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
Endocrine
Attachments
Pineal
Gland
MENINGES
Same setup as
spinal cord—
Dura mater most
superficial,
Arachnoid,
Pia mater closest
to brain
• Mesencephalic or CEREBRAL aqueduct
CHOROID PLEXUSES
Specialized capillaries in
ventricles
Produce CSF—Circulates
from here to central canal (s.
cord) & around outside of
brain/cord too
MIDBRAIN
CORPORA
QUADRIGEMINA
HINDBRAIN
HINDBRAIN-cerebellum
Don’t Forget!
• Sheep Brain Dissection next class!
Sensory Nerve
Attachments
Optic nerves: to eyes
Optic chiasm:
cross
Optic tracts: to brain
CRANIAL NERVES
12 pairs
Connect to brain:
CN I
cerebrum
CN II
thalamus
CN III-XII
brain stem
Nerve names:
OOOTTAFVGVAH
Nerve functions: S S M M B M B S B B M M
Brain Overload!!
• Oh, Once One Takes The Anatomy Final,
Very Good Vacations Are Heavenly…
Or
– Oh, Oh, Oh, To Touch And Feel Very Good
VIOLINS, AH!
• Some Say Marry Money, But My Brother
Says Big BROWNIES Matter Most
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 Dissection
• Safety First!
– Sharps: blades and blade holders
– Goggles
– Gloves
– Biohazard waste disposal
• No tissue down the drain!
• Gloves also
– Cleaning the dissection trays & your
instruments
Sheep Brain Dissection
• http://www.gwc.maricopa.edu/class/bio201/brain/brshpx.ht
m
Sheep Brain
•
•
Dura mater, pia mater
Lobes (frontal, parietal, temporal, occipital)
Superficial
•
•
•
Pituitary gland
Olfactory bulbs
Optic nerves, optic chiasm, optic tract
Superficial
Sheep Brain
•
•
•
•
•
•
•
•
•
•
•
•
Cerebral cortex (gray matter)
Cerebral white matter
Corpus callosum
third, 4th ventricles
Thalamus
Hypothalamus
Pineal gland
Superior colliculi
Inferior colliculi
Pons
Medulla oblongata
Cerebellum (arbor vitae, cerebellar cortex)
Longitudinal section
Sheep Brain
•
Lateral ventricles
Transverse section
Sheep Brain
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Dura mater, pia mater
Pituitary gland
Superficial
Olfactory bulbs
Optic nerves, optic chiasm, optic tract
Cerebral cortex (gray matter)
Cerebral white matter
Corpus callosum
Lateral, third, 4th ventricles
Thalamus
Hypothalamus
Longitudinal section & Transverse section
Pineal gland
Superior colliculi
Inferior colliculi
Pons
Medulla oblongata
Cerebellum (arbor vitae, cerebellar cortex)