SPECIAL SENSES: VISION
MARTINI, FUNDAMENTALS OF ANATOMY &
PHYSIOLOGY, 8TH EDITION, CHAPTER # 17
Exercise # 21
NOTE:
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THIS IS A STUDY GUIDE, NOT AN ALL INCLUSIVE REVIEW.
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THERE MIGHT BE THINGS NOT COVERED BY THIS STUDY
GUIDE THAT MIGHT BE ASKED IN YOUR PRACTICUMS /
QUIZZES.
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STUDENTS ARE RESPONSIBLE FOR READING THEIR
TEXBOOK (S) AND FOR ALL THE MATERIAL COVERED
DURING THE LABORATORY PERIOD, AS PER THE COURSE
SYLLABUS
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OBJECTIVES
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Identifying the structures of the eye and
describe their functions.
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VISION
Accessory structures of the eye
Eyeball
Aqueous humor
Scleral venous sinus
Vitreous humor or body
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ACCESSORY STRUCTURES OF THE EYES:
MUSCLES
MUSCLE
ACTION
SUPERIOR RECTUS
EYE LOOKS UP
INFERIOR RECTUS
EYE LOOKS DOWN
LATERAL RECTUS
EYE ROTATES LATERALLY
MEDIAL RECTUS
EYE ROTATES MEDIALLY
SUPERIOR OBLIQUE
EYE ROLLS, LOOKS DOWN
& TO THE SIDE
INFERIOR OBLIQUE
EYE ROLLS, LOOKS UP &
TO THE SIDE
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ACCESSORY STRUCTURES: GLANDS
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Lacrimal gland- tear production
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Lacrimal sac- collect tears & send them to the nasolacrimal duct
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Nasolacrimal duct- to drain excess of tears to the nasal cavity
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EYEBALL: COATS
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Cornea (clear outer part)- it allows the light to come in
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Sclera (white part)- it protects & gives the shape to the eyes
Choroids - to nourish &to absorb excess of light
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Ciliary body- to contain the ciliary muscle and ciliary process
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Suspensory ligament- it holds the lens in place
Iris (part with color)- to control the size of pupil
Pupil (hole)- it lets the light to go inside
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Retina- it contains photoreceptors
Ganglion cells (their axons form the optic
nerve)-they carry visual info
Bipolar cells-to connect the ganglion cells
to the photoreceptors
Photoreceptors- to capture the light
Rods- night, white & black vision
Cones- bright & color vision
Optic disc (blind spot)- area without
photoreceptors where the optic nerve goes out
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Macula lutea- it contains high
concentration of cones (yellow spot)
Fovea centralis (inside the macula lutea)To give sharpest vision
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Lens- to focus the light
Cavities
Anterior cavity- it contains the aqueous humor
Anterior chamber (space between the cornea
& Iris)- it contains aqueous humor
Posterior chamber (between iris & lens)- it also contains
aqueous humor
Posterior cavity (area behind the lens)it contains vitreous humor
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AQUEOUS HUMOR, SCLERAL VENOUS SINUS
& VITREOUS HUMOR
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Aqueous humor- to nourish the lens & the cornea
Because they do not have blood vessels
Sclera venous sinus (canal of schelmm)- to drain
the aqueous humor.
Important- if obstruction = glaucoma = blindness
Vitreous humor- it maintains the shape of the
lens & prevents collapse
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REMEMBER!
GO TO THE TUTORING ROMM
AND PRACTICE WITH MODELS.
ROMM 3326.
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