OcAnat_Test 2 Flashcards
What are the names of the bones in the orbital cavity?
Palantine, Lacrimal,Zygomatic, Maxillary, Ethmoid, Sphenoid and Frontal
How many bones are there altogether in the Orbital Cavity?
11
Which bones are shared between the orbits?
Ethmoid, Sphenoid, and Frontal, That is why there is only 1 of them.
What is the numerical number of the bones that make up the orbital cavity?
7
Which two bones compose the roof of the orbital cavity?
The anterior portion of Frontal bone
The posterior portion of Lesser wing of the Sphenoid bone
What are the three landmark structures for the roof?
Lacrimal Fossa
Supra-Orbital notch
Trochlear fossa
Where is the lacrimal fossa found?
Anterior-lateral angle.
What passes through the supra-orbital notch?
Supraorbital nerve
Supraorbital artery
What interrupts the superior orbital margin?
Supra-orbital notch
What is situated close to the anterior-medial angle?
The trochlear fossa.
What makes up the lateral wall of the orbita
Anteriorly: Zygomatic bones
Posteriorly: Greater wing of Sphenoid
When he says to know what is inside of circle and what is outside???
Double check
What are located inside the circle of the Lateral wall?
CN 3, CN 6
Ophthalmic artery
What are located outside the circle of the Lateral wall?
Nerves
Veins (superior ophthalmicvein)
CN 4
What makes up the floor of the orbital cavity?
Zygomatic(anterior-lateral)
Palantine(just posterior to the maxilla)
Maxillary(large central area)
What is the purpose of the inferior orbital fissure?
Separation of the posterior section of lateral wall and floor
What bones are involved in the inferior orbital fissure?
Sphenoid
Palantine
Maxillae
What is significant about the medial wall of the orbit?
Thinnest of the walls
Translucent in nature
What are the four bones that compose the Medial wall?
Maxillae(forms the frontal process)
Lacrimal(Anteriorly and slight inferiorly)
Ethmoid(central)
Sphenoid(small part of opsterior portion wall)
The roof has 4 foramina…
Lacrimal fossa
Trochlear fossa
Supr-orbital margin
Optic canal
The lateral wall has 3 foramina
Zygomatic canal
Meningeal foramen
Superior Orbital fissure(seps the sphenoids)
The floor has 2 foramina
IOF
Infra-orbital groove
The medial wall has 3 foramina
Naso-lacrimal canal
anterior ethmoid foramen
Posterior eethmoid foramen
Who dumps into the middle meatus?
Frontal sinus
Ethmoid sinus
Maxillary sinus
Who dumps into the superior meatus?
The Sphenoid sinus
How does the eye position itself naturally?
Just over the superior limbus
1mm within inferior limbus
Where is the gray line found?
Just between the tarsal gland orifice and the eyelashes
Does the gray line contain blood vessels?
Nope
What does the gray line divide?
The lids: anteriorly and posteriorly
What is anterior to the gray line?
Skin
subcutaneous areolar tissue
orbicularis oculi
What is posterior to the gray line?
Tarsal plate
Smooth muscle
Conjunctiva
What are the 7 different layers of the eyelid?
Skin Subcutaneous areolar tissue Striated muscle layer Submuscular areolar tissue Fibrous layer Smooth Muscle layer Conjunctiva or mucous membrane
What composes the fibrous layer of the eyelid?
Orbital septum
Tarsal plate
What composes the smooth muscle layer of the eyelid?
Superior tarsal muscle
Inferior tarsal muscle
Which layer contains no fat of the eyelid?
Subcutaneous areolar tissue.
What are the portions of the orbicularis oculi?
Orbital portion
Palpebral portion
Ciliary
Muscle of Horner
What is the function of the orbital portion?
Closes lids forcefully
What is the function of the palpebral portion?
closes lids gently as in blinking
What is the function of the muscle of Riolan?
Holds lids to the globe.
What is the function of Horner muscle?
Dilates lacrimal sac to assist the entrance of tears into it and also out of the lacrimal sac.
What are the insertions of the Levator Palpebrae Superioris?
Cutaneous - skin below upper palpebral furrow, passes through orbicularis muscle
Osseous attachments.
What are the osseous attachments of Levator palpebral superioris
Lateral horn of aponeruosis is attached to whitwalls tubercle
Medial horn of aponeurosis is attached to medial palpebral ligament.
Up and Low tarsal plates purpose of
Anterior and posterior surfaces?
Anterior = convex: Insertion of levator tendons Posterior = concave: for eye via conjunctiva
Does the upper and lower tarsal plates contain Meibomian glands?
Yes
What is anterior to tarsal plates?
aponeurosis of levator Fat Orbicularis oculi Hair follicle .............
