Sheep Eye: Pre-OpMay 16, 2016 We will: Go over Eye Structures Notes View Sheep Eye dissection Virtual Lab You will: Complete dissection tomorrow
What is a sensory organ? • The purpose is how we interact with our environment. • Sensory Input • Integration (Brain choice) • Motor Output
Human eyes are only about 1” in diameter with only about 1/6th being seen.
The Conjunctiva The conjunctiva is a delicate membrane that lines the eyelids and covers part of the outer surface of the eyeball. Conjunctivitis (pink eye) is inflammation of the conjuntiva and is caused by a bacteria or virus.
LacrimalGlands release a dilute salt solution (tears) onto the anterior surface of the eyeball. These secretions contain antibodies and lysozymes that clean and protect the eye’s surface and add moisture.
There are 6 muscles that attach to the eye. These muscles allow our eyes to follow moving objects.
Cornea: Clear surface of the eye; It is the most exposed part of the eye. It can be transplanted without rejection because there is no blood supply, however is can easily repair itself. Sclera: White part of the eye
Iris: the colorful part of the eye. The iris controls how much light passes through the pupil. Pupil: dark spot in the middle of the eye Bright light →pupil constricts Dim light → pupil dilates
Retina : contains millions of receptor cells called rods and cones. Rods see black and white. Conesseecolors. They work together, so we see the world in color.
Night Blindness – Anything that interferes with rod functions. The most common cause is vitamin A deficiency
VIRTUAL https://www.youtube.com/watch?v=zcumLASlKHI http://science.jburroughs.org/resources/skeleton/eye/eyedissection.html