Physiology / Fetal Pig Dissection

Transcription

1 486 P a g e

2 Physiology / Fetal Pig Dissection At the end of this unit, I will: explain the structure and function of organs and organ systems and how they work cooperatively within an organism. be able to carefully dissect, reveal, and identify anatomical features of a fetal pig. Roots, Prefixes and Suffixes I will be able to understand when I see them in words are: cardio-, veno-, arterio- lymph-, ova-, spermato-, reno-, caudo-, cephalo-, hemo-, lympho-, spleno-, thymo-, laryngo-, naso-, pharyngo-, tracheo-, esophago-, colo-, pancreato-, gastro-, nephron-, uretero-, urethro-, sebo-, gonado-, utero- The terms I can clearly define are: Group 1: cell, tissue, organ, organ system, organism Group 2: cardiovascular system, muscular system, lymphatic system, immune system, respiratory system, digestive system, urinary system, nervous system, integumentary system, endocrine system, reproductive system, skeletal system. Group 3: Complement System, Phagocytes, Macrophages, Lymphocytes, T- cells, B-cells, Antigens, Antibodies, Plasma Cells, Memory Cells The assignments I will have completed by the end of this unit are: Dissection Cover Page Fetal Pig Virtual Dissection Fetal Pig Dissection Fetal Pig Dissection Practical 487 P a g e

3 Physiology / Fetal Pig Dissection Student Design Cover Page (see guidelines on page 16) 488 P a g e

4 Topic: Immune System: Holly Jones Gets the Flu 1. Which part of the body must the influenza-b virus reach in order to survive and multiply? 2. How does the influenza-b virus trick healthy cells? 3. About how many influenza-b viruses will be produced within a couple of hours of initial infection? 4. What is the human body's front line of defense against the influenza-b virus? 5. What do macrophages do? 6. What is the cause of symptoms of the flu? 7. What is the role of interleukin in the immune response? 8. Why do you get a fever in response to the flu? 9. What is a major role of dendritic cells in fighting the influenza-b virus? 10. Where are T-cells located? 11. What is the role of the T-cell in fighting infection? 12. What is the role of B-cells in fighting infection? 13. What happens to the T-cells that don t die? 14. Will a person who has had the influenza-b virus have immunity from ALL flu viruses in the future? 489 P a g e

5 Immune System (The Basics) 490 P a g e

6 The Immune System: Mark the following text about the immune system. I. Introduction The immune system is one of nature's more fascinating inventions. With ease, it protects us against billions of bacteria, viruses, and other parasites. Most of us never reflect upon the fact that while we hang out with our friends, watch TV, or go to school, inside our bodies, our immune system is constantly on the alert, attacking at the first sign of an invasion by harmful organisms. The immune system is very complex. It's made up of several types of cells and proteins that have different jobs to do in fighting foreign invaders. In this section, we'll take a look at the parts of the immune system in some detail. If you're reading about the immune system for the first time, we recommend that you take a look at the Immune System Overview first (see link below). II. The Complement System The first part of the immune system that meets invaders such as bacteria is a group of proteins called the complement system. These proteins flow freely in the blood and can quickly reach the site of an invasion where they can react directly with antigens - molecules that the body recognizes as foreign substances. When activated, the complement proteins can 1) trigger inflammation (swelling) 2) attract macrophages 3) coat intruders so that macrophages can devour them 4) kill intruders. III. Phagocytes This is a group of immune cells specialized in finding and "eating" bacteria, viruses, and dead or injured body cells. There are three main types, the granulocyte, the macrophage, and the dendritic cell. The granulocytes often take the first stand during an infection. They attack any invaders in large numbers, and "eat" until they die. The pus in an infected wound consists chiefly of dead granulocytes. A small part of the granulocyte community is specialized in attacking larger parasites such as worms. 491 P a g e

