Anatomy of the Eye (Part 3)

Among the organs of the visual system are the eyes. These organs are responsible for providing living organisms with vision, which permits them to receive and process visual detail as well as enable several photoreactive processes independent of vision. The eyes detect light and convert it to electrical impulses in neurons.

Take this quiz to learn about the anatomy of the eye and its functions.

  • Question of

    An innervating muscle that originates on the upper, medial side of the orbit (i.e. beside the nose) and abducts, depresses, and internally rotates the eye. This is the only extraocular muscle innervated by the trochlear nerve (fourth cranial nerve).

    • Superior oblique muscle
    • Superior rectus muscle
    • Medial rectus muscle
    • Inferior oblique muscle

    Correct Wrong

    The superior oblique muscle inserts into the sclera on the posterotemporal surface of the eyeball through a pulley-like structure. Although inserted on the superior surface, it causes depression of the eyeball due to the pulley system.

  • Question of

    This extraocular muscle primary action is extorsion (external rotation).

    • Inferior oblique muscle
    • Medial rectus muscle
    • Lateral rectus muscle
    • Ora serrata

    Correct Wrong

    A primary action of the inferior oblique muscle is extorsion (external rotation), a secondary action is elevation, and a tertiary action is abduction (i.e. it extorts the eye and moves it upward and outward). Its maximum elevation is in the adducted position. It is only the inferior oblique muscle that is capable of elevating the eye when the eye is fully adducted. Innervation of the inferior oblique muscle comes from the cranial nerve III (oculomotor nerve).

  • Question of

    A point of exit for the ganglion cell axons of the eye.

    • Optic disc
    • Vorticose veins
    • Inferior rectus muscle
    • Central retinal artery

    Correct Wrong

    It is the exit point for ganglion cell axons that leave the eye that is called the optic disc. In each eye, this corresponds to a small blind spot because no rods or cones are overlying the optic disc.

  • Question of

    A blood vessel that supplies blood to all fibers of the optic nerve.

    • Central retinal artery
    • Optic nerve
    • Schlemm’s canal
    • Cornea

    Correct Wrong

    Branched from the ophthalmic artery, the retinal artery runs inferior to the optic nerve within the eyeball's dural sheath. All nerve fibers that make up the optic nerve receive blood from the central retinal artery.

  • Question of

    A blood vessel that is short and runs through the optic nerve.

    • Central retinal vein
    • Tenon capsule
    • Sclera
    • Iris

    Correct Wrong

    The central retinal vein is short and runs through the optic nerve. Blood is carried from the retina to the heart by this vein.

  • Question of

    It is a cranial nerve that conveys visual information from the retina to the brain.

    • Optic nerve
    • Fovea centralis
    • Optic disc
    • Superior oblique muscle

    Correct Wrong

    Optic nerves, or cranial nerves II, transmit visual information from the retina to the brain.

  • Question of

    The veins that drain the ocular choroid.

    • Vorticose veins
    • Conjunctiva
    • Posterior segment
    • Central retinal artery

    Correct Wrong

    The vorticose veins, or vortex veins, drain the choroid of the eye. According to research, the number of vortex veins can vary from 4 to 8, with about 65% of the population having 4 or 5.

  • Question of

    The thin membrane that surrounds the eyeball from the optic nerve to the corneal limbus, separating it from the orbital fat and forming the socket in which the eyeball moves.

    • Tenon capsule
    • Pupil
    • Choroid
    • Inferior rectus muscle

    Correct Wrong

    An eyeball's Tenon capsule, also called the fascial sheath, encloses the eyeball from the optic nerve until the corneal limbus, separating the eyeball from the orbital fat and forming a socket in which the eyeball resides.

  • Question of

    It is the part of the retina at the back of the eye that allows good light to produce central, high-resolution, color vision.

    • Macula lutea
    • Tenon capsule
    • Ciliary muscle
    • Ciliary zonule

    Correct Wrong

    Near the center of the retina is a pigmented area called the macula lutea. In good light, the macula is responsible for central, high-resolution, color vision; and if the macula is damaged, such as in macular degeneration, this type of vision is impaired.