What are lateral and medial palpebral ligaments sometimes considered?
Extineions of the tarsal plates
Where does the MPL attach?
frontal process of the maxilla bone
What does the MPL contain?
canaliculi of the lacrimal drainage apparatus
Where does the LPL attach?
Orbital tubercle of zygomatic bone (Whitnall’s tubercle
Where does the LPL lie?
Behind the lateral palpebral raphe
What is the nerve innervation for smooth muscle layer
Sympathetic innervation: droopy lid???
Where is the land of moll located
Eyelid margin with ducts opening up in eyelid margin
What does the gland of moll secrete?
Sweat
What is the function of glands of moll?
Unknown
Where is the glands of zeis located?
On eyelash follicles. There are 2 for each.
What does the Gland of zeiss secrete?
sebum
What is the function of the gland of zeiss?
keeps eyelashes flexible
T/F?
Is the gland of zeiss more anterior to gland of moll?
True
Where can you find the accessory palpebral lacrimal gland of wolfring?
Peripheral aspect of the tarsal plate
What is the function of the accessory palpebral lacrimal gland of Wolfring?
Similar to the lacrimal glands as its serous secretion(accessory lacrimal glands)
Where can you find the accessory conjunctiva lacrimal gland of Krause?
Conjunctival fornix
What is the function of accessory conjunctiva lacrimal gland of krause?
Similar to the lacrimal gland (accessory lacrimal glands)
What are the two pathways for venous drainage?
Superficial (pre-tarsal) system
Deep (post-tarsal) system
What does the anterior facial vein drain into?
Which system?
Internal Jugular Vein
Superficial System
What does the superficial temporal vein drain into?
Which system
External jugular vein
Pre-tarsal system
What does the Ophthalmic vein drain into?
Which system?
Cavernous sinus
Post-tarsal system
What does the Deep facial vein drain into first?
Pterygoid plexus, later into cavernous sinus like the ophthalmic veins
Deep system
Where does the lateral portion of upper and lower lids drain?
Pre-auricular and parotid lymph nodes
Where does the medial portion of upper & lower lids portion drain?
Submental and submandibular nodes
What is the sensory innervation of:
- Upper lid
- Lower lid
- Medial
- Lateral
- Supraorbital nerve
- infraorbital nerve
- Supratrochlear nerve and Infratrochlear
- Lacrimal branches of the Ophthalmic Nerve
What is the motor innervation of:
- Orbicularis Oculi
- Levator
- Muller
- CN 7
- CN 3
- Sympathetic nerves
What are the two different portions of the palpebral conj?
Tarsal Conj
Orbital Conj
Between the two palpebral conj structures, who is more anterior?
The tarsal conj is more anterior than the orbital palpebral conj
Name the four divisions of the Palpebral fornix?
Superior Fornix
Inferior Fornix
Medial Fornix
Lateral Fornix
Which fornix has the most depth?
Superior FOrnix
14-15mm in depth
It is connected by fascial expansion
Which fornix has the lest depth?
Medial Fornix; none
Filled by plica and caruncle
What are the two layers associated with the Conj? WHich is more anterior
Stromal
Epithelial
Stroma is more anterior(closer to tarsal plate)
What kind of cells make up the epithelium layer of conj?
Stratified squamous
2-6 layers. THickets at eyelid margin and limbus
Goblet cells are missing in these aras.
What kind of cells make up the stromal layer of the conj
Connective tissue.
Has an adenoid and deep fibrous layer(more anterior)
What kind of epithelial tissue makes up the skin of the lids?
Stratified, squamous keratinized
serves as protection-skin
What kind of epithelial tissue makes up the palpebral conj from the mucocutaneous junction?
Stratified, squamous non-keratinized
4-5 layers
(still serves as a protection, but mucous membrane)
What kind of epithelial tissue makes up the conjunctival-fornix?
Stratified, columnar non-keratinized.
2 cells thick, goblet cells
(serves as protection, rarely seen)
What kind of epithelial tissue makes up the limbus?
Stratified squamous, nonkeratinized
10 cells thick
(serves as protection, mucous)
What kind of epithelial tissue makes up the cornea
Stratified, squamous, non-keratinized
2-5 cells thick
(serves as protection, mucous; has nuclei up top)
What are the two layers of the lympathic system?
Superficial plexus(drains adenoid layer;stroma) Deep plexus (drains the deep fibrous layer; stroma)
Who supplies the layers of the conj nervewise?
Sennsory orginated
CNV: Ophthalmic and Maxillary
How is the distribution of the vasculature to the layers of the conju?
dually automatic.
Meaning both para and symp components
Where does the sympathetic comp of vasculature for layers of conj come from?