7 The macrophages ("big eaters") are slower to respond to invaders than the granulocytes, but they are larger, live longer, and have far greater capacities. Macrophages also play a key part in alerting the rest of the immune system of invaders. Macrophages start out as white blood cells called monocytes. Monocytes that leave the blood stream turn into macrophages.. The dendritic cells are "eater" cells and devour intruders, like the granulocytes and the macrophages. And like the macrophages, the dendritic cells help with the activation of the rest of the immune system. They are also capable of filtering body fluids to clear them of foreign organisms and particles. IV. Lymphocytes - T cells and B cells The lymphatic system. The receptors match only one specific antigen. White blood cells called lymphocytes originate in the bone marrow but migrate to parts of thelymphatic system such as the lymph nodes, spleen, and thymus. There are two main types of lymphatic cells, T cells and B cells. The lymphatic system also involves a transportation system - lymph vessels - for transportation and storage of lymphocyte cells within the body. The lymphatic system feeds cells into the body and filters out dead cells and invading organisms such as bacteria. On the surface of each lymphatic cell are receptors that enable them to recognize foreign substances. These receptors are very specialized - each can match only one specific antigen. wouldn't be able to pick up anything else. To understand the receptors, think of a hand that can only grab one specific item. Imagine that your hands could only pick up apples. You would be a true apple-picking champion - but you In your body, each single receptor equals a hand in search of its "apple." The lymphocyte cells travel through your body until they find an antigen of the right size and shape to match their specific receptors. It might seem limiting that the receptors of each lymphocyte cell can only match one specific type of antigen, but the body makes up for this by producing so many different lymphocyte cells that the immune system can recognize nearly all invaders. 492 P a g e

8 V. T cells T cells come in two different types, helper cells and killer cells. They are named T cells after the thymus, an organ situated under the breastbone. T cells are produced in the bone marrow and later move to the thymus where they mature. Helper T cells are the major driving force and the main regulators of the immune defense. Their primary task is to activate B cells and killer T cells. However, the helper T cells themselves must be activated. This happens when a macrophage or dendritic cell, which has eaten an invader, travels to the nearest lymph node to present information about the captured pathogen. The phagocyte displays an antigen fragment from the invader on its own surface, a process called antigen presentation. When the receptor of a helper T cell recognizes the antigen, the T cell is activated. Once activated, helper T cells start to divide and to produce proteins that activate B and T cells as well as other immune cells. The killer T cell is specialized in attacking cells of the body infected by viruses and sometimes also by bacteria. It can also attack cancer cells. The killer T cell has receptors that are used to search each cell that it meets. If a cell is infected, it is swiftly killed. Infected cells are recognized because tiny traces of the intruder, antigen, can be found on their surface. 493 P a g e

9 VI. B Cells The B lymphocyte cell searches for antigen matching its receptors. If it finds such antigen it connects to it, and inside the B cell a triggering signal is set off. The B cell now needs proteins produced by helper T cells to become fully activated. When this happens, the B cell starts to divide to produce clones of itself. During this process, two new cell types are created, plasma cells and B memory cells. The plasma cell is specialized in producing a specific protein, called an antibody, that will respond to the same antigen that matched the B cell receptor. Antibodies are released from the plasma cell so that they can seek out intruders and help destroy them. Plasma cells produce antibodies at an amazing rate and can release tens of thousands of antibodies per second. When the Y-shaped antibody finds a matching antigen, it attaches to it. The attached antibodies serve as an appetizing coating for eater cells such as the macrophage. Antibodies also neutralize toxins and incapacitate viruses, preventing them from infecting new cells. Each branch of the Y-shaped antibody can bind to a different antigen, so while one branch binds to an antigen on one cell, the other branch could bind to another cell - in this way pathogens are gathered into larger groups that are easier for phagocyte cells to devour. Bacteria and other pathogens covered with antibodies are also more likely to be attacked by the proteins from the complement system. The Memory Cells are the second cell type produced by the division of B cells. These cells have a prolonged life span and can thereby "remember" specific intruders. T cells can also produce memory cells with an even longer life span than B memory cells. The second time an intruder tries to invade the body, B and T memory cells help the immune system to activate much faster. The invaders are wiped out before the infected human feels any symptoms. The body has achieved immunity against the invader. 494 P a g e

10 Immune System Concept Map Create a concept map based on your reading from pages Unlike your other concept maps, each reading section marked by roman numerals must be represented by at least 5 terms; thus 30 terms total minimum!! Some sections may need more terms. Because this concept map is so extensive, you will thoroughly explain your concept map on the following page. Be sure to clearly show an understanding of the immune system in your summary. 495 P a g e

