Download Head Forum 2008

HEAD FORUM 2008
1. What is the significance of the arachnoid granulations? Where are they located?
Arachnoid granulations leak CSF into the venous system to control
intracranial pressure. Evaginations of Arachnoid….bring CSF from
Arachnoid to the Superior Sagittal sinus (dural venous sinus).
2.
Which major vessel supplies the major arterial supply to the dura?
a. Anterior branches from middle meningeal a.: Anterior cranial fossa
floor
b. Middle meningeal a.: Middle cranial fossa entrance, supplies most of
dura, and all supratentorial dura
c. Accessory meningeal a.: Middle cranial fossa
d. Posterior branches from middle meningeal a.: Posterior cranial fossa
e. Occipital a.
f. Ethmoidal arteries…
g. Vertebral a. (supplies meninges)
h. Ascending Pharyngeal a.
3.
Identify the major sensory nerves which supply the dura.
a. CN V (trigeminal n.): Anterior/Middle cranial fossa dura
b. C1/C2 (C3): Posterior cranial fossa dura (get into the skull by
following CN XII through the hypoglossal canal.
c. Tentorium is V1 (has a recurrent meningeal branch….Dr. K’s favorite
dura question.
d. What supplies the Falx Cerebri? V1
4.
In which layer of the scalp do the vessels travel? Muscles located? Danger
layer? (S-C-A-L-P)
a. Vessels travel in Dense Connective Tissue layer (directly below skin)
b. Muscles: Epicranius m. (frontalis/occipitalis) is in Aponeurosis layer
(galea aponeurotica)
c. Danger layer is in the Loose Connective Tissue layer (connected via
emissary vv. to internal skull)
5.
Identify by landmarks the distribution of CN V to the face.
a. V1 (ophthalmic division): Above upper eyelid and tip of the nose
b. V2 (maxillary division): Below the level of the eyes and above the
upper lip
c. V3 (mandibular division): Face below the level of the lower lip,
chin…distribution is like a beard.
6.
Identify the 4 major arteries which contribute to the circulation of the face.
a.
b.
c.
d.
7.
Facial a.
Transverse facial a. (from Superficial Temporal a.)
Maxillary a. (gives Mental a., Infraorbital a., Inferior Alveolar a.
Supraorbital a. (from Ophthalmic a.)
Identify the course and branches of CN VII after it exits the stylomastoid
foramen.
a. Enters the parotid gland and divides into temporofacial division (T, Z,
B branches) and cervicofacial division (B, M, C branches)
8.
Paralysis of CN VII leads to: _BELL PALSY, which is characterized by: Eyelid
droop (Ptosis), Mouth Droop (paralysis of facial muscles), Unable to close eyelids
(Orbicularis Oculi- CN VII), food/saliva falls out of mouth (Orbicularis Oris),
Chewing is inefficient (Buccinator cannot keep food btwn. Lip and teeth), Atrophy of
facial expression m.m., Facial m. asymmetry, Sounds may appear louder
(Hyperacusis, due to Stapedius m. not working to dampen sounds).
9.
Where does the parotid duct open?
1.
10.
11.
Opens inside the cheek, superiorly opposite the 2nd maxillary molar.
Identify the important structures which course through the parotid gland.
a.
Transverse Facial a./v. (superficial temporal)
b.
CN VII
c.
External Carotid a.
d.
Auriculotemporal n.
e.
Retromandibular v.
f.
Lymph nodes- superficial parotid nodes (from “collar group of
superficial nodes”) and deep parotid nodes (superior Deep Cervical Group)
Identify the muscles which: close the eye, close the mouth, keep food between
the teeth. What is their innervation and embryological origin?
a.
b.
c.
d.
e.
12.
Close the eyes: Orbicularis occuli
Close the mouth: Orbicularis oris
Food between teeth: Buccinator
Innervation: CN VII (facial n.)
Embryonic origin: 2nd arch
Identify muscles which elevate the larynx and pharynx during swallowing.