Superior cervical ganglion
Where does the parasym comp of vasculature for layers of conj come from?
Pterygopalantine ganglion
Which conjunctiva has complex sensory nerve endings(corpuscles)
Bulbar Conj
In the bulb conj, where is the location of the most corpuscles?
limbal conj
Mechanoreceptor role belongs to who?
Bulbar conj
Touch sensitivity
What is so special about the conjunctiva?
It is the most immunologically active tissue of the external eye.
How do you distinguish papillae formation from follicle formation?
Presence of blood vessels at the centers for papillae
What is papillae
Substantia propria abnormally bulges into overlying epithelial layer, elevating the latter tissue.
Which of the two formations is a specific clinical sign?
Follicle. Prsent in conditions of cell immune reaction(viral infections, hypersensitivity)
What re follicles
Aggregates of lymphocytes and macrophages in the adenoid layer.
FOllicles are clear, fluid-filled pockets and have blood vessels passing either above or below, never within the adenoid layer.
Where is the lacrimal gland located?
In the fossa for the lacrimal gland in the frontal bone
WHat are the two portions for the lacrimal gland?
Orbital and palpebral portion
What divides the two portions of the lacrimal system?
THe aponeurosis of the levator muscle
Which portion of the lacrimal gland is more superior
THe orbital portion
How much of the lacrimal gland does the orbital portion represents?
65-75% of the gland
How much of the lacrimal gland does the palpebral portion represent?
25-35%
How many secretory ducts are there in the lacrimal system?
12 ducts
How many ducts originate in the orbital portion?
2-5
How many ducts originate from the palpebral portion?
6-8
If you cut out the palpebral portion, what do u run the risk of doing?
interrupting the drainage from the orbital portion of the lacrimal gland.
Where do the ducts exit from posteriorly?
Superotemporal portion of the conjunctival fornix. Orbital ducts have to go through palpebral ducts to exit.
When is the lacrimal gland mature?
Until after birth, 2 weeks-babies can produce tears.
What kind of gland is the lacrimal gland?
A serous tubuloacinar gland
What are the three types of ducts of the Lacrimal gland
- Intralobular ducts
- Interlobular ducts
- Main excretory ducts
What is the final destination of the three ducts of the lacrimal gland?
Superior lateral aspect of the conjunctival fornix.
What forms the acini?
single layer of pie-shaped secretory cells enclosed by a BM
What types of cells make up the acinI?
Mucous cell( light granules) Serous cell(dark granules, they are seriously dark)
What surrounds the ascinar cell?
loose collagen fiber
capillary network
lymphatic
Rich nerve supply
What are myoepithelial cells?
Sourrounds the outside of the acinar secretory cell.
More active when you are crying
What lines the ductile lumen of the lacrimal gland?
microvilli
Names of the accessory lacrimal glands?
Accessory palpebral lacrimal gland of Wolfring
Accessory conjunctival lacrimal gland of Krause
What is the functions of the accessory lacrimal glands?
Secretes Tear fluid
Functions provide everyday or basic secretion for water-tear film layer of pre-corneal film
Which is accessory lacrimal gland is more numerous?
Accessory conjunctiva lacrimal gland of krause.
But more smaller than Wolfring
What kind of nerve fibers does the lacrimal nerve carry?
Sensory
From ophthalmic branch of CNV
Innervation sympathetics for Lacrimal gland?
Derived from the superior cervical ganglion
What happens when u stimulate the symp nervous system for the lacrimal gland?
No change in tear secretion
If destroy superior cervical ganglion, secretion is not affected.
Innervation parasymp for Lacrimal gland
Derived from nervus intermedius CNVII.
Responsible for secretion and is main contributor to tera film
Which nerve fiber is the only one inside of the lacrimal gland?
Parasym fibers are the only fibers inside the acinus
What is the reflex secretions of main lacrimal glands?
CNV - sensory (afferent) pathway
CNVII - parasymp (efferent) pathway
Myoepithelial cell innervation?
No nerve terminals next to the myoepithelial cells in the acinus
Directly innervated myoepithelial cells in the intermediate and main ducts.
What is the drainage apparatus for the lacrimal system?
- Lacrimal papillae
- Lacrimal puncta
- Lacrimal canaliculi
- lacrimal sac
- Nasolacrimal duct and boney nasolacrimal canal
- Nasal sinus
How much tears get drained through the lacrimal system?
75-80%
The rest is evaporated
Where is the location of lacrimal papillae?
Directed backwards out of view. Functions to keep the punctum open.
WHere is the location of the lacrimal puncta?
In line with the tarsal gland openings
What are the components of the Lacrimal canaliculi?
Vertical part 2mm
Horizontal part 8mm
Ampulla
Horner’s muscle
Horner’s muscle significance in the lacrimal canaliculi?
