PNS Flashcards
How many pairs of spinal nerves are there?
Study them on the picture provided
There are 31 pairs of spinal nerves
8 cervical nerves
12 thoracic nerves
5 lumbar nerves
5 sacral nerves
1 coccygeal nerve
Spinal Nerves
Each peripheral nerve consist of
1.Epineurium-Outer layer (tough layer of connective tissue)
2.Perineurium- Layer surrounding a fascicle inside the nerve
*A fascicle is a bundle of axons
3.Endoneurium - Layer surrounding a single axon
CRANIAL NERVES
How many pairs of cranial nerves are there?
There are 12 pairs of cranial nerves
They are numbered CN I to CN XII From anterior to posterior
All Cranial Nerves are what?
And what does that word mean
Ipsilateral
They innervate the same side they are on
So the right nerve controls the right and the left controls the left
What is the first Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN I : The Olfactory Nerve
Sensory
It is for smell
Anosmia (loss of smell)
What is the Second Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN II : The Optic Nerve
Sensory
For Vision
Anopsias (Complete or Partial loss of vision)
What is the Third Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN III : The Oculomotor Nerve
Motor
Controls “4” of the 6 extra ocular eye muscles
Function: responsible for moving the eye superiorly, inferiorly, and medially
External Strabismus- the eye wonders to the side laterally “lazy eye”
One eye goes forward and the other goes to the side
What is the fourth Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN IV : The Trochlear Nerve
Motor
Controls “1” of the 6 extra ocular muscle
The 1 muscle is
“Superior Oblique Muscle”
Function: The Superior Oblique Muscle moves the eye Inferolaterally
Trochlear Nerve Palsy- Patient experiences double vision due to the inferior oblique muscle being unoposed and moving the eye supromedially
“The side eye”
What is the fifth Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN V: The Trigerminal Nerve
Both but mostly sensory with 3 branches
Function
Ophthalmic branch -sensory from the the forehead, eyelids and nose.
Maxillary branch - sensory from lower eyelid, upper lip, cheek, and maxillary teeth.
Mandibular branch - sensory from lower jaw, tongue, mandibular teeth and gums ; and motor to the muscles of mastication (chewing)
Dental Anesthesia- when we are numbed for a dental procedure, this is the nerve that is numbed
What is the sixth Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN VI : The Abducens Nerve
Motor
Controls “1” of the 6 extra-ocular eye muscle
The “Lateral rectus muscle” moved the eye laterally
Internal Strabismus- is when the medial
muscle is unopposed(having no opponent-meaning it’s strong in this case) and moves the eye medially. The patient experiences double vision.
What is the seventh Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN VII : The Facial Nerve
Both but mostly motor
It innervates the muscles of the face and
The sensory portion is for gustation(taste)
The motor portion is for control of the facial muscles( facial expression)
Bells Palsy- facial muscle becomes distorted. It’s “unilateral” so it affects one side.
The side that doesn’t move is where the damage is.
What is the eight Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN VIII : The Vestibulocochlear Nerve
Sensory
It’s for Audition(hearing)
and equilibrium (balance)
There are two branches ;
Cochlear branch: for hearing
Vestibular branch : for balance (goes into our inner ear which determines balance)
Nerve Deafness and Vertigo
If the cochlear branch is damaged- nerve deafness occurs
If the vestibular branch is damaged- vertigo( dizziness, loss of balance, nausea, involuntary rapid eye-movement) can occur
* bonus
Nystagmus- rapid eye movement (spinning)
What is the ninth Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN IX : The Glossopharyngeal Nerve
Both
Sensory function: gustation(taste) from posterior 1/3 of tongue
Motor function: pharyngeal muscle( swallowing)
and parotid gland ( salivation)
Impaired Swallowing
Loss of taste - “ageusia” in the posterior tongue
What is the tenth Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN X : The Vagus Nerve
Only cranial nerve that doesn’t just innervate the head and the neck, it goes further down
Both
Sensory : sensations from the organs (visceral)
Motor : primary parasympathetic (“rest and digest”) nerve to the internal organs(visceral motor division)
Complete damage -Death
Partial damage- impairments to digestion, or lead to hoarseness or loss of voice
What is the eleventh Cranial Nerve?
What is the Roman Numeral?
Is it Sensory, Motor, or Both?
What is the Function?
Pathology-What is the symptom if this nerve is damaged?
CN XI : The Accessory Nerve
Motor
Controls the sternocleidomastoid(turns head) and trapezius(elevates the shoulder) muscles
Accessory Nerve Damage
When one shoulder doesn’t elevate properly
