EXERCISE 19: EXERCISE 19:
BRAIN AND CRANIAL BRAIN AND CRANIAL NERVESNERVES
http://www.vision.caltech.edu/feifeili/101_ObjectCategories/brain/image_0026.jpg
FOREBRAINFOREBRAIN
MIDBRAINMIDBRAIN
HINDBRAINHINDBRAIN
CEREBRUM
Transverse Fissure
ON FRONTAL LOBE ON FRONTAL LOBE Primary motor areaPrimary motor area
ON PARIETAL ON PARIETAL LOBE LOBE Primary Primary
somatosensory somatosensory areaarea
Cortex (superficial) is gray matterCortex (superficial) is gray matterWhite matter is deeperWhite matter is deeper
DIENCEPHALON= thalamus + DIENCEPHALON= thalamus + hypothalamushypothalamus
Sensory Nerve Sensory Nerve AttachmentsAttachments
Optic nerves: to eyes
Optic tracts: to brain
Optic chiasm: cross
Pineal Gland
Endocrine Endocrine AttachmentsAttachments
MIDBRAINMIDBRAIN
CORPORA CORPORA QUADRIGEMINAQUADRIGEMINA
HINDBRAINHINDBRAIN
HINDBRAIN--HINDBRAIN--cerebellumcerebellum
MENINGESMENINGES
Same setup as Same setup as spinal cord—spinal cord—
Dura mater most Dura mater most superficial,superficial,
Arachnoid,Arachnoid,
Pia mater closest Pia mater closest to brainto brain
CHOROID PLEXUSESCHOROID PLEXUSES
Specialized capillaries in Specialized capillaries in ventriclesventricles
Produce CSF—Circulates Produce CSF—Circulates from here to central canal (s. from here to central canal (s. cord) & around outside of cord) & around outside of brain/cord toobrain/cord too
CRANIAL NERVES12 pairs
Connect to brain:CN I cerebrumCN II thalamusCN III-XII brain stem
O O O T T A F V G V A H S S M M B M B S B B M M
Nerve names:Nerve names:
Nerve functions:Nerve functions:
CN I: OLFACTORY
• SENSORY• Smell• From olfactory
epithelium• Olfactory nerve-bulb-
tract• (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
14-23
• Mostly motor
• To lateral rectus eye muscles
• (superior orbital fissure)
CN VII: FACIAL
14-25
• Mixed
• To parts of face
• Expressions, tear/salivary glands
CN VIII: VESTIBULOCOCHLEAR
14-26
• Sensory, from inner ear
• Vestibular branch
– Balance, equilibrium
• Cochlear branch
– Hearing
CN IX: GLOSSOPHARYNGEAL
14-27
• Mixed to head and neck
• Sensory: posterior tongue
• Motor: pharyngeal muscles (swallowing), salivary gland
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.html
• http://darwin.baruch.cuny.edu/gelfond/Bio1005/neural.htm
• http://a-s.clayton.edu/biology/biol1151L/lab10/lab_10.htm