Rat Dissection

On Thursday and Friday of last week, my class and I began the dissection of a living (well, technically dead) animal. I'd been anticipating something like this from the beginning of the semester, and was quite ecstatic when I finally learned we would actually be dissecting an animal. This required not as many tools as previous dissections, which was pretty good, although this one was a bit more messy. The only tools we had to use were our hands, a small scalpel, pins and a few various other items. Gloves were also required, and made the task a lot more easier! When I first saw the rat, I expected a horrid stnech of kinds, but that wasn't the case, for the rat had been drained of all bodily fluids, and had been preserved, which essentially helped it lose it's smell. With that said, the rat felt squishy, yet kind of hard considering all of its organs were inside. The purpose of this dissection was to gain a better understanding of an animals anatomy by viewing it's external organs, as well, after careful incisions, viewing the inside of the rats anatomy. For the past 2 weeks, my classes focus has been on vertebrates, and that relates to why we dissected a rat instead of any other animal in the animal kingdom. The reason we dissect things is to gain a better understanding of how the body works through physical actions, rather than sitting down half asleep in a drowsy classroom. People tend to retain information better when they experience something before their eyes, rather than reading about it. For example, someone would probably learn more about the esophagus and where it's located by actually dissecting and seeing it rather than simply learning about it.

To start off, we observed the external anatomy of the rat. My group and I looked at things like the eyes, the number of fingers on each hand, the tail etc. Then we got to do some real dissecting! We were given a handout + guideline to follow, so our first incision started in the middle, for there was more space to work with there, and then it branched out ward, both up and down the body. I was half expecting some blood to spew out, or the wrong cut to be made (considering I had no idea it'd been drained of all fluids), but that didn't happen. Instead, everything went normally, and we cut the rat open without a problem. After all the major cutting was done, our next objective was to look for certain bod structures and organs, like the esophagus, and take down what they look like (and maybe even how they feel!). The internal body was pretty messy, and very clumped together, probably because the body has to fit a long digestive tract + several other organs all into one tiny space. Unlike the previous dissections of the Annelid and Squid, this one was really, really messy for me. Mostly because the scalpel was so small, so I used the tweezers to rip off the flesh that was in my way/ jutting out, which caused a lot of fur and guts to go everywhere. Unfortunately, this is most likely the last dissection we will probably do in Biology, until Bio 12 next year. I'm glad I joined this class because doing things like dissections to learn is always great fun!

Set 1

1.) Why are your hands the best tools for dissection?
Your hands are the best tools for dissection because you're already so used to using them that doing almost any task shouldn't be a problem (unless you're queasy around dead things!). This also gives you a literal hands on feel of what you're learning about.

2.) What is the purpose of having all the different labels and titles for the dissection?
The purpose behind this is to give you a better understanding through diagram and drawing, as well as to get you to think. If you're trying to come up with a title, you're subconciously using the information you've learned to do so. Also, labels help with memorization of facts and knowledge.

3.) In what way does the tail differ from the rest of the body?
The tail differs from the rest of the body because it doesn't have any specific use or function, and is more or less just an addition to the body of the animal. It probably does some sensory things, but isn't a primary sense organ. (Picture Down Below)

4.) What purpose is served by the vibrissae?
The purpose of the vibrissae is navigation and sensing. They feel vibrations (most mammals with these tend to put their face close to the ground), and also feel air speeds/ current. It helps them avoid any danger, most of the time at least.

5.) Your specimen is Bilaterally Symmetrical. What does this mean?
This means that if the specimen is cut in half, both sides will have the same features, just in opposite directions.

Set 2

1.) The sphincter is descrbed as a circular muscle. Why is it this shape and what does it do?
The sphincter helps mediate the release and entrance of liquids trhoughout the body of the rat, and is shaped like a circle to help give out maximum efficiency.

2.) Why is there a difference in size between the small and large intestine?
Small intestine helps in digestion and absorption of food, while the large intestine helps in reabsorption of food and elimination of wastes.

3.) The liver is the largest organ in the body. What are its function?
The liver helps clear the blood of drugs and other poisonous substances, it creates bile, and deoxifies & purifies oxygen.