Surrounds vertical and horizontal parts.
When Orbic oc contracts, puncta pulled medially, ampullae narrows, canaliculi shortens.
What happens to the ampulla when you blink?
Ampulla contracts
Drives tears into lacrimal sac
How long is the lacrimal sac?
12 mm long
Sits in the lacrimal fossa(Lacrimal bone and Frontal process of maxilla).
T/F
Most of the lacrimal sac lie underneath the Anterior limb of the MPL
True
T/F
The posterior branch of MPL connects to the fascia of lacrimal sac.
tRUE
Which limb of MPL is anterior to the lacrimal sac?
The anterior limb of MPL.
HOrner’s muscle role with lacrimal sac?
Dilate the sac.
Orbic oris does this too.
Location of horner’s muscle in lac sac
just posterior to the lacrimal sac and limbs of MPL.
What are the two parts of the nasolacrimal duct?
Intra-osseous part
Intra-meatal part
What is the intra-osseous part
surrounded by bones of bony nasolacrimal, maxillary, and inferior conchae bones
What is the intra-meatal part
Not completely surrounded by bone.
Sourrounded by soft tissue of lateral part of nasal cavity.
Purpose of valve of Hasner
Prevents air entrance on sneezing and coughing
Which part of drainage system does orbital septum belong to?
Nasolacrimal sac.
Septum is attached to area just behind posterior lacrimal crest.
Outer layer(thin) of tear film is produced by
Oily layer
Tarsal glands (meibomian)
Zeiss: sebum
Moll: sweat
The middle layer(thick) of tear film is produced by
Aqueous layer
Lacrimal glands: Krause & Wolfring
The inner layer(thin) of tear film is produced by
Mucin layer
Goblet cells of the conjunctiva
Lacrimal gland cells
WHat is the purpose of the outermost layer?
Prevent evaporation of the underlying watery layer.
What is the purpose of the middle layer?
Lysozyme, immunoglobulins, beta lysine
Defense against invaders
What is the purpose of the inner layer
Wets the microvilli of the corneal epithelium.
Which fiber type is predominant in the orbital layer of rectus and oblique muscles?
%?
Orbital Singly-innervated Fiber
80%
What kind of neuromuscular sites does the Orbital SIF have?
Neuromuscular contacts are at a single site.
Which orbital layers has oil droplets?
Orbital SIF(1st) Global Red SIF (2nd) Intermediate Red SIF (3rd) Global White SIF Associated with the mitochondria and glycogen granules
How does the twitching vary for the Orbital MIF?
Fast twitch near center
Slow twitch at proximal and distal end.
Where do the red SIFs predominate?
Transition zone b/w
Orbital and global layers
They decrease in number w/ progression into global layer
Which fiber layer is distributed equally throughout transition zone and global layer?
Global Intermediate SIF
What type of response is exhibited
Slow graded
Nonpropagated response following neural or pharmacological activation
What are oculomotor regulatory centers?
Coordinate and regulate muscle actions
Who keeps the Oculomotor reg centers updated?
Muscle Spindles Golgi tendon organs Myotendinous cylinders(palisade endings)
What are myotendinous cylinders
AKA Palisade endings
Specialized sensory receptors for global multiply innervated fibers.
What do the global MIFs display that no-one else can?
Sensory receptors called
Myotendinous cylinders aka palisade endings
Which special muscle does not arise from the annulus of zinn?
Inferior Oblique
Where does the IO take origin?
Front of the orbit
What angle does the SR and IR make with the visual line?
23 degrees
What angle does SO make with the visual axis?
54 degrees
What angle does IO make with Visual axis?
51 degrees
Which muscle has the smallest distance from the limbus?
Medial Rectus
Closest to the Cornea
Covered by Caruncle
Which muscle is farthest from the limbus?
Superior rectus
Farthest from the cornea
Inferior Branch = Medial Branch
Supplies….
IO, IR, MR
Superior Branch = Lateral Branch
SO, SR, LR, levator
Which is the largest extraocular muscle?
Medial rectus
Stronger than the lateral rectus
Which is the shortest recti muscle?
IR
Which is the longest and thinnest recti muscle?
SO
Which extraoc muscle has the shortest tendon of insertion
IO
Which muscles have innervation from the inferior branch of CNIII
MR (innervates on lateral surface)
IR
IO
Who innervates the SO muscle
Trochlear nerve on the upper-surface near its lateral border.
Who does the LR receive its only blood supply from?
Lacrimal artery
Who uses a stiff pulley made out of cartilage
SO
All the other muscles use soft pulleys.
What additional things are posterior to Gray Line?
Meibomian gland orifices
Mucocutaneous Junction