Eyebrows and Eyelids Flashcards
Where do the eyebrows lie?
At the junction of the forehead and the upper lid
Where does the medial end of each eyebrow arch usually lie?
Just inferior to the orbital margin
Where does the lateral end of each eyebrow arch lie?
Above the orbital margin
What is the direction of the hairs in the eyebrows?
Thick and directed horizontally laterally
Which muscle raises the eyebrows?
Frontalis muscle
Which muscle lowers the eyebrows?
Orbital part of the orbicularis oculi
Which muscle draws the eyebrows medially?
Corrugator supercilii muscle
What supplies the muscles controlling eyebrow movement?
Seventh cranial nerve
What is the arterial supply of the eyebrows?
Supraorbital and supratrochlear branches of the ophthalmic artery
Describe the venous drainage of the eyebrows
angular vein –> facial vein
Where does lymphatic drainage from the lateral end of the eyebrows go vs the medial end?
Lateral - Superficial parotid nodes
Medial - Submandibular nodes
What is alopecia areata?
A trophic disorder in which patches of hair are lost
In hypothyroidism, where is hair loss in the eyebrows most recognized?
Outer third of the eyebrow
What may happen to the skin wound in eyebrow lacerations?
The skin wound may gape open due to the pull of muscles.
What muscles may be involved in eyebrow lacerations?
- Frontalis
- Corrugator supercilii
- Orbicularis oculi
In what order should the eyebrow be closed after a laceration?
- Muscle
- Subcutaneous tissue
- Skin
Fill in the blank: The eyebrow is usually burst open as a result of a _______.
[blunt object striking the skin against the underlying frontal bone]
What are the 3 functions of the eyelids?
1) Protect the eye from injury
2) protect eye from excessive light
3) aid in tear distribution when blinking
Eyelids also assist in the distribution of tears.
What is the superior palpebral sulcus? What forms this sulcus?
A horizontal furrow dividing the eyelid into orbital and tarsal parts
Formed by the insertion of the levator palpebrae superioris aponeurotic fibers into the skin.
What differentiates the sulcus of the upper eyelid from that of the lower eyelid? What forms this sulcus
Upper eyelid sulcus is more pronounced; lower eyelid sulcus is less obvious
The lower eyelid sulcus is produced by connections between the skin and orbicularis oculi muscle.
What are the lateral and medial sulci seen in older individuals?
Lateral/malar sulcus and medial/naso-jugal sulcus
They are produced by the skin being tethered to the underlying periosteum.
Which eyelid is larger and more mobile?
The upper eyelid
This difference in size and mobility affects their function.
What are the medial and lateral angles of the eyelids called?
Canthi
The eyelids meet at these angles.
What is the palpebral fissure?
The elliptical opening between the eyelids
It serves as the entrance into the conjunctival sac.
What angle does the palpebral fissure form when wide open?
About 60 degrees laterally and rounded medially
This angle varies slightly among different ethnic groups.
How does the height of the lateral canthus compare to the medial canthus in different ethnicities?
In whites and blacks, lateral canthus is about 2 mm higher thank medial canthus; in Orientals, about 5 mm higher than medial canthus
This reflects anatomical variations in eyelid structure.
Where is the palpebral fissure widest?
At the junction of the medial third with the lateral two-thirds in whites and blacks; in Orientals, halfway aloing its length
This anatomical feature is significant for understanding eyelid morphology.
What is the medial angle of the eye overlapped by in Orientals?
A vertical skin fold, the epicanthus
When the eye is closed, what does the upper eyelid cover?
The cornea of the eye
When the eye is open and looking straight ahead, what does the upper lid cover?
The upper margin of the cornea
Where does the lower lid lie when the eye is open?
Just below the cornea
lower lid doesn’t move up much on closing
What is the relationship between the lateral angle of the eye and the eyeball?
The lateral angle is directly in contact with the eyeball
How far medially from the eyeball does the medial rounded angle lie?
About 6 mm
What is the small triangular space between the eyelids called at the medial canthus?
Lacus lacrimalis
What is the small, pinkish elevation in the center of the lacus lacrimalis?
Caruncula lacrimalis
What is the name of the semi-lunar fold on the lateral side of the caruncle?
Plica semilunaris
What is the thickness and length of the margin of each eyelid?
