Chapter 8 pt1: Head and Neck Flashcards by Michelle Krebs

cranial cavity
2 ears
2 orbits
2 nasal cavities
oral cavity
air filled paranasal sinuses
hard and soft palates

head and neck

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continuous with the nasal cavity

air filled paranasal sinuses

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separate the nasal and oral cavities

hard and soft palates

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posterior to upper jaw

- acts as a conduit for the mandibular nerve between cranial and oral cavities

infratemporal fossa

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just posterior to upper jaw

- communicates with: cranial cavity, infratemporal fossa, the orbit, nasal and oral cavities

Pterygopalatine fossa

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passes through the pterygopalatine fossa

maxillary nerve

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contains unique muscles that move the skin relative to underlying bone

the face

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also open and close openings to orbits and oral cavities

face muscles

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covers the superior, posterior, and lateral regions of the head

scalp

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extends between the head and thorax

neck

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extends higher than the anterior neck

posterior neck

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is made up by the top of the sternum, clavicle, and acromion

inferior border of the neck

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what are the 4 major compartments of the neck?

vertebral
visceral
two vascular

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houses musculoskeletal elements

vertebral compartment of neck

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houses glands and structures associated with the respiratory and digestive systems

visceral compartment of the neck

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house major blood vessels and vagus nerve

two vascular compartments of the neck

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are specialized structures associated with the respiratory and digestive tracts
are joined by the laryngeal inlet

larynx and pharynx

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connects the esophagus to the oral and nasal cavities

pharynx

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joins the trachea to the pharynx

larynx

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connected by sutures

most bones of the skull

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fibrous immovable joints

sutures

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found on each side of the head

3 pairs of synovial joints

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synovial joints on each side of the head

The temporomandibular joint and 2 between the 3 inner ear bones

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are large unossified gaps between bones

- fetuses and newborns have them

fontanelles

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are modified for moving the head

CI and CII

form the boney framework of the neck

the 7 cervical vertebrae

have posterior and anterior tubercles on their transverse processes

cervical vertebrae

- is small and U-shaped bone, found just superior to the larynx - free floating and attaches the floor of the mouth, larynx, and pharynx

hyoid

forms the base of the U of hyoid bone

the body

form the arms of the hyoid bone

the greater horns

is a soft tissue flap-like structure that hangs off the hard palate

soft palate

opens directly into the base of the neck

The superior thoracic aperture (thoracic inlet)

opens into the base of the neck

axillary inlet

what are the two important vertebrae

CIII-CIV and CV-CVI

bracket the larynx and mark the bifurcation of the common carotid artery

CIII-CIV and CV-CVI

anterior to the digestive tract

larynx and trachea

how can the larynx and trachea be assessed in cases of emergency?

cricothyrotomy (through the cricothyroid ligament) and a tracheostomy

- 12 pairs | - innervate structures in the head

cranial nerves

also innervates viscera

vagus (CN X) nerve

leave the brain in CN III, VII, IX, X

Parasympathetic fibers

leave these nerves and join CN V

Parasympathetic fibers from CN III, VII, IX

leaves head and neck

CN X

how many cervical nerves?

8 (C1-C8)

form the cervical plexus

Anterior rami of C1-C4

form the brachial plexus

Anterior rami of C5-C8

innervates: strap muscles, skin on anterior and lateral neck, skin on upper thoracic wall, skin on inferior parts of head

cervical plexus

innervates upper limb

brachial plexus

pass through the oropharynx

food and air

what can food NOT enter?

trachea

seal the mouth when food or liquid are in the mouth

oropharyngeal isthmus and tongue

- can pass through the nose and mouth | - can pass just through the nose with food in the mouth

air

closes the laryngeal inlet when swallowing

epiglottis

raised superiorly which allows suckling and nasal breathing

Larynx of infants

divide the neck into anterior and posterior triangles

trapezius and sternocleidomastoid

between the thorax and head

anterior triangle

between the thorax and the arm

posterior triangle

how many bones are in the skull?

22 bones

- covers cranial cavity that houses the brain | - upper dome

calvaria

the facial skeleton or viscerocranium

lower part of skull

provide passage ways for blood vessels and nerves

foramen of skull

- shows many of the face bones | - shows maxilla, sphenoid, vomer, zygomatic, and occipital bones

anterior view of skull

shows many of the sutures between skull bones

lateral view of skull

what are the structures seen on the lateral side of skull?

