Head & Neck: Skull, Face, Eye & Ear Flashcards
(113 cards)
1
Q
What is the skull composed of? & what are the 2 parts?
A
- Composed of 22 bones
- Divided into two parts:
o Neurocranium
o Viscerocranium
2
Q
How many bones is the neurocranium composed of? & function?
A
8
houses brain
3
Q
How many bones is the viscerocranium (facial bones) composed of? & function?
A
14
houses organs of face
4
Q
What are the bones of the Neurocranium?
A
Two paired bones (n=4) 1. Parietal
2. Temporal
Four singular bones (n=4)
3. Frontal
4. Occipital
5. Sphenoid
6. Ethmoid
5
Q
Describe the Newborn skull and Sutures/Fontanelles
A
- Flat bones of the neurocranium are separated by narrow seams of connective tissue called sutures
- At points where more then one bone meets is called a fontanelle
(imp. for when babies are born (helps to tell if something is wrong with them & is imp. to be overlapped (cone head when born)
6
Q
What is a fontanelle?
A
At points where more then one bone meets
7
Q
Anterior fontanelle closes by ____ months and posterior closes by ____ months of age
A
18
2
8
Q
What is Craniosynostosis?
A
- Premature closure of one or more CRANIAL SUTURE
- 1 in 2500 live births
- More common in males
9
Q
Early closure of _______ ______ results in skull becoming long and narrow (scaphocephaly; 57% of cases)
A
sagittal suture
10
Q
Early closure of _____ _____ results in skull becoming short (brachycephaly; 30 % of cases)
A
coronal suture
11
Q
What is the Craniosynostosis treatment? What are the benefits?
A
- Corrected by surgery (>1 yr)
- Molding helmet worn
- help protect skull as it corrects itself
- help mould skull in a rounded shape
12
Q
What is flat head in babies?
A
when baby lies on back for too long but isn’t a premature closure of sutures
13
Q
What are the bones of the Viscerocranium?
A
Bones of the Viscerocranium (n=14): Six Paired bones (n=12)
1. Nasal
2. Zygomatic
3. Lacrimal
4. Maxilla
5. Inferior conchae (*independent bones - gives underlying shape)
6. Palatine
Two Singular bones (n=2)
7. Vomer
8. Mandible (*develops as 1 bone - not 2 that come together)
14
Q
Describe the muscles of facial expressions
A
- From skull to skin
- Sphincters and dilators (closing & opening various places)
- 17 different muscles of facial expression
- *All innervated by the FACIAL NERVE (CN VII) (exits via the STYLOMASTOID FORAMEN) - 1 main gland that splits to go to other places
15
Q
Facial expressions are all innervated by the…
A
Facial nerve (CN VII) (exits via the stylomastoid foramen)
- 1 main gland that splits to go to other places
16
Q
Muscles of Facial Expression: Frontalis
A
- ELEVATES eyebrows and WRINKLES skin on forehead; PROTRACTS scalp
- Expression: Surprise/Curiosity
17
Q
Muscles of Facial Expression: Orbicularis Oculi (orbital sphincter)
A
Closes the eyelids
- Protection
- Moistens eyes by
spreading tears
Blinking, Sleeping, (both use palpebral - passive closing) Winking, Squinting (both use orbital & palpebral)
2 parts: Orbital part & Palpebral part (refers to eyelid)
18
Q
Muscles of Facial Expression: Orbicularis Oris (oral sphincter)
A
Closes oral fissure
* Compresses and protrudes lips
(kissing)
* Resists distention (when blowing)
Attaches into the ANGLE OF THE MOUTH
19
Q
Muscles of Facial Expression: Buccinator
A
- Compresses cheeks against teeth
- Works with tongue to keep food
out of oral vestibule - Resists distention when blowing; suckling
(sits behind mouth)
*NOT a muscle of mastication
babies get big buccinator muscles when they’re eating
20
Q
How would you test facial nerve function?
A
Facial expressions!
Frontalis - crease up the forehead
Orbicularis - keep eyes closed against resistance
Elevators & Depressors of the lips - reveal the teeth
Orbicularis Oris - squeeze lips together
(have to do all of these to see if facial nerve is working/functioning)
21
Q
What is Botox?
