STUDY GUIDE – HEAD AND NECK

(Like always, this hits the major points of lecture. Be sure to add and supplement with your own notes and other information from the book. I will also upload another study guide from the previous SI leader this weekend – let that be a final check of what you need to go over)

Skull

· ____________ are unossified areas of the skull (baby head soft spots)- larger ant. and post.; smaller sphenoidal and mastoid- ossify b/t 6 – 36 months

· Foramen-By Cranial Nerve

Cranial Nerve

Hole

Other content

1

2

3

4

5 i

5 ii

5 iii

6

7

8

9

10

11

12

* Other foramen (p. 474)

· Mandibular nerve branches into _________ n. and _______ ________ n. (this enters into _________ foramen and becomes ________ n.)

Major Innervations

· Cervical plexus (roots = )

· Sensations to face - three branches of ____________ n.

· Mimetic m.m. - __________ n. - know major functions (i.e. expressions)- Bell’s palsy

· Masticatory muscles (4 m.m.) - ______________ n. (branch = _____________ n.)

· Neck m.m (2 m.m.) = _____________ n.- Torticollis (problem with sternocleidomastoid m.) -two types (Congenital and spasmodic): know signs, causes, etc.- CN XI test – have patient shrug shoulders (_______________ m.); if unable, then positive indication of damage

· Infrahyoid m.m. (4 m.m.) - _____________ __________ (roots = )

· Suprahyoid m.m. (4 m.m.) – don’t follow a specific pattern- digastric m.m. = hybrid muscle ant. belly - post. belly –

Other Muscle Groups

· Scalene m.m.- scalene gap made by _______ and _______ scalene m.m. -transmits:

Blood Supply

· Branches of external carotid a. (supplies “outer” head)--------

· Branches of internal carotid a. (supplies “inner” head/ brian)----

Venous and Lymphatic Drainage (p. 491)

(Review these pathways you guys get the chance. )

· Head injury may lead to large hematomas (bruises) below subaponeurotic layer infection in that layer spreading to dura via __________ v.v.(infection can also be spread via _________ diploic v.v.)

· Cavernous sinus- possible source of infection to the brain:

Regional Anatomy

(There are a lot of various regions in this unit for which it would be good to know contents. I’d focus my attention on the areas that Dr. Samsam stressed in class first. For example, the drawing on page 505 is VERY good to know. But there are others too if you guys have the time)

· Mandibular nerve block (p. 499)- inject anesthesia in ______________ fossa- extraoral approach:

- intraoral approach:

· Carotid angiography (p. 505)- X-ray diagnosis of cerebral- observe internal __________ a. with contrast medium by catheterization of _________ a.

Retropharyngeal Space

I. Thyroid gland- secretions:

- Hyperthyroidism vs Hypothyroidism?

II. Parathyroid gland- secretions:

III. Larynx- major ligaments, muslces, and cartilage?

IV. Know the paired and unpaired bones of the skull

· Paired: Temporal and Parietal bones, maxillae, zygomatic, nasal, lacrimal, palatine, and inferior nasal concha.

· Unpaired: Sphenoid ,ethmoid, frontal, occipital, vomer, mandible

V. Within the meninges, where would you find cerebral spinal fluid (CSF)? How is CSF “produced?” How is CSF recycled back into the blood? What is the importance of the choroid plexus? Where is it located?

Meninges: Dura, Arachnoid, Pia Mater

CSF located in subarachnoid space. CSF helps clean and protect the brain/spinal cord.

·

VI. Know the Clinical significance of hydrocephalus and meningitis. What causes these conditions? How are they diagnosed? How are they treated?

· Hydrocephalus is: Fluid accumulation in cranium (more common in children due to unfused skull bones)

· Diagnosis: Imaging, enlarged cranium size

· Symptoms: Seizures, enlargement of cranium

· Treatment: Shunt put in place to drain fluid.

· Meningitis is: inflammation due to infection of meninges

· Diagnosis: CSF sample via lumbar puncture to determine if infection is bacterial or viral

· Treatment: Antibiotic for bacteria, antifungal for fungus, vaccine for viral, steroids

VII. How could the facial artery and cavernous sinus be involved in the development of encephalitis or meningitis?

· facial makes anastomoses with dorsal nasal artery, dorsal nasal artery drains into the ophthalmic artery, ophthalmic artery drains into cavernous sinus, which drains into jugular, which would then be connected to subarachnoid where CSF is

VIII. Know all cranial nerves (CN), their location, function, and if they are categorized as being motor, sensory, or both regarding function

· I.