4.)  How did the duodenum get it's name?
The duodenum was given its name in latin because it is usually 12 fingerbreadths long, about 25 cm, which is what duodenum means.

5.) What is the purpose of the appendix in animals who retained this as a functional organ?
The appendix has a lot of digestive enzymes in it, and helps with the breaking down of tough-to-digest foods that animals eat. Considering how far humans have evolved, we no longer need use of this.

Set 3

1.) In each of the cavities, there is a membrane that cover both the wall of the cavity and the organ it contains. What is the function of the membrane?
It helps to keep all the fluids inside, working efficiently, and makes sure that the fluids don't accidenlty leave the cavity somehow.

2.) What us the function of the spleen?
It removes old red blood cells from the blood, and supplies and stores white blood cells, which in turn produce anitbodies, and so on and so forth

3.) What is the function of the diaphragm?
The diaphragm controls the flow of air into the lungs of this mammal, helping the respiration system tremendously. Without it we can't breath because it contracts and moves down to make us inhale and goes upward and expands to make us exhale.

4.) What distinguishes the atria from the ventricles?
There are a number of differences between the atria and the ventricles. For one, the atria are smaller than the ventricles. Atria also consists of thinner muscle tissue than the lower positioned ventricles. Atria also pump blood to the ventricles, while the ventricles distribute blood around the entire body. Because of the more complex job of the ventricles, they are larger than the atria

5.) Why is the wall of the left ventricle thicker than that of the right?
The left ventricle needs to be thicker than the right because it needs to pump blood through the entire body. The right ventricle only pumps to the lungs to oxygenate the blood. Hence why the left is thicker, due to needed more muscle to do so.

6.) What similarities exist between the male and female reproductive system?
Many reproductive organs of males and females are derived from the same embryologic structures. In addition, some hormones are the same in males and females, even though they act in very different ways. The anatomy of the vulva is related to the anatomy of the male genitalia by a shared developmental biology. The clitoral glans are also homologous to the glans penis in males.

7.) What do the kidneys do?
They function by filtering out wastes to be excreted in the urine, but their main purpose is to separate mineral salts, toxins, and other waste products from the blood. In addition, the kidneys also conserve water, salts, and electrolytes.

8.) In the dissection, you located the thyroid, the thymus, and the adrenal glands. To which system do they belong, and what do they do ?
The thyroid,thymus and adrenal glands are a part of the lymphatic and endocrine organ system. The role of the thyroid is to stimulate metabolism, and control the body’s circulating calcium levels. The Thymus gland is where leukocytes aquire means to chemically identify specific foreign invaders and where Immature T cells from bone marrow move to thymus gland and mature. The Adrenal Glands are responsible for producing cortisol and aldosterone. These hormones regulate our heart rate, as well as, sexual desire and other bodily functions

Giant Asian Hornet

Giant Asian Hornet

Phylum: Arthropoda
Class: Insecta

7 Essential Functions:

Wasps and Hornets are more or less similar, with only a few changes.

                                                                      Body Structure: 

 

 

Digestion (Feeding):

They have a complete digestive system, meaning that they have a long tube-like structure running down their body, from mouth to anus. The digested food usually travels in one direction. Feeding habits vary amongst the Hornets.

 

 

Circulatory System:

Have Open circulatory system, meaning that the blood within the body moves freely throughout the entire organism. The circulatory system is responsible for movement of nutrients, salts, hormones, and metabolic wastes throughout the hornets body. Usually have hearts to help with blood flow etc.

 

Respiratory System:

All insects are aerobic organisms, meaning they must obtain oxygen from their environment in order to survive. Air enters the insect's body through valve-like openings in the exoskeleton, called spiracles.

 

Excretion:

In insects, a system involving Malpighian Tubules is used to excrete wastes. These wastes diffuse or are actively transported into the tubule, which transports the wastes to the intestines. The wastes are then released from the body along with fecal matter. Wastes exit through the anus, like almost any organism.

 

Movement:

Insects tend to have many different forms of movement. The hornet shows some of that variation because it has wings and feet. Using the wings, it can propel itself forward, up, down and all around, going great distances. When it's in it's nest or simply landing on a surface, it uses it's legs to walk around.

 

Reproduction:

Have 3 main types of Hornet; The Queen, worker and drone.