A
Botox is botulinum toxin, produced by the bacteria Clostridium botulinum
Powerful neurotoxin that prevents neurotransmitter release and paralyzes muscles (i.e. paralyzing facial nerves - so it’s smooth)
22
Q
What is Botox used to treat? What about cosmetically?
A
Used to treat muscle stiffness, muscle spasms, excessive sweating, overactive bladder, or loss of bladder control, and chronic migraine headaches
Cosmetically used to reduce the appearance of wrinkles by paralyzing muscles of the face
23
Q
What are the Muscles of Mastication?
A
Mastication = Chewing
Four Muscles:
1. Temporalis
2. Masseter
3. Lateral Pterygoid
4. Medial Pterygoid
(1st two are Superficial & last 2 are Deep)
24
Q
What are Muscles of Mastication innervated by?
A
Innervated by the MANDIBULAR BRANCH (CN V3) of the TRIGEMINAL NERVE
- only CN that does motor function
25
Functions of the Muscles of Mastication: Close mouth
Masseter, Temporalis, Medial pterygoid
26
Functions of the Muscles of Mastication: Open mouth
Lateral pterygoid (pulling it anteriorally)
27
Functions of the Muscles of Mastication: Protrusion
Lateral pterygoid, Masseter, Medial pterygoid
(pull open jaw forward)
28
Functions of the Muscles of Mastication: Retrusion
Temporalis
(pull jaw backwards)
29
What is the External Carotid Artery?
Supplies blood to the head OUTSIDE of the cranium
Anastomoses between the internal & external carotid artery
30
What are the branches of the External Carotid Artery?
Branches:
1. Superior Thyroid a.
2. Ascending Pharyngeal a.
3. Occipital a.
4. Lingual a. (goes to tongue)
5. Facial a.
6. Posterior Auricular a.
7. Maxillary a.
8. Superficial Temporal a. (see it on side of forehead when someone mad it sticks out for ex)
Left Internal Carotid a.
Left External Carotid a.
Left Common Carotid a.
31
What are the Veins of the Face?
1. Superficial Temporal vein
2. Maxillary vein
3. Retromandibular vein
(Ant. & Post. Branches)
- vein that's behind mandibular
4. Facial vein
4a. Angular vein
5. Internal Jugular
6. Posterior Auricular vein
7. External Jugular
*study slide 19
32
What is the Orbit?
houses the eyes
* Comprised of 7 bones
* Floor and medial wall are thin (sinuses) while roof and lateral wall are strong
33
What are the 7 bones that the Orbit is comprised of?
1. Frontal
2. Ethmoid
3. Palatine
4. Lacrimal (has hole that drains)
5. Maxilla
6. Sphenoid
7. Zygomatic
34
Describe Orbital Blowout Fractures
* Fracture of an orbital wall with an intact orbital margin
* Commonly occurs in FLOOR OF ORBIT formed by maxilla
* Often present with EXOPHTHALMOS (protrusion of eye from orbit)
TREATMENT: Reconstruction with titanium mesh
(floor blowouts b/c v. thin spot)
35
What are the Fissures & Foramina?
Optic Canal
- CN II, Ophthalmic A (comes through it)
Supraorbital Notch
- Supraorbital Nerves & Vessels
Nasolacrimal Canal
- Nasolacrimal Duct (tears drained from eye to nose)
Infraorbital Foramen
- Infraorbital Nerve & Vessels (pop out here - exit)
Inferior Orbital Fissure
- Infraorbital Nerve & Vessels (enter)
Superior Orbital Fissure
- CN III, CN IV, CN V1, & CN VI, Superior & Inferior ophthalmic veins
36
What are the functions of eyelids?
1. Protect from injury, irritation, & excess light 2. Maintain moist cornea (b/c it doesn't get any nutrients from things other than tears)
37
What are the Orbital Muscles to Eyelid?