Suprahyoid m. digastrics, stylohyoid, mylohyoid lift larynx. (lift hyoid bone)
What lifts the pharynx? All pharyngeus m.m. Palatopharyngeus, Stylopharyngeus, &
Salpingopharyngeus.
a. Palatopharyngeus
b. Thryohyoid
c.
d.
e.
f.

13.
Digastric
Myohyloid
Stylopharyngeus
Salpingopharyngeus
What are the innerations to these muscles???
Identify the muscle which, when it contracts, opens the auditory-pharyngeal
tube.
a. Tensor veli palatini (I: CN V3 via the branch to the medial pterygoid
m.)
14.
Paralysis of the right levator palatini muscle results in deviation of the uvula
to which side?
Deviation to the Left side. Goes towards the opposite side, palate sags.
Sagging palate indicates injury to CN X, the Vagus n. (musculae uvulae)
15. Identify two antagonistic muscles working at the cricothyroid joint.
Cricothyroid: moves thyroid cartilage forward to increase tension of
vocal folds (increases pitch)
Thyroarytenoid: moves thyroid cartilage back to decrease tension (decreases
pitch)
16.
Identify the muscle which acts to abduct the true vocal folds.
Posterior Cricoarytenoid muscle.
17.
Innervation of the larynx is accomplished by which cranial nerve?
18.
Identify the nerve responsible for innervating the majority of the intrinsic
muscles of the larynx. The cricothyroid? The mucosa of the true vocal fold?
Superior Laryngeal Nerve: Internal- sensory to above vocal cords &
External-muscular branch only to muscles.
Recurrent Laryngeal Nerve: Motor & Sensory, but provides Sensory
BELOW vocal cords. Innervates all muscles EXCEPT Cricothyroid.
a. Intrinsic muscles of larynx: Recurrent laryngeal n. (from CN X)
b. Cricothyroid: External laryngeal n. (from External laryngeal n. off of CN
X)
c. Posterior Cricoarytenoid opens the vocal folds (opens rima glottis).
Lateral Cricoarytenoid opens the vocal folds.
d. Innervation to Mucosa of true vocal fold: Recurrent laryngeal n.
19.
Identify the muscles of mastication that close the mandible.
a. Temporalis
b. Massester
20.
Identify the innervation of the muscles of mastication.
a. CN V3 (Mandibular n. from Trigeminal n.). From 1st Arch.
21.
Identify the muscles which are responsible for side to side movements of the
mandible.
Medial and Lateral Pterygoid m.m.
22.
Identify two specific branches of GVE - P cranial nerves whose postganglionic
fibers travel with V3.
Lesser petrosal n (from CN IX) to parotid gland
Chorda tympani (from CN VII) hitchhikes on lingual n. to the
submandibular and sublingual glands
Greater Petrosal n. innervates Lacrimal duct. (Lacrimal n. comes from
Opthalmic, V1.)
23.
24.
The lingual and inferior alveolar nerves pass between which two muscles?
Medial and Lateral Pterygoid muscles.
Identify the nerve which innervates both the inside and the outside of the cheek:
Buccal branch, of CN V….innervates sensory only, skin/mucosa.
25.
The superior and middle nasal conchae are part of which bone?
26.
Identify the 3 components of the nasal septum.
Ethmoid bone. (Inferior conchae is its own bone.)
a. Perpendicular plate of the ethmoid
b. External part of the cartilaginous nasal septum (Septal Cartilage)
c. Vomer
27.
Identify the paranasal sinuses which open into the middle meatus. (space under
middle conchae)
a. Frontal sinus
b. Anterior ethmoid cells
c. Maxillary sinus
28.
Identify the arteries which form Kiesselbach's plexus (the arterial plexus on the
nasal septum).
a. Anterior and Posterior Ethmoidal arteries (branches off Opthalmic a.),
Sphenopalatine a.(from Maxillary a.)…comes through Incisive Foramen.
29.
Identify three major areas to which venous blood of the nasal cavity drains.
