Download Anatomy Outline Test #3

Anatomy Outline Test #3
Lec. 19,20: Muscles of Facial Mastication
Facial Muscles
Groups of Muscles
 Epicranial: wrinkle forehead, move eyebrows (frontoccipital m. )
 Orbital: close eyelids
o Obricularis oculi
 Orbital: orbits eye: elliptical arrangement of
fascicles- circles eye
 Palpebral: covers eyelid
 Origin: medial margin of orbit
 Fxn: close the eyelids, lateralmedial direction
(squeegie of tears)
 Ptosis: drooping of eyelid  corneal ulcerations from
lack of lacrimal fluid
 Nasal: dilate/flare nostrils
 Oral: change shape of mouth, posture of lips
o Many muscles insert on modiolus
o Modiolus: mobile fibromuscular mass, convergence of 9
muscles, integrating activities (dimple)
o Buccinator
 Substance of cheek
 Origins: maxilla, mandible, pterygomandibular raphe
 Insertion: modiolus, orbicularis oris
 Fxn: keeps cheek taunt (smiling, expel air when
speaking)
 Paralysis: food remains in oral cavity
o Zygomaticus major
 Fxn: elevates labrial commissures (corners of lips)
snear, smile
o Orbicularis oris: 4 quadrants  peripheral part, marginal
part  better control over mouth because of quadrants
 Crossing of fibers medially  ridges of philtrum
 Fxn: squeeze lips together
 Paralysis: drooping of corner of mouth (food dribbles
out)
Innervation
 All muscles of facial expression innervated by facial nerve
(motor)
o Longest interosseus course of any CN
o Exits sylomastoid foramen in skull  parotid gland 
parotid plexus 5 branches (temporal, zygomatic, buccal,
marginal, cervical branches)
 Trigeminal nerve (sensory)
o V1: opthalamic nerve supraorbital nerve by supraorbital
notch (test for sensory innervation)
o V2: maxillary nerve infraorbital nerve at infraorbital
foramen
o V3: mandibular nerve mental nerve at mental foramen
 Sensory and motor of muscles of mastication
Vasculature
 External carotid a.  majority of face
o facial a. (branches deep to mandible) angular a. (nose)
and superior and inferior labial a.
o  superficial temporal a. (temporal pulse)  transverse
facial a. branch
o Maxillary a. muscles of mastication, mandible, maxillay,
nose, palate, dura mater
 Opthalamic a. Internal carotid artery (medial forehead)
 Veins: Triangular Danger zone: connections form facial veins to
dural venous sinuses (valveless?)
o Superior labial vein and angular vein cavernous sinus
 Lymphatic Drainiage:
o Submandibular nodes: forehead and anterior part of face
o Submental nodes: lower lip and chin
o Pre-auricular and parotid nodes: lateral part of face
Muscles of Mastication: act on TMJ joint: only movable joint of the
head
 Temporal fossa: above zygomatic arch
 Infratemporal fossa: below zygomatic arch
 TMJ: synovial joint: articulation between head of mandible and
mandibular fossa of temporal bone (on skull)
o Fibrocartilage, weight bearing (opposite side of bite
force)
o Ligaments:
 Lateral (temporomandibular) ligament: prevents post.