* Orbicularis Oculi
o ORBITAL part: close eye TIGHTLY
o PALPEBRAL part: close eyelid GENTLY
* Levator Palpebrae Superioris (LPS)
o Elevates superior eyelid
o Innervation: Oculomotor Nerve (CN III)
(*only have muscle for upper lid not lower b/c lower can open by gravity)
38
What is the Lacrimal Apparatus?
LACRIMAL GLAND produces lacrimal fluid (tears)
Lacrimal fluid drains through LACRIMAL PUNCTA and LACRIMAL CANALICULI to LACRIMAL SAC
NASOLACRIMAL DUCT then conveys fluid from lacrimal sac to nasal cavity
(from lateral side to medial side of body)
39
Runny nose when crying is caused by tears draining through the ______ ____ into nasal cavity
nasolacrimal duct
40
Parasympathetics: _______ lacrimal gland secretion - ______ Nerve (CN ____)
STIMULATE
FACIAL
VII
41
Sympathetics: ______ production of tears – ______ ________ ____
DECREASE
T1-2 Sympathetic chain (any symp. are coming from T1-2 always!)
42
What are the 3 layers of the eyeball?
1. Outer fibrous layer
2. Middle vascular layer
3. Inner layer
43
Outer fibrous layer of eyeball contains:
Sclera, Conjunctiva & Cornea
44
Middle vascular layer of eyeball contains:
Choroid, Iris, & Ciliary Body
45
Inner layer of eyeball contains:
Retina
46
Sclera:
* Tough & opaque
* Attachment site for extraocular muscles
47
Cornea:
* Transparent
* Completely avascular
* Very sensitive to touch
* Sensory via OPHTHALMIC NERVE (CN V1)
*PRIMARY REFRACTORY MEDIUM OF EYE
*can test cornea but holding a cotton ball close to it
48
Conjunctiva:
* Transparent mucous membrane (like plastic wrap)
* Covers eyelid and sclera
* Well vascularized
(blood vessels dilate!)
conjunctivitis = pink eye!
49
Choroid:
* Pigmented layer between sclera & retina
* Contains DENSE NETWORK OF BLOOD VESSELS
- lot of blood gets to eye & is imp. (why eyes look red in photo)
50
Iris:
* Thin, circular structure responsible for controlling the diameter & size of the PUPIL
* Pigmentation determines eye color
2 muscles: sphinctor pupillae & dilator pupillae (imp. to let light in eye)
51
Sphincter pupillae:
* Circular muscle that CONSTRICTS pupil
* PARASYMPATHETIC INNERVATION: CN III
52
Dilator pupillae:
* Radially arranged muscle that DILATES pupil
* SYMPATHETIC INNERVATION: T1-2 sympathetic fibers
(make pupil bigger)
53
What is the Pupillary Light Reflex?
Sensory: OPTIC NERVE (CN II)
Motor: OCULOMOTOR NERVES (CN III) to
SPHINCTER PUPILLAE (constrict)
Normal Response: BOTH PUPILS CONSTRICT
(light hits optic nerve & both eyes should contract)
54
CN II Damage:
(to optic nerve)
Absent reflex in BOTH eyes when light shined into affected eye (neither eye will constrict)
55
CN III Damage:
(to oculomotor nerves)
Reflex ABSENT ON INJURED SIDE, but present on unaffected eye when light shined into affected eye
56
Ciliary Body:
Ring like thickening of vascular layer which connects CHOROID with edge of IRIS and provides attachment for lens
- ciliary muscle
- ciliary processes
- zonular fibers
57
Ciliary muscle:
changes shape of lens (ACCOMMODATION)
- change lens shape to see close/far away
58
Ciliary processes:
secrete AQUEOUS HUMOR (clear fluid filling front of eye)
- b/c light travels through liquid quicker
59
Zonular fibers:
connect lens to the ciliary muscle
60
What is Accommodation?
* Thickening of LENS in response to looking at something close to your eyes
* Lens becomes Round to Read
* Accomplished by CILIARY MUSCLES which adjust the shape of LENS to best focus light onto the retina
61
What is the Sympathetic Innervation of Accommodation?