Facial vein, Cavernous Sinus, Pterygoid Venous Plexus.
30.
Identify the major nerves which supply branches to the nasal mucosa.
1.
2.
3.
4.
5.
6.
31.
Olfactory n. (CN I)
Posterior superior lateral nasal n. (off PPG)
Posterior inferior lateral nasal n. (off PPG)
Nasopalatine n.
Nasociliary n.
Infraorbital (small contribution)
Identify the cranial nerve and its specific GVE - P branch which provides
preganglionic parasympathetic innervation to nasal mucosal glands.
CN VII: Greater Petrosal Nerve. Goes into PPG and follows nerves above in
Q#30 to nasal cavities.
32.
The pterygopalatine ganglion provides postganglionic parasympathetic
innervation to which general areas\structures of the head?
a. Lacrimal gland
b. Mucous membranes of nasal and oral cavities
c. Nasopharynx
33.
Identify the three major osseous and cartilaginous attachments of tongue
musculature.
Genial Tubercles of Mandible (spines), Hyoid body, Styloid process,
Mandible, Palate.
34.
A patient protrudes his tongue and it deviates to the right. Identify the nerve and
the general site of the lesion.
Injury of Right Hypoglossal n. CN XII, peripheral lesion on the R.
Genioglossus weakness. Left taking over, tongue protrudes to R b/c these
muscles cross each other.
35.
Identify the nerves which supply SVA fibers to the tongue. GSA fibers. GVA
fibers. WHICH PART OF TONGUE DO THEY SUPPLY. CN X supplies root of
tongue/epiglottis.
a. SVA: CN IX, CN VII (chorda tympani), CN X
b. GSA: Lingual n. (CN V3) (anterior 2/3rds of tongue)
c. GVA: CN IX, CN X
36.
Identify the route by which sublingual nitroglycerin reaches the heart.
a. Enter sublingual vv. (sublingual plexus facial v.  IJV 
Brachiocephalic v.  SVC  RA) and then quickly into caval venous
circulation (no liver!) No First-Pass through the liver.
37.
Where do you locate the deep portion of the submandibular gland?
a. In the Paralingual space…Deep portion of gland folds over mylohyoid m.
The Submandibular gland duct comes off the Deep portion of gland.
Superficial part is actually in the neck.
38.
39.
What structure crosses the submandibular duct twice?
The Lingual Nerve.
Describe the route of sympathetic and parasympathetic innervation to the
submandibular and sublingual salivary glands.
1. Sympathetic: Postganglionic fibers from superior cervical ganglion give
external carotid plexus on facial a. (or can hop onto Maxillary a.)and
follows its branches to the submandibular and sublingual glands
2. Parasympathetic: Facial n. to chorda tympani (hitchhikes on lingual n.) to
submandibular ganglion to the salivary glands
40.
41.
42.
Identify the cranial nerve used to adduct the eye. (towards the nose)
Medial Rectus, I: Occulomotor n., CN III.
Identify the cranial nerve used abduct the eye. (away from nose)
Lateral Rectus. I: Abducens n., CN VI.
Accommodation involves what three actions? By what cranial nerve are they
mediated?
1. Actions:
i. Accomodation of lens – parasympathetics (ciliary muscles contract to fatten
the lens)
ii. Convergence of eyes- Medial rectus adducts the eyes.
iii. Constriction of pupil – parasympathetics (sphincter papillae)
2. CN III, Occulomotor.
43.
Identify the innervation of the tympanic membrane:
External surface ¾ by Auriculotemporal n., ¼ by CN X, some by CN VII.
Internal surface  all by the Tympanic plexus, made of Tympanic branch of
CN IX. Tympanic membrane is set at an angle 55 degrees from meatal floor.
Thickened where it is attached to bone.
44.
Identify the mucosal innervation of the middle ear cavity.
Mucosal innervation is from the parasymp. From Tympanic plexus
(including the pharyngotympanic tube and the mastoid area). The
Tympanic Plexus is formed by the Tympanic n., a branch of CN IX and from
branches of the internal carotid plexus.