- zygomatic arch - temporomandibular joint -mastoid and styloid processes - external acoustic meatus

shows the parietal, temporal, and occipital bones

posterior view of skull

what are the structures of skull in the posterior view?

- external occipital protuberance - superior and inferior nuchal lines - external occipital crest

sometimes exist within the sutures

sutural bones

shows the top of the calvaria- frontal, parietal and occipital bones and sutures between cranial bones

superior view of skull

- Consists of layers of dense internal and external compact bone - Middle layer is made up of spongy bone- diploe

bone of calvaria

what are the structures of the skull in the anterior view?

- hard palate - pterygoid process - zygomatic arch - mandibular fossa - foramen magnum - occipital condyles

what are the external foramina of the anterior view of the skull?

- supra orbital foramen - infra orbital foramen - mental foramen

passes through the supra-orbital foramen

Supra-orbital nerve and vessels

passes through Infra-orbital foramen

infra-orbital nerve and vessel

passes through mental foramen

mental nerve and vessel

what is the external foramina of the skull in the lateral view?

Zygomaticofacial foramen

passes through Zygomaticofacial foramen

Zygomaticofacial nerve

what is the external foramina of the skull in the superior view?

Parietal foramen

passes through the Parietal foramen

emissary vein

what are the external foramina of the skull in the interior view?

- incisive foramen - greater palatine foramen - less palatine foramen - pterygoid canal - foramen ovale - foramen lacerum - carotid canal - foramen magnum - condylar canal - hypoglossal canal - jugular foramen - stylomastoid foramen

passes through incisive foramen

Nasopalantine nerve; sphenopalatine vessels

passes through greater palatine foramen

Greater palatine nerve and vessel

passes through lesser palatine foramen

Lesser palatine nerve and vessel

passes through pterygoid canal

pterygoid nerve and vessel

passes through foramen ovale

Mandibular nerve (V3); lesser petrosal nerve

passes through foramen lacerum

filed with cartilage

passes through carotid canal

Internal carotid artery and nerve plexus

passes through foramen magnum

Continuation of brainstem and spinal cord, vertebral arteries and nerve plexuses, anterior spinal artery, posterior spinal arteries, roots of accessory nerve (XI), meninges

passes through condylar canal

emissary

passes through hypoglossal canal

Hypoglossal nerve (XII), vessels

passes through jugular foramen

Internal jugular vein, inferior petrosal sinus, glossopharyngeal nerve (IX), vagus nerve (X), accessory nerve (XI)

passes through stylomastoid foramen

facial nerve (VIII)

has: frontal crest, groove for sagittal sinus, and granular foveolae

inner surface of the calvaria roof

- divided into anterior, middle, posterior fossa | - above the nasal cavity and orbits and houses the frontal lobes

Floor of Calvaria (Anterior Cranial Fossa)

elevated in the midline and lateral to this the greater wing of sphenoid form depressions

middle cranial fossa

housed in the sella turcica

pituitary gland

- Formed largely by the occipital bone | - Obvious structures include: the foramen magnum, internal occipital crest, and internal occipital protuberance

Posterior Cranial Fossa of Calvaria

pass into the posterior cranial fossa

formina

surrounded by 3 meninges (dura, arachnoid, pia)

brain

has 2 layers (periosteal and meningeal layer)

cranial dura mater

has 1 layer (meningeal)

spinal dura mater

separates to form 2 unique structures- dural partitions, intracranial venous structure

cranial dura

project into the cranial cavity

dural partitions

what are the dural partitions of the cranial cavity?

- falx cerebri (between cerebral hemispheres) - tentorium cerebelli (between cerebellum and cerebrum) - falx cerebelli (between cerebellar hemispheres) - diaphragm sella (covers hyophyseal fossa of sella turcica)

travels in the outer periosteal layer of dura

Arterial supply of dura mater

consists of anterior, middle, accessory, and posterior meningeal arteries

outer periosteal layer of dura mater

the largest and supplies the greatest part of the dura

middle meningeal artery

give rise to anterior, middle, and posterior meningeal arteries respectively

ethmoid, maxillary, and occipital arteries

what is the innervation of the dura mater by?

