Eyelids

Approved & Edited by ProProfs Editorial Team
The editorial team at ProProfs Quizzes consists of a select group of subject experts, trivia writers, and quiz masters who have authored over 10,000 quizzes taken by more than 100 million users. This team includes our in-house seasoned quiz moderators and subject matter experts. Our editorial experts, spread across the world, are rigorously trained using our comprehensive guidelines to ensure that you receive the highest quality quizzes.
Learn about Our Editorial Process
| By Tunstillt
T
Tunstillt
Community Contributor
Quizzes Created: 2 | Total Attempts: 1,112
Questions: 32 | Attempts: 790

SettingsSettingsSettings
Eye Quizzes & Trivia

Questions and Answers
  • 1. 

    Which of the following is when the accessory row of eyelashes either partial or complete emerjes adjacent to or from the opening of the meibomian glands?

    • A.

      Distichiasis

    • B.

      Trichiasis

    • C.

      Horner syndrome

    • D.

      Entropian

    Correct Answer
    A. Distichiasis
    Explanation
    Distichiasis is the correct answer because it refers to a condition where an extra row of eyelashes, either partially or completely, emerges adjacent to or from the opening of the meibomian glands. This can cause irritation, redness, and discomfort in the eye. Trichiasis, on the other hand, is a condition where the eyelashes grow inward towards the eye, while Horner syndrome is a neurological condition that affects the eye muscles, and entropion is the inward turning of the eyelid.

    Rate this question:

  • 2. 

    Which of the following is part of the posterior lamella (pick three)

    • A.

      Tarsal plate

    • B.

      Conjunctiva

    • C.

      Meibomian glands

    • D.

      Zeis and moll glands

    • E.

      Orbicularis oculi muscle

    • F.

      Skin

    Correct Answer(s)
    A. Tarsal plate
    B. Conjunctiva
    C. Meibomian glands
    Explanation
    The posterior lamella of the eyelid is composed of the tarsal plate, conjunctiva, and meibomian glands. The tarsal plate is a dense connective tissue that provides structural support to the eyelid. The conjunctiva is a thin, transparent membrane that lines the inner surface of the eyelid and covers the white part of the eye. The meibomian glands are located within the tarsal plate and secrete an oily substance that helps lubricate the eye.

    Rate this question:

  • 3. 

    Which of the following is part of the anterior lamella (pick three)

    • A.

      Tarsal plate

    • B.

      Conjunctiva

    • C.

      Meibomian glands

    • D.

      Zeis and moll glands

    • E.

      Orbicularis oculi muscle

    • F.

      Skin

    Correct Answer(s)
    D. Zeis and moll glands
    E. Orbicularis oculi muscle
    F. Skin
    Explanation
    The anterior lamella of the eyelid is composed of several structures. The Zeis and Moll glands are sebaceous glands located within the anterior lamella. The orbicularis oculi muscle is a circular muscle that surrounds the eyelid and is also part of the anterior lamella. Additionally, the skin is another component of the anterior lamella. Therefore, the correct answer is zeis and moll glands, orbicularis oculi muscle, and skin.

    Rate this question:

  • 4. 

    Which of the following can result in inflammation leading to hordeolum or chalazion?

    • A.

      Abnormality of keratinization

    • B.

      Lack of enzyme tyrosinase

    • C.

      Too much osmolarity of the tear film

    • D.

      None of the above

    • E.

      All of the above

    Correct Answer
    A. Abnormality of keratinization
    Explanation
    Abnormality of keratinization can result in inflammation leading to hordeolum or chalazion. Keratinization is the process by which cells in the outer layer of the skin become filled with keratin, a protein that provides protection. If there is an abnormality in this process, such as excessive production or improper differentiation of keratinocytes, it can lead to blockage of the oil glands in the eyelids. This blockage can then cause inflammation and the formation of hordeolum or chalazion.

    Rate this question:

  • 5. 

    Which of the following is when the accessory row of eyelashes either partial or complete emerjes adjacent to or from the opening of the meibomian glands?

    • A.

      Distichiasis

    • B.

      Trichiasis

    • C.

      Horner syndrome

    • D.

      Entropian

    Correct Answer
    A. Distichiasis
    Explanation
    Distichiasis is the correct answer because it refers to the condition when an additional row of eyelashes, either partially or completely, emerges adjacent to or from the opening of the meibomian glands. This can cause irritation and discomfort to the eye, and in severe cases, it may lead to corneal abrasions or other complications. Trichiasis, horner syndrome, and entropian are all different eye conditions that do not specifically involve the accessory row of eyelashes emerging from the meibomian glands.