45.
What mechanism is provided to keep the middle ear ossicles from over vibrating?
The Stapedius muscle helps to dampen sound, it is innervated by the Facial
n. CN VII.
Tensor Tympani assists with reducing the force of vibrations in response to
loud noises by pulling on the malleus medially, which tenses the tympanic
membrane. Tensor Tympani is innervated by CN V3.
46.
Define the terms otosclerosis and hyperacusis.
1. Otosclerosis: Degeneration of the synovial joints between ear ossicles
(can even fuse together)…that leads to hearing loss
2. Hyperacusis: Hypersensitivity to sound….CN VII injury…would be
injured around IAM, somewhere in Facial Canal…inside the skull to
affect Stapedius m.
47.
List and describe the origin, course and importance of the following nerves associated
with the middle ear:
1. Chorda tympani, branch of CN VII 
2. Origin: From CN VII (facial n.)
3. Course: Traverses the posterior canaliculus, runs in the mucosa over the
handle of the malleus and leaves via the anterior canaliculus
4. Importance: Innervate submandibular, sublingual, and lingual glands; taste to
anterior 2/3rd of the tongue.
2.
3.
4.
5.
48.
Identify the cranial nerves, including their specific modalities, which are involved in
the following reflexes:
a.
b.
c.
d.
49.
Tympanic branch of IX 
Origin: Forms the tympanic plexus on the medial wall of the middle ear
Course: Continues as the lesser petrosal n.
Importance: Conveys GVA fibers to the tympanic cavity, the mastoid antrum
and air cells, and the auditory tube
Light reflex: IN: CN II OUT: CN III
Corneal reflex: IN: V1 OUT: CN VII
Gag reflex: IN: IX OUT: X
Cough reflex: IN: CN X OUT: CN X
List the major branches of the following cranial nerves:
a. CN V1  “NFL”  nasociliary n., frontal n., lacrimal n.
b. CN V2 Zygomatic n., Infraorbital n.
c.
CN V3
Recurrent meningeal n.
Medial pterygoid n.
Anterior trunk:
i. Deep temporal n.
ii. Masseteric n.
iii. Lateral pterygoid n.
iv. Buccal n.
Posterior trunk:
v. Lingual n.
vi. Inferior alveolar n.
vii. Auriculotemporal n.
d.
CN VII
Temporal n
Zygomatic n.
Buccal n.
Mandibular n.
Cervical n.
Chorda tympani
e. CN IX







50.
Tympanic n.
Communicating branch
Pharyngeal branch
Carotid sinus branch
Tonsillar branches
Motor branch
Lingual branch
Name the sensory ganglia which house the cell bodies of origin of the sensory
components of the following cranial nerves: (PPG & Submandibular are parasympathetic
ganglia.)
a. CN V Trigeminal Ganglion
b. CN VII Geniculate Ganglion
c. CN IX 
(1) Superior Ganglion of CN IX GSA
(2) Inferior Ganglion of CN IX GVA
d. CN X 
(1) Superior Ganglion of CN X  GSA
(2) Inferior Ganglion of CN X  GVA
51.
What are the signs of injury of the cervical sympathetic chain and what is
this condition called? (get decreased sympathetic innervations due to
interruption of the sympathetic pathway from spinal cord to superior cervical
sympathetic ggl. (SCSG)
Horner’s Syndrome:
Miosis- constricted pupil (sphinctor papillae unopposed b/c dilator pupillae not
innervated)
Ptosis-superior tarsal m. gets sympathetic innervations, to keep eye open, so this
would not work.
Flushing-blood vessels dilate b/c you have lost vascular control, so the vessels pool
with blood.
Anhydrosis-no sweating b/c sympathetic are superficial and deep, so no
sympathetic are reaching the sweat glands, no sweating….dry skin.
Incomplete Horner’s Syndrome:
Ptosis & Miosis…implies injury to the Superior Cervical Ganglion (sympathetic)