Dislocation of TMJ (intrinsic, part of joint capsule)
 Sphenomandibular and stylomandibular: extrinsic
 Lateral and sphenomandibular lig. Are “swinging
hinges” for mandible
o Divided by fibrous articular disc
 Superior articular cavity: attaches disc to temporal
bone
 Loose capsule
 Gliding occurs here
 Inferior articular cavity: attaches disc to mandible
 Tight capsule
 Hinge and pivot motion occur here
o Movements of TMJ
 Gliding, hinge, pivot
 mouth open 15 deg, only hinge action= depression of
mandible (head of mandible remains in mandibular
fossa)
 mouth open >15 deg, hinge action + gliding of
mandibular head = depression and protraction of the
mandible
 physiologically dislocate jaw

mandibular head glides forward and inferior to
articular tubercle
o Grinding: one mandibular head rotates vertically (pivots)
while the other swings/glides anteriorly = lateral motion
 Movement of the Mandible
o Elevation/depression
o Protraction/retraction aka protrusion/retrusion
o Lateral excursion/medial excursion
o Mouth open 15 d
 If TMJ dislocated, usually anteriorly, mouth depressed, person
unable to close mouth, reduce by pressing on mandibular teeth
 Muscles of TMJ joint (all innervated by V3- sensory and motor)
o Temporalalis: inserts on side of cranium, inserts on
coronoid process
 Upward and backward pull
o Masseter: mashing/pounding food between molars- elevation
of mandible
 From zygomatic arch  lateral surface of angle of
mandible
o Medial Pterygoids
 Deep head
 Superficial head
 Inserts on deep surface of ramus of mandible and
lateral plate of pterygoid process (on sphenoid bone)
 Lateral movement of the jaw, some elevation
o Lateral Pterygoids
 Upper head: inserts on TMJ capsule, articular disc
 Lower head: inserts on condylar process
 Mouth opening, chief protruder of mandible (opening
mouth wide)
Lec. 22 Cranial Osteology
The Cranium
 Neurocranium: calvarium (domed roof) and skull base, direct
ossification of mesenchyme
 Viscerocranium: from cartilaginous precurstors, and direct
ossification of mesenchyme
 Norma Lateralis: pterion: area of skull where sphenoid, parietal,
frontal, temporal bone meet  thinnest part of skull, flexible
can tear middle meningeal a. (even w/o a fracture)
 Cranial Fossae: 3 steps- anteriormiddle posterior fossae
**remember 1,5,6) for the # cranial nerves in each fossa
o Anterior fossa: cribiform plate: CN1
o Middle fossa (5):
 Optic canal: CN II and opthalamic a.
 Superior orbital fissure: CN III, IV, V1, VI (eye
muscles and opthalamic branch of trigeminal nerve),
opthlamic veins
 Blowout fx
 Foramen rotundum: CN V2 (maxillary branch)
 Foramen ovale: CN V3 (mandibular)- move your mandible
open to make an “oval” with your mouth
 Foramen spinosum: middle menigneal a.
 Foramen lacerum: nothing of consequence
o Posterior fossa


Internal auditory(acoustic) meatus: CN VII, VIII,
labyrinthine a.
 CN VII  greater petrosal n. (mucosal secretion
of nose-nose bleeds)
 Bells Palsy- CN VII
 Jugular foramen: CN IX, X, XI and superior jugular
bulb (origin of internal jugular vein, and inferior
petrosal sinus)
 CN XI exits here
 If no gag reflex (choking)- CN IX
 If shoulders depressed- CN XI
 bowel sounds- CN X
 Hypoglossal canal: CN XII (hypoglossal n.)
 Foramen magnum: SC, meninges, CSF, spinal a./v,
vertebral a. , CN XI (goes into skull)
The hyoid bone: no articulations with other bones!! * attached to
the mandible, sternum, scapula, skull base via muscles
o Lesser horn, greater horn
o Speech, deglutition
Lec. 23: Craniofacial Embryology
Day 18: Prechordal plate + notochord induce overlying
neuroepitheliumneural plateneural groove
 neural tube (cranial neuropore closes first)
  neural crest cells
o Melanocytes
o DRG
o Sympathetic chain ganglia
o Chromaffin cells of adrenal medulla
o Pre-aortic ganglia
o Enteric ganglia of PNS
o Odontoblast (teeth)
o CT of eye, papillary, ciliary m.
o Truncocanal septum (separates aorta and pulmonary trunk)
o Pharyngeal arch cartilage
o Dermis/hypodermis of face/neck
o Glial cells in peripheral ganglia, schwann cells,
arachnoid, pia mater
o *Albinism, Hirshprungs (no motor ganglia in GI
tractconstipation, mega-colon)
Base of skull
 3 paired cartilages
o Prechordal cartilage  base of occipital bone
o Hypohyseal cartilage around pituitary gland (sphenoid
bone)
o Parachordal cartilage
 3 pairs of sensory capsules
o otic capsules: develop around otic vesicles
o nasal capsulesethmoid bone (nasal cavity)
o optic capsules eye
Calvaria forms by intramembranous ossification- dermal or membranous
bones (temporal, maxillary, zygomatic bones)
Cartilaginous viscerocranium
 1st PA (Merkel’s cartilage): malleolus, incus, EAM
o muscles of mastication, tensor tympani
o terminal maxillary a.
o mandible, maxillary prominences
nd
 2 PA: stapes, styloid process, hyoid bone (lesser horns, upper
horn of hyoid)
o stapedial a. (embryo)/corticotympanic a. (adult)
o stapedius muscle
o 2nd PA normally expands, fills in rest of the pharyngeal
clefts/grooves
 if problemlateral cervical sinus (fluid filled
cysts), fistulas (external/internal), “leaky baby”
 3rd PA: lower rim, greater horns of hyoid, common carotid a., roof
of internal carotid
 4th PA: Laryngeal cartilage, arch of aorta, R. subclavian a.