About 2 mm thick and 30 mm long
What portion of the eyelid margin has squared edges?
The ciliary portion (lateral five-sixths)
What portion of the eyelid margin has rounded edges?
The lacrimal portion (medial one-sixth)
What is the small elevation about 5 mm from the medial angle called?
Papilla lacrimalis
What is the small hole on the summit of the papilla lacrimalis called?
Punctum lacrimale
Sits in lacus lacrimalis
What is the diameter range of the punctum lacrimale?
Approximately 0.4 to 0.8 mm
What does the punctum lacrimale lead into?
Canaliculus lacrimalis
What do the punctum and canaliculus lacrimale serve to carry?
Tears down into the nose
How are the eyelashes arranged on the upper and lower lids? How many roughly on each lid?
Upper lid: longer and curve upward (150); Lower lid: curve downward (75)
What type of glands are located just in front of the posterior edge of the margin of the lids?
Tarsal glands (meibomian glands)
How many tarsal glands are typically found in each eyelid?
About 20 to 25
What do the orifices of the tarsal glands mark?
The site of junction between the skin and the conjunctiva
What represents the line of demarcation between the anterior and posterior portions of the eyelid?
A grayish line or slight sulcus
Anterior portion = skin, subcutaneous tissue, orbicularis; posterior = tarsus and conj
This line runs along the eyelid margin between the eyelashes and the openings of the tarsal glands.
What is the significance of the line of demarcation in surgical procedures?
It serves as a plane along which the eyelid may be split with minimal scarring.
List the structure of the eyelid from superficial to deep
1) Skin
2) Subcutaneous tissue
3) Striated Muscle of orbicularis oculi
4) Tarsal plates
5) Smooth muscle
6) Conjunctiva
(levator palpebrase superioris also inserts into upper lid)
What microscopic features are found in the skin of the eyelids?
Small hairs, sebaceous glands (zeiss), small sweat glands (moll), numerous melanocytes
What happens to the dermis at the margin of the eyelid?
Becomes denser and the papillae are higher
Where does the skin of the eyelids become continuous with the conjunctiva?
In front of the posterior edge at the site of the orifices of the tarsal/meibomian glands
How many eyelashes are typically found on the upper and lower eyelids?
150 in the upper lid and 75 in the lower lid
What characteristics do eyelashes have compared to scalp hairs?
Darker, do not become gray with age, replaced every 100 to 150 days
How are the hair follicles arranged along the eyelids?
In two or three rows along the anterior edge
What type of muscles do the hair follicles of the eyelids lack?
Erector pili muscles
What glands open into each eyelash follicle?
Sebaceous glands of Zeis
What are the modified sweat glands associated with the eyelashes called?
Ciliary glands of Moll
Open into follicle or onto eyelid margin
Describe the subcutaneous tissue of the eyelids.
Very loose and rich in elastic fibers; almost devoid of fat in caucasians
What is the structure of the orbicularis oculi muscle?
Flat, elliptical muscle surrounding the orbital margin
What are the three parts of the orbicularis oculi muscle?
Orbital part - extends onto temporal region and cheek
palpebral portion - eyelids
lacrimal portion - behind lacrimal sac
What type of muscle is the orbicularis oculi?
Striated muscle
What is the palpebral portion of the orbicularis oculi muscle composed of?
Thin bundles of fibers
From where do the fibers of the palpebral portion of the orbicularis oculi muscle arise?
Medial palpebral ligament (from superficial and deep surface of ligament. NOT from lower margin!) and neighboring bone
Sweep laterally and concentrically across the eyelids and in front of the orbital septum
What is located at the lateral angle of the eye regarding the orbicularis oculi muscle?
The fibers interlace at the lateral palpebral raphe
What small group of fine muscle fibers is found at the lid margin?
Ciliary muscle
What lies beneath the orbicularis oculi muscle?
A thin layer of connective tissue containing blood vessels and nerves of eyelid
Which branches of the facial nerve supply the orbicularis oculi muscle?
Where fo they enter the muscle from?
Temporal and zygomatic branches
Enter deep surface of muscle from lateral side
What is the action of the orbital portion of the orbicularis oculi muscle?
Pulls skin of forehead, temple, and cheek like pursestring, pulling it toward the medial angle of the orbit
This action is largely voluntary but can contract reflexively.
