The conjunctiva
is the mucous membrane that lines the eyelid and eye surface. In a healthy eye, the conjunctiva is clear and colourless.
What is the thin transparent membrane covering the eye?
Near the front of the eye, in the area protected by the eyelids, the sclera is covered by a thin, transparent membrane (
conjunctiva
), which runs to the edge of the cornea. The conjunctiva also covers the moist back surface of the eyelids and eyeballs.
What is a thin transparent membrane covering the eye and inner surface of the eyelids?
Conjunctiva
– the transparent mucous membrane that lines the inner surfaces of the eyelids and covers the sclera, except at the cornea. Conjunctivitis – an inflammation or infection of the conjunctiva. Also known as “pink eye.”
What covers the inner surface of the eye and eyelids?
The conjunctiva
is a thin membrane that covers the inner surface of the eyelid and the white part of the eyeball (the sclera). Inflammation of the conjunctiva is called conjunctivitis. It makes the white of the eye look red.
Which of these is a transparent mucous membrane that covers the inner surface of the eyelid?
The conjunctiva
is the transparent mucous membrane that lines the eyelids (palpebral conjunctiva) and covers the membrana nictitans and the anterior sclera (bulbar conjunctiva).
In what ways are the eyes protected?
The visible part of the eye is
protected by the eyelids and the eyelashes
, which help keep dirt, dust, and even harmful bright light out of the eye. Eyes are also protected by tears, which moisten them and clean out dirt, dust, and other irritants that get past the defenses of the eyelashes and eyelids.
Where is the retina most sensitive?
So the retina is most sensitive at
fovea centralis
. Periphery: Peripheral vision is the work of the rods and nerve cells located largely outside the macula i.e. the centre of the retina. These rods are responsible for night vision and low light vision but insensitive to colour.
What is the inner part of your eyelid called?
The inner aspect of the eyelid is called
the inner canthal region
. At this region runs a fold of skin called the nasojugal fold. From an anatomical point of view, this fold lies between the orbicularis oculi and the levator labii superioris.
What is the pathway of light through the eye?
Light passes through
the front of the eye (cornea) to the lens
. The cornea and the lens help to focus the light rays onto the back of the eye (retina). The cells in the retina absorb and convert the light to electrochemical impulses which are transferred along the optic nerve and then to the brain.
What is the tarsal plate of the eyelid?
The tarsal plates serve
as the main structural component of the eyelids
. They are made of dense connective tissue and contain the Meibomian glands and eyelash follicles. There are approximately 30 meibomian glands in the upper eyelid and 20 meibomian glands in the lower eyelid.
What nerve opens eyelids?
The oculomotor nerve (CNIII)
innervates the main upper eyelid retractor, the levator palpebrae superiorus, via its superior branch.
What fluid prevents eyelids from sticking together?
The eyelid has
sebaceous
glands that make an oily secretion that prevents the watery film on the eye from evaporating and the eyelid from sticking together.
What are 4 structures that protect the eye?
The
orbit, eyelashes, eyelids, conjunctiva, and lacrimal glands
help protect the eyes.
What is the name of the muscle that raises the eyelid?
The function of
the levator palpebrae superioris muscle
is to raise the upper eyelid and to maintain the upper eyelid position. The levator palpebrae superioris muscle origin is the periosteum of the lesser wing of the sphenoid bone, superior to the optic foramen.
What is the main function of the rods in the eyes?
Rod, one of two types of photoreceptive cells in the retina of the eye in vertebrate animals. Rod cells function as
specialized neurons that convert visual stimuli in the form of photons (particles of light) into chemical and electrical stimuli that can be processed by the central nervous system
.
What surface of the eye is not covered by the conjunctiva?
The
bulbar conjunctiva
covers the anterior part of the sclera (the white of the eye). It does not cover the cornea. The palpebral conjunctiva covers the inner surface of the upper and lower eyelids. The bulbar and palpebral conjunctiva are both continuous, making it impossible to lose a contact lens behind your eye.