small meningeal branches from: CN V1, 2, 3 , X, and the 1st, 2nd, and sometimes 3rd cervical nerves

innervated by branches of CN V1, 2, 3

Dura mater of the anterior and middle cranial fossae

innervated by the 1st, 2nd, and 3rd, cervical nerves

Dura mater of the posterior cranial fossa

thin membranes that are found deep to the dura

Arachnoid and pia mater

the only naturally occurring space and is filed with CSF

subarachnoid space

returns to the venous system via arachnoid granulations which project into the superior sagittal sinus

CSF

divided up based on development and adult structures

the brain

becomes the cerebral hemispheres

telencephalon

becomes the thalamus and hypothalamus

Diencephalon

becomes the midbrain

Mesencephalon

becomes the cerebellum

Metencephalon

becomes medulla oblongata

Myelencephalon

receives blood from the internal carotid and vertebral arteries

brain

meet in the cranial cavity to form the cerebral arterial circle

internal carotid and vertebral arteries

enter the cranial cavity through the foramen magnum

2 vertebral arteries

enter the cranial cavity through the carotid canals

internal carotids

join to form the basilar artery

vertebral arteries

gives off: anterior inferior cerebellar, pontine, superior cerebellar, and posterior cerebral arteries

basilar artery

give off: ophthalmic, posterior communicating, middle and anterior cerebral arteries

internal carotids

begins as small venous channels that lead to cerebral and cerebellar veins

Venous drainage of the brain

drain into the dural venous sinus

Cerebral, cerebellar, emmissary, and diploic veins

eventually drains into the internal jugular vein

dural venous sinus

what are the dural sinuses?

- superior sagittal - inferior sagittal - straight - transverse - sigmoid - occipital sinuses - confluence of sinuses - the cavernous - sphenopariteal - superior and inferior petrosal - basilar sinuses

found on either side of the sphenoid bones

paired cavernous sinuses

pass through the cavernous sinus

Internal carotid and abducent nerve

pass through walls of the cavernous sinuses

Occulomotor, trochlear, ophthalmic, and maxillary nerves

pass through foramina or fissures of the skull

12 pairs of cranial nerves

All pairs of cranial nerves except for the............extend off the brain

hypoglossal nerve

what are the components of the cranial nerves?

- somatic component - visceral component - sensory component - special motor component

numbered I-XII, starting anteriorly with the olfactory nerve and moving posteriorly ending with the hypoglossal

cranial nerves

conveys emotional information and is an important cue for a physician

face

- develop from the 2nd pharyngeal arch and are innervated by the facial nerve (CN VII) - They are in superficial fascia, with origins from either bone or fascia and insert into skin

muscles of face

orbital and palpebral parts for eye closure

Orbicularis oculi

functions in frowning

Corrugator supercillii

what does the orbital group of facial muscles consist of?

- Orbicularis oculi | - Corrugator supercillii

what does the nasal group of facial muscles consist of?

- nasalis - procerus - depressor septi nasi

- largest and best developed muscle of the nasal group | - consists of a transverse and alar parts

nasalis

compresses the nares

transverse part of nasalis

draws the alar cartilages downward and laterally and opens the nares

alar part of nasalis

superficial to the nasal bones- draws medial border of eyebrows downward

procerus

widens the nares

depressor septi nasi

muscles of this group move the lips and cheek

oral group

what is the oral group divided into?

- upper group - lower group - orbicularis oris - buccinator

- forms muscular part of cheek | - arises from posterior part of mandible and maxilla opposite the molar teeth and pterygomandibular raphe

buccinators

- pushes cheeks against teeth | - helps in mastication and suckling

contraction of buccinators

help move the ear

auricular muscles

what are the 3 auricular muscles?