What is the function of the palpebral portion of the orbicularis oculi muscle?
Closes the eyelids, lowers the upper lid, and raises the lower lid
Its action is both voluntary and involuntary, contributing to the blinking reflex.
What role does the lacrimal portion of the orbicularis oculi muscle play?
Pulls eyelids medially and pulls lacrimal fascia to dilate the lacrimal sac
This action helps in tear pumping and positioning the puncta lacrimalia.
What is the orbital septum?
A membranous sheet that separates eyelids from orbital contents
It is attached to the orbital margin and continuous with the periosteum.
What are the tarsal plates?
Thickening of orbital septum. Forms dense fibrous tissue in the eyelids providing firmness and shape
The upper tarsal plate is larger and crescent-shaped, while the lower is smaller.
How does the size of the upper tarsal plate compare to the lower tarsal plate?
The upper tarsal plate is about 10 mm in height, while the lower is about 5 mm
Both plates narrow toward their ends.
What is attached at the upper border of the superior tarsal plate?
orbital septum
Smooth muscle fibres of levator palebrae superioris
What is the function of the medial palpebral ligament?
Describe its borders
Attaches medial ends of the tarsi to the lacrimal crest and frontal process of the maxilla
It has an indefinite upper border and a thick lower border.
True or False: The lateral palpebral ligament attaches the lateral ends of the tarsi to the zygomatic bone.
True
DO NOT CONFUSE WITH LATERAL PALPEBRAL RAPHE
It connects to the marginal tubercle on the orbital margin formed by the zygomatic bone.
Fill in the blank: The _______ portion of the orbicularis oculi muscle is responsible for the blinking reflex.
palpebral
The reflex is initiated by drying of the cornea.
What happens to the skin during the action of the orbital portion of the orbicularis oculi muscle?
It is thrown into prominent folds that overlap the eyelids
This provides additional protection to the underlying eye.
What is the antagonist muscle to the orbital portion of the orbicularis oculi and what is the antagonist muscle to the palpebral portion of the orbicularis oculi?
Frontal belly of the occipitofrontalis muscle
The palpebral portion’s antagonist is the levator palpebrae superioris.
What muscle is responsible for raising the upper eyelid?
Levator palpebrae superioris
This muscle is distinct from the lower eyelid and plays a critical role in eyelid elevation.
What is the anatomical structure that descends into the upper lid posterior to the orbital septum?
Aponeurosis of the levator palpebrae superioris. Tendinous fibres then pierce orbital septum and become attached to anterior surface of superior tarsal plate. Some fibres pass forward between muscular bundles of orbicularis oculi to attach to the skin (creating horizontal furrow of upper lid)
What are the medial and lateral expansions of the levator palpebrae superioris aponeurosis called?
Horns
These expansions are important for the muscle’s attachment and function.
What anatomical feature does the lateral horn of the levator palpebrae superioris indent?
Lacrimal gland
This indentation creates a division of the lacrimal gland into palpebral and orbital portions.
Where do the medial and lateral horns of the levator aponeurosis attach?
Medial horn fuses with orbital septum + medial palpebral ligament
Lateral horn attaches to marginal tubercle of the zygomatic bone (along with lateral palpebral ligament)
Insertions act to check action of muscles on upper eyelid
What is origin and insertion of superior tarsal muscle?
What arises from the superior surface of the superior tarsal muscle, where does it course and attach to?
Superior tarsal muscle arises from inferior surface of aponeurosis of levator palpebrae superioris. Inserts into upper edge of superior tarsal plate
Layer of fascia arises from superior surface. THis ascends behind the orbital septum and attaches to the periorstium of the orbital rim.
Where does levator palpebrae superioris originate?
Inferior surface of lesser wing of sphenoid above and anterior to optic canal
What is the primary nerve supply to the striated part of the levator palpebrae superioris?
Superior branch of the oculomotor nerve
This nerve is crucial for the muscle’s function in eyelid elevation.
Which structures does the inferior tarsal muscle connect? What is the role of this muscle?
Connects lower margin of inferior tarsal plate to fascial sheath of inferior rectus
Function = lower the lower lid
What is the function of the superior tarsal muscle?
Further elevation of the upper lid during fear or excitement
This smooth muscle is affected by sympathetic nerve supply.
