Learn about the anatomy of the White Rat. Gain dexterity with instruments used in the dissection procedure. Compare and /or contrast the anatomy of the White Rat with that one of the Human body. MATERIALS AND INSTRUMENTS: Cadaver of a White rat, preserved in chloroform. A dissection pan, Butcher’s twine, Bounty paper towels, latex gloves. Instruments used in the dissection kit: Scissors; Forceps; Scalpel; and the Probe
The first step was to obtain the White Rat and to tie it in the supine position, anterior surface facing up in side the dissection pan. To tie the animal, we used butcher’s twine and secured the front and hinds legs using a “lasso” technique, careful not touch the sharp claws. To make the first insicion I had to locate the Xifoid Process of the rat (distal aspect of the sternum). Once I had located the Xifoid Process, I had to use forceps to pull the skin of the animal’s abdomen up and use the scissors to cut. The first incision is made from stem to sternum, cutting through the errectos abdomen muscle down to the groin. The second incision ion is perpendicular to the first below the diaphragm. Because of this technique we were able to open the abdominal cavity first. The third and forth incisions were made bilaterally above the legs. The last two incisions were made in upside down “V” shape on the collarbone, to expose the thoracic cavity. This dissection was both sharp, because of the use of the scissors and scapel and blunt because of the use of the probe and forceps to move organs and skin to expose other organs not yet identified.
SKIN: Yellowish in color covered with white fur, hard and stiff in texture
LARYNX: Off white in color. Long tubular structure descending from the upper area (mouth) of the rat.
TRACHEA: Pinkish in color, looked like a stack of cartilage rings with some space between the rings.
LUNGS: Dark reddish brown in color. It had 6 lobes. One on the left side, 2 lobes in the middle, and 3 on the right side.
HEART: Located inferior to the trachea and superior to the diaphragm and liver, light pink in color. It appeared to be the size of a lima bean, surrounded by a bright pink rubbery substance, said to be a ruptured blood vessel. The left and right atrium was dark brown and located at the coronal end of the heart. It appeared that there was only one ventricle which was light brown in color.
AORTA: Located superior tot he heart between the two atriums, was reddish in color and bean-shaped, the Vena Cava was attached at the dorsal side of the ventricle, and it was blue in color with a threadish appearance.
SPLEEN: Located inferior to the one lobe of the liver, lateral to the stomach. It was dark brown in color, vertically lengthened, flat and smooth.
THYMUS GLAND: Located superior to the heart, surround the trachea, pinkish brown in color and bean shaped.
ADRENAL GLAND: superior to the kidneys, they are small and light brown in color
DIAPHRAM: Medial area of the rat, separating the thoracic cavity from the abdominal cavity. It was tan in color, thin, sturdy, but still quite flexible in structure.
LIVER: Inferior to the diaphragm, dark brown with 7 lobes, three lobes on both sides with one lobe on the underside of the liver. It appeared to be the largest internal organ of the white rat.
STOMACH: Beige in color, kidney bean shaped. Anterior to the liver, “full” to the touch as if it was filled with matter. It was 1 ½ “ vertically, and 1 ½ “ horizontally in size.
DUODENUM: Connected at the top of the stomach and below to the small intestine, whitish in color with a long, flat balloonish appearance.
PANCREAS: Inferior to the liver and stomach, light brown in color, the pancreas was long and it’s appreance resembled many different small particles held together in a single membrane.
MESENTERY: Inferior to the liver, thin transparent in color, resembling a cross section of cauliflower. It couldn’t be determined if it contained the small intestines but it was visible to note that they were beige in color and looked like a pile of worms stuck together.
ESOPHAGUS: Pinkish in color, thin tissue-like structure that was cited around the tracheal area and descended to the area of the stomach.
GREAT OMENTUM: Beige in color, looked like actual kidney beans, quite hard and slippery. The left kidney appeared to be attached to the posterior wall, while the right kidney was not as close to the all as the left. It was located on the right transverse side respectively. Both kidneys were posterior to the liver in the retroperitoneal area of the rat.
UNINARY BLADDER: Inferior to the kidneys. Grayish in color with a small peanut shape.
RIGHT RENAL ARTERY: Reddish in color coming off the medial side of the kidney.
The reproductive system was mainly located towards the anal area and inferior to the stomach. The penis was located in the middle. It was white in color and looked like a mealworm. The seminal vesicles were located on both sides of the penis. They were grayish pink in color and looked like walnuts.
COMPARE AND CONTRAST:
There were a few observations proven to be different between the rat’s anatomy in comparison to the human anatomy. First of all, the rat has no gallbladder present in it’s anatomy which a human does. Secondly, the rat’s lungs appeared dark red in color where as a human’s lungs are pink in color. Also the rat’s liver has more lobes as does their lungs compared to a human’s liver and lungs. Besides these said differences, the rat’s anatomy is basically very similar to that of the human body.
none---hands on information