 6th PA: laryngeal cartilage, ductus arteriosus a.
Face

5 swellings
o Maxillary swellings (2)
o Mandibular swellings (2)
o Frontonasal Prominence (1)  nasal placodesnasal pit
 medial and lateral nasal processes
 medial processes fuse medially intermaxillary
process bridge of nose, philtrum, primary
palate
 lateral process nostrils
 ectodermal nasal sac  nasal fin (vacuolize)
oronasal membrane (separates nasal, oral cavity) 
primitive choana (opening)
 Palate
o Medial nasal processintermaxillary process primary
palate
o Maxillary processespalatine shelves (medial expansions of
maxillary processes) proliferate, fuse in midline to each
other, primary palate  seals off primary choana leaves
definitive choanae open
o Incisive foramen: little hole where primary palate meets
palantine shelves artery (hold for severe nose bleeds)
Lec. 24: Ear Anatomy
External Ear
 Auricle: concha (floor), helix (elevated margin), antihelix,
Tragus, anti-tragus
o Cervical plexus (lesser occipital C2, greater auricular
C2,C3) – majority of back of ear
o Vagus, glossopharyngeal n. (concha)
o Trigeminal n. , auriculotemporal n. (front of ear/anterior,
tragus)
o Facial n. (random dots)
 EAM: tympanic part of temporal bone
o Mandibular n. (V3), vagus n. *makes you cough when you
stimulate
o Cartilage 1/3  ceruminous, sebaceous glands
o Bony medial 2/3
 Vasculaization
o Superficial temporal  anterior auricular a.
o Posterior auricular branches
 Lymphatic drainage
o Anterior: parotid nodes  deep cervical nodes
o Posterior: Mastoid nodes deep cervical nodes
o Lower: deep cervical nodes
 Tympanic Membrane
o Gray-reddish tinge, cone of light at 5’o clock
o Pars flaccida (less collagen), pars tensa (more collagen),
malleolar stria: light colored streak
o Outer surface innervated by auriculotemporal n., facial,
vagus
o Inner surface: glossopharyngeal n. (middle ear cavity)
o Anterior tympanic a. (branch of maxillary a.)
Middle Ear/Tympanic Cavity
 Petrous part of temporal bone
 Epitympanum (attic), Mesotympanum (medial to membrane),
hypotympanum
 Roof = tegmental wall
o Tegment tympani: small piece of bone
o *unossified petrosquamous suture in kids  possible spread
of infection to cranial cavity
 Floor= jugular wall (separates it from internal jugular a. )
 Lateral wall: tympanic membrane, bony wall of epithymapnic recess
 Medial Wall= labyrinthine wall
o Separates from inner ear
o Promontory prominence (cochleatympanic plexus)
o Prominence of facial canal
o Prominence of lateral semicircular canal
o 2 openings: oval window (stapes), round window (cochlea)
 Posterior Wall=mastoid wall
o Aditus to mastoid antrum (air cells)
o Chorda tympani n. (CN VII branch) from prominence of facial
canal
 *taste to ant. 2/3 tongue, motor for salivary glands
 Anterior Wall= carotid wall
o Opening to pharyngotympanic/auditory tube (tensor tympani,
exit for chorda tympanic n.)
o Carotid canal
 Muscles
o Tensor tympani: inserts on handle of
malleoluscartilagionous part of auditory tube
 V3 branch
o Stapedius: neck of stapes to posterior wall (tightens
attachment to oval window)
 Nerve to stapedius
 Vasculature: mostly external carotid a. (branches), some internal
carotid.