What condition results from division of the cervical sympathetic nerve affecting the superior tarsal muscle?
Ptosis
This condition is characterized by drooping of the upper eyelid.
What are the names of the fascial spaces present in the eyelids?
1) Subcutaneous
2) submuscular
3) pretarsal
4) preseptal
These spaces are named according to their anatomical positions.
From which artery do the lateral palpebral arteries arise?
Lacrimal artery
The lacrimal artery is a branch of the ophthalmic artery.
Fill in the blank: The medial palpebral arteries arise from the _______.
Ophthalmic artery
medial palpebral artery branches below the trochlea of the superior oblique muscle.
True or False: The medial horn of the levator palpebrae superioris fuses with the orbital septum.
True
This fusion helps in stabilizing the muscle’s action on the eyelid.
What arteries supply blood to the eyelids?
The arteries that supply blood to the eyelids are branches from the ophthalmic artery
These arteries pass behind the lacrimal sac and enter the eyelids, forming arches.
What happens to the medial palpabral arteries after they pass behinf the lacrimal sac?
Enter eyelids. Divide into two branches that pass laterally and form **two arches ** in each eyelid. The branches anastomose with the **lateral palpebral arteries ** and with branches of the superficial temporal, transverse facial, and infraorbital arteries
This connection helps ensure a rich blood supply to the eyelids.
What is the venous drainage of the eyelids?
The veins of the eyelids drain medially into the ophthalmic and angular veins and laterally into the superficial temporal vein
The veins are larger and more numerous than the arteries.
Where do the lymphatic vessels from the lateral two-thirds of the eyelids drain?
The lymphatic vessels from the lateral two-thirds of the upper and lower lids drain into the superficial parotid nodes
This drainage is part of the lymphatic system’s role in immune defense.
Where do the lymphatic vessels from the medial angle of the eyelids drain?
The lymphatic vessels from the medial angle drain into the submandibular nodes
This indicates a difference in drainage patterns between the medial and lateral aspects of the eyelids.
What provides the sensory nerve supply to the upper eyelids?
The sensory nerve supply to the upper lids is from the infratrochlear, supratrochlear, supraorbital, and lacrimal nerves from the ophthalmic division of the trigeminal nerve
These nerves are responsible for sensation in the upper eyelid area. All branches of V1.
Which nerve supplies the skin of the lower eyelid vs the skin of the lower eyelid at the medial angle?
The skin of the lower lid is supplied by the **infraorbital nerve ** (terminal branch of V2)
The medial part of the lower lid is supplied by the infratrochlear branch of the ophthalmic division of the trigeminal nerve (ie branch of V1)
This branch specifically targets the medial aspect of the lower lid.
What muscle is innervated by the temporal and zygomatic branches of the facial nerve?
Orbicularis oculi muscle
This muscle is responsible for closing the eyelids.
Which nerve fibers supply the smooth muscle of the eyelids?
Sympathetic nerve fibers from the superior cervical sympathetic ganglion
These fibers innervate the superior and inferior tarsal muscles.
What determines the position of the eyelids at rest?
Tone of the orbicularis oculi and levator palpebrae superioris muscles and the position of the eyeball
This balance affects how much of the iris is covered by the eyelids.
When looking forward with eyes open, how much of the iris is covered by the upper lid?
About half the width of the superior portion of the iris
The lower lid crosses the lower edge of the cornea.
What happens to the palpebral fissure during times of fear or excitement?
It is further widened by increased tone of the smooth muscle fibers of the superior and inferior tarsal muscles
This response is part of the body’s reaction to heightened emotions. (sympathetic response)
Which muscles are involved in closing the eyelids?
By contracting the orbicularis oculi and relaxing the levator palpebrae superioris muscles
This muscle action is essential for blinking and closing the eyes.
What muscle contracts to open the eye?
Levator palpebrae superioris
This muscle raises the upper lid.
What muscle contraction occurs when looking upward?
The levator palpebrae superioris contracts and the upper lid moves with the eyeball
The lower lid rises slightly but lags behind the eyeball.
What pulls the lower lid downward when looking downward?
Contraction of the inferior rectus muscle pulls the conjunctiva downward, affecting the lower lid position.
Why is it difficult to match a skin graft to the eyelids?
