranial Nerve VII
The Facial Nerve
VIIa Temporal VIIb Zygomatic VIIc Buccal VIId Mandibular VIIe Cervical

74. Cranial Nerve VII
Enter skull via internal auditory meatus

75. Cranial Nerve VII
Exit skull via stylomastoid foramen

76. Cranial Nerve VII a Temporal b Zygomatic c Buccal d Mandibular
e Cervical

77. Detail on Facial (VII) Function:
Motor to muscles of the hyoid arch: posterior digastric, mm. of facial expression.
Sends parasympathetic fibers via greater petrosal branch and pterygopalatine ganglion to lacrimal gland (secretomotor fibers).
It may also supply parasympathetic innervation to palatine, pharyngeal, and nasal glands.

78. An Evolutionary Branch of VII
VIII
An Evolutionary Branch of VII

79. Cranial Nerve VIII
Vestibulocochlear Nerve
Sensory
Hearing
Internal Auditory Meatus

80. IX

81. Cranial Nerve IX
The Glossopharyngeal Nerve
Both
Pharynx, posterior tongue
Jugular foramen

82. Cranial Nerve IX
The Glossopharyngeal Nerve
Both
Pharynx, posterior tongue
Jugular foramen

83. Detail on Glossopharyngeal (IX) Function:
Motor to stylopharyngeus muscle.
Parasympathetic secretomotor fibers to parotid gland.
Sensory to pharynx, tonsils, and posterior 1/3 of tongue.
Taste fibers for posterior 1/3 of tongue.

84. X

85. Cranial Nerve X
The Vagus Nerve
Both
Throat to end of midgut
Jugular foramen

86. Cranial Nerve X
The Vagus Nerve
Both
Throat to end of midgut
Jugular foramen

87. An Evolutionary Branch of XXI
An Evolutionary Branch of X

88. Cranial Nerve XI The Accessory Nerve Mainly Motor Foramen Magnum
larynx, pharynx, trapezius and sternocleidomastoid
Foramen Magnum

89. Names

90. I Olfactory II Optic III Occulomotor IV Trochlear V Trigeminal VI
Abducens
VII
Facial
VIII
Vestibulochochlar IX
Glossopharyngeal X
Vagus XI
Accessory
XII
Hypoglossal

91. Motor, sensory, or both

92. I
Sp. Sense
Sensory II
III
Ventral Rt.
Mainly motor IV V
Dorsal Rt.
Both VI
VII
VIII IX X XI
XII

93. Route

94. I
SENSORY
Cribriform plate II
Optic Canal

95. Superior orbital fissure
III
MAINLY MOTOR
Superior orbital fissure IV V
BOTH VI

96. Superior orbital fissure
III
MAINLY MOTOR
Superior orbital fissure IV V
BOTH VI

97. III MAINLY MOTOR IV V BOTH V1 V2 V3 VI Superior orbital fissure
Foramen Rotundum
Foramen Ovale VI

98. Internal Auditory meatus
VII
BOTH
Internal Auditory meatus
VIII
SENSORY

99. Internal Auditory meatus
VII B
Internal Auditory meatus
Exits through stylomastoid foramen
VIII
SENSORY

100. IX
BOTH
Jugular foramen X

101. XI
MAINLY MOTOR
Foramen Magnum
XII
Hypoglossal Canal

102. Functional Summary (Note other details)

103. I
OLFACTORY
SENSORY
CRIBRIFORM PLATE
SMELL

104. II
OPTIC
SENSORY
OPTIC CANAL
Vision

105. III
OCCULOMOTOR
MAINLY
MOTOR
SUPERIOR ORBITAL FISSURE
Focusing

106. IV
TROCHLEAR
MAINLY
MOTOR
SUPERIOR ORBITAL FISSURE
Superior obliques

107. V TRIGEMINAL BOTH SUPERIOR ORBITAL FISSURE FORAMEN OVALE
FORAMEN ROTUNDUM
Ophthalmic,
maxillary,
mandibular

108. VI
ABDUCENS
MAINLY
MOTOR
SUPERIOR ORBITAL FISSURE
Lateral rectus

109. VII FACIAL BOTH INTERNAL AUDITORY MEATUS
EXITS THROUGHSTYLO-MASTOID FORAMEN
Temporal
Zygomatic
Buccal
Mandibular
Cervical

110. VIII
AUDITORY
SENSORY
INTERNAL
MEATUS
Hearing

111. IX
GLOSSO
PHARYNGEAL
BOTH
JUGULAR FORAMEN
Taste, saliva, throat

112. X
VAGUS
BOTH
JUGULAR
FORAMEN
Motor and Sensory.
Parasympathetic from throat to end of midgut

113. XI ACCESSORY MAINLY MOTOR FORAMEN MAGNUM
Trapezius, sterno-cleidomastoid, throat

114. XII
HYPOGLOSSAL
MAINLY
MOTOR
CANAL
Tongue and throat

115. Meninges (All from Neural Crest)
Outermost: Dura mater
Middle: Arachnoid mater
Deepest: Pia mater
Cerebrospinal fluid between Arachnoid and Pia mater

116. Meninges: Dura mater

117. Dural Reflections
Falx cerebri
Tentorium cerebelli

118. Vasculature: Venus Sinuses

119. Vasculature: Venus Sinuses

120. Vasculature: Venus Sinuses

121. Vasculature:
Arterial Supply

122. Vasculature: Arterial Supply

123. Muscle and Nerve Stuff…

124. Jaw Moving Musculature:

125. Jaw Opening Musculature: Diagastric Muscle
Anterior belly – innervated by Mandibular (V3) nerve
Posterior belly – innervated by Facial (VII) nerve

126. Note! Stylohyoid, styloglossus, tongue muscles in general.

127. Superficial Facial Muscles (all innervated by VII)

128. Some muscles of mastication (Innervated by V3)
Deeper Facial Muscles (All innervated by VII)

129. Tongue: Surface

130. Extrenisc and Intrensic Tongue Muscles