Anatomy of the Pig By Tori Lev Fetal Pig Dissection umans and fetal pigs share very similar intermediate school. Pigs are also important Hanatomy as they are both mammals. to study because recent research has found Fetal pigs are also a popular choice for that they are so similar to humans that dissections as they are a bi-product of the their heart tissues can be used for human pork industry, therefore as long as people transplants, after the tissue is treated retain their love for bacon, they will always to reduce potential rejection. For this be available in abundance. Furthermore, article, two nine inch pigs were dissected. fetal tissue is soft and easy to cut through, making it an ideal specimen, especially for
Key Terms
Dorsal - the back Ventral - the front (belly-side) Median - the middle/central Median plane - divides body into two similar halves Lateral - the side Anterior - the front (head-end) Posterior - the back (tail-end) Proximal - situated near the point of attachment on body Distal - farthest away from point of attachment on body Superficial - near the surface Deep - below the surface 1 | Anatomy of the Pig The Heart 9 he heart and lungs are both located 7 Tin a region of the pig known as the 8 thoracic cavity, which is separated from the digestive system by the diaphragm, a thin, sheet-like muscle. Between the lungs we 6 find the heart swaddled in the pericardial 1 sac. Here we can begin to see that the 2 heart is separated into four chambers - the right and left atrium as well as the right 3 and left ventricle. The right atrium is the ear-shaped section of the heart labeled “1” on the figure to the right; it receives blood 5 from the body back to the heart via the 4 vena cava (see diagram below). Blood flows from the right atrium to the right ventricle - located just below the right atrium - through the tricuspid valve. From there, the blood flows through the pulmonary valve on to the pulmonary artery where deoxygenated blood is moved to the lungs. When the blood becomes oxygen-rich it is returned to the heart through the pulmonary vein to the left atrium. Similar to the right atrium, Aorta the left atrium contracts when filled forcing Pulmonary Superior Artery blood through the mitral valve into the left Vena Cava ventricle and backflow is prevented. The Pulmonary Left Vein oxygen-rich blood is then transported to the Right Atrium Atrium aorta and distributed to the rest of the body.
Tricuspid Valve 1 - Right atrium 2 - Left atrium Inferior Mitral Vena Cava 3 - Right Ventricle Valve 4 - Left ventricle 5 - Coronary Vein Right Left Pulmonary Ventricle Ventricle 6 - Pulmonary trunk Valve 7 - Aortic arch 8 - Superior vena cava 9 - Aorta
Anatomy of the Pig | 2 The Lungs oth human and pig lungs 4 their mouth or external Bhave the same function naires, commonly known of delivering oxygen to the as nostrils. From there, organs of the animal. The the air moves through fetal pigs lungs are flatter 1 the larynx to the than those of a human. trachea and finally on Techniques are being to the lungs. The lungs mastered to transplant are spongy in texture 2 2 porcine(pig) lungs into because they are humans. The lungs intended to have have the responsibilty maximum surface of removing carbon 2 area in order to dioxide and adding 3 gain the greatest oxygen to blood possible benefit that will then be from the air taken distributed back to in. The trachea 2 the body through 2 that brings the air the capillaries. Pig to the lungs divides lungs have multiple into the bronchi lobes, or subdivisions, which further divides on either side. Unlike into the bronchioles. humans who have three From here, they are sent to the lobes on one side and two on the alveoli, which are responsible for the other, the right lung of a pig has spongy texture of the lungs because they four lobes and are small air pockets creating a less solid the left lung structure (see figure to the left). From is divided the alveoli comes a network of capillaries into three. that deliver oxygen to the blood to Much like be sent back to the heart through the humans, pulmonary vein as discussed previously. pigs inhale air through
1 - Heart within the pericardial sac 2 - Lobes of the lungs 3 - Posterior vena cava Above: close up detail 4 - Thymus gland of the alveoli. 3 | Anatomy of the Pig The Digestive System his system is primarily located posterior Tto the diaphragm, the thin, sheet-like muscle dividing the abdominal cavity of the 1 pig into two sections. The food to be digested enters the system through the mouth where it undergoes its initial process of digestion through chewing and mixing with saliva to begin the chemical breakdown. It then moves to the pharynx, then the esophagus to the stomach where the food is further broken down with acidic gastric juices. From there the food moves through the small intestine, where the majority of nutrient absorption occurs. It then passes through the large intestine for absorption 2 of water and is finally excreted through the anus. Both the liver and pancreas assist in the digestive process with the secretion of digestive enzymes and insulin. These enzymes help breakdown the fats, 3 carbohydrates, and proteins as the food passes through the small intestine. Whereas in humans the intestines are coiled flat in one layer, the pig’s intestines are coiled, 8 specifically the colon.
8 7 4
1 - Liver 5 2 - Small intestine 6 3 - Large intestine 4 - Stomach 5 - Duodenum 6 - Pancreas 7 - Spleen 8 - Kidneys
Anatomy of the Pig | 4 Photographic Technique hen photographing the fetal pig in its entirety as well as its various internal anatomy, I Wset up white reflectors surrounding the subject, shining light on two sides parallel each other to reflect back onto the subject. The camera was set up on a copy stand, so rather than a typical horizontal path it was vertical. To achieve a black background I placed the subject onto a clean sheet of glass that was held over a sheet of black velvet with wood blocks. All images were made using Top-down view the Canon 6D, either a 100mm macro or 65mm macro lens.
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5 | Anatomy of the Pig About the Author ori is a third year in the independent project photographing TBiomedical Photographic anesthetic equipment. When Communications program not spending time at the at the Rochester Institute hospital, she was seeking of Technology; she is out new adventures by graduating this year. traveling around the Her biggest passions United Kingdom. Tori in life are education enjoys finding new and research, which places and exploring drive her to pursue the natural world a career in clinical around her. When she photography. During is not going on one this past summer she of these adventures, took an internship at the she is spending her time University Hospital of Wales volunteering with Habitat where she shadowed the clinical for Humanity or participating photography staff and worked on an in one of the clubs she is a part of.
To contact the author, please email [email protected] Acknowledgments Nebraska Scientific Thank you to Nebraska Scientific for the fetal pig specimens. The two fetal pigs were sent in a very timely fashion and in pristine condition. Did you know... Pork is the Finger Lakes Mini Pigs name for the Thank you to Johanna at Finger Lakes Mini Pigs for meat derived being flexible and allowing me to photograph their from pigs; it nine-day-old teacup piglets for the cover image. is the most consumed meat RIT Photo Equipment Cage worldwide. Thank you to the equipment cage for allowing me the opportunity to use photographic equipment that I would typically not have access to. Resources “Anatomy of the Heart.” Biological Sciences. Santa Barbara City College, 2003. Web. 2015.