- superior auricular - anterior auricular - posterior auricular

elevates ear

superior auricular

pulls ear upward and forward

anterior auricular

retracts and elevates ear

posterior auricular

closes eyelids

orbicularis oculi

origin: Medial palpebral ligament

Palpebral part of orbicularis oculi

insertion: Fibers form an uninterrupted ellipse around orbit

Palpebral part of orbicularis oculi

innervation: Facial nerve (VII)

ALL muscles of face

function: Closes eyelids gently

Palpebral part of orbicularis oculi

origin: Nasal part of frontal bone; frontal process of maxilla; medial palpebral ligament

orbital part of orbicularis oculi

insertion: Fibers form an uninterrupted ellipse around orbit

orbital part of orbicularis oculi

function: Closes eyelids forcefully

orbital part of orbicularis oculi

origin: Medial end of the superciliary arch

Corrugator supercilii

insertion: Skin of the medial half of eyebrow

Corrugator supercilii

function: Draws the eyebrow medially and downward

Corrugator supercilii

origin: Maxilla just lateral to nose

transverse part of nasalis

insertion: Aponeurosis across dorsum of nose with the muscle fibers from the other side

transverse part of nasalis

function: Compresses nasal aperture

transverse part of nasalis

origin: Maxilla over lateral incisor

alar part of nasalis

insertion: Alar cartilage of nose

alar part of nasalis

function: Draws cartilage downward and laterally, opening nostrils

alar part of nasalis

origin: Nasal bone and upper part of lateral nasal cartilage

Procerus

insertion: Skin of lower forehead between eyebrows

Procerus

function: Draws down medial angle of eyebrows, producing transverse wrinkles over bridge of nose

Procerus

origin: Maxilla above medial incisor

Depressor septi

insertion: Mobile part of the nasal septum

Depressor septi

function: Pulls nose inferiorly

Depressor septi

origin: Oblique line of mandible below canine, premolar, and first molar teeth

Depressor anguli oris

insertion: Skin at the corner of the mouth and blending with orbicularis oris

Depressor anguli oris

function: Draws corner of mouth downward and laterally

Depressor anguli oris

origin: Anterior part of oblique line of mandible

Depressor labii inferioris

insertion: Lower lip at midline; blends with muscle from opposite side

Depressor labii inferioris

function: Draws lower lip downward and laterally

Depressor labii inferioris

origin: Mandible inferior to incisor teeth

mentalis

Insertion: Skin of chin

mentalis

function: Raises and protrudes lower lip as it wrinkles skin on chin

mentalis

origin: Fascia over masseter

Risorious

insertion: Skin at the corner of the mouth

Risorious

Function: Retracts corner of mouth

Risorious

origin: Posterior part of lateral surface of zygomatic bone

Zygomaticus major

insertion: Skin at the corner of the mouth

Zygomaticus major

function: Draws the corner of the mouth upward and laterally

Zygomaticus major

origin: Anterior part of lateral surface of zygomatic bone

Zygomaticus minor

insertion: Upper lip just medial to corner of mouth

Zygomaticus minor

function: Draws the upper lip upward

Zygomaticus minor

origin: Infra-orbital margin of maxilla

Levator labii superioris

insertion: Skin of upper lateral half of upper lip

Levator labii superioris

function: Raises upper lip; helps for nasolabial furrow

Levator labii superioris

origin: Frontal process of maxilla

Levator labii superioris alaeque nasi

insertion: Alar cartilage of nose and upper lip

Levator labii superioris alaeque nasi

function: Raises upper lip and raises nostrils

Levator labii superioris alaeque nasi

origin: Maxilla below infra-orbital foramen

Levator anguli oris

insertion: Skin at the corner of mouth

Levator anguli oris

function: Raises corner of mouth; helps with nasolabial furrow

Levator anguli oris

origin: From muscles in area; maxilla and mandible midline

Orbicularis oris

insertion: Forms ellipse around mouth

Orbicularis oris

function: Closes lips; protrudes lips

Orbicularis oris

origin: Posterior parts of maxilla and mandible; pterygomandibular raphe

Buccinator

insertion: Blends with orbicularis oris into lips

Buccinator

function: Presses cheeks against teeth; compresses distended cheeks

Buccinator

origin: Anterior part of temporal fascia

Anterior auricular

insertion: Into helix of ear

Anterior auricular

function: Draws ear upward and forward

Anterior auricular

origin: Epicranial aponeurosis on side of head

Superior auricular

insertion: Upper part of auricle

Superior auricular

function: Elevates ear

Superior auricular

origin: Mastoid process of temporal bone

Posterior auricular

insertion: Convexity of concha of ear

Posterior auricular

function: Draws ear upward and backwards

Posterior auricular

origin: Skin of eyebrows

frontal belly of Occipitofrontalis

insertion: Into galea aponeurotica

frontal belly of Occipitofrontalis

function: Wrinkles forehead; raises eyebrows

frontal belly of Occipitofrontalis

origin: Lateral part of superior nuchal line of occipital bone and mastoid process of temporal bone