 Ossicles
o First bones to ossify-mature at birth, mucous covering
Inner Ear
o Bony labyrinth (w/in otic capsule)
o Cochlea, vestibule, semicircular canals
o Membranous labyrinth
o Vestibular labyrinth
 Utricle: 3 ampullae of semicircular ducts (crista
ampularris) rotational movements of head
 Saccule: contains 2 maculae (head position, linear
acceleration)
o Cochlear labyrinth
 Cochlear duct (endolymph)  spinal organ of corti,
suspended by spiral ligament
 Scala vestibuli (upper), scala tympani (lower) 
perilymph
o
internal auditory a. (branch of AICA)- travels though IAC (w/
CN VII and VIII)
Lec. 25: Ear Embryo
o 4th-26 weeks
o Mesenchyme: from mesoblast, neural crest cells
o Placode= thickening of surface ectoderm
Inner Ear Development
o Finished my middle of fetal period
o Requires induction of mesenchyme, hindbrain, notochord  oral
placodes (on hindbrain)  invaginates otic pit 
o Statoacoustic ganglion vestibular cochlear ganglions
o Otic vesicle membranous labyrinth (except melanocytes in
stria vascularis of cochlea)
 Dorsal utricle utricle, semicircular canals
(ampulla, cristae ampularris)
 Ventral saccule saccule, cochlear duct
 Cochlear ductinner and outer ridge of
epithelial cells
o Inner ridge spinal imbus (part of spinal
lig)
o Outer ridge 1 row of inner hair cells,
3-4 rows of outer hair cells
o Membranous cochlea attached to saccule by
ductus reuniens
o Otic vesicle induces cartilaginous otic capsule
vacuolization of perilymphatic space scala vestibuli,
scala tympani (perilymph filled)
o Cartilaginous otic capsule bony labyrinth (ossification of
surrounding mesenchyme)
Middle Ear Development
o 1st PA endoderm
o pharyngeal pouch contacts 1st pharyngeal groove 1st pharyngeal
membrane=tympanic membrane
o tubotympanic recess
o
tympanic cavity: envelopes ossicles, tendons, ligaments,
nerves
o pharyngotympanic tube
o ossicles
o Mastoid Antrum: mastoid cells don’t develop until 2 y/o
External Ear Development
o EAM: 1st pharyngeal groove/cleft (ectoderm)  meatal plug (solid
epithelial plate) central cells degenerate  internal part of
EAM
o Tympanic membrane
o Ectoderm
o Endoderm
o Mesoderm
o Auricle: auricular hillocks on PA 1&2
o Fusion of auricular hillocks
 CN V (auricular temporal nerve from PA 1)
 Cervical plexus n. (PA 2)
o **Expect chromosomal abnormalities w/ ear anomalies!!!
Lec. 25: Eye and Orbit
Eyelids (Palpebrae)
 skin
 subcutaneous tissue
 orbicularis oculi m- palpebtral part
 Tarsus and orbital septum
o Tarsus: thickenings of orbital septum, strengthens eyelids,
contains Meibomian glands that secrete oily substance
o Orbital septum: thin membrane, spans orbital opening
between margins of orbit and tarsi
 Palpebral conjunctiva
Lacrimal Apparatus
 Lacrimal gland (has its own fossa)  bactericidal nourishing
fluid (because the cornea is avascular)
 Accessory ducts
o Lacrimal glandexcretory ducts spreads across
conjunctivalacrimal puncta (holes) lacrimal
caniliculilacrimal sac (own fossa) nasolacrimal duct
 Innervation: sensory, sympathetic, parasympathetic
Innervation of the eye:
 CN II: only sensory (though optic canal)
 CN IV, VI: only motor
o CN IV: superior oblique
o CN VI: lateral rectus
o Enter via superior orbital fissure
 CN III, V, VII: motor and sensory
o CN III: occulomotor
 Through superior orbital fissure
 Superior: superior rectus, levator palpebrae
superioris
 Inferior: medial rectus, inferior rectus, inferior
oblique
 Also carry parasympathetics to smooth muscle of
ciliary body/iris
o V2: Maxillary N.
 Infraorbital nerve (goes though infraorbital
fissureinfraorbital canalinfraorbital
foramensensory to face)
o V1: opthlamic n.
 Superior orbital fissure
 3 branches:
 Frontal n. – largest branch supraorbital and
supratrochlear nerves (sensory to forehead)
 Lacrimal n.
