Questions and Answers
What are the three layers of the eyeball?
Fibrous, vascular and nervous tunics
What does the fibrous tunic consist of?
Cornea and sclera
What is the function of the cornea?
Helps to focus light entering the eye
What is the sclera commonly referred to as?
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Where do the extraocular muscles attach?
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What composes the vascular tunic?
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What is the iris?
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What does the choroid do?
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What do ciliary bodies connect to?
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What does the nervous tunic consist of?
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What is the retina made up of?
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What is aqueous humor?
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What is vitreous humor?
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What is the pupil?
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What role does the lens play in vision?
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What are the names of the six extrinsic eye muscles?
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What is the function of eyebrows and eyelashes?
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What do eyelids do?
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What is conjunctiva?
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What does the lacrimal apparatus do?
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What direction does the inferior rectus muscle move the eye?
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What direction does the medial rectus muscle move the eye?
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What direction does the superior rectus muscle move the eye?
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What direction does the lateral rectus muscle move the eye?
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What direction does the inferior oblique muscle move the eye?
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What direction does the superior oblique muscle move the eye?
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Which extraocular muscle(s) receives innervation from CN III (Oculomotor Nerve)?
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Which extraocular muscle(s) receives innervation from CN IV (Trochlear Nerve)?
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Which extraocular muscle(s) receives innervation from CN VI (Abducens Nerve)?
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Study Notes
Tunics of the Eye
- The eye has three main layers known as the tunics: fibrous, vascular, and nervous tunics.
Fibrous Tunic
- Composed of two parts: the cornea and sclera.
- The cornea is the transparent front part that helps focus light.
- The sclera is commonly referred to as the "white of the eye."
Vascular Tunic
- Made up of the iris, choroid, and ciliary bodies.
- The iris gives the eye its color and surrounds the pupil.
- The choroid is a vascular layer that nourishes the retina.
- Ciliary bodies are connected to suspensory ligaments and support the lens.
Nervous Tunic
- The retina comprises the nervous tunic.
- The retina consists of photoreceptors called rods and cones, essential for vision.
Fluids of the Eye
- Aqueous humor is a thin fluid found in the anterior cavity, providing nourishment and maintaining pressure.
- Vitreous humor is a gelatinous substance located in the posterior segment of the eye.
Key Structures
- The pupil is the opening in the iris that allows light to pass through to the retina.
- The lens focuses images on the retina and adjusts shape for distance or near vision.
Extrinsic Eye Muscles
- Six extraocular muscles control eye movement:
- Superior Rectus: Moves the eye up.
- Inferior Rectus: Moves the eye down.
- Medial Rectus: Moves the eye medially.
- Lateral Rectus: Moves the eye laterally.
- Superior Oblique: Rolls the eye down and laterally.
- Inferior Oblique: Rolls the eye up and laterally.
Muscle Innervation
- CN III (Oculomotor Nerve) innervates the Superior Rectus, Inferior Rectus, Medial Rectus, and Inferior Oblique.
- CN IV (Trochlear Nerve) innervates the Superior Oblique.
- CN VI (Abducens Nerve) innervates the Lateral Rectus.
Protective Structures
- Eyebrows and eyelashes help prevent debris from entering the eye.
- Eyelids protect the eyes from debris and keep them lubricated with tears.
- The conjunctiva is the epithelial layer covering the inner eyelids and outer eye surface.
- The lacrimal apparatus produces tears and drains them from the eye to the nose.
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Description
This quiz covers the three tunics of the eye, including their definitions and components. Learn about the fibrous tunic, its parts like the cornea and sclera, and the function of the extraocular muscles. Perfect for students studying eye anatomy!