The Queen is the only one able to lay eggs, so protecting her is vital. Queen mates with the drones. The workers essentially keep the hive nice and 'tidy'.

 

Hornets are Bilaterally symmetrical. And have 3 germ layers; Ectoderm, Mesoderm and Endoderm. Other organisms found in this phylum are Spiders, Scorpions, Lobster, Millipedes and Centipeds, etc.

 

Scorpion

Lobster

Ecology:

Hornets don't seem to have a purpose in the world, but they do in fact serve society and nature.

 

Hornets are classified as Protosomes.

 

INTERESTING FACTS:

The Giant Asian Hornet is the largest hornet in the world, reaching up to 2 inches in length, with a wingspan of 3 inches. The stinger is 1/4 inches in length, and can produce lethal stings.

 

The stinger can inject a dangerous poison, which can cause death to those who are not even allergic. They can bite at the same time, so that basically means twice the pain.

 

Nests are built out of wood and paper found in the trash or on the ground

 

 

The hornets can devastate a colony of honey bees: a single hornet can kill as many as 40 honey bees per minute thanks to its large mandibles which can quickly strike and decapitate a bee. The honeybee stings are ineffective because the hornets are five times the size and too heavily armoured.

 

Hornets can't eat their prey, so instead chew them up and feed them to larvae. The larvae then spew up liquids that the adults eat.

 

 

 

 

 

 

 

 

 

Squid Dissection

On friday, I was kind of surprised to find that my class was dissecting a squid, mostly because I kind of forgot. Nevertheless, it was awesome to dissect something larger than an earthworm! To start off, we were to go with our partners and get supplies consisting of Scissors, forceps and other items that would all help with the procedure. Before anything, I went to the front of the class, where some sheets were set up so I could do a small pre-lab activity of naming certain body parts of a squid. Then, my teacher opened up a container full of squids, which may I say, did not smell too good. But once I received a single squid, the smell was unnoticeable, and my partner and I were able to get to work. Our objective was to find and observe the exterior parts of the squid, and then after careful cutting, view the internal organs of the squid. During all of this we were to locate the body parts that perform functions, and then analyze how those functions would be performed. By making these connections, the brain can have a better and easier time remembering and retaining the knowledge learned. You can learn more by first hand cutting than by reading large paragraphs. For example, one could look at the beak and see how it opens and closes, and also find where the food comes and goes, and by doing that observing learn more than reading 5-6 sentences on the subject.
To begin the dissection, we first had to look at all the external parts of the squid, like the tentacles and arms. Just seeing these was awesome, because they looked like how I'd always seen them in movies and t.v; were long and had suckers, although, only some had suckers. After careful observation of the exterior, we began to cut. Some groups were too hasty and directly went to cut up the squid, which took away from the first few steps on the hand-out we were given. Aside from this, my partner and I made a good, clean cut, and carefully spread apart the squid to see it's insides. Unlike the earthworm, we didn't have guts fall out or soil. In fact, everything seemed to stay in place, which was good. We then carefully observed it's insides and what parts were which. Some if it kind of looked like an egg to me, but the thought didn't last very long considering I could see a whole bunch of other things as well. All in all, this was a great and fun learning experience, and I hope to do something similar again in class!

1.) How many arms does your squid have? How many tentacles?
The squid I had dissected had 8 arms, and only 2 tentacles with suckers. This picture isn't very good, but it does have all the feet shown.

2.) Based on the structure of the arms and tentacles, describe how their purposes differ. What do the arms do and what do the tentacles do?
This is a close up of the suckers of a squid, located on the tentacle. The tentacle is better for grabbing prey that swims by, and holding onto them, as well as latching onto surfaces like rocks. (Look below for Arms)

This is a close up of just a regular arm of a squid. The arms are much better for the locomotion of the squid, for they are shorter and can move quicker.

3.) Draw arrows on the squid (above) to indicate the direction that water comes out of the funnel and the direction that the squid moves

4.) Name two external features that are adaptations for the squids predatory life. How do these adaptations help the squid?
One of these adaptations, is the suckers on the tentacles. These suckers attach onto prey and hold them down from escaping. This leads to the 2nd adaptation, which is the beak. The beak can pick apart prey, making it easier for digestion. Since there is already a picture of the suckers up above, I only used this close up of the beak.