11 496 P a g e

12 On-line Virtual Pig Dissection To prepare ourselves for the task of dissection, we will explore a virtual dissection online. It is your task to complete the following quizzes prior to dissection in class. Due dates will be assigned by your individual classroom teacher. To complete the virtual dissection, go to the following web-page to complete the quizzes on pages of your interactive notebook: During this dissection, we will be exploring the following systems in detail. Digestive System Day One Respiratory System Day Two Circulatory System Day Two Excretory System Day Three Reproductive System Day Three 497 P a g e

13 Anatomical References Quiz Label the regions: Pelvic region, Cranial region, Caudal region, Pectoral regions Label the regions: Ventral, Posterior, Dorsal, Anterior Point of Reference A B Circle the correct choice 1. On the pig above, letter A is (medial, lateral). Letter B is (medial, lateral) 2. With respect to marker A, marker B is (proximal, distal) to the point of reference. 3. With respect to marker B, marker A is (proximal, distal) to the point of reference. 498 P a g e

14 Sexing Your Pig Quiz 1. An easy way to determine the sex of your pig is to check for the presence or absence of nipples. True or False? 2. Only the male pig has a urogenital opening. True or False? 3. The male fetal pig has a developing scrotal sac, a penis, and a urogenital papilla. True or False? 4. The pig featured below is what sex? 5. Label the diagram using the following terms. Urogenital papilla, umbilical cord, teats (nipples), anus 499 P a g e

15 Respiratory System Quiz Fill in the blank using the following terms: lungs, bronchi, diaphragm, nares, trachea. Following each definition, what number (1-5) did you used to label each of the structures on your on-line virtual quiz? Connects upper and lower respiratory system (number ) Distributes air into both lungs (number ) Contraction creates negative pressure (number ) Air enters the respiratory system (number ) Aids gas exchange with its large surface area (number ) Trace the path of gas molecules throughout the body. For this activity, use red arrows to trace the path of Oxygen (O2) and blue arrows to trace the path of carbon dioxide (CO2). Draw these arrows using red or blue ink. The first one is done for you as an example. This would be a red arrow. Mouth or Nose Arteries Tissues Veins 500 P a g e

16 Circulatory System Quiz Determine the proper cycle of blood throughout the body by filling in the flowchart with the terms: body, right atrium, lungs, left ventricle, right ventricle, left atrium, CO2 and O2 exchange 501 P a g e

17 Digestive System Quiz Identify the organs and their functions by filling in the following descriptions with the appropriate terms: mesentery, pharynx, gall, nares, pyloric, spleen, rectum, rugae, large, papillae, salivary, small, pancreas. 1. These ridges in the stomach allow the stomach to expand and hold more food for digestion. 2. The gland secretes some of the first enzymes in the digestion process. 3. Located on the tongue of the pig, the sensory are responsible for the sense of taste. 4. The sphincter controls the movement of food from the stomach to the small intestine. 5. This structure appears purplish due to the close proximity of the veins and arteries running through it. 6. It is the bladder that stores and concentrates bile for release in the stomach. 7. The intestine helps finish the digestive process by reabsorbing water and creating fecal matter. 8. The intestine is the main structure responsible for the absorption of essential nutrients into the body. 9. This structure stores fecal matter prior to excretion. 10. This small structure takes in red blood cells and other cells and breaks them down to recycle back to the body. 11. The paired are holes in the snout of the pig that facilitate breathing while warming in-coming air. 12. This organ manufactures digestive juices and enzymes to help portions of the digestive process. Identify the organs 1-6 from the digestive system quiz. Organ #1 Organ #3 Organ #5 Organ #2 Organ #4 Organ #6 502 P a g e

