Fetal Pig Dissection Day 6: Nervous System

Day 6:

Day 6 was an investigation of the fetal brain. In class we covered a few topics about the nervous system such as the neuron (never cell), the way the impulse travels though a neuron, and the components of the synapse.

  

The nerve cell in the body is called a neuron and it is what delivers the messages from your brain. A single nerve cell contains a nucleus, dendrites, cell body, nodes of ranvier, axon, myelin, and an axon terminal.

 

 The synapse happens when when the axon terminal of one nerve cell transfers neurotransmitters to the dendrites of another nerve cell. The axon terminal would be the pre-synaptic site and then the dendrites would be the post-synaptic site. The myelin of the cell helps the impulse skip along rather then traveling right though the cell because that would take longer.

The brain have three parts cerebrum, autonomic brain stem, and the cerebellum. The cerebrum is the conscious part of the brain that a person is in complete control over, The autonomic brain stem is the part of your brain that controls the reactions that you don't think about, and finally the cerebellum is the part of the brain that controls your balance and allows you to do things like walk and talk at the same time. In our dissection we could only see the cerebrum and the cerebellum because the brain stem was to difficult to get at through the skull. 

 

 Also in our dissection we found the spinal cord. The spinal cord plays an important part because for certain reactions that require you to react suddenly will send a nerve impulse to the spinal cord and then the spinal cord will send a reaction message right back to the body tissues without being processed in the brain

The picture about is neat because it shows you the point where the spinal cord and the brain meet. The spinal cord receives that messages from the body and sends it to the brain then the brain decides how to react to them.

Day 6 also happened to be our final part of dissection. Hope you enjoyed my dissection blog!

 

Works Cited. 

http://www.google.ca/imgres?imgurl=http://www.daviddarling.info/images/neuron_labeled_diagram.jpg&imgrefurl=http://www.daviddarling.info/encyclopedia/N/neuron.html&h=268&w=468&sz=26&tbnid=-EU3dHn55q1RZM:&tbnh=73&tbnw=128&prev=/search%3Fq%3Dneuron%255C%26tbm%3Disch%26tbo%3Du&zoom=1&q=neuron\&hl=en&usg=__-FzNdO8pin-ixvnq6pxRPnV0o2k=&sa=X&ei=hDwBToyrE5DWiAKmhNWqCA&ved=0CEUQ9QEwBA  

Fetal Pig Dissection Day 5: Urogenital & Urinary Systems

Day 5 :

Day 5 of our dissection was about the urogenital system and urinary system. That includes the sexual reproductive organs of the pig which in our case is a female. Since we have a female we look at the ovaries, fallopian tubes, uterus and vagina. Both the male and female urinary system is the same except the exit point is different. They both have kidneys, ureter, bladder, and urethra.

 This is a picture of the kidney which is the place where urine is created. Inside the kidney is a whole bunch of nephrons. A nephron has many different parts that include glomerulus, bowmans capsle, proximal tubule, loop of henle, distal tubule, and finally the collecting duct. Each one of these components of a nephron have important jobs. The Glomerulus is a mass of capillaries that has very high pressure and is the site of filtration, Bowmans Capsle surrounds the Glomerulus and receives the filtered fluids from the Glomerulus. Proximal means near or close to so the Proximal Tubule is the tube that is near the begging of the nephron this tube brings the fluid into the Loop of Henle. The Loop of Henle is surrounded by Peritubular Capillary Network and is the site of salt and water concentration.

  

From the kidneys is a tube that travels from the pelvis of the kidney right to thee bladder this tube is called the ureter and it tastes the urine from each collecting duct in the kidney to store in the bladder

 from the bladder there is another tube called the urethra which takes the stored urine in the bladder and excretes it out of the body. The female and male differ when it comes to the urethra because the females have a urethra that excretes the urine out of the body and then a vagina cavity for sexual reproduction where as the males urethra is attached to the vas defferens which means that is carries both sperm and urine but never at the same time.