5.) Do you remember the general traits of mollusks we discussed in the lecture? Name two traits that the squid shares with other mollusks.
A.) The visceral mass is the soft bodied portion of mollusks that contains the internal organs, and in this case, is the mantle of the squid (shown above).
B.) Feet are also found in all mollusks, and in this case, are the arms and tentacles of the squid. (Shown Below)

1.) How many pairs of gills does the squid have?
The squid that my partner and I dissected had 2 pairs of gills

2.) Where does the ink sac empty into and what is it's function?
The ink sac (shown above) empties into/ out of the funnel, and the ink itself serves as a distraction to help get away from predators. The funnel works to dispel the ink and propel the squid forward.

3.) What is the function of the pen? What would happen if the squid didn't have the pen?
The pen serves as structural support for the squid, holding the organs together and stabilizing the squids body. Without it, the squid itself would be a floppy mess. The pen is shown above and below.

4.) How do you think wastes exit the squid?
I believe that larger, more solid wastes exit through the anus, and smaller wastes exit through the funnel (shown above).

Annelid Dissection

On friday in class, we were allowed to dissect an earthworm as a part of group assignment. This was one of the coolest things we've done all year, apart from the Aquarium trip! The purpose of this dissection was to get a hands on experience of the external and internal structures of an annelid. With experiences such as dissecting, one can retain information better from the things they see, and it can provide a better learning environment. Our class had just finished learning about Annelids, and what better way to keep that information than being active! From the start of the class, we were given some brief precautions and instuctions, and the we were able to get started. Using scalpels, forceps, pins and other various tools, my group and I began our dissection, starting with the head of the worm and lightly slicing toward the centre. Once we had done this, black ooze (soil) fell out from inside of the worm, along with blood, which did kind of disgust me, considering it's not something I see everyday. There was a faint odor that didn't smell too good either, but you had to lean in close to really breathe it in. At this point, you could see the insides of the worm, and under a microscope could see he internal organs of it, all of which looked squishy and sticky. Following all of this, we then cut further down, and sliced open the bottom half, revealing the excretory and reproductive systems. There wasn't much there besides the ovaries, testes and nephridia, and some soil as well. This whole lab was an amazing new experience that I hope everyone else enjoyed as much as myself! Although touching the worm wasn't exactly an option for me, because I have cuts on my fingers, it was still an awesome lab to participate in. Using a scalpel and slicing open something is always a cool experience, so I was glad to be there on friday!

1.) What is the name of the pumping organs of an earthworm?

The name of the pumping organs of an earthworm is called the Aortic Arches.

Although I couldn't get a clear picture of them, hopefully these "hearts" (black orbs) will suffice.

2.) Trace the parts of the digestive tract through which food passes.

This is a picture of an Annelids digestive tract, that I drew myself.

3.) Which parts of the earthworm serve as it's brain? How are these parts connected to the rest of the body?

The brain is made up of many nerves, all through cephalization. The brain rests above the gut, and is connected to 2 large nerves which are, in turn, connected to a pair of ganglia. These ganglia are then connected to a ventral nerve cord which runs the length of the body.

4.) Which parts of the worms body that you saw included the excretory system?

This was the only close up picture I could get of what the excretory system looks like. There appears to be a lot of soil in the mix, as well as some reproductive organs.

5.) How can you find out whether an earthworm eats soil or not?

The black muck that surrounds the pin is the undigested soil, that was once travelling through the worms digestive tract.

6.) Among the earthworms structural adaptations are it's setae. How do you think the earthworms setae make it well adapted to its habitat?

I couldn't get a picture of the Annelids setae because they were too small. As for the question, The earthworms setae make it well adapted to it's environment because they help it feel around the soil, as well as for vibrations in the surrounding area, essentially helping the, escape predators. The setae also help with avoiding obstacles.

7.) How is the earthworms digestive system adapted for extracting relatively small amounts from large amounts of ingested soil?

The food ingested goes through the digestive tract, going down the esophagus until it reaches the crop and gizzard. The crop stores some food, while the gizzard grinds it up into smaller pieces. These small pieces are then finally digested. This process shows how worms digestive systems are adapted for extracting small amounts of food from large amounts of soil. This picture is of the Crop, unfortunately I couldn't get one of the gizzard.