· II.

· III.

IX. What is the sensory innervation of the face?

· CN V: Trigeminal n.

X. What are the seven bones that form the eye orbit? (see color coded diagram on ppt. or pg. 169)

· Frontal, Zygmotic, sphenoid, ethmoid, lacrimal, maxilla and palatine bone

· For My Little Eyes See Z’s & P’s

XI. What is the lacrimal apparatus, and where is it located?

· It keeps the surface of the eye moist with tears (lacrimal fluid). It has a gland and ducts that drain the lacrimal fluid into the nasal cavity. Includes: Lacrimal gland , lacrimal canaliculi, lacrimal sac, nasolacrimal duct. Drains into Inf. Meatus.

XII. What are the names, locations, and innervations for the extraocular muscles?

· Sup. Oblique: moves eye diagonally (intorsion). Inn: CN IV, Trochlear n.

· Lateral Rectus: Abducts eye laterally. (CN VI, Abducens n.)

· Medial Rectus: Adducts eye medially (CN III, Oculomotor)

· Superior Rectus: (CN III, Oculomotor)

· Inf. Rectus: (CN III, Oculomotor)

· Inf. Oblique: Extorsion, everts instead of inverts the eye. (CN III, Oculomotor)

XIII. Know the Clinical significance of the following:

· Horner’s Syndrome: One constricted pupil, drooping eyelid (ptosis), and loss of sweating. Symptoms are unilateral.

· Direct and Consensual Light Reflex: Constriction of ipsilateral and contralateral pupil. Reflex may be lost due to head trauma.

· Glaucoma: The build up of fluid in the eye - can cause pressure on the nerves and can lead to nerve damage. The canals of schlemm are not able to drain properly so it increases intraocular pressure

· Cataracts:

XIV. Know the names, locations, and innervations of the muscles of mastication

· T

· M

· L

· M

XV. Know the location and function of the paranasal sinuses

· Location: Laterally to nasal bone

· Function: Purify, moisten, and add resonance to sound.

XVI. Know the contents of the middle and inner ear

· Middle ear contains:

· Inner ear is home to the:

XVII. What is the function and innervation of

· Tensor tympani:

· Stapedius muscle:

· Which is important in the development of hypercusis?

XVIII. What is Otis externa?

XIX. Chronic Otitis media?

· How is a myringotomy used to treat the latter of the two conditions?

XX. Inner ear:

· Within the inner ear, what structure is considered the organ of balance?

· Which is considered the organ of hearing?

XXI. Know the clinical significance of the following: Cleft palate and Cleft lip.

XXII. Know the locations and innervations of the following muscles: sternocleidomastoid, infrahyoid muscles, suprahyoid muscles, genioglossus, styloglossus, and hyoglossus

XXIII. What is the location, function, and hormones produced by the thyroid and parathyroid glands?

XXIV. What are the names, functions, and locations of the paravertebral muscles?

XXV. Know the blood supply and drainage of the head and neck.

Clinical tips to keep in mind

· Eye

· Direct and Consensual light reflex: constriction of ipsilateral and contralateral pupil when a light is shone into one eye. It shows the function of CN III and also the optic pathway. These reflexes may be lost in head trauma.

· Pupillary dilation due to CN III palsy may be due to tumors or an aneurysm

· Cataract: progressive degeneration and opacity of the lens which leads to impaired vision and blindness; due to the deposition of aggregated proteins

· Glaucoma: optic neuropathy, retinal ganglion cell loss, and blindness due to impaired drainage of the aqueous humor from the Schlemm’s canal. Leads to increased intraocular pressure and increased retinal blood flow

· Papilledema: when the optic disk bulges out due to increased intracranial pressure

· Ear

· “Infection of the middle ear may penetrate through roof and from mastoid cells to the meninges, then into the brain (meningitis and cerebral abscess in the temporal lobe) •Also, through the floor into internal Jugular vein (jugular thrombosis)”

· The auditory (eustachian) tube opens into the anterior wall of the tympanic cavity•It connects the middle ear to the nasopharynx and helps to equalize the pressure in the cavity

· A pressure difference of 100-150 mmHg can rupture the tympanic membrane Infection from nasopharynx can get into the middle ear through the auditory tubes.

· Otosclerosis at the edges of the oval window disturbs the movement of Stapes and is the most common cause of deafness in adults