Nervous System - Cranial Nerves Flashcards
How many Cranial Nerves are there?
- 12: Labeled CNI-CNXII
What is the name of CNI? Where is it located?
Name
- Olfactory
Location
- Sits on the Cribriform Plate
Where does the Olfactory Cranial Nerve pass through?
- The cribriform plate
Where is the cribriform plate?
- on the ethmoid bone
What is the function of the CNI Nerve? What is special about it?
Function
- Pure Sensory
- Smell
Special
- Olfactory Bulb: a sensory ganglion associated with it
- The Tract does NOT pass through the Thalamus
- Extension of the brain tissue (still called a nerve)
What Nerve is the Optic Nerve? Where does it exit?
Nerve
- CNII
Exits
- Optic Canal
What Function does the CN II nerve have?
- Pure Sensory: Vision
What forms the optic nerve?
- Several layers of neurons in the retina converge
Where does the CN II nerve fibers go after they converge in the Retina? What happens there?
Location
- Optic Chiasm
Happens
- Some fibers (about half) from each eye cross
What is the Optic Nerve called after it passes through the Optic Chiasm?
- The optic Tract
Where to the Optic Tracts convey visual information?
- Thalamus: the lateral geniculate nucleus
- Occipital Cortex: Through Optic radiation
What is the name of Cranial Nerve III? Where does it start and where does it exit?
Name - Oculomotor Location - Midbrain Exits - Superior Orbital Fissure
What is the name, origin, and exit of Cranial Nerve IV?
Name - Trochlear Origin - Midbrain Exits - Superior Orbital Fissure
What is the number, origin, and exit of the Trigeminal Nerve?
Number - Cranial Nerve V Origin - Pons Exit - V1: Superior Orbital Fissure - V2: Foramen Rotundum - V3: Foramen Ovale
What is the name, origin, and exit of Cranial Nerve VI?
Name - Abducens Origin - Midline of Pontomedullary Sulcus Exits - Superior Orbital Fissure
What is the name, origin, and exit of Cranial Nerve VII
Name - Facial Origin - Lateral of Pontomedullary Sulcus Exit - Internal Acoustic Meatus
What is the Number, Origin, and Exit of the Vestibulocochlear Nerve?
Number - Cranial Nerve VIII Origin - Lateral of Pontomedullary Sulcus Exits - Internal Acoustic Meatus
What is the Name, Origin, and Exit of Cranial Nerve IX?
Name - Glossopharyngeal Origin - Medulla Exit - Jugular Foramen
What is the Name, Origin, and Exit of Cranial Nerve X?
Name - Vagus Origin - Medulla Exit - Jugular Foramen
What is the Number, Origin, and Exit of the Accessory Nerve?
Number - Cranial Nerve XI Origin - Medulla Exit - Jugular Foramen
What is the Name, Origin, and Exit of Cranial Nerve XII?
Name - Hypoglossal Origin - Behind the Pyramid of Medulla Exit - Hypoglossal Canal
What three nerves share the same origin and exit? what are the names of the origin site and exit site?
Nerves - CN IX: Glossopharygeal - CN X: Vagus - CN XI: Accessory Origin - Medulla Exit - Jugular Foramen
What two cranial nerves exit through the Internal Acoustic Meatus?
- CN VII: Facial
- CN VIII: Vestibulocochlear
What 4 Nerves exit through the Superior Orbital Fissure?
- CN III: Oculomotor
- CN IV: Trochlear
- CN V: Trigeminal (only the V1 branch)
- CN VI: Abducens
What 3 Nerves have Unique Exits from the other Cranial Nerves?
- CN I: Olfactory (Cribriform Plate)
- CN II: Optic (Optic Canal)
- CN XII: Hypoglossal (Hypoglossal Canal)
V2 and V3 of the CN V: Trigeminal Nerve have Unique exits too, but V1 does not
What kind of nerve is the Oculomotor Nerve?
- CN III: Motor and Parasympathetic
What are the functions of the CN III Nerve?
