Chapter 19: Special Senses Part II (Vision) Flashcards
superficial anatomy of the eye
-superior & inferior palpebrae
-medial & lateral palpebral comissures
-pupil
-iris
what are the palpebrae?
eyelids
provide a superficial covering over its anterior exposed surface
conjunctiva
where are the eyelids united at?
medial and lateral palpebral commissures
parts of the conjunctivial sac
-specialized bursa
-bulbar & palpebral conjuctivia
-covers sclera
parts of the lacrimal apparatus
-lacrimal gland
-lacrimal ducts
-lacrimal canaliculi
-nasolacrimal ducts
located within the superolateral depression of each orbit
lacrimal gland
drains lacrimal fluid into a rounded lacrimal sac
lacrimal canaliculi
what is lacrimal fluid
commonly known as tears
receives the lacrimal fluid from the lacrimal sac
nasolacrimal duct
3 layers of the eyeball
-fibrous layer
-vascular layer
-inner layer (retina)
parts of the fibrous layer
-sclera
-cornea
part of the outer layer that is called the “white” of the eye
sclera
forms the anterior surface of the fibrous tunic
cornea
features of the sclera
-covers 5/6 of eyeball
-opaque, white (irregular fibers)
-attachment for muscles
-has blood vessels
features of the cornea
-convex anterior to iris/pupil
-transparent
-completely avascular
meaning of the cornea being completely avascular
nourishment from ringing capillaries, aqueous humor and tears
parts of the vascular layer
-choroid
-ciliary body
-iris
-pupil
most extensive and posterior region of the vascular tunic & lines most of sclera
choroid
located anterior to the choroid
ciliary body
features of the ciliary body
-attaches the lens
-controls lens focus
-ciliary processes secrete aqueous humor
what type of muscles does the iris have?
involuntary muscles
two groups of smooth muscle layers
-sphincter pupillae
-dilator pupillae
what is the sphincter pupillae controlled by?
-under the control of parasympathetic division of the ANS
-constricts the pupil
what is the dilator pupillae controlled by?
controlled by the sympathetic division of the ANS to dilate the pupil