    Rate this question:

  • 6. 

    Which of the following is when the normal eyelashes develop and have an abnormal orientation, and grow in instead of out.

    • A.

      Distichiasis

    • B.

      Trichiasis

    • C.

      Horner syndrome

    • D.

      Entropian

    Correct Answer
    B. Trichiasis
    Explanation
    Trichiasis is a condition where the normal eyelashes grow inwards instead of outwards, causing them to irritate the eye. This abnormal orientation of the eyelashes can lead to discomfort, redness, and even damage to the cornea if left untreated. Distichiasis, on the other hand, refers to the development of extra rows of eyelashes, while horner syndrome and entropian are unrelated conditions.

    Rate this question:

  • 7. 

    Which of the following is true of distichiasis? (select 3)

    • A.

      Usually occurs from chronic inflammation

    • B.

      A mucocutaneous disease

    • C.

      Can result from ocular cicatricial pemphigoid and stevens-johnson syndrome

    • D.

      Can result from bell's phenomenom

    • E.

      When normal eyelashes develop and have an abnormal orientation

    Correct Answer(s)
    A. Usually occurs from chronic inflammation
    B. A mucocutaneous disease
    C. Can result from ocular cicatricial pempHigoid and stevens-johnson syndrome
    Explanation
    Distichiasis is a condition where normal eyelashes develop but have an abnormal orientation. It is usually caused by chronic inflammation and is considered a mucocutaneous disease. It can also result from ocular cicatricial pemphigoid and Stevens-Johnson syndrome, which are both inflammatory disorders affecting the mucous membranes.

    Rate this question:

  • 8. 

    In what way does contraction of the orbicularis oculi muscle help in lacrimal pump mechanism?

    • A.

      The pretarsal muscle surrounding the canaculi helps squeeze in the lacrimal drainage system

    • B.

      The preseptal muscle surrounding the canaculi helps squeeze in the lacrimal drainage system

    • C.

      The orbital portion surrounding the canaculi helps squeeze in the lacrimal drainage system

    • D.

      All of the above

    Correct Answer
    A. The pretarsal muscle surrounding the canaculi helps squeeze in the lacrimal drainage system
    Explanation
    The pretarsal muscle surrounding the canaliculi helps squeeze in the lacrimal drainage system. This contraction of the orbicularis oculi muscle aids in the lacrimal pump mechanism by creating pressure on the lacrimal sac, which helps to propel tears through the lacrimal ducts and into the nasal cavity.

    Rate this question:

  • 9. 

    Which muscle is not involved in opening the eye?

    • A.

      Orbicularis oculi

    • B.

      Levator palpebrae superioris

    • C.

      Retractors of the lower lids

    • D.

      Smooth muscle of muller

    Correct Answer
    A. Orbicularis oculi
    Explanation
    The orbicularis oculi muscle is responsible for closing the eye, not opening it. When this muscle contracts, it causes the eyelids to close. Therefore, it is not involved in the process of opening the eye. The other options listed, such as the levator palpebrae superioris, retractors of the lower lids, and smooth muscle of Muller, are all involved in the movement and opening of the eye.

    Rate this question:

  • 10. 

    Which of the following is true of the levator palpebrae superioris? (select 3)

    • A.

      Chief retractor

    • B.

      Innervated by cranial nerve 3

    • C.

      Equal innervation: R&L yoked

    • D.

      Innervated by cranial nerve 7

    • E.

      Chief closer

    Correct Answer(s)
    A. Chief retractor
    B. Innervated by cranial nerve 3
    C. Equal innervation: R&L yoked
    Explanation
    The levator palpebrae superioris is a muscle that functions as the chief retractor of the upper eyelid. It is innervated by cranial nerve 3 (oculomotor nerve). It receives equal innervation from both the right and left sides, causing the eyelids to move in a coordinated manner.

    Rate this question:

  • 11. 

    The superior tarsal muscle is also called muller or mueller's smooth muscle

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    The statement is true because the superior tarsal muscle is indeed referred to as Muller or Mueller's smooth muscle. This muscle is responsible for elevating the upper eyelid and is composed of smooth muscle fibers. It is named after its discoverer, Johannes Peter Muller, a German physiologist.

    Rate this question:

  • 12. 

    Which of the following muscles is analagous to mullers?

    • A.

      Inferior tarsal

    • B.

