Rat Dissection!

     On Thursday, January 17 and Friday, January 18, our Biology class dissected a Rat! Yes, those disgusting rodents that almost every person loathes *yuck. I missed Friday's class, but I was still able to see the rat get cut open on Thursday, and it looked both fascinating and disgusting at the same time. The purpose of this dissection was to learn about the anatomy of the rat, both inside and out. The rats were preserved, so there was no presence of blood (thankfully). Before this lab, we learned about the different classes of vertebrate animals within the Phylum Chordata living on our planet. These different classes include Class Amphibia (Amphibians), Class Agnatha (Jawless Fish), Class Chondrichthyes (Cartilagenous Fish), Class Osteichthyes (Bony Fish), Class Reptilia (Reptiles), Class Aves (Birds) and finally Class Mammalia (Mammals). After learning more about all the different classes of animals, I couldn't wait to delve into this rat dissection.


     We started this dissection by observing the external anatomy of the rat and checking its gender first. Our rat was a male since it had a pair of testes. Since this rat was preserved, it was pretty stiff, especially its tail. After quickly observing the external anatomy of the rat, it was time to finally cut it open! Since there was an open slit near its neck, we decided to start there for a nice and clean cut through. After precise cutting, we were able to open up the rat. Upon opening the rat, a number of organs were within our sights, including both the small and large intestines, the lungs, the liver, the stomach and many more organs. After observing all these organs, my group decided to pull out the intestines, and soon afterwards, the heart. I was not there physically to be able to observe the intestines or the heart being pulled out, but judging from the pictures, I could tell it wasn't an easy job. Overall, this dissection was a fascinating experience and out of all the dissections that I've taken part of in this class, this one would have to be the most fulfilling one yet.  



   

1) Why are your hands the best tools in dissection?
Your hands are the best tools in dissection simply because we use them everyday . We also get a hands on experience for the betterment of our learning and hands on experience. 

2) What is the purpose of having all the different labels and titles for the dissection?

The purpose of having all the different labels and titles for the dissection so its easy to organize and identify each structure.

3) In what way does the tail differ from the rest of the body?
The tail differs from the body since it has no specific function.  

4) What purpose is served by the vibrissae?
The purpose of the vibrissae is to help the rat take in its surroundings. 

5)Your specimen is bilaterally symmetrical. What does this mean?
Being bilaterally symmetrical means that if the specimen is cut in half, the two sides would mirror each other. 

6) The Sphincter is described as a circular muscle. Why is it this shape and what does it do?

The Sphincter is in the shape of a circle and it lets food through.

7) Why is there a difference in size between the small and large intestine?
There is a size difference in the intestines so that large intestine breaks down the food and the small intestine breaks down and spreads out the nutrients.

8) The liver is the largest organ in the body. What is its function?
The liver clears out any poisonous substances within the body and purifies and deoxifies  oxygen.

9) How did the duodenum acquire its name?
The duodenum was given its latin name because of its 12 fingerbreadths  long (25 cm) meaning, which is what the meaning of duodenum implies. 

10)  What is the purpose of the appendix in animals who retained this as a functional organ?The appendix aids in digesting tough foods since it contains special digestive enzymes.

11) In each of the cavities, there is a membrane that covers both the wall of the cavity and the organ it contains. What is the function of the membrane?
The membrane keeps all fluids within the body so that there are no accidental leaking from the body.

12) What is the function of the spleen?
It discards old red blood cells and stores in it healthy, white blood cells.

13) What is the function of the diaphragm?

The function of the diaphragm is to aid in breathing and respiration by contracting and expanding.

14) What distinguishes the atria from the ventricles?

The atria pumps blood to the ventricle while the ventricle pumps blood to the rest of the body.

15) Why is the wall of the left ventricle thicker than that of the right?

The left ventricle is responsible for pumping blood to the rest of the body while the right ventricle is only  responsible for the lungs.

16) What are the similarities exist between male and female reproductive systems?

The male and female reproductive systems are very different, and the only similar thing they share is the pituitary gland.

17.) What do kidneys do?

Kidneys are used for getting rid of waste by processing blood through it. The kidney collects the wasted from the blood and then it is excreted from the body.

18.) In the dissection, you located the thyroid, the thymus, and the adrenal glands. To which system does this belong to?

The thyroid, the thymus and the adrenal glands belong to the respiratory system. 

      

Squid Dissection!

