EXERCISE 19:
BRAIN AND CRANIAL
NERVES
http://www.vision.caltech.edu/feifeili/101_ObjectCategories/brain/image_0026.jpg
FOREBRAIN
MIDBRAIN
HINDBRAIN
CEREBRUM
Transverse
Fissure
ON FRONTAL LOBE
Primary motor area
ON PARIETAL
LOBE
Primary
somatosensory
area
Cortex (superficial) is gray matter
White matter is deeper
DIENCEPHALON= thalamus +
hypothalamus
Sensory Nerve
Attachments
Optic nerves: to eyes
Optic chiasm:
cross
Optic tracts: to brain
Endocrine
Attachments
Pineal
Gland
MIDBRAIN
CORPORA
QUADRIGEMINA
HINDBRAIN
HINDBRAIN-cerebellum
MENINGES
Same setup as
spinal cord—
Dura mater most
superficial,
Arachnoid,
Pia mater closest
to brain
CHOROID PLEXUSES
Specialized capillaries in
ventricles
Produce CSF—Circulates
from here to central canal (s.
cord) & around outside of
brain/cord too
CRANIAL NERVES
12 pairs
Connect to brain:
CN I
cerebrum
CN II
thalamus
CN III-XII
brain stem
Nerve names:
Nerve functions:
OOOTTAFVGVAH
SSMMBMBSBBMM
CN I: OLFACTORY
• SENSORY
• Smell
• From olfactory
epithelium
• Olfactory nerve-bulbtract
• (Cribriform foramina of
ethmoid)
14-21
CN II: OPTIC
•
•
•
•
SENSORY
From retina
Optic nerve-chiasm-tract
(Optic canal-sphenoid)
14-22
CN III:
OCULOMOTOR
• Mostly MOTOR
• To eye muscles
• (superior orbital fissures-sphenoid)
14-22
CN IV: TROCHLEAR
• Mostly MOTOR
• To superior oblique eye muscles
• (superior orbital fissures-sphenoid)
14-22
CN V: TRIGEMINAL
• Mixed (sensory and motor)
• Ophthalmic Branch
– Sensory-orbital, upper face structures
• Maxillary Branch
– Sensory-lower face structures
• Mandibular Branch
– Mixed-mouth
14-24
CN VI: ABDUCENS
• Mostly motor
• To lateral rectus eye muscles
• (superior orbital fissure)
14-23
CN VII: FACIAL
• Mixed
• To parts of face
• Expressions, tear/salivary glands
14-25
CN VIII:
VESTIBULOCOCHLEAR
• Sensory, from inner ear
• Vestibular branch
– Balance, equilibrium
• Cochlear branch
– Hearing
14-26
CN IX:
GLOSSOPHARYNGEAL
• Mixed to head and neck
• Sensory: posterior tongue
• Motor: pharyngeal muscles
(swallowing), salivary gland
14-27
CN X: VAGUS
• Mixed to visceral
organs, larynx,
pharynx
• Sensory: ear,
diaphragm, organs
• Motor: pharynx,
digestive,
respiratory,
cardiovascular
systems
14-28
CN XI: ACCESSORY
• Mostly motor
• To muscles of neck,
upper back
• Cranial root
– Fibers originate in
medulla
• Spinal root
– Some motor fibers
originate in spinal cord
• Join at foramen
magnum
14-29
CN XII:
HYPOGLOSSAL
• Mostly motor
• To tongue muscles
14-29
CRANIAL NERVES
Sheep Brain Dissections
• http://www.gwc.maricopa.edu/class/bio201/brain/brshpx.
htm
• http://www.biology.ualberta.ca/courses.hp/zoo.225/lab8.h
tml
• http://darwin.baruch.cuny.edu/gelfond/Bio1005/neural.ht
m
• http://a-s.clayton.edu/biology/biol1151L/lab10/lab_10.htm