      Superior tarsal

    • C.

      Orbicularis oculi

    • D.

      Levator palpebrae superioris

    Correct Answer
    A. Inferior tarsal
    Explanation
    The correct answer is inferior tarsal. The inferior tarsal muscle is responsible for elevating and retracting the lower eyelid. Müller's muscle, also known as the superior tarsal muscle, is responsible for elevating the upper eyelid. Therefore, the inferior tarsal muscle is analogous to Müller's muscle in terms of their function in eyelid movement.

    Rate this question:

  • 13. 

    Which of the following is true of the levator aponeurosis of the levator palpebrae superioris? (Select 3)

    • A.

      Inserts into the anterior tarsal

    • B.

      Inserts into the posterior tarsal

    • C.

      If disinserts from the tarsal can leads to ptosis

    • D.

      Passes through the orbicularis muscle

    • E.

      Inserts into the epidermis

    Correct Answer(s)
    A. Inserts into the anterior tarsal
    C. If disinserts from the tarsal can leads to ptosis
    D. Passes through the orbicularis muscle
    Explanation
    The levator aponeurosis of the levator palpebrae superioris inserts into the anterior tarsal, which means it attaches to the front surface of the tarsal plate. If it becomes disinserted from the tarsal, it can lead to ptosis, which is drooping or sagging of the upper eyelid. Additionally, the levator aponeurosis passes through the orbicularis muscle, which is the muscle responsible for closing the eyelids.

    Rate this question:

  • 14. 

    Which of the following is true of the mullers muscle? (select 3)

    • A.

      Minor retractor of the upper eyelid (2 mm of upper lid elevation)

    • B.

      Innervated by the sympathetic nervous system

    • C.

      Main receptor type is alpha 2

    • D.

      Chief retractor of the upper eyelid

    • E.

      Main receptor type is beta 1

    • F.

      Innervated by cranial nerve 3

    Correct Answer(s)
    A. Minor retractor of the upper eyelid (2 mm of upper lid elevation)
    B. Innervated by the sympathetic nervous system
    C. Main receptor type is alpHa 2
    Explanation
    beta1 is for the LPS

    Rate this question:

  • 15. 

    What are other names for horner's syndrome? (select 2)

    • A.

      Claude bernard-horner syndrome

    • B.

      Oculosympathetic palsy

    • C.

      Ocular cicatricial pemphigoid

    • D.

      Stevens-johnson syndrome

    Correct Answer(s)
    A. Claude bernard-horner syndrome
    B. Oculosympathetic palsy
    Explanation
    ocular cicatricial pemphigoid and stevens-johnson sydnrom lead to distichiasis

    Rate this question:

  • 16. 

    Which of the following is true of the force generation test (select 3)?

    • A.

      It helps determine the functioning of the levator

    • B.

      Can help one differentiate between the types of ptosis

    • C.

      Done by attaching a force transducer to the lashes and measuring the maximum force generated during upgaze

    • D.

      It's done by measuring the amount of displacement of the upper eyelid from down gaze to upgaze after fixing the frontalis muscle at the brow

    • E.

      Done by attaching a force transducer to the lashes and measuring the median force generated during downgaze

    Correct Answer(s)
    A. It helps determine the functioning of the levator
    B. Can help one differentiate between the types of ptosis
    C. Done by attaching a force transducer to the lashes and measuring the maximum force generated during upgaze
    Explanation
    The force generation test is a diagnostic tool used to assess the functioning of the levator muscle and differentiate between different types of ptosis. It involves attaching a force transducer to the lashes and measuring the maximum force generated during upgaze. This test helps determine the strength and efficiency of the levator muscle, which is responsible for lifting the upper eyelid. By measuring the force generated during upgaze, it can provide valuable information about the muscle's functionality and identify any abnormalities or weaknesses. Additionally, the test can also help differentiate between different types of ptosis, a condition characterized by drooping of the upper eyelid.

    Rate this question:

  • 17. 

    Which of the following is true of the LPS? (select 3)

    • A.

      Hering's law can be applied to its innervation

    • B.

      Motor neurons arise from the oculomotor complex

    • C.

      Multiple neurons innervate the levator unilaterally

    • D.

      A single neuron innervates the levator muscle bilaterally

    • E.