On Friday, December 7, our Biology class made some calamari! Just kidding, but on the other hand, we did get to dissect a squid! This was our class' 2nd dissection, and after dissecting the squids, we got to learn more about both the internal and external anatomies of the squid. Before doing this dissection, I usually thought of squid as a delicious seafood delicacy (especially calamari), but after completing this dissection, it was a cool sight to see the actual insides of a squid. Before this lab, we learned about the Phylum Molluska on Thursday. There are 3 classes within the Phylum Molluska: Class Gastropoda, Class Bivalvia, and Class Cephalopoda. The squid is part of the Class Cephalopoda. After learning more about this delicious seafood, I couldn't wait to delve into this dissection. I started this dissection by observing the squid's external anatomy first. I looked at the external parts of the squid, including the funnel, the tentacles and arms, the mantle, the fin, the mouth and the beak. The squid was really slimy, and it didn't have the most pleasant smell either. After observing the squid's external anatomy, it was time to cut this calamari open. I made the incision by using the scissors to cut open the squid from the side of its body. After cutting it open, I used  pins to spread it out so I could get a better view at the internal anatomy. I got a good view of all the internal parts, like the ink sac, stomach, anus, gills, and visceral mass. After opening up and spreading the the squid, I cut off its mouth so I could get a closer look at its beak. The beak overall wasn't very big. After observing the internal parts, me and my partner decided for fun to try and remove the eye, which ended up in disaster. This dissection was a fun and enriching experience since I got to learn more about the squid's anatomies more in depth. It was quite exciting to be able to dissect some calamar- I mean, squid. Speaking of calamari, I can't wait till the next time I have some!

             External Anatomy Questions

1) My squid had 6 arms and 2 tentacles.

2) The purpose of the arms and tentacles differ since both do different tasks. Since the suctions cups are located on the tentacles, they're used to latch onto prey and other surfaces, while the arms are used to move quickly.

3) The 2 arrows pointing down is the direction which the water comes out of the funnel. The squid will move the opposite direction of the arrows. 

4) Two external features that are adaptions for the squid's predatory life are as follows"
1. The suction cups on the tentacles are used to grab prey and latch on to surfaces.
2. The beak is used to pick away at their prey so that it's easier to digest.

5) Two traits that squids share with other mollusks are:
1) Bilateral Symmetry
2) Visceral Mass

Internal Anatomy Questions

1) The squid has one pair of gills (2 gills). The arrow in the picture points to one of them.

2) The ink sac is emptied into the water jet so that the squid can defend itself from its predators. Here is a zoomed in ink sac. 

3) The function of the pen is to support the mantle and help keep the squid steady while swimming.  Here is picture of my fellow classmates squid's pen, since I was unable to pull mine out. 

4) I think the squid excretes its waste through the anus. Here is a zoom in picture of the anus. 

Annelid (Earthworm) dissection!

On Friday, November 30, our Biology class dissected Earthworms! Yes, those icky brown things that look slimy and disgusting. Our class did this so we could learn more about the Earthworm's anatomy. Before doing this dissection, I had no interests in Earthworms at all, and to be honest, I thought dissecting one would be the last thing I would do. But after completing this dissection, I learned so much more about Earthworms. Even as exciting as dissections are, cutting this thing open was no walk in the park. Me and my partner had to be extra careful to not cut any internal organs by accident. After making a cut, a black, slimy liquid came out of the worm, and it did not smell good. Starting our way from the top to the bottom of the worm, we managed to successfully cut open the worm. Prior to this dissection, I had no clue what was inside an Earthworm, but after doing this, I didn't know it would look so fascinating. We were able to see many parts of the worm, including the heart, gizzard and brain. After completing this lab, I learned more valuable information about the Earthworm I didn't know before. This being our first dissection, I thought this was an enriching and exciting experience. As natural decomposers of dead and non-living organisms, the Earthworm is a vital part of the biological world.


1) The name of the Earthworm's pumping organs are the 5 aortic arches, or hearts. (to put it in simpler terms)

The arrow points towards the one of the hearts.

2) The digestive tract begins at the mouth, which is the opening. The food would then get sucked in by the Pharynx and then moves through the Esophagus and into the Crop. The Crop then moistens the food and is then grinded up by the Gizzard. The food then moves to the Large Intestine for more digestion, and then wastes are excreted through the anus. 

The whole worm in its entirety cut open.

3) The Cerebral Ganglion is the part that serves as the Earthworm's brain. The rest of the body is connected through a ventral nerve cord, and at each segment, it is connected to a ganglion which is a cluster of nerves that connects the segments to the brain.

A close up image of a worm brain taken through the microscope lens.

4) The anus and the nephridia are 2 parts of the excretory system that I saw.

Lower half of the worm.

5) By taking a look at the inside of  worm, you can see soil in its digestive system.

The digestive system is visible in this picture.

6) Setae, in latin means "bristle." They help Earthworms attach to surfaces and prevent them from backsliding while they move.

A fun cartoon showing what setae is, since I wasn't able to get
a picture.

7) From the large amounts of soil, the Gizzard grinds down all the food from the Crop (where food is stored) and ingests the distinguished food from the soil.

The upper part of the of the worm shows the digestive system.

8) Beyond segment 32 would be the rest of the digestive system and the worm's digested food.

An up close shot of the lower part of the worm.

