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Rat dissection. Learning Objective : To understand where the different organs are in an animal. Collect the equipment you need.
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Rat dissection Learning Objective: To understand where the different organs are in an animal
Locate the vibrissae (whiskers) and the pinna (ears). Rats are gnawing mammals and two large incisor teeth should be visible. Eyes are usually pink or black with a black pupil and covered by a nictitating membrane
The sex of the rat can be determined by looking for external testes, found on males and the presence (or absence) of teats, which are only found on female rats. Female Male
Carefully remove the skin of the rat to expose the muscles below. This task is best accomplished with scissors and forceps where the skin is gently lifted and snipped away from the muscles. Gently peel the skin from the muscles, using scissors and a probe to tease away muscles that stick to the skin
Find the three salivary glands, which are on the sides of the neck, between muscles and the external layer of skin. You should not have to cut very deep. Peel the skin back to expose the salivary glands. They are soft spongy tissue.
Cut lower down to locate the trachea which looks like a tube
1. Locate the diaphragm and the heart is centrally located in the thoracic cavity. The thymus gland, may be visible at the upper part of the heart. • 2. The lungs are spongy organs that lie on either side of the heart and should take up most of the thoracic cavity. They lie closer to the back of the rat, you will need to push the ribs to the side to find them. • 3. A sheet of muscle can be found just under the heart (and above the liver) - this is the diaphragm. This muscle is only found in mammals. (The diaphragm may have been cut when you opened the thoracic cavity.)
Locate the kidneys- These are two bean shaped organs located behind the digestive system on either side of the spine. Locate the delicate ureters that connect the kidneys to the bladder. Wiggle the kidneys to help locate these tiny tubes.
Remove a single kidney (without damaging the other organs) and dissect it by cutting it longitudinally. Locate the cortex (the outer area) and the medulla (the inner area).