      LPS relaxes with tarsal muscle stimulation

    Correct Answer(s)
    A. Hering's law can be applied to its innervation
    B. Motor neurons arise from the oculomotor complex
    D. A single neuron innervates the levator muscle bilaterally
    Explanation
    Hering's law can be applied to the innervation of the LPS, meaning that the LPS follows the principles of Hering's law of equal innervation. Motor neurons that control the LPS arise from the oculomotor complex. Additionally, a single neuron innervates the levator muscle bilaterally, meaning that both sides of the muscle are controlled by one neuron.

    Rate this question:

  • 18. 

    Which of the following is true of lid closure? (select 3)

    • A.

      Palpebral portion: more excitable, rapid blink, relex. spontaneous or basic blink

    • B.

      Orbital portion: less excitable, forced, prolonged closure

    • C.

      Voluntary wink uses palpebral and orbital portion

    • D.

      Orbital portion: more excitable, rapid blink, relex. spontaneous or basic blink

    • E.

      Palpebral portion: less excitable, forced, prolonged closure

    • F.

      Voluntary wink uses only orbital portion

    Correct Answer(s)
    A. Palpebral portion: more excitable, rapid blink, relex. spontaneous or basic blink
    B. Orbital portion: less excitable, forced, prolonged closure
    C. Voluntary wink uses palpebral and orbital portion
    Explanation
    The palpebral portion of lid closure is more excitable, resulting in a rapid blink and reflexive or spontaneous blinking. The orbital portion, on the other hand, is less excitable and is responsible for forced and prolonged closure of the eyelids. During a voluntary wink, both the palpebral and orbital portions are involved in the closure of the lids.

    Rate this question:

  • 19. 

    The chronaxie of the palpebral orbicularis oculi is related to the orbital potion how?

    • A.

      Since it is a slower motion it is 1/2X the orbitals chronaxie

    • B.

      Since it is a faster motion it is 1/2X the orbitals chronaxie

    • C.

      Since it is a slower motion it is 2X the orbitals chronaxie

    • D.

      Since it is a faster motion it is 2X the orbitals chronaxie

    Correct Answer
    B. Since it is a faster motion it is 1/2X the orbitals chronaxie
  • 20. 

    Rapid movement requires low chronaxie

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    The statement is true because chronaxie is the time it takes for a nerve to respond to an electrical stimulus. A low chronaxie means that the nerve can respond quickly to the stimulus, indicating that rapid movement can be achieved.

    Rate this question:

  • 21. 

    Which of the following is true of the sensory innervation of the lid? (select 3)

    • A.

      Comes from the ophthalmic branch of the trigeminal nerve

    • B.

      It comes from cranial nerve 3

    • C.

      The plexus of nerves is deep to palpebral fibers of the tarsal muscle

    • D.

      The plexus of nerves is deep to palpebral fibers of the orbicularis oculi muscle

    • E.

      Requires deep penetration for anesthesia

    Correct Answer(s)
    A. Comes from the opHthalmic branch of the trigeminal nerve
    D. The plexus of nerves is deep to palpebral fibers of the orbicularis oculi muscle
    E. Requires deep penetration for anesthesia
    Explanation
    The sensory innervation of the lid comes from the ophthalmic branch of the trigeminal nerve, as it supplies sensory input to the area. The plexus of nerves is deep to palpebral fibers of the orbicularis oculi muscle, meaning it is located beneath the muscle fibers. This is important to note because it helps in understanding the anatomical arrangement of the nerves in the lid. Lastly, anesthesia for the lid requires deep penetration, indicating that the nerves are located deeper within the lid and not easily accessible.

    Rate this question:

  • 22. 

    Rapid movement requires high chronaxie

    • A.

      True

    • B.

      False

    Correct Answer
    B. False
    Explanation
    LOW chronaxie

    Rate this question:

  • 23. 

    Which of the following is true of Bell's phenomenon? (Select 3)

    • A.

      It is a normal protective response

    • B.

      Disappears when there is a lesion above the pons

    • C.

      It is the upward and outward rotation of globe with forced closure, sleep

    • D.

      It is an abnormal response due to a brainstem lesion

    • E.

      Signals are NOT intact in the midbrain or infranuclear pathway in lower motor neuron palsy

    Correct Answer(s)
    A. It is a normal protective response
    B. Disappears when there is a lesion above the pons
    C. It is the upward and outward rotation of globe with forced closure, sleep
    Explanation
    disappears in brainstem lesion above the pons and is absent in 10% of the population

    Rate this question:

  • 24. 

    Which of the following matches are correct? (select 3)

    • A.

      Simple: dystrophy of the levator muscle. lid lags on down gaze and higher than normal lid crease

    • B.