* Ciliary muscle RELAXES, increases its diameter
* Zonular fibers TENSE, stretching the lens
* Flat for Far vision
62
What is the Parasympathetic Innervation of Accommodation?
* Ciliary muscle CONTRACTS (VIA CN III), deceases its diameter
* Zonular fibers RELAX, allowing lens to rebound to a more spherical shape
* Round for Reading vision
63
What are the parts of the inner layer - Retina?
- Pigmented layer
- Neural layer
- Optic disk
- Fovea
- Macula
64
Pigmented layer:
* Single layer of pigmented cells
* Helps absorb excess light
* Adjacent to the choroid
65
Neural layer:
* Layer of rod (b&w) & cone (colour) receptors
* Info sent from rods & cones to OPTIC NERVE (CN II)
* Superficial to the pigmented layer
66
Optic disc:
o Where nerves & vessels conveyed by
OPTIC NERVE (CN II) enter the eye
o No photoreceptors --> BLIND SPOT!
67
Fovea:
o Sharpest and colored vision
o Rich in cone receptors
68
Macula:
o Functional center of the eye (processing)
69
What are the Chambers of the Eye?
- Anterior Chamber
- Posterior Chamber
- Canal of Schlemm
- Vitreous Chamber
70
Anterior Chamber:
BETWEEN CORNEA & IRIS
AQUEOUS HUMOR supplies oxygen & nutrients to the posterior side of cornea
71
Posterior Chamber:
BETWEEN IRIS & LENS
AQUEOUS HUMOR is produced by ciliary processes & flows through pupil to anterior chamber
72
Canal of Schlemm:
drains excess AQUEOUS HUMOR
-b/c we don't want a buildup/too little fluid
73
Vitreous Chamber:
BETWEEN LENS & RETINA
Contains VITREOUS HUMOR which holds the retina in place & supports lens
74
Retinal detachment...
not enough vitreous chamber?
75
What are the Extraocular Movements?
- Intorsion (medial rotation)
- Extorsion (lateral rotation)
- Lateral Rectus (LR)
- Medial Rectus (MR)
- Superior Rectus (SR)
- Inferior Rectus (IR)
- Superior Oblique (SO)
- Inferior Oblique (IO)
76
Intorsion (medial rotation):
pupil rotates in place while SUPERIOR PART OF EYE MOVES TOWARDS THE NOSE
77
Extorsion (lateral rotation):
pupil rotates in place while SUPERIOR PART OF EYE MOVES AWAY FROM THE NOSE
78
Eyes can move ______
independently (doesn't have to be in sync)
79
Lateral Rectus (LR):
Innervation: Abducens N. (CN VI)
Action: ABDUCTS EYE
(pull out laterally)
80
What does Abducens Nerve (CN VI) Damage look like?
looks like one eye looking toward nose (b/c asked to look straight)
81
Medial Rectus (MR):
Innervation: Oculomotor N. (CN III)
Action: ADDUCTS EYE
(rectus - straight)
82
Superior rectus (SR):
Innervation: Oculomotor N. (CN III)
Primary Action: ELEVATES EYE
Secondary Actions: Adducts & Intorts eye
83
Inferior rectus (IR):
Innervation: Oculomotor N. (CN III)
Primary Action: DEPRESSES EYE (or look down)
Secondary Actions: Adducts & Extorts eye
84
Superior Oblique (SO):
InnervaMon: Trochlear N. (CN IV)
Primary Action: INTORTS EYE
Secondary Actions: Abducts & depresses eye
(when asked to look to right they pull inwards & upwards)
85
Inferior Oblique (IO):
Innervation: Oculomotor N. (CN III)
Primary Action: EXTORTS EYE
Secondary Action: abducts & elevates eye
86
Oculomotor Nerve (CN III) Palsy CAUSE
Nerve compression or rapidly increasing ICP
87
Oculomotor Nerve (CN III) Palsy SYMPTOMS
PTOSIS: nonfunctioning LEVATOR PALPEBRAE SUPERIORIS
- droppy eyelid
EYE ABDUCTED & DIRECTED INFERIORLY: unopposed LR & SO
DILATION OF PUPIL: DILATOR PUPILLAE UNOPPOSED (no pupillary light reflex on affected side)
NO ACCOMMODATION: CILIARY MUSCLE PARALYZED
("Down & Out" Pupil)
88
What is the Clinical Testing of Extraocular Muscles (EOM)?