18 Excretory System Quiz Fill in the blank using the following terms: renal artery, ureter, bladder, renal vein, kidney. Following each definition, what numbers, (1-5), did you used to label each of the structures on your on-line virtual quiz? Takes filtered blood from the kidney back to the heart. (Number ) Transports urine to the bladder for storage. (Number ) Transports unfiltered blood from the heart to the kidney. (Number ) Reabsorbs nutrients, secretes wastes by filtering blood. (Number ) Takes filtered blood from the kidney back to the heart. (Number ) Stores urine until it can be excreted out of the body. (Number ) Fill in the blank using the following terms: cortex, ureter, renal pelvis, medulla. Following each definition, what numbers, (1-4), did you used to label each of the structures on your on-line virtual quiz? Collects filtrate from the kidney (Number ) The outer region of the kidney (Number ) Takes collected waste from the kidney to the bladder(number ) Inner portion of the kidney. (Number ) 503 P a g e

19 Reproductive System Quiz Label the parts of the female reproductive system based on the image you see on your virtual quiz Label the parts of the male reproductive system based on the image you see on your virtual quiz Put the structures in order that the unfertilized egg passes through the reproductive system P a g e

20 Reproductive System Quiz Put the structures in order that the male sperm passes through Match the following terms with the description of its function: cervix, oviducts, testes, testosterone, urethra, vagina, scrotal sac, ovaries, uterus, epididymus, vas deferentia contain eggs and release hormones the principal sex hormone in the male is the fetus develops in the These tubes carry sperm from the testes to the urethra Fertilization normally occurs in the contain eggs and release hormones produce sperm and release sex hormones 505 P a g e

21 Label the anatomical direction, according to the lecture notes. 506 P a g e

22 Topic: Introduction to Fetal Pig Dissection Define the following anatomical regions: Cranial Caudal Dorsal Ventral Anterior Posterior Cranial head region Caudal tail region Dorsal back region Ventral stomach region Anterior towards the front Posterior towards the back What is the difference between medial and lateral? What is the difference between proximal and distal? : closer to the trunk. : further from the trunk. : closer to a reference point. : further from a reference point. For example, the elbow is to the shoulder, while the wrist is more to the shoulder. Consider their classification and think about the similarities between human and pig. 507 P a g e

23 We study and dissect pigs due to their physiological and anatomical similarities to humans. Brainstorm ways in which their basic appearance and internal anatomy may be similar or different. 508 P a g e

24 Topic: Introduction to Fetal Pig Dissection What lab safety rules must we follow in order to protect ourselves, our classmates, and to respect the life of the fetal pig during the dissection lab? To determine the age of your pig: To determine the sex of your pig: What feature is unique to females? males? Decide on ventralincision style based upon the gender of your fetal pig 509 P a g e

25 Fetal Pig Dissection External Anatomy Gender 510 P a g e

26 Fetal Pig Dissection Objective: In this exercise you will examine the organization of the many body systems studied this semester in the context of a single specimen, the fetal pig. Be sure to identify the major organs as you explore the extent of each system. Day 1: External Anatomy and Digestive System External Anatomy Examine the fetal pig and locate the external features shown to the left. Two rows of nipples of mammary glands are present on the ventral abdominal surface of both males and females. Mammary glands later develop only in maturing females. Determine the gender of your specimen. Female: The urogenital opening in the female is immediately ventral to the anus and has a small genital papilla marking its location. Male: The scrotal sac is ventral to the anus and a urogenital opening is just posterior to the umbilical cord. What is the gender of your pig? Gestation for the fetal pig is days. The length of the fetal pig can give you a rough estimate of its age. 11 mm 21 days 17 mm 35 days 2.8 cm 49 days 4 cm 56 days 22 cm days 30 cm or greater full term How old is your pig? Observe the toes of the pig. How many toes are on the feet? Do they have an odd or even number of toes? 511 P a g e

