Unit 1 Vision Flashcards
Where do the light rays from the image you view pass through?
Through the pupil. then lens, where they are focused on the retina.
What is the function of the iris?
It allows the right amount of light to enter the eye for proper focusing.
What is the orbital region?
It is the region that we see around the face. (external structure of our eye)
What is the Orbital region made up of?
Face around the eye and Lacrimal Apparatus.
What does the Lacrimal Apparatus do?
Tear production
What is the function of the Eyelids and which cranial nerve is used when we close our eyes reflexively?
Protects our eyes, and the corneal reflects where it closes the eyelids reflectively (CN7)
When we blink, it spreads the lacrimal fluid throughout the eye
What are three parts of the Lacrimal Apparatus?
Lacrimal gland
Lacrimal Canaliculi
Nasolacrimal Duct
What is the orbit?
Cone shaped cavity formed by the skull that houses and protects the eyeball.
What is the orbit (cavity formed by the skull) padded with?
Padded With fatty tissue that acts as a cushion to prevent injury
How many short muscles connect the eyeball to the orbit?
Six short muscles
What is the function of the six short muscles that connects the eyeball to the orbit?
It allows rotary movement so we can see in all directions.
Why do the eyelids close over the eye?
To protect it from light, foreign particles, or impact injury
What is the role of the Eyelashes in the eyelid?
It helps prevent large particles from entering the eye.
What is the role of the sebaceous glands (sties) of the eyelids?
They secrete oil to keep the eyelids soft and pliant (나긋나긋한) and make the eyelashes slightly sticky to trap particles.
What is the conjunctiva?
It is a membrane over the surface of the eyeball that acts as a protective covering for the exposed surface.
What is the role of the lacrimal apparatus?
Produce and Store tears
What does the lacrimal apparatus contain?
The lacrimal gland and its corresponding ducts.
What is the role of the tear that is produced by the lacrimal gland?
For cleaning and lubrication
Tears also act as an antiseptic
(prevents or slows the growth of microorganisms on the body’s external surfaces)
What is crying?
Crying is when there is too much fluid for the canal to handle
What is the globe-shaped eyeball organ of?
It is the organ of vision
What is the eyeball separated into?
It is separated into two chambers of fluid that help to protect the eye.
What are the fluids of the eye called?
Humors
What is the Aqueous humor and where does it bath?
It is watery and bathes the iris, pupil, and lens.
Which part of the chamber does the Aqueous humor fill?
Anterior and posterior chambers.
What is the Vitreous humor?
It is a clear jelly-like fluid.
Which part does the Vitreous humor occupy?
It occupies the entire cavity behind the lens
How many layers does the eye have?
Three layers
What are the three layers of our eye?
Fibrous Layer
Vascular layer
Inner Layer
What are part of the Fibrous Layer?
Sclera
Cornea
Which part of the eye is Sclera?
It is the tough, opaque part of the eye.
(the outer white part)
(opaque means not able to be seen through; not transparent.)
What is the role of the Sclera?
It provides attachment site for both the intrinsic and extrinsic muscles.
-Extrinsic muscles are muscles that originate outside of a body part and insert into that part.
-Intrinsic muscles are muscles that are located deep within the body or close to the axial and appendicular skeleton.
Which part of the eye is Cornea?
Transparent part of the eye
How many layers does Cornea contain?
6 layers
What are part of the Vascular Layer?
Choroid
Ciliary body
Iris
Pupil
What is the role of Choroid?
Blood supply to the eye
What is the role of the Ciliary Muscle?
It helps change the shape of our lens when our eyes focus on a near object.
Where is the Iris?
It is the area around our pupil
Iris has two muscles. What are they called?
Sphincter pupillae
Dilator pupillae
What do the Sphincter pupillae do?
Muscle contracts: Pupil constricts (size decreases)
What do the Dilator pupillae do?
muscle contracts: Pupil dilates (size increases)
Is Sphincter pupillae Parasympathetic or Sympathetic?
Parasympathetic
Is Dilator pupillae Parasympathetic or Sympathetic?
Sympathetic
What is the Choroid?
It is highly vascularized, pigmented middle layer that provides nourishment to the eye
Which portion is the Iris?
The colored portion that controls the opening of the pupil where light passes into the eye
What is the another role of the Iris?
A sphincter (괄약근) that, in low light relaxes, allows the pupil to dilate so more light can enter.
What is located behind the pupil?
Lens
What is the Lens surrounded and attached by?
Ciliary muscles
What can the Ciliary muscles do?
They alter the shape of the lens, making it thinner or thicker to allow the incoming light rays to focus on the retina.
What is accommodation of the eye?
It is the eye’s ability to change the shape of its lens and size of the pupil to focus on objects at different distances.
This process allows the eye to see objects that are both near and far away.
What happens when you are looking at an object at a far distance? (Accommodation related)
Ciliary muscle is relaxed
Zonular fibers pull the Lens and flatten to focus on distant object.
What happens when you are looking at an object at a close distance? (Accommodation related)
Ciliary muscles contract
Zonular fibers relax and allow the lens to thicken to focus on close object
What is the shape of Lens controlled by?
Ciliary muscle
What happens to the Lens when we are looking at something that is close?
Lens gets thicker
What happens to the Lens when we are looking at something that is far?
Lens gets thinner
What is the normal Lens called?
Emmetropia
What is it called when Lens is not in the correct shape and the light is short?
Myopia
What is it called when Lens is not in the correct shape and the light overshoots?
Hyperopia
What is the role of the Retina?
It converts light into synapse (신경 접합부)