Have patient follow H-shaped pattern: allows for isolation of EOM & their nerves
- isolates each muscle independly to test them individually)
* When the eye is initally ABDUCTED by LR, only SR and IR can produce ELEVATION and DEPRESSION, respectively
* When the eye is ADDUCTED by MR, only the IO & SO can produce ELEVATION & DEPRESSION, respectively
89
A helpful way to remember the innervation of the EOM is LR6SO4AO3
Lateral Rectus (CN VI), Superior Oblique (CN IV), and All Others (CN III)
90
What are the 3 parts of the ear?
- External Ear
- Middle Ear
- Inner Ear
91
External ear parts:
- Auricle
- External Acoustic Meatus
- Tympanic Membrane
92
Auricle:
Directs sounds down into the ear
93
Tympanic Membrane:
Separates external ear from middle ear
94
External Acoustic Meatus:
Vibrates with sound wave & transmits vibrations to ossicles in middle ear
95
Middle Ear parts:
- Pharyngotympanic Tube
- Tympanic Membrane
- Malleus
- Incus
- Stapes
- Oval Window
96
Pharyngotympanic Tube:
- Connects the TYMPANIC CAVITY with the NASOPHARYNX
(sources of ear infections)
97
What is the Middle Ear function:
- EQUALIZES PRESSURE in the middle ear with atmospheric pressure
(vibrates appropriately so we can hear)
- Allowing FREE MOVEMENT of the TYMPANIC MEMBRANE
98
What is Otitis Media?
Infection of the middle ear, often secondary to an upper respiratory infection
99
What is Otitis Media's symptoms?
Ear pain
Diminished hearing
100
What is Otitis Media's Physical Exam Findings?
RED, BULGING TYMPANIC MEMBRANE
Auricle nontender to palpation
101
What is Otitis Media's treatment?
Oral antibiotics
Myringotomy (chronic infections)
102
What age is Otitis Media more common in & why?
More common in children due to their shorter/ more horizontal pharyngotympanic tube
103
Inner Ear:
*Embedded in the petrous part of the temporal bone
104
What is the function of the Inner Ear?
* Reception of sound
* Maintenance of balance
105
What is the Cochlea?
* Snail shell-shaped bony cavity in the inner ear
* The cochlea contains the fluid-filled
COCHLEAR DUCT
* Fluid in the COCHLEAR DUCT is displaced as sound waves move from the middle to inner ear
Fluid displacement is sensed by hair cells and transmitted to the COCHLEAR DIVISION of CN VIII (that info is then sent to the brain)
106
Fluid displacement is sensed by hair cells and transmitted to the ____ ____ of CN ___ (that info is then sent to the brain)
COCHLEAR DIVISION
VIII
107
What are the steps for Sound Transmission?
Sound waves -->
Auricle/External Acoustic Meatus --> Tympanic Membrane --> Ossicles (Malleus --> Incus --> Stapes) --> Oval Window --> Fluid in cochlea --> Sensory cells along cochlear duct --> Cochlear Nerve --> Brain
108
What is the Vestibular System?
Controls posture, co-ordinates body, head, and eye movements, maintains balance, and spatial orientation
109
What are the 2 parts of the Vestibular System?
1. Semicircular Canals
2. Vestibule (Saccule and Utricle)
Both send information
to the brain via the VESTIBULAR DIVISION of
CN VIII
110
Semicircular Canals:
* 3 fluid-filled loops within the bony labyrinth situated at right angles to each other
111
What is the function of the Semicircular Canals?
Detects rotational movements of the head
112
Vestibule (Saccule & Utricle):
* Small oval chamber in the bony labyrinth between the cochlea and semicircular canals
113
What is the function of Vestibule (Saccule & Utricle)?
Detect LINEAR ACCELERATION/DECCELERATION of
the head (forward/backward and up/down)
(activated while we're driving so we don't move & car does)