occipital belly of Occipitofrontalis

insertion: Into galea aponeurotica

occipital belly of Occipitofrontalis

function: Draws scalp backward

occipital belly of Occipitofrontalis

the largest of the 3 pairs of salivary glands

parotid gland

carries saliva into the oral cavity

parotid duct

passes through the parotid and provides motor inputs for muscles of the face

facial nerve (VII)

is formed in the parotid gland by superficial temporal and maxillary veins

Retromandibular vein

divides into: posterior auricular, maxillary, transverse facial, and superficial temporal arteries

External carotid

provides sensory inputs for the skin of the face

trigeminal nerve (V)

what are the 3 major branches of the trigeminal nerve?

- ophthalmic (V1) - maxillary (V2) - mandibular (V3)

branches into : supra-orbital, supra-trochlear, infra-trochlear, lacrimal, and external nasal nerves

ophthalmic nerve

branches into: zygomaticotemporal branch, zygomaticofacial branch, infra-orbital nerve

maxillary nerve

branches into: auriculotemporal, buccal, and mental nerves

mandibulalr nerve

originate from the second branchial arch, embryonically, and are therefore innervated by CN VII

muscles of the face

exits via stylomastoid foramen

CN VII

what are the branches of CN VII?

- temporal - zygomatic - buccal - marginal mandibular - cervical

give rise to inferior and superior labial, angular, and lateral nasal vessels

facial vessels

branch off superficial temporal vessels

Transverse facial vessels

branch from ophthalmic vessels

Zygomatico- facial and temoral and dorsal nasal artery

branches into infra-orbital, buccal, and mental arteries

maxillary artery

major draining vessel of the face that also receives blood from deep regions of the head

facial vein

interconnected with the intracranial cavernous sinus through emissary veins

venous channels of the face

why can infections move from the mouth into the intracranial region?

because there are no valves between the systems

what groups of lymph nodes does lymphatic drainage move towards?

- submental - submandibular - pre-auricular - parotid

- Extends from the superciliary arch (anteriorly) to the external occipital protuberance and superior nuchal lines (posteriorly) - And laterally to the zygomatic arches

