As I take you through the path of light I will be explaining what each structure is responsible for and how it handles light. As I get to the path light takes as it enters our eyes I will point out four mechanisms that have to function in order for us to see. Each of our eyeballs have six muscles that attach them to our skull. Four of these muscles pull straight and are called rectus muscles. Two of these muscles pull on an angle and are called oblique muscles. The first mechanism is the coordination of these muscles (both eyes) so that our eyes move together. As we open our eyelids (provides protection and lubrication of eyeballs) the light will hit the outer most part of our eye called the cornea. The cornea is in charge of allowing light
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Mechanism two requires is the correct amount of light allowed by the pupils. The light will travel through the aqueous humor which is a watery substance between the cornea and lens. Once the light hits the lens, attached to the ciliary body, it is focused onto the retina. The ciliary bodies pull on the edge of the lens in order to change its shape so that it can focus the light onto the retina correctly. The third mechanism requires the correct focus of light onto retina by the lens. As the light is being reflected onto the back of our eyeballs (retina) it is traveling through vitreous humor which is an almost solid gel substance. When the light strikes the retina it provokes rods and cones located there. Rods and cones are sensory receptors that detect light rays. Rods are responsible for gray tones and are active in dim light. Cones are the opposite; color tones and are active in bright light. The area of the retina where an actual image is formed is called the macula lutea that contains a depression in the center, with a high number of cones, called the fovea centralis. This is the point where our vision is the …show more content…
I’ll start by describing the parts we can see without medical tools. The top part of your ears that is harder to bend is the pinna or auricle. It actually has a function (I was surprised too!) and that is to direct sound waves toward the external auditory meatus which is the sunk in part leading to the “hole” in our ears. The other part we can see is the lobe and has no active part in helping us hear. Now moving further into the outer ear the sound travels through the external auditory canal. At the end of the canal the sound will hit our eardrum, known as the tympanic membrane, and cause it to vibrate. Once past our eardrums the sound/vibration has entered the middle ear. The middle ear is a small cavity embedded in the temporal bone of our skull. The first thing the vibrations will hit will be one of three ossicles (tiny bones) called the malleus. It is notorious for its hammer shape. Keep in mind that the vibrations are amplifying as they move on the ossicles. The second ossicle is the incus which is notorious for its anvil shape. The incus extends to the next ossicle called the stapes, notorious for its stirrup shape. On the end of the stapes is the oval window which is the start of the inner ear. The inner ear is also located in a small cavity embedded into our temporal bone. This cavity is known as the labyrinth. The movements of the oval window that the vibrations
Mechanism two requires is the correct amount of light allowed by the pupils. The light will travel through the aqueous humor which is a watery substance between the cornea and lens. Once the light hits the lens, attached to the ciliary body, it is focused onto the retina. The ciliary bodies pull on the edge of the lens in order to change its shape so that it can focus the light onto the retina correctly. The third mechanism requires the correct focus of light onto retina by the lens. As the light is being reflected onto the back of our eyeballs (retina) it is traveling through vitreous humor which is an almost solid gel substance. When the light strikes the retina it provokes rods and cones located there. Rods and cones are sensory receptors that detect light rays. Rods are responsible for gray tones and are active in dim light. Cones are the opposite; color tones and are active in bright light. The area of the retina where an actual image is formed is called the macula lutea that contains a depression in the center, with a high number of cones, called the fovea centralis. This is the point where our vision is the …show more content…
I’ll start by describing the parts we can see without medical tools. The top part of your ears that is harder to bend is the pinna or auricle. It actually has a function (I was surprised too!) and that is to direct sound waves toward the external auditory meatus which is the sunk in part leading to the “hole” in our ears. The other part we can see is the lobe and has no active part in helping us hear. Now moving further into the outer ear the sound travels through the external auditory canal. At the end of the canal the sound will hit our eardrum, known as the tympanic membrane, and cause it to vibrate. Once past our eardrums the sound/vibration has entered the middle ear. The middle ear is a small cavity embedded in the temporal bone of our skull. The first thing the vibrations will hit will be one of three ossicles (tiny bones) called the malleus. It is notorious for its hammer shape. Keep in mind that the vibrations are amplifying as they move on the ossicles. The second ossicle is the incus which is notorious for its anvil shape. The incus extends to the next ossicle called the stapes, notorious for its stirrup shape. On the end of the stapes is the oval window which is the start of the inner ear. The inner ear is also located in a small cavity embedded into our temporal bone. This cavity is known as the labyrinth. The movements of the oval window that the vibrations