Chapter 12 Connect part 2:

small pupil diameter

-contraction of the circular set of contractile cells of the iris -contraction of pupillary constrictor muscles -less light enters the eye

large pupil diameter

-more light enters the eye -contraction of the radial set of contractile cells of the iris -contraction of pupillary dilator muscles

vestibular nerve

Nerve impulses arising from the maculae of the vestibule travel next through what structure?

near

accommodation of the lens occurs for ______ vision.

ciliary body

anterior portion; responsible for accommodation of the lens

iris

anterior portion; responsible for control of light entering the eye

cupula

bending of the gelatinous structure called a _______ leads to nerve impulses for the sense of dynamic equilibrium.

extrinsic muscles

during reading, the _____ contracts to move the focus of the eye across the page.

conjunctive

each eyelid(palaebra) is composed of four layers; muscle, connective tissue, and an inner lining called the _____.

processes and muscles

found within the ciliary body are two structures: the ciliary ________ and _________.

false

if a bright light was flashed into an eye, the pupil would dilate.

nervous tunic

innermost layer

-it controls the amount of light coming into the eye -it is the colored portion of the eye -it contains smooth muscle

list three characteristics of the iris of the eye.

-contain enzyme that kills bacteria, reducing the risk of infection -lubricate the eye surface and lining of the lids -moisten the eye surface and lining of the lids

list three functions of secretions produced by the lacrimal glands.

-levator palpebrae superioris -orbicularis oculi

list two muscles that move the eyelid.

vascular tunic

middle layer

ampullae

name the structures within the semicircular canals that contain the receptors for dynamic equilibrium.

fibrous tunic

outermost layer

for close objects, the ciliary muscles contract, which over time causes eye strain

people who gaze at close objects for long periods of time often feel eye strain. Why does this occur?

choroid coat

posterior portion; provides blood supply and contains pigments that prevent reflection

inner

rods and cones are found in the _____ tunic of the eye.

nasal

tears drain from the eye through the nasolacrimal duct into the _______ cavity.

anterior

the _______ chamber is located between the cornea and the iris.

choroid coat

the _______ is the pigmented layer found in the posterior five-sixths of the eye. It is very vascular, and helps nourish surrounding tissues. Its dark color helps keep the interior of the eye dark.

dynamic equilibrium

the cerebellum is involved in which of the special senses?

cornea

the clear, anterior-most structure of the eye, part of the fibrous tunic, is called the ______.

true

the extrinsic eye muscles are considered accessory organs of the eye.

cupula

the hair cells of the crista ampullaris have hairs that extend into what structure?

apparatus; gland

the lacrimal ________ is a series of accessory structures of the eyes. It consists of the lacrimal ______, which secretes tears, and a series of ducts which carry the tears into the nasal cavity.

accommodation

the process of changing the shape of the lens to view a close object is called ______.

iris

the pupil is a hole in the center of what structure of the eye?

outer

the sclera and the cornea make up the _____ tunic, or layer, of the eye.

lens

the transparent structure of the eye that changes shape to focus light onto the retina is the _______.

iris

the variations in eye color are determined by the amount and distribution of melanin in what structure of the eye?

cristae ampullaris

what are the sensory organs for the sense of dynamic equilibrium?

to produce pigments, which absorb excess light

what is the function of the melanocytes in the choroid coat?

sclera

what is the name of the protective outer layer covering the posterior five-sixths of the eye?

macula lutea

what is the yellow patch of cells in the central region of the retina called?

ciliary body

what part of the middle layer of the eye holds the lens in place via the suspensory ligaments?

maculae

what sensory receptor has an otolithic membrane associated with it?

optic nerve

what structure exits the back of the eye?

lining eyelids and covering anterior eyeball(except the cornea)

where is the conjunctiva found?

between the stapes and the inner ear

where is the oval window located?

hair cells

within the cochlea, different ____ respond to different sound frequencies(pitches).

tympani; vestibuli

within the cochlea, the scala ________ is associated with the round window; and the scala ______ is associated with the oval window.

aqueous humor

within the eye, what fluid is secreted into the posterior chamber, circulates into the anterior chamber and leaves through the scieral venous sinus?

constriction; diator

within the iris; the pupillary ______ is a set of circular muscles that act as a sphincter. the pupillary _____ is a set of muscles that act to increase the size of the pupil.