27 Oral Cavity First Incisions P a g e

28 Oral Cavity To expose the structures of the mouth and pharynx, start by inserting a pair of scissors in the angle of the lips on one side of the head and cut posteriorly through the cheek. Open the mouth as you make your cut and follow the curvature of the tongue to avoid cutting the roof of the mouth. Now, repeat the procedure on the other side so that the lower jaw can be pulled down to expose the structures of the mouth and pharynx as shown in the image to your left. Locate the hard and soft palate on the roof of the mouth. Feel your own hard and soft palate with your tongue. Note the taste buds (sensory papillae) on the side of the tongue. Locate the esophagus at the back of the mouth. The esophagus eventually leads to what large J-shaped digestive organ? Feel the edge of the mouth for teeth. Does the fetal pig have teeth? Are humans born with teeth? Locate the epiglottis, a cone-shaped structure at the back of the mouth. This is a flap that helps to close the larynx that leads down to the lungs when the pig swallows, preventing food from entering the respiratory pathway. Preparing for the first incisions Use the scalpel only when absolutely necessary. You will mainly be working with blunt probes and scissors. Lift up as you cut, putting the blunt area of the scissors facing down and the sharp end facing up. Always cut away from you. Place the pig on its dorsal surface in the dissecting tray. Tie a piece of string or twine around the wrist of one forelimb. Then, pass the string under the tray and tie it to the other wrist. Tie and spread apart the pig s hind legs as you did with the forelimbs. Use dissecting scissors to cut through the skin and muscles along lines 1 4 to open up the abdominal cavity. (do not make incision 5 to open up the thoracic or chest cavity) Transverse incision #4 is made just below the rib cage. The flap formed by incision 2 will remain attached to the main part of the pig s body. To free this flap of tissue, cut the vein leading into the umbilical cord. 513 P a g e

29 Body Cavity bladder Umbilical vessels 514 P a g e

30 Locate each of the following organs below. Check the box when you have located the structure. Do not cut out any structure, unless instructed to do so. Diaphragm. This muscle divides the thoracic (chest) and abdominal cavity. It is located near the ribcage. The diaphragm aids in breathing. Liver. This structure is lobed and is the largest organ in the body. The liver is responsible for making bile for digestion. Gall bladder. Lift the liver to see this structure. This greenish organ is located underneath the liver. It may look like a raisin. The bile duct attaches the gall bladder to the duodenum, or the first section of the small intestines where the absorption of nutrients begins, particularly bile helps to digest lipids. The gall bladder stores bile and sends it to the duodenum, via the bile duct. Stomach. A J shaped organ that rest just beneath the liver to the pig s left. At the top of the stomach, you will find the esophagus. The stomach is responsible for churning and breaking down food. This is where the mechanical digestion takes place. Food is also stored in the stomach, and released a little at a time into the small intestine. Small intestine. The stomach leads down to the small intestine, which is composed of the duodenum (straight portion just after the stomach) and the ileum (curly part). The ileum is held together by mesentery. In the small intestine, further digestion occurs and nutrients are absorbed through the arteries in the mesentery. Pancreas. A bumpy organ located along the underside of the stomach. A pancreatic duct leads to the duodenum. The pancreas makes insulin, which is necessary for the proper uptake of sugars from the blood. It is part of both the digestive and endocrine systems. Spleen. A flattened, long organ that lies slightly under the stomach and toward the extreme left side of the pig. The spleen removes old red blood cells. Cecum. At the end of the ileum, where it widens to become the large intestines, a dead-end branch called the cecum is visible. The cecum helps the pig digest plant material. Large intestine. This organ follows the small intestines and can be traced to the rectum. The rectum lies toward the back of the pig and will not be moveable. The rectum opens to the outside of the pig, or anus. The large intestine reabsorbs water from digested food. Any undigested food is stored in the rectum as feces. Kidneys. Lying on either side of the spine are two bean shaped organs, the kidneys. The kidneys are responsible for removing harmful substances from the blood. These substances are excreted as urine. Urinary bladder. Two umbilical vessels can be seen in the umbilical cord, and the flattened urinary bladder lies between them. 515 P a g e