8.) Your dissection of the earthworm did not go beyond segment 32. What will you observe if you dissect the remainder of the worm to it's posterior end?

If I had dissected beyond segment 32, I would find digested food, blood and the ventral nerve cord, which runs the length of the body. I would then find the anus and nephridia. This picture is of the lower half of the dissected earthworm, whose guts and soil were splattered around it, and inside it.

9.) During mating, two earthworms exchange sperm. Fertilization is external, and cocoons are produced from which the young eventually emerge. Refer again to steps 5 and 11, where you located the Earthworms reproductive organs. Use a reference to identify the role of each organ in the reproductive process of the earthworm. On a separate paper, summarize your findings.

Summary: To reproduce, earthworms attach themselves to one another, and then excrete sperm into each other. The sperm is then stored in special sacs, awaiting for the eggs to be ready for fertilization. When the eggs and sperm are ready, the clitellum secretes a sticky ring, in which both the eggs and sperm can fertilize in. If you look closely at the end of the worm, you can see the reproductive organs, or whats left of them.

3 Platyhelminthes Photo's

Genus: Pseudoceros
Species: Ferrugineus
Family: Pseudocerotidae
Order: Polycladida
Location: Hawaii
Date Identified: N/A

Genus: Pseudoceros
Species: Ferrugineus
Family: Pseudocerotidae
Order: Polycladida
Location: Okinawa, Japan
Date Identified: May 25, 2002
Depth: 8m
Length: 25mm

Genus: Prosthecereas
Species: Vittatus
Family: Euryleptidae
Order: Polycladida
Location: Bazi Luzzo, Panarea, Italy
Date Identified: 8/ 2001
Depth: 18m
Length: 6mm

To The Aquarium !

So, today we went to the Vancouver Aquarium to see all the marine life, and it was quite fascinating! Upon arrival, we were seperated into our two classes: Block 3 and Block 4, and from there went on to do two seperate assignments. One of these, was the Marine Lab, in which we were able to touch and observe sea 'critters'. This helped me personally understand some of the biological world, because through experience and some story telling (thanks to our helper) I was able to learn, just like in class. With experiences like seeing how Sea Cucumbers react to environments of just water, and environments of just air, it helps people form better understandings of what they're learning. After around an hour and 20 mins, we then proceeded to have lunch, which might I add, was not cheap. Following this, we were then given the task of walking around/ observing the Aquarium itself, searching for answers to a sheet of questions we were given. Some of the questions were more difficult to answer than others (i.e 'Describe the symbiotic relationship of the Clown Anemone Fish', opposed to 'Describe the colour of the crocodile'). It was kind of tedious, not being knowing where to start, but I got the job done with the help of some friends. All in all, I thought going to the Aquarium was good fun, and I enjoyed watching the Sea life and learning new information.

Clown Anemone Fish + Sea Anemones
1.) The Clownfish depends on the sea anemones for protection form predators
In return, the fish cleans the anemone, and thus, a symbiotic relationship is formed

Sea Otter Swimming!
2.) Sea Otters spend a lot of time cleaning their coats because clean fur is better for trapping oxygen.
3.) Before the 1900's, Sea Otters were found near Amchitka Island, Alaska, and Monterey, California.
They were later re-introduced to Canada in the years 1969 and 1970

Sea Anemones
4.) These Sea Anemones are a vibrant green colour

Japanese Sea Nettle
5.) Their adaptations for survival, are their ability to throw powdered sea nettle on an attackers  faces,
causing them to sneeze. This is my favourite marine invertebrate because it looks awesome,
and has a cool 'ability'.

Beluga Whale getting fed
6.) The scientific name for a Beluga whale is " Delphinapterus Leucas" There are 2 Beluga whales found in the Vancouver Aquarium.

Sea Horse wading through the kelp
7.) Unfortunately, the Aquarium got rid of Potbelly Seahorses, but in turn they had these little guys. The way they move is unique from other species, for they use their long tail to propel them to and fro, and allow them to grab onto things.