Extreme thinness
What condition is characterized by occlusion of the tarsal gland openings?
Meibomian Gland Dysfunction
It leads to reduced secretion and can cause dry eye.
What results from chronic inflammation of a tarsal gland?
Chalazion
This condition presents as a localized, progressive, painless swelling of the lid.
What is the recommended surgical approach for a chalazion?
Incision through the conjunctival surface of the lid
This is because the gland lies on the conjunctival surface of the tarsal plate.
Fill in the blank: The _______ is responsible for closing the eyelids.
Orbicularis oculi
This muscle plays a crucial role in eyelid movements.
What is an external hordeolum?
An acute infection of a lash follicle or a sebaceous gland (of Zeis) or a ciliary sweat gland (of Moll) that drains externally to the skin surface of the lid.
External hordeolum is commonly known as a stye.
What is an internal hordeolum?
An acute infection of a tarsal gland (of Meibom) that drains through the conjunctival surface of the lid.
Internal hordeolum is less common than external hordeolum.
What results from paralysis of the orbicularis oculi muscle?
Prevents closure of the eye, permits the lower lid to sag (ectropion), and causes tears to escape over the lower lid (epiphora).
This paralysis can result from a lesion of the seventh cranial nerve.
What is ptosis?
Severe drooping of the upper eyelid.
It can be caused by paralysis of the levator palpebrae superioris muscle from third nerve palsy
What is Horner’s syndrome?
ptosis, myosis, anhydrosis and enophthalmos, resulting from a lesion of the cervical part of the sympathetic nervous system.
It indicates disruption of sympathetic nerve pathways.
What is the function of the orbital septum?
Separates the lid connective tissue spaces from the orbital contents and forms a barrier to prevent infection.
It also holds the orbital fat in position.
What are tarsal plates?
Dense connective tissue structures that give the eyelids shape and support.
They limit distortion from scar tissue formation following surgery.
What are the subcutaneous pretarsal and preseptal spaces?
Potential areas for accumulation of blood or inflammatory exudate in the eyelids.
The preseptal space is not continuous with the potential space of the scalp because this fuses with peiostium at orbital margin
Fill in the blank: Paralysis of the levator palpebrae superioris muscle is associated with _______.
ptosis
True or False: The orbital septum is strongest on the medial side of the lower lid.
False
The orbital septum is weakest on the medial side of the lower lid.
What is the last part of the cornea to be covered by the eyelids during a protective reflex?
Just below the center of the cornea
The cornea moves upward with approaching danger, which may lead to unexpected damage.
How does corneal damage differ in the elderly?
It may be more extensive due to poor tone of the orbicularis oculi
This can result in less effective closure of the eyelids.
Where do the sensory nerves to the eyelids run?
In the areolar tissue beneath the orbicularis oculi muscle
Local anesthetic must be injected deep to this muscle to block these nerves.
What is the gray line in the eyelid?
The area between the rows of eyelashes and the orifices of the tarsal glands
It appears gray due to relative avascularity.
What are the two portions of the eyelid split during surgery?
- Anterior portion
- Posterior portion
The anterior consists of skin, subcutaneous tissue, and orbicularis oculi muscle; the posterior consists of tarsal plates, orbital septum, and conjunctiva.
What is the typical tissue loss in eyelid lacerations?
Usually little or no tissue loss occurs
Necrosis of lid tissue is rare due to the excellent blood supply.
What is the order of closure for through-and-through lacerations of the eyelid?
- Suturing the conjunctiva and tarsal plate first
- Suturing the muscle and skin as a single layer
The posterior lid margin suture should be placed first and its ends left long for traction.
What is required for lacerations involving the lacrimal canaliculus?
Placement of a stent within the lumen
This helps maintain the function of the canaliculus.
How can lacerations parallel to the lid margins be closed?
With simple interrupted sutures
This minimizes the risk of an unsightly scar due to the alignment with the pull of the orbicularis muscle.
What is the protocol for reconstructing the eyelid after excision of a small tumor?
The skin incision can be closed directly if 25 percent or less of the eyelid margin is removed
Care must be taken to avoid undue tension.
What type of surgery may be required for larger tumors on the eyelids?
Plastic surgery with rotational cheek skin flaps
This method helps to cover larger defects created by tumor removal.