      Synkinetic: innervation of the levator muscle by V# known as Marcus Gunn jaw-winking syndrome where eyelid retracts with ipsilateral pterygoid muscle contraction

    • C.

      Aponeurotic: failure of the aponeurosis to insert on the anterior surface of the tarsus and skin crease is high

    • D.

      Myotonic: epicanthus inversus, telecanthus, and amblyopia

    • E.

      Collier's sign: dystrophy of the levator muscle. lid lags on down gaze and higher than normal lid crease

    • F.

      Blepharophimosis: seen with myotonia and progressive muscle weakness and possible cataracts

    Correct Answer(s)
    A. Simple: dystropHy of the levator muscle. lid lags on down gaze and higher than normal lid crease
    B. Synkinetic: innervation of the levator muscle by V# known as Marcus Gunn jaw-winking syndrome where eyelid retracts with ipsilateral pterygoid muscle contraction
    C. Aponeurotic: failure of the aponeurosis to insert on the anterior surface of the tarsus and skin crease is high
    Explanation
    The correct matches are:

    1. Simple: dystrophy of the levator muscle. Lid lags on down gaze and higher than normal lid crease.
    2. Synkinetic: innervation of the levator muscle by V# known as Marcus Gunn jaw-winking syndrome where eyelid retracts with ipsilateral pterygoid muscle contraction.
    3. Aponeurotic: failure of the aponeurosis to insert on the anterior surface of the tarsus and skin crease is high.

    These matches describe different types of eyelid disorders and their associated symptoms.

    Rate this question:

  • 25. 

    Which of the following can lead to blepharospasm

    • A.

      Idiopathic causes

    • B.

      Drug induced

    • C.

      Keratitis

    • D.

      Parkison's

    • E.

      All of the above

    Correct Answer
    E. All of the above
    Explanation
    All of the options mentioned can lead to blepharospasm. Blepharospasm is a condition characterized by involuntary spasms or contractions of the muscles around the eyelids. Idiopathic causes refer to cases where the exact cause is unknown. Drug-induced blepharospasm can occur as a side effect of certain medications. Keratitis, which is inflammation of the cornea, can also lead to blepharospasm. Additionally, Parkinson's disease, a neurodegenerative disorder, can cause involuntary muscle movements including blepharospasm. Therefore, all of the above options can contribute to the development of blepharospasm.

    Rate this question:

  • 26. 

    Match the afferent pathways: (Select 3)

    • A.

      Tactile: V CN> Gasserian Ganglion> midbrain

    • B.

      Dazzle: II CN> superior colliculus and supraoptic nuclei

    • C.

      Menace: II CN> LGN> primary visual cortex and association fibers to rolandic area

    • D.

      Dazzle: V CN>Gasserian Ganglion> midbrain

    • E.

      Menace: II CN> superior colliculus and supraoptic nuclei

    • F.

      Tactile: II CN> LGN> primary visual cortex and association fibers to rolandic area

    Correct Answer(s)
    A. Tactile: V CN> Gasserian Ganglion> midbrain
    B. Dazzle: II CN> superior colliculus and supraoptic nuclei
    C. Menace: II CN> LGN> primary visual cortex and association fibers to rolandic area
    Explanation
    The answer is correct because it accurately matches the afferent pathways for each sensory modality. Tactile sensation is transmitted through the trigeminal nerve (V CN), which synapses at the Gasserian Ganglion before reaching the midbrain. Dazzle sensation is transmitted through the optic nerve (II CN), which synapses at the superior colliculus and supraoptic nuclei. Menace sensation is also transmitted through the optic nerve (II CN), but it follows a different pathway, synapsing at the lateral geniculate nucleus (LGN) before reaching the primary visual cortex and association fibers to the rolandic area.

    Rate this question:

  • 27. 

    Which of the following is true of the tactile reflex? (select 3)

    • A.

      Requires cortical input

    • B.

      Absent due to rolandic and cerebellopontine lesions

    • C.

      Absence most commonly due to V CN damage

    • D.

      Entirely brainstem mediated

    • E.

      Can be lost with mesencephalic lesions showing no other neurological defects

    • F.

      Absence most commonly due to II CN damage

    Correct Answer(s)
    A. Requires cortical input
    B. Absent due to rolandic and cerebellopontine lesions
    C. Absence most commonly due to V CN damage
    Explanation
    persists with brainstem transection below the thalamic level

    Rate this question:

  • 28. 