Since our pig was of the female gender our urogenital check list was ovaries, fallopian tubes, and uterus. A neat thing about the fetal pigs uterus is that unlike us it has a "Y" shaped uterus in order to have multiple babies where as we have a "Pear" shaped uterus. The reproductive system is not one that is very easy it is a complicated system and is different for both male and females. Males have a penis instead of a vagina, testes instead of ovaries, and ovum instead of sperm. The penis is the male sex organ and has many sensitive nerves on the out side in order for sexual stimulation where as the female has the clitoris as a sexual stimulation and the vagina as the location for intercourse. Testes are where semen is made into mature sperm and the ovaries is where the females store their eggs. Males can make sperm to fertilize an egg in the moment where as females are born with a certain amount eggs.   

work cited

http://www.ivy-rose.co.uk/HumanBody-Images/Urinary/Kidney_Nephron_cIvyRose.jpg

Fetal Pig Dissection Day 4: Digestive System

Day 4:

Day 4 was all about the digestive system which includes the 

stomach, gallbladder, pancreas, small intestine, liver, rectum, anus, and large intestine.

Gallbladder

The gallbladder is that stores bile salts that are made in the liver. Bile salts emulsify fats in the duodenum which is the first part of the small intestine

Liver

The liver has a wide range of functions that help with many of the systems in the body including the digestive system. The liver is necessary for survival and is one of the only organs that can be surgically cut and it will regrow back and just like the lungs the liver contains lobes. The liver creates bile salts which in the digestive system helps emulsify fats that are located in the stomach the liver stores it's bile salts in the gallbladder like I had said above. 

  The stomach is a very main part of digestion because it secrets protein enzymes and the stomach has a pH of 2 so it contains very strong acids  that aid in the break down of foods. An enzyme that works well in such a low pH is pepsin which helps break down proteins into amino acids. Because the acids are so strong there are sphincters located at the top and at the bottom of the stomach so the acid does not burn the esophagus or the small intestine. The one located at the top is called the esophageal sphincter and the one located at the bottom is called the pyloric sphincter.

  

Small Intestine

This is where the last part of digestion and absorption happens because the small intestine has a pH of 8 the pancreas secrets bicarbonate ions that then buffers the chyme before it enters the small intestine. Most of digestion and absorption take place in the small intestines. Because of the intense fold and the villi(which are like small cilia and line the walls of the intestine) the villi increase the surface area of the small intestine which allows a lot more absorption.

   

The Large Intestine is the last portion that I got a picture of. The large intestines goal is to take the remaining waste and try to and get all the water absorbed out of it then pass the waste. Because the fetal pig does not eat for itself the waste in the colon(large intestine) is amniotic fluid. It them travels to the rectum where 

the waste is stored then excreted by the anus.

 This photo is of a cross section of the large intestine.

 

Fetal Pig Dissection Day 3: Respiratory System

DAY 3:
Day 3 was all about the respiratory system. Locate the lungs, take them out, and rip them apart and do some investigating. 

Front View Of The Lungs

In the fetal pig there are two lungs one on the left and one on the right side of the fetal pigs body. The right lung has 3 lobes and the left side has 2 lobes. Each lung has a Brochus stem that breaks off in to Bronchioles and on the end of each Bronchioles are stretch receptors called Alveoli. Each Alveous has a capillary network in it in order to have diffusion between O2 and CO2 to oxygenate the blood in the lungs and take it back to the heart. 

Here Are Some Pictures Of The Bronchioles.

I've added some pictures of the bronchioles in side one of the lungs that we cut open so you can get a good sense of what they look like.

 

 Back View Of The Heart

You have your Esophagus and your Trachea and when you eat you don't want food to go down your Trachea and in to your lungs so in order to stop that from happening you have Epiglottis which when you eat blocks off your Trachea. The Trachea has cartilage rings in order for it to stay open where as your Esophagus in smooth muscle and is collapsed, food moves down by peristalsis.

    

Since the lungs are the site of oxygenation of the blood there are lost of veins and arteries that are linked to the lungs. The Pulmonary veins take the oxygenated blood that comes from the lungs and sends it out to the body tissues and organs, and the pulmonary arteries take the deoxygenated blood from the heart to the lungs to become oxygenated.