 Nasociliary n.
o Enters via common tendinous ring
o ethmoid nerves (sensory to nasal cavity)
o long ciliary nerves (sympathetics to
dialator pupilae)
 Short ciliary n. (from ciliary ganglion):
sensory/parasympathetic, sympathetic
Extraocular muscles
 Fascial sheath: fascia of extraoccular muscles=periosteum of
orbit
 7 extraocular m.
o
o
o
o



4 rectus muscles
2 oblique muscles
Levator palpebrae superioris: most superior muscle in orbit
All muscles originate on common tendinous ring EXCEPT
inferior oblique
o All innervated by CN III EXCEPT CN IV: superior oblique,
and CN VI: Lateral abducens
Movements of eyeball
o Vertical: abduction/adduction
o Transverse: Elevation/Depression
 If gaze @ ocular axis: superior rectus elevates,
inferior rectus depresses
 If gaze in vertical plane: inferior oblique elevates,
superior oblique depresses
o A/P: Lateral/medial
o If at any other angle
 Superior rectus: MAddE “superior Maddy” – Medial
rotation, adduction, elevation
 Inferior rectus: LAddD: inferior “lad” – Lat.
Rotation, Adduction, depression
 Superior oblique: MAD: Medial rotation, abduction,
depression
 “got MAD because they got abducted because they
were oblique/not normal”
 Inferior Oblique: LAE: Lat. Rotation, Abduction,
Elevation
Blood supply
o Internal carotid Opthalamic a. (through optic canal)
 supraorbital, supratrochlear, dorsal nasal a. 
face
 central a. of retina (in optic n)
 lacrimal a.
 ethmoid a.
Venous Return
o Superior and inferior opthlamic veinssuperior orbital
fissurecavernous sinus
Lec. 26: Development of the Eye
Week 4 (Day 22)-Week 20 (not able to see well at birth)
Eye development
 Comes from
 neuroectoderm (forebrain) = retina, optic n.
o optic stalkoptic nerve
o optic cup retina
 Mesenchyme = choroid, sclera
 Surface ectoderm of head= cornea, lens
 Optic grooves/sulci on side of forebrain (inside of neural folds)
 evaginates to form diverticulum optic vesicles (project into
mesenchyme)  optic stalk and optic cup (double walled)
o Optic cup:
 outer, thinner layer pigmented layer of retina

inner, thicker layer neural layer of retina
(neuroepithelium)
Lens Development
 Optic cup induces lens placode on surface ectoderm invaginates
lens vesicles lies w/in optic cup
 3 layers of lens
o basil lamina of surface ectoderm lens capsule
o anterior lens epithelium subcapsular epithelium (cuboidal)
o posterior lens: Primary lens fibers (last lifetime)
equatorial zone of lens secondary lens fibers (adds to external
sides of primary lens fibers)
Choroid Fissure
 Invagination in optic stalk and cup (on ventral surface) 
choroid/retinal/optic fissure (also contains vasculature for
hyaloids a. )
 Hyloid a. supplies blood to inner optic cup and lens vescile
obliterates except for central a. of retina (since lens is
avascular)
 Fissure fuses pupil and optic n. (as neural cells proliferate,
obliterate lumen)
Ciliary Body
 Stroma (muscle, CT)= from mesenchyme (edge of optic cup)
 2 layered epithelium (continuous w/ 2 layers of retinal
epithelium and iris)
 Outer layer of optic cup pigmented layer
 Inner layer of optic cup nonpigmented layer (neural retina)
Iris
 Most anterior part of vascular coat
 Contractile diaphram  pupil
 Highly vascularized CT stroma
 2 layered pigmented epithelium (continuous w/ 2 layers of
retina/ciliary body)
 stroma of iris: neural crest mesenchyme
 epithelium of iris inner and outer layers of optic cup
Cornea
 sclera and cornea from mesenchyme (neural crest)
 3 layers of cornea:
o corneal epithelium (from surface ectoderm)
o stroma (from mesenchyme)
o corneal endothelium (neural crest cells)
Eyeball
 Anterior segment: aqueous humor, circulating
o Anterior and posterior chambers
 Posterior segment: vitreous body, filled w/ vitrous humor by age
4/5, stagnant
Eyelids
 Mesenchyme
 2 cutaneous folds of ectoderm
 lids adhere to each other, remain closed until 26-28 weeks