Pacific Sea Nettle
8.) This sort of looked like a human heart, just for the way it moved. While wafting through the water, it  sort of contracted itself, like it was a "beating & pumping" heart. Based on this, I figured that this was an organism that looked most like a Human Nervous System organ.

Starry Flounder lying still
9.) The adaptations this organism has are advantageous to their environment. They usually lie still to look dead at the bottom of the ocean, and then ambush prey, and due to their exterior skin/ colour this can also act as a camouflage from predators.

Moon-Jellies
10.) They move slowly, propelling themselves forward with the head part of their body, or Medusa, wafting through the water. To feed on plankton and other organisms, Moon-jellies kill their prey by stinging it with nematocysts found on its tentacles.

Pacific Octopus in hiding
11.) The suction cups located on their arms are good for grabbing prey as they swim by, or attaching to things such as a cave wall, or rock. They are also considered some of natures best predators because they are hard to spot and are great at hiding, just like in the picture.

Stellar Sea Lion swimming in the water
12.) These animals eat fish and squid, and hunt using techniques most mammals use (i.e they hunt in packs or chase down prey in large groups.) 

Caiman just chilling
13.) The Caiman come from Brazil, Bolivia, Argentina and Paraguay. They are mostly found in South America.
14.) Crocodiles, or in this case, Caimans, appear to be brownish-grey in colour. This helps with its survival, for it camouflages them in the murky waters they reside in, and helps it ambush its prey. 

The Arapaima, looking at me
15.) This is the largest fish in the Aquarium, apart from some of the sturgeons, and is called the Arapaima

Redhook Silver Dollar
16.) This is a vegetarian fish, which eats the seeds of riverside shrubs

Piranhas
17.) Piranhas are not considered threats to humans, even when swimming in their waters. Some can be hostile, but most are not. They become a threat only when removing a hook from within it's mouth when fishing.

Shark just swimming
18.) Sharks don't have bones, they have a skeleton made of cartilage instead

Two fishes swimming together
19.) Other animals that can be found in the shark tank are, the Green Sea Turtle, Blacktip Reef Shark, White Spotted Bamboo shark, Stingray, Laced Moray, Common Bluestripe Snapper, Redtail Butterfly fish, Yellowface Angelfish and the Indo-Pacific Sergeant.

A picture of a picture of a Red Sea Urchin
20.) The scientific name of the Giant Red Sea Urchin is the Strongylocentrotus Franciscanus. It has developed spiky needles that surround it's body, defending it from predators.

Archerfish
21.) It feeds from the water on the surface, leaping for insects or spitting prey down with water

Sea Turtle
22.) This sea turtles scientific name is Chelona Mydas, and the name of the one found in the Vancouver Aquarium is "Schoona".

Me and Joshua posing in front of some Jellies :D

Fungus Hunt

       On Friday my classmates and I were given the task to find many different types of Fungi. To my misfortune, I was unable to participate in the event, and therefore can not describe exactly what was seen. Although, judging from what I've heard, it was pretty exciting. My friends said that just walking around the park they were able to find tons of different types of things, like Lichen, Basidiomycota (Club Fungi) and even Ascomycota (Sac Fungi)! For example, I believe that the Lichens would have most likely been found on trees, logs etc., and most likely varied in shape and form. They could have resembled leaves (Foliose Lichen), or even be flat (Crustose Lichen). As for the Basidiomycota and Ascomycota, I believe they would be found under/ near decaying matter, having their own 'meal'. You can spot them by looking for their fruiting bodies.
     Being on the trip myself would have been quite exciting, but dentistry comes first! I could have gotten to see some things in nature that, as Ms.I said "Some don't have the luxury to walk outside and find..". And in that aspect, it is entirely true, and we're quite lucky to have a forest full of these wonderful things! All in all, I hope that everyone enjoyed themselves, and that the trip was inciting, and everyone was able to come back with a little bit of knowledge.

Because I wasn't able to walk around on Friday, I'm just gonna post 8 pictures of what I think people may have seen:  

Basidiomycota (Mushrooms)

Basidiomycota (Mushrooms)

Lichen

Foliose Lichen

Foliose Lichen

Crustose Lichen

Ascomycota (Sac Fungi)

Basidiomycota (Club Fungi)