scalp

what are the layers of the scalp?

``` S-skin C-connective tissue (dense) A-aponeurotic layer L- loose connective tissue P-pericranium ```

anchors skin to the aponeurotic layer

Dense connective tissue layer

- separates the aponeurotic layer from the pericranium | - facilitates movement of scalp over calvaria

loose connective layer

the periosteum of the outer surface of the calvaria

pericranium

consists of the occipitofrontalis muscle and the epicranial aponeurosis (galea aponeurotica)

aponeurotic layer

made up of the frontal and occipital bellies

occipitofrontalis muscle

nerves anterior to the ears and vertex

* branches of CN V - supratrochlear - supra-orbital - zygomaticotemporal - auriculotemporal

nerves posterior to the ears and vertex

C1 and C2 spinal nerves form greater auricular, lesser and greater occipital, and 3rd occipital nerves

arise from external and internal carotid/ophthalamic

Arteries that supply the scalp

where does venous drainage go?

the jugulars

what are the scalp vessels?

- supra- trochlear - orbital - posterior auricular - occipital - superficial temporal arteries

drains into the occipital nodes which drain into upper deep cervical nodes

occipital region

drainage is into the mastoid nodes that also drain into the upper deep cervical nodes

posterior to the vertex of the head

the scalp drains into pre-auricular and parotid nodes`

anterior to the vertex

formed by: maxilla, zygomatic, frontal, ethmoid, lacrimal, sphenoid, and palatine bones

the orbits

includes, possibly the trochlear fovea (for muscle attachment) and the lacrimal fossa

superior wall of orbits

contains: the anterior and posterior ethmoidal foramina, lacrimal groove, and part of the optic canal

medial wall of orbits

has part of the inferior orbital fissure

floor of the orbit

where the superior orbital fissure is found

lateral wall of orbit

what are the layers of the eyelids?

- skin - subcutaneous tissue - voluntary muscle - orbital septum - tarsus - conjunctiva

2 additional muscles of the upper eyelid

-levator palebrae superioris -superior tarsal muscles

voluntary muscle of the eyelid

orbicularis oculi

made up of 3 parts: the orbital, palpebral, and lacrimal parts

orbicularis oculi

is anchored medially and laterally via the medial and lateral palpebral ligaments

palpebral part of orbicularis oculi

passes deep and medially, attaching to the lacrimal crest and may drain tears

lacrimal part of orbicularis oculi

an extension of the periosteum that extends into the upper and lower lid

orbital septum

attaches to the tendon of the levator palpebrae superioris

orbital septum of the upper lid

attaches to the tarsus

orbital septum of the lower lid

covers the full extent of the inner surface of the eyelid and reflects onto the outer surface of the eye (sclera)

conjunctiva

formed when the eyelids are closed

* conjunctiva sac | - with upper and lower extensions of sac formed by super and inferior conjunctiva fornices

provides major support for each eyelid

tarsus

plates of dense connective tissue that attach laterally and medially via the lateral and medial palpebral ligaments

inferior and superior tarsus

attaches to the levator palpebrae superioris muscle via a tendon, which raises the upper eyelid

superior tarsus

bloody supply of eyelid

- supratrochlear - supraorbital - lacrimal - dorsal nasal arteries - veins from the ophthalmic vessels

come from the facial vessels

angular artery and vein

come from the temporal artery

transverse facial artery

drain mostly into parotid and submandibular nodes

lymphatics of eyelids

innervated with both motor and sensory components

eyelids

are all branches of the trigeminal (V)

sensory components of eyelid innervation

where do palpebral branches arise from?

- Supraorbital - supratrochlear - infratrochlear - lacrimal branches of the ophthalmic nerve (V1)

what are the motor components of eyelid innervation supplied by?

- facial (VII) (innervates orbicularis oculi) - oculomotor (III) (innervates levator palpebrae superioris) - sympathetic fibers that innervate superior tarsal

Makes, moves, and drains fluid of the eyeball

Lacrimal Apparatus

made up of the: lacrimal gland, lacrimal canaliculi, lacrimal sac, and naso-lacrimal duct

Lacrimal Apparatus

what is the lacrimal gland divided by and what are the two parts?

-divided by tendon of levator palpebrae -divided into: ~orbital part ~palpebral part

Fluid leaves the gland and passes medially over the eye into the lacrimal sac via....?

the puncta and canaliculi

Superiolateral to the eye and divided into orbital and palpebral parts by the tendon of the levator palpebrae superioris

lacrimal gland

enter the lacrimal sac by passing medially

canaliculi

drains into the nose

nasolacrimal duct

what happens when the orbicularis oculi muscle contracts during blinking?

the small lacrimal part of the muscle may dilate the lacrimal sac and draw tears through the canaliculi

what are the 3 components of innervation of the lacrimal apparatus?

- sensory - secretomotor (parasympathetic) - postganglionic sympathetic fibers

from lacrimal nerve that return to CNS through ophthalamic (V1)

sensory innervation of lacrimal apparatus

preganglionic fibers from CNVII enter petrosal nerve and meet postganglonic fibers in pterygopalantine ganglion; postganglionic fibers innervate gland via CN V2, zygomatic, zygomaticotemporal nerves

secretomotor (parasympathetic) innervation of lacrimal apparatus

follow parasympathetic pathway