    Which of the following is true of the dazzle reflex? (select 3)

    • A.

      Requires cortical input

    • B.

      Involves the superior colliculus and supraoptic nuclei

    • C.

      Absence most commonly due to V CN damage

    • D.

      Entirely brainstem mediated

    • E.

      Can be lost with mesencephalic lesions showing no other neurological defects

    • F.

      Absence most commonly due to VII CN damage

    Correct Answer(s)
    B. Involves the superior colliculus and supraoptic nuclei
    D. Entirely brainstem mediated
    E. Can be lost with mesencepHalic lesions showing no other neurological defects
    Explanation
    persists with brainstem transection below the thalamic level

    Rate this question:

  • 29. 

    Which of the following is true of the menace reflex? (select 3)

    • A.

      Requires cortical input

    • B.

      Involves the parietal and frontal lobes

    • C.

      Absence most commonly due to V CN damage

    • D.

      Entirely brainstem mediated

    • E.

      May be a learned reflex after the age of 2-4 months

    • F.

      Affect dazzle and tactile reflexes

    Correct Answer(s)
    A. Requires cortical input
    B. Involves the parietal and frontal lobes
    E. May be a learned reflex after the age of 2-4 months
    Explanation
    persists with brainstem transection below the thalamic level

    Rate this question:

  • 30. 

    Which reflexes can lead to blinking? (select 3)

    • A.

      Visual

    • B.

      Auditory

    • C.

      Tactile

    • D.

      Olfactory

    • E.

      Babinski

    Correct Answer(s)
    A. Visual
    B. Auditory
    C. Tactile
    Explanation
    Blinking is a reflex action that occurs in response to certain stimuli. Visual stimuli, such as bright lights or objects coming towards the eyes, can trigger the blinking reflex. Auditory stimuli, such as loud noises or sudden sounds, can also cause blinking. Additionally, tactile stimuli, such as a touch or a foreign object touching the eye, can lead to blinking as a protective response. Olfactory stimuli, related to smell, and the Babinski reflex, which is a reflex in the foot, are not directly associated with blinking.

    Rate this question:

  • 31. 

    Which of the following is true of the cortical control of elevation of the eyelids? (Select 3)

    • A.

      by the frontal cortex

    • B.

      Stimulus of central caudal subdivision of III nucleus results in bilateral elevation

    • C.

      Involves the oculogyric center

    • D.

      By the motor cortex

    • E.

      Involves the precentral gyrus

    • F.

      Descends in the corticobulbar tracts via VII nucleus in pons to orbicularis oculi

    Correct Answer(s)
    A. by the frontal cortex
    B. Stimulus of central caudal subdivision of III nucleus results in bilateral elevation
    C. Involves the oculogyric center
    Explanation
    The correct answer is that the cortical control of elevation of the eyelids involves the frontal cortex, the stimulus of the central caudal subdivision of the III nucleus results in bilateral elevation, and it involves the oculogyric center. This means that the frontal cortex is involved in controlling the elevation of the eyelids, the stimulus from a specific area of the III nucleus causes both eyelids to elevate, and the oculogyric center plays a role in this process.

    Rate this question:

  • 32. 

    Which of the following is true of the cortical control of closure of the eyelids? (Select 3)

    • A.

      It is by the frontal cortex

    • B.

      Stimulus of central caudal subdivision of III nucleus results in bilateral elevation

    • C.

      Involves the oculogyric center

    • D.

      It is by the motor cortex

    • E.

      Involves the precentral gyrus

    • F.

      Descends in the corticobulbar tracts via VII nucleus in pons to orbicularis oculi

    Correct Answer(s)
    D. It is by the motor cortex
    E. Involves the precentral gyrus
    F. Descends in the corticobulbar tracts via VII nucleus in pons to orbicularis oculi
    Explanation
    The cortical control of closure of the eyelids is mediated by the motor cortex, specifically the precentral gyrus. The motor cortex sends descending signals through the corticobulbar tracts, which pass through the VII nucleus in the pons, and ultimately reach the orbicularis oculi muscle. This pathway allows for the coordinated bilateral elevation of the eyelids in response to stimulation of the central caudal subdivision of the III nucleus. The involvement of the oculogyric center is not mentioned in the explanation.

    Rate this question:

Quiz Review Timeline +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Mar 21, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Sep 17, 2017
    Quiz Created by
    Tunstillt
Back to Top Back to top
Advertisement
×

Wait!
Here's an interesting quiz for you.

We have other quizzes matching your interest.