Rat DIEssection

Fresh Alcochol-drowned-rat

 When I first heard that we were dissecting rats, I was shocked.Although we had few dissection labs, I didn't think I would dissect a chordate. I mean, I can dissect worms and squids no problem, but rats are just too real and vivid for me to dissect. Anyhow, the purpose of this lab was to dissect the rat and by doing that,

understand the internal and external features of the general chordate, especially those of class mammalia. 

Nathan preparing surgeory

Last week, I arrived in class highly worried, in contrast to other dissection labs where I felt nervous and exciting. Our group got a female rat. Firstly, we observed the odd external features of the rat. The rat, being classed under mammalia, had mammary glands. 12 of them. It also had hair on its body, which is the second characteristic of the mammals. I assumed the rat had a diaphragm because throughout class, I learned that all mammals had a diaphragm, mammary glands, and hair. I also knew that these rats were viviparous, and was afraid that when I opened up the rat, I would see babies inside.  Our group started dissecting by carefully and passively cutting the rat's body. Luckily for us, there were no babies. Nathan and Alan lead the surgery, and later on, I subbed in for Alan. When we cut its body, I could finally see the rat's internal organs. The 4-chambered heart, intestines, and liver caught my attention. We proceeded on to further investigate the deepest areas of rat's anatomy, and took out the intestine. As a result, we were able to thoroughly investigate the whole internal organs of the rat's body. 

After cutting it open

Upon completion of this lab, I gained many things. Those were: improved knowledge on mammal's external and internal features and confidence in dissecting. Without this lab, I wouldn't have known that rats had 12 nipples. Despite myself being grossed out by the rat, in the end, I really enjoyed the lab. This lab was meant to be the finale of Biology 11- it simply had a huge impact on me. 

Discussion Questions:

1. Because god gave us 10 styluses; It is the most precise and controllable.

2. To differentiate between all other organs and structures. This will act as your guide line.

3. Tails are different because they are slimier and more disgusting than bodies. Other than that, it is used to keep itself stable and control its body heat

4. Vibrissae is a feeler.

5. This means that it is more developed than those of radially symmetrical organisms. Also it means, that both sides are equal when cut in half.

Discussion Questions

1. The circular muscle, sphincter, controls the passage of material

2. Small and Large intestines differ in sizes because they carry out different jobs. Large intestine absorbs water from undigested material, and small intestine absorbs nutrients as well as water.

3. The liver transforms the nutrients (breaks down) into a body-suitable nutrient.

After taking out the
intestines of the rat

4. Duodenum is a latin name for 12 finger-lengths. So it got its name by being approximately being 12 finger-legnths long.

5. The appendix is there because it digests cellulose

Discussion Questions:

Intestines of the rat

1. The membrane that cover both the wall of the cavity and the organ in contains is called the peritoneum. It holds all the organs in place.

2. The function of spleen is to remove red blood cells and to replace them with new lymphocytes

3. Diaphragm's function is to help breathing of the animal by lifting up the chest.

4. Atria and Ventricles are different. Atria holds the blood which then goes to the ventricles that contract blood and pump the blood to the lungs, and body.

5. The left ventricle is thicker because it pumps blood to the body, and is faced against the pressure of the aorta.

6.  They both are used to reproduce. They mature at the same rate.

7. Kidneys regulates the body fluid

8. The thyroid, thymus, and the adrenal glands are all part of the endocrine system. They have different jobs. Thyroid coverts iodine to thyroid hormones, thymus produces t-cells, and the adrenal glands produce hormones against stress.

***PICTURE TO BE ADDED