Cow’s eye dissection
To locate and distinguish specific parts to an eye of a cow, in particular, its lens. OBSERVATIONS ~
Before actually beginning the dissection of the cow’s eye, we were about to sketch a fairly relative picture of our observing’s of the exterior body of the eye. The eye, having almost completely being sheltered in fat and muscle, was quite firm and only the cornea and optic nerve was identified. By further cutting down the fat, we were able to spot a rather tough pinkie white outer covering of the eyeball, which we later discovered to be known as the sclera. We also noticed the blue covering over the front of the eye, known as the cornea, which became cloudy after death. Finally beginning the dissection, we made an incision in between the sclera and cornea which took much effort as it was quite tough. However once slit, a clear liquid named the aqueous humour was able to ooze out. Dissecting further, we were able to remove the lens, the iris and the pupil. The iris, suspended between the cornea and lens, came out as a rather brown coloured circle. The pupil, distinguished as the dark circle in the centre of the iris was rather quite oval. The lens was a tiny blob of white which resembled an ice capsule but however had a rather pasty soft, smooth and easily damaged texture. When splitting the eye in half, we were able to discover its rather liquid-filled chamber in which a black, jelly-like substance called the vitreous humour seeped out. Deep near the end of the inner eye with all the vitreous humour removed, was the retina. Shaped like a bowl, the light blue retina contained red blood vessels which are assumed to receive the oxygen transmitted from the blood. The eye was quite warm, considering its defrosting methods and emitted little odour which in turn suggest that its rotting stage hasn’t yet begun.
1. The cornea of your eye is clear. The cornea of your dissected eye is cloudy. Why? No oxygen via the bloodstream is being sent to the eye because the living organism’s system is dead and stops working, thus clouding it. 2. Why is it important for the cornea and lens to be clear? What would happen if it wasn’t clear? It is very important that both the cornea and lens are clear as this allows the light to pass directly through the front of the eye to the retina. If it were black for example, the light would be restricted and without being able to see light, our vision would also be restricted. For another example, if the lens were clear but however was damaged in any fashion with maybe a scratch, what we see will also be affected. 3. In dim light, the pupil opens wide to become larger. Why is this important? What would happen if it didn’t do this? The pupil can choose to alter its size in response to light intensity by constricting and increasing its size in the dark by dilating. If the pupil was restricted and unable to alter its size due to the luminosity rates in the external environment, we would be exposed to too much light which could make us prone to discomfort and affect our ability to see clearly. At the same time, if we were exposed to low luminosity rates without our pupil changing in size, we would not be able to see in dim light. 4. In regards to question 3, would you consider this to be an adaptation? Explain. Yes. The pupil’s ability to adapt to the luminosity rates in our environment enables us to be able to withstand bright light and darkness. Without this adaptation, we would not be able to see in dim light and we would be prone to sight abnormalities. Conclusion ~
Overall, the dead eye of a cow was seen to be cloudy signifying its loss of life and lack of intake of oxygen. The eye was discovered to be mostly filled with fluids of the vitreous and aqueous humour. The eye overall was discovered to be quite firm considered its shelter of fat and muscles. As such, cutting through the eye took quite an effort. It was also discovered that the eye...
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