31 Thoracic Cavity Fetal Pig Heart, Ventral View 516 P a g e

32 Day 2: Circulatory and Respiratory Systems It is important that you do not break the vessels since it is very difficult to determine the name of the vessels unless you can see where it comes from and where it goes. The blood vessels have been stained in your pigs. Red blood vessels carry oxygenated blood (typically arteries) and blue blood vessels carry deoxygenated blood (typically veins). Open the chest cavity, by making incision #5 with dissecting scissors, as marked on page 305 of your interactive notebook. To open the thoracic cavity, you will have to cut through the sternum that connects the ribs. Heart. Remove the pericardium, which is a membrane that surrounds the heart to view the heart. The heart pumps blood throughout the body, circulating oxygen, carbon dioxide, nutrients, hormones, and other dissolved substances. The structures visible on the heart are the two atria (upper heart chambers) and the ventricles (lower heart chambers). The two ventricles are divided by the coronary artery that runs down the middle of the heart. The prominent pulmonary artery can be seen leaving the pig s right ventricle. This artery goes to the lungs. A large aorta (vessel) arches and leaves the heart and delivers blood throughout the body. The aorta will branch toward the head and curves around to go to the lower part of the body. Lift the heart to look at its dorsal side (toward the back). You should be able to see the anterior and posterior vena cavae, stained blue. The anterior vena cava returns blood to the heart from the head, while the posterior vena cava returns the blood to the heart from the lower half of the body. Above the heart is the thymus gland. This gland extends into the neck on each side of the trachea. The thymus is part of the immune system, where T- cells mature. Find the diaphragm again. Remember that the diaphragm separates the abdominal cavity from the thoracic cavity and it aids in breathing. The lungs are spongy and are found to the left and right side of the heart. The lungs are connected to bronchial tubes which connect to the trachea. The trachea is easy to identify due to the cartilaginous rings, giving it the appearance of a bendy straw. The cartilage keeps it from collapsing as the animal inhales and exhales. 517 P a g e

33 Male Reproductive and Excretory Systems 518 P a g e

34 Day 3: Reproductive and Excretory Systems You will dissect your own pig, but make sure to view both male and female pigs by examining other groups dissections. Locate the kidneys. The blue veins leading out of the kidneys are the renal veins, returning blood to the heart. The red arteries leading towards the kidneys are the renal arteries, delivering blood from the heart. The tubes that lead from the kidneys that carry urine are the ureters. The ureters carry urine to the urinary bladder where urine is stored until it is ready to be excreted. The urinary bladder is found in between the umbilical vessels. Follow the urinary bladder and you will find the urethra, the tube that carries urine out of the body. Male Reproductive System Find the scrotal sacs at the posterior end of the pig. The testis is located in each sac. Open the scrotal sac to locate the testis, being careful not to damage the testis. On each testis, find the coiled epididymis. Sperm cells produced in the testis pass through this tube, where they mature. After maturation, they enter a tube called the vas deferens. (in humans, a vasectomy involves the cutting of this tube.) The vas deferens crosses over the ureter and enters the urethra, which leads to the penis. The penis will be located in the flap that has the umbilical cord. Cut away the skin to reveal the penis. 519 P a g e

35 Female Excretory and Reproductive System Fallopian tube 520 P a g e

36 Female Reproductive System In the female pig, locate the two bean shaped ovaries found just posterior to the kidneys. The ovaries are connected to the fallopian tubes, which carry eggs from the ovaries to the uterine horns. (The uterus of the pig is different from that of the human, as it is divided into two horns before joining together as one uterus. Remember pigs give birth to litters.) The uterus can be traced posteriorly to the vagina, which simply appears as a continuation of the uterus. The common area between the vagina and the urethra is called the urogenital sinus. Finishing Up Time permitting, feel free to revisit any part of this exercise. Make sure that you can identify all terms that are in bold, as you will be responsible for identifying these parts on your lab practical. Identify both male and female structures. Dispose of your specimen, according to your teacher s instructions. Disinfect and sanitize your lab space, wash your hands, and clean up. 521 P a g e

37 Dissection Unit Concept Map 522 P a g e

38 Parent/ Significant Adult Review Page Student Portion Unit Summary (write a summary of the past unit using 5-7 sentences): Explain your favorite part of the dissection: Adult Portion Dear Parent/ Significant Adult: This Interactive Notebook represents your student s learning to date and should contain the work your student has completed. Please take some time to look at the unit your student just completed, read his/ her reflection and respond to the following Ask your child to explain to you the pig dissection process. What three facts did you learn from your child? Do you think your child benefited from this dissection? Please explain. Parent/ Significant Adult Signature: Comments? Questions? Concerns? Feel free to your child s teacher. 523 P a g e

39 Intentionally Left Blank 524 P a g e