     

 

 

 

 

 

Works Sited

http://www.mhhe.com/biosci/ap/dynamichuman2/content/respiratory/visuals.mhtml    
  http://www.google.ca/imgres?imgurl=http://www.infomat.net/1/staffroom/worksheets/science/11_14/Nutrition/heart.gif&imgrefurl=http://www.infomat.net/1/staffroom/worksheets/science/11_14/Nutrition/nutrition_pt4answers.htm&usg=__kgVXjZagyQcQMnm6Wiup7XVjVrU=&h=406&w=440&sz=43&hl=en&start=0&sig2=PW4gJlO2GFKoKi1hJIP81g&zoom=1&tbnid=dvpuylfU3iaQwM:&tbnh=145&tbnw=155&ei=OeDyTfmLMI2CsQPaspiRDQ&prev=/search%3Fq%3Dpulmonary%2Barteries%2Band%2Bveins%26um%3D1%26hl%3Den%26sa%3DN%26biw%3D1366%26bih%3D616%26tbm%3Disch&um=1&itbs=1&iact=rc&dur=398&page=1&ndsp=21&ved=1t:429,r:6,s:0&tx=41&ty=84&biw=1366&bih=616

Fetal Pig Dissection Day 2: Cardiovascular System

Day 2:

Day 2 of our dissection was to take a look at the cardiovascular system and identify fetal shunts, main vessels, and the chambers and valves of the heart.  

FETAL SHUNTS

There are 3 fetal shunts: Ductus Venous a shunt that puts blood into the hepatic veins, Foramen Ovale which is the shunt the right atrium to the left skipping the lungs, and the last fetal shunt is the Ductus Artious which takes the blood from the right ventricle and it then enters the pulmonary trunk. 

 In the picture above we have located one of the three fetal shunts. This shunt is the Foramen Ovale. Once the heart is cut into sections you can find this fetal shunt rather easily. This shunt bypasses the lungs.

 MAIN CARDIOVASCULAR VESSELS

Main vessels in the Cardiovascular System are Pulmonary trunk, superior and inferior vena cava, pulmonary veins, aorta, and the coronary arteries and veins.

Here we have found one of the main coronary arteries in the heart. The coronary arteries run along the surface of the heart if a coronary artery gets block it can cause a heart attack.

 

In the picture above we have located some more important vessels in the cardiovascular system. The subclavian arteries and veins supply the body with oxygenated blood(arteries) and bring the deoxygenated blood from the body to the heart then to the lungs. You can also see the Trachea which is attached to the lungs. The surperior vena cava brings deoxygenated blood from the head, neck, and arms and puts it in the right atrium.

 

  In this next photo we can see one very important vessels this is the Aorta and you can see the aortic arch very nicely in this photo. The Aorta is the largest artery in the body it comes out of the left ventricle and supplies oxygenated blood to all parts of the body.

 

HEART CHAMBERS AND VALVES

The Heart has four chambers and two different types of valves. The chambers are Right Atrium, Right ventricle, Left Atrium, and Left Ventricle. Semi-lunar and Atrioventicular valves are the two different valves located in the heart.

front of the heart.

As you can see this is the front of the heart. All the chambers are located in the picture above. The right atrium is where deoxygenated blood comes into the heart through the superior and inferior vena cava and holds the blood until it is ready to enter the right ventricle. The right ventricle takes the deoxygenated blood from the right atrium and then send it out the pulmonary truck and pulmonary veins which takes it to the lungs to become oxygenated. The left atrium receives oxygenated blood from the pulmonary arteries once in the atrium it then goes into the left ventricle. The left ventricle sends the oxygenated blood into the aorta and the aorta then sends the oxygenated blood throughout the body. 

 

back of the heart.

At the back of the heart you get a great view of the 

veins and arteries that are entering and exiting the heart.

The Heart has two different types of valves located in four different places in the chambers of the heart. The heart is a one way blood flow system and valves insure that the blood only travels in one direction. In the picture above we found the semi-lunar valve, a semi-lunar valve can be found at the pulmonary veins and the aorta. This valve opens either in the right(pulmonary valve) or left(aorta valve) ventricle sending the blood down the pulmonary veins or the aorta. The second type of valve is atrioventricular valve which we could not find in our dissection. The atriocentricular valve is located in two different places in the heart. The first atrioventricular valve is located between the right atrium and right ventricle this is called the tricuspid valve  and the second one is located between the left atrium and the left ventricle and is call the bicuspid valve. Both the tricuspid and bicuspid valve send blood from the atrium to the ventricle. Chordae Tendineae is a type of muscle that contacts in order for it to open and then once it relaxes the valve shuts.