- Motor: Supplying 5 of 7 extraocular eye muscles (1 lifting eyelid / 4 eye movement muscles)
- Parasympathetic: Supplies the iris constrictor muscle to cause Myosis
What is the associated ganglion with the Oculomotor Nerve?
- Ciliary ganglion
What kind of nerve is the Trochlear Nerve? Function? What makes it Unique?
Type
- CN IV: Pure motor
Function
- Innervates the superior oblique muscle of the eye
Unique
- Only nerve that exits brainstem from the posterior aspect
How many Branches does Cranial Nerve V have? What are they?
- V1: Ophthalmic Nerve
- V2: Maxillary Nerve
- V3: Mandibular Nerve
What is the associated ganglion with the Trigeminal Nerve?
- CN V: Semilunar Ganglion
What kind of nerve is the Trigeminal Nerve?
- Sensory and Motor
What is the name, type and function of the V1 branch of the Trigeminal Nerve?
Name - Ophthalmic Nerve Type - Pure Sensory Function - Supplies sensation of the orbital cavity and sinuses - Sensation to the front part of nose skin - Sensation to Forehead skin
What is the Name, Type and Function of the V2 Branch of Cranial Nerve V?
Name - Maxillary Nerve Type - Pure Sensory Function - Supplies sensation of nasal cavity and upper half of oral cavity and teeth
What are the Name, Type, and Function of the V3 branch of the Trigeminal Nerve?
Name - Mandibular Type - Sensory - Motor Function - Sensation of the lower half of the oral cavity - Pain sensation of lower jaw and tongue - sensation of jaw skin - motor for muscles of mastication
What is the Type and Function of the Abducens Nerve?
Type
- Pure Motor
Function
- CN VI: Innervates the Lateral Rectus Muscle of the eye (abduction of eyeball)
What nerve type is the Facial Nerve?
- CN VII: Mixed Nerve (motor, sensory, and parasympathetic)
What Motor Functions does the CN VII have?
- movement of facial expression muscles (or superficial muscles of the face)
What sensory function does the Facial Nerve Provide?
- CN VII: Taste for the anterior 2/3 of the tongue
What parasympathetic function does CN VII provide?
- Facial Nerve: Salivary glands (sublingual and submandibular)
- small glands in the nose
- lacrimal glands (tears)
What does the Vestibulocochlear Nerve do?
- Special sensory
- The cochlea nerve branch is for hearing
- Vestibule nerve branch is for balance
What Type of nerve is Cranial Nerve IX?
Glossopharyngeal Nerve
- Mixed Nerve: sensory, parasympathetic and a little motor
What sensory functions does the Glossopharyngeal nerve have?
CN IX
- Sensation of the posterior 1/3 of the tongue (pain, touch and taste)
- Sensation of the pharynx
- Sensory from Carotid Body (baroreceptors: blood pressure sensor in neck)
What Parasympathetic function does CN IX have?
Glossopharyngeal Nerve
- Parotid Gland: contribute to saliva secretion
What type of nerve is the Vagus Nerve?
Cranial Nerve X
- Mixed Nerve: sensory, motor, and parasympathetic (largest in body)
What Sensory functions does cranial nerve X have?
Vagus Nerve
- Sensation of the Larynx and Trachea
What motor functions does the Vagus Nerve have?
Cranial Nerve X
- Pharyngeal muscle innervation
- Laryngeal Muscle innervation
What Parasympathetic function does the Vagus Nerve have?
CN X
- Provides parasympathetic innervation for:
- All thoracic Organs (heart and lungs)
- Most Abdominal Organs (Liver, pancreas, stomach, small intestine, ascending colon) until 1/3 way into the transverse colon.
- not to pelvic viscera
What is the Type and Function of Cranial Nerve XI?
Accessory Nerve
- Type: Pure Motor
- Function: Innervates Trapezius and Sternocleidomastoid (SCM)
What is the Type and Function of the Hypoglossal Nerve?
Cranial Nerve XII
- Type: Pure Motor
- Function: Innervates all muscles of the tongue (except one muscle)