9) Since earthworms are hermaphroditic, the mating worms exchange sperm with one another. The sperm would then be stored in until matured. After maturing, the worms clitellium will make a sticky liquid that forms a ring, which now has the fertilized eggs.

An overall picture of the dissected earthworm.

  

Vancouver Aquarium!

On Thursday, November 22, our Biology class went on a field trip to Vancouver Aquarium! Having not been there since I was a little kid, I was excited to see the various sea animals that inhabit the oceans of the world. This time was more exciting, since both Biology blocks were given the opportunity to go into the Marine Lab to touch and feel some of the smaller sea creatures. There were a vast array of animals and organisms, including  sea snails, hermit crabs, anemones, sea cucumbers and many more. It was fascinating and exciting being able to feel these animals. After about an hour of touching sea creatures, we went to go do some experiments with snails. In each group, there were 2 snails. My group had one active fast moving snail that moved all over the place, while the other snail was a lazy bum who didn't want to move what so ever. We then conducted our experiment, which started with the question "Do Snails have a sense of gravity?". We tested this by placing a snail on its back to see if it could flip itself right side up. By itself, it wasn't able to, but it did make an effort to do so. We then placed rocks beside for help, and little did we know, the snail stuck on to the rock. Our other lazy snail was unable to do anything. We firstly concluded that it might have been dead, but it moved a little by itself, so that out of the question. In conclusion, the active snail was able to flip itself, while the lazy snail was, well, lazy. After completing the lab, our class went to get lunch, which was expensive. $7.28 for a small poutine isn't my ideal choice for lunch, but food is food. While eating lunch, we watched the Beluga Whale show, which included the 2 Beluga Whales living at Vancouver Aquarium; Aurora and Qila. They displayed a lot of cool tricks and made some cool sounds. After the Beluga show, everyone split up into the Aquarium to answer the questions on a worksheet we received. Exploring the entire Aquarium was extraordinary. There were TONS of species of fish, sharks, sea otters, sea lions and even monkeys. Yes, monkeys. The little information boards with each animal had some interesting facts about them. My favourite animal in the aquarium were the Sea Otters because let's face it; Sea Otters are adorable. After about 2 hours of roaming the aquarium and with the help of some friends, I finished the worksheet. This field trip to Vancouver Aquarium was a fun-filled and exciting experience and I hope to go back there someday.           

The symbiotic relationship between the Clown Anemone fish and the sea  anemones is that the Clown Fish depend on the anemone for protection and in return, the Clown Fish clean the sea anemone.

Sea otters spend so much time cleaning their coats because only clean coats can trap air.  They don't have blubber to keep them warm, so they depend on these air coats for warmth instead. 

Before the 1900's, Sea Otters were found mainly in Alaska and were hunted to near extinction because of the fur trade.  Some Sea Otters were taken from Alaska to re-populate and breed in 1969 to 1970. 

The Sea Anemones next to the sea otters were the colour green..

Me and my friend Jordan in front of the Japanese Sea Nettles, our favourite marine invertebrates. These guys were interesting cause they were like ninjas since they threw powered sea nettles at their enemies to make them "sneeze".

The scientific name of the Beluga Whale is Delphinapterus Leucas. There are currently  2 Beluga Whales living at Vancouver Aquarium: Aurora and Qila. 

Since there were no Potbelly Seahorses at the Aquarium anymore,  I found another species of seahorse. This one is currently keeping still for a camera shot :)

The Starry Flounder has 2 interesting adaptations: its scales blend in with the ocean floor so its stays camouflaged , and its a flat shaped fish, which is unique compared to others.

The Mon Jellies move by propelling themselves forward with their heads. Through this unique way of moving, Moon Jellies can forcefully push water and plankton into their mouths, which is how they eat.

The Pacific Octopus has white suction cups for grappling on to surfaces and catching their prey. It's known as one of nature's best predators since it is a master hider and hard to spot.

Sea Lions feed on fishes and squids and hunt in large packs to obtain their food.

The Caiman, neither a Crocodile nor Alligator but a close cousin of both, is located in Brazil, Bolivia, Argentina and Paraguay.

The largest fish in the aquarium would be the Arapaima. This monster can grow up to 3 metres in length!

This Redhook Silver Dollar is a vegetarian fish that lives in the Amazon and feeds off of riverside shrubs. 

Piranhas become the biggest threat to humans when we remove hooks from their mouths.

Fun fact: Sharks don't have bones. Instead, they have cartilage.

I was unable to get an actual picture of a Red Sea Urchin cause of all the fish, so I just took a picture of the picture on the wall. The scientific name for Red Sea Urchin is Strongylocentrotus Franciscanus.

The Archerfish find their food by shooting water at insects up to 3 metres above the water's surface. In other words, Archerfish are quite literally, archers.

The scientific name of the Sea Turtle is Chelonia Mydas. People at the aquarium call her "Schoona".