postganglionic sympathetic fibers innervation of lacrimal apparatus

optic nerve, ophthalamic artery pass through this

optic canal

CN III, IV, V1 branches (lacrimal, frontal, nasociliary), VI, and superior ophthalamic vein pass through thi.....

superior orbital fissure

CN V2, infraorbital vessels pass through this...

inferior orbital fissure

nasolacrimal duct passes through this....

nasolacrimal canal

ethmoid nerves and vessels pass through this....

anterior and posterior ethmoidal openings

- The periosteum lining the bones of the bones of the orbit | - continuous with the dural periosteum

periorbital

thickens into the common tendinous ring

the periorbital in the posterior part of the orbit

the origin for the 4 rectus muscles

common tendinous ring

encloses the major part of the eyeball

fascial sheath

what is the fascial sheath attached to posteriorly?

to the sclera at the point the optic nerve enters

what is the fascial sheath attached to anteriorly?

is firmly attached to the sclera at the edge of the cornea

restrict the medial and lateral rectus muscles

check ligaments of lateral and medial rectus

what are the groups of rectus muscles?

- intrinsic (control pupil size and lens shape) | - extrinsic (control eye movement and eyelid raising)

origin: Lesser wing of sphenoid anterior to optic canal

Levator palpebrae superioris

insertion: Anterior surface of tarsal plate

Levator palpebrae superioris

innervation: oculomotor

Levator palpebrae superioris

function: Elevation of upper lid

Levator palpebrae superioris

origin: Superior part of common tendinous ring

Superior rectus

insertion: Anterior half of eyeball superiorly

Superior rectus

innervation: oculomotor

Superior rectus

function: Elevation, adduction, medial rotation of eyeball

Superior rectus

origin: Inferior part of common tendinous ring

Inferior rectus

insertion: Anterior half of eyeball inferiorly

Inferior rectus

innervation: oculomotor

Inferior rectus

function: Depression, adduction, lateral rotation of eyeball

Inferior rectus

origin: Medial part of common tendinous ring

medial rectus

insertion: Anterior half of eyeball medially

medial rectus

innervation: oculomotor

medial rectus

function: Adduction of eyeball

medial rectus

origin: Lateral part of common tendinous ring

lateral rectus

insertion: Anterior half of eyeball laterally

lateral rectus

innervation: abducent

lateral rectus

fucntion: Abduction of eyeball

lateral rectus

origin: Body of sphenoid, superior and medial to optic canal

superior oblique

insertion: Outer posterior quadrant of eyeball (superior surface)

superior oblique

innervation: trochlearr

superior oblique

function: Depression, abduction, medial rotation of eyeball

superior oblique

origin: Medial floor of orbit posterior to rim; maxilla lateral to nasolacrimal groove

inferior oblique

insertion: Outer posterior quadrant of eyeball (inferior surface)

inferior oblique

innervation: oculomotor

inferior oblique

function: Elevation, abduction, lateral rotation of eyeball

inferior oblique

moves the pupil superiorly

elevation

moves pupil inferiorly

depression

moves pupil laterrally

abduction

moves pupil medially

adduction

rotating the upper part of pupil medially

Internal rotation (intorsion)

rotating upper part of pupil laterally

External rotation (extorsion)

slightly lateral

axis of each orbital

directed anteriorly

each eyeball axis

raises upper eyelid

Levator palpebrae superioris

have complicated actions due to apex of orbit being medial to insertion

Rectus muscles- 4 muscles (medial ,lateral, superior, inferior)

both insert posterolaterally on the eyeball

oblique muscles

arises from body of sphenoid and passes along medial border, through trochlear notch

superior oblique

crosses floor of orbit from medial side

inferior oblique

originate from the common tendinous ring

4 rectus muscles

originate from the sphenoid bone

Superior oblique and levator palpebrae

have a downward (superior) and upward (inferior) action on the eye due to inserting laterally and posteriorly

obliques

what is the arterial supply to the orbit and eyeball?

the ophthalmic which is a branch off the internal carotid

passes into the orbit, through the optic canal with the optic nerve

Ophthalmic artery

branches into: lacrimal, central retinal, long and short posterior ciliary, muscular, supra-orbital, posterior ethmoidal, and anterior ethmoidal

ophthalmic artery

venous drainage of the eyeball

2 venous channels in the orbit- superior and inferior ophthalmic veins

forms from the supraorbital and angular veins

superior ophthalmic vein

can either leave the orbit on its own, join the inferior ophthalmic or connect to the pterygoid plexus

infraorbital

innervates many of the extrinsic eye muscles

oculomotor

innervates the superior rectus and levator palpebrae superioris

superior branch of oculomotor

innervates medial and inferior rectus and inferior oblique

inferior branch of oculomotor

innervates the superior oblique

trochlear nerve (IV)

passes through the trochlear notch before turning laterally toward the eye

superior oblique

gives rise to the nasociliary, frontal, lacrimal nerves

ophthalmic nerve (V1)

innervates the lacrimal gland

lacrimal nerve

innervates the conjunctiva, skin of upper eyelid, parts of the forehead, and middle of scalp

frontal nerve

innervates the pupil, ethmoidal cells, sphenoid sinus, upper and lower lids, lacrimal sac, skin of nose, anterior cranial fossa, nasal cavity, skin of nose

nasociliary nerve