 In this picture you can see some Chordae Tendineae.

 

FUN FACT

In a fetal pig because it has not been born yet a lot of the blood in the heart is mixed because they do not have functional lungs that take in oxygen, so when we were dissecting our pigs heart we found a very good example of this. When you look at the picture below you can see the mixture of red a blue which shows you that the blood in this fetal pig has been mixed and by mixed blood I mean a mixture between oxygenated blood and deoxygenated blood.

 

 

Fetal Pig Dissection Day 1: Sexing, Initial Incisions, And Looking At The Organs.

In Biology we have started our Fetal Pig Dissection. I have created a blog to go through the day by day steps that we will be covering in class including pictures of what we did that day, what system we are looking at, and how those different systems function. Pigs are mammals like us and we share basic body forms.

 This is a picture of our fetal pig it has no incisions. Fetal pigs use to be preserved in formaldehyde but research shows that formaldehyde can cause cancer so now most fetal pigs are preserved in alcohol. Fetal pigs are unborn and come from a sow that has been butchered and the butchers were not aware the sow was pregnant which makes them an ideal  and common specimen for Biology 12 dissection. 

Day 1: 

 Day 1 was for sexing our pig and making the initial cuts so we could open it up to see all the organs. You can determine the sex of your pig by looking for the urogenital opening. The Urogenital opening is the exit point for both urine (uro) and egg/sperm (genital). Females urogenital opening is near the anus which is located under the tail and on males the urogenital opening is located by the umbilical cord.

SEXING THE PIG

As you can see our fetal pig was a female. This picture shows you where the urogenital opening is and it's location which is under the anus. Once we have figured out the sex of our pig it was then time to make the initial incisions and take a look at the organs that can be found inside.

INITIAL INCISIONS

This was how we were shown how to make the initial incisions with the scalpel. You want to be really careful you don't cut to deep because that could result in harming the organs.  

Once the pig was all cut open we got to play a little detective work and look around for some organs. In the picture above you can see the Liver, Large Intestine, Small Intestine, Umbilical Cord, and the Spleen. The Liver is one of the bodies vital organs and has many different functions like detoxification, protein synthesis, and producing biochemicals for digestions. The Large Intestine is attached to the Small Intestine and the Rectum its purpose is to absorb water from food that were indigestible and then pass waste from the body. Small Intestine is attached to the bottom of the Stomach and to the Large Intestine this is where most of digestion and nutrients are absorbed. The Umbilical Cord connects the fetus to the placenta and is how the fetus gets its needed nutrients and how it releases its wastes. The Spleen deals with Red Blood Cells and the Immune system, removes old red blood cells and recycles Iron. The anterior end of the pig would be located at the bottom of the picture above and the posterior end is located at the top of the picture that is above. 

Work Cited.

 http://www.google.ca/imgres?imgurl=http://www.biologycorner.com/resources/pig_incision.gif&imgrefurl=http://www.biologycorner.com/worksheets/fetal_pig_dissection.doc&usg=__mCEh_vks8rq5art3lzsN1yp-VOc=&h=278&w=220&sz=5&hl=en&start=0&sig2=-y6WLcgYvojBJuRwtRBkow&zoom=1&tbnid=DSxCLbNnsbtM3M:&tbnh=157&tbnw=122&ei=3a_VTea9CerWiAKdtdjmBw&prev=/search%3Fq%3Dfetal%2Bpig%2Bdissection%2Bcutting%26um%3D1%26hl%3Den%26sa%3DN%26biw%3D1366%26bih%3D616%26tbm%3Disch0%2C349&um=1&itbs=1&iact=hc&vpx=861&vpy=47&dur=1173&hovh=222&hovw=176&tx=121&ty=143&sqi=2&page=1&ndsp=22&ved=1t:429,r:19,s:0&biw=1366&bih=616