Lab Report on Guinea Pig
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The document provides a lab report summarizing the dissection and examination of the external and internal anatomy of a guinea pig. The student identified and described the guinea pig's key physical characteristics, senses, coat, behavior, locomotion, communication, feeding habits, and internal body systems. Through comparing the guinea pig's anatomy and physiology to humans, the student concluded that guinea pigs are a useful model for understanding mammalian anatomy and investigating potential cures for illnesses due to their similarities to humans.
Lab Report on Guinea Pig
- 1. CHURCH TEACHERS’ COLLEGE MANDEVILLE LAB REPORT ON THE ANATOMY OF A GUINEA PIG Name: Chevance V. Henry I.D#: CH20149495 Date: October 16, 2014 Course: Animal Diversity Course Code: SC203SEB Course Lecturer: Tillack Hardeen
- 2. TITLE: The dissection of a Guinea Pig ABSTRACT: This investigation was intended to study the external and internal anatomies of the Guinea pig. Due to their class Mammalia, which is the same as humans, a comparative study was necessary to examine the structures and behavioral patterns of the Guinea pig for a greater understanding of the body systems of mammals. Guinea pigs are very popular pets because of their availability, docile temperaments, tendency not to bite or scratch when handled and relatively clean habits. There are lots of different breeds of Guinea Pig and they come in lots of colors and fur textures. This study has provided useful information on the general characteristics of mammals. The examination of the external and internal anatomies of the Guinea pig started by firstly by using chloroform to subdue the organism to allow for an undisturbed observation. The Guinea pig was then placed on its dorsal and ventral side on a dissecting tray to observe and identify its external features. A dissection of the Guinea was necessary to fully examine its internal anatomy. Pictures, measurements and drawings were made of the external and internal body parts which were identified and labeled. The reasons why these animals are a part of the class Mammalia were easily identified when the Guinea pig was examined. Their body systems were quite similar to that of humans and further conclusive study has revealed that their physiological process occur in the same way.
- 3. INTRODUCTION: This investigation serves as a tool to analyze the physiological mechanisms in animals to understand the dynamics of life and to establish a basic knowledge about the anatomy and morphology of guinea pig. Guinea Pigs are rodents related to chinchillas and porcupines that originated from the Andes Mountains region of South America. Their scientific name is 'Cavia Porcellus' and so they are called 'Cavies' for short. Guinea pigs belong to the Phylum Chordata, Class Mammalia and Order Rodentia. Physical Characteristics A Guinea Pig is a small and measure 20 to 40 cm from head to rump. It is a burrowing rodent that has a compact body. Guinea pigs have small ears and eyes, a small snout with sensory whiskers each side and no tail. Like most rodents, they have two gnawing teeth at the front which continue to grow throughout their life. Because these teeth are continuously growing, it is very important that Guinea Pigs have something to gnaw on to help keep the teeth trim. Guinea Pigs have short legs and little feet with claws on. Their front feet have four toes or claws; however, their back feet have only three. Se ns e s Adult guinea pigs seem to be able to discern brightness, but not hue. Young are born with their eyes open, but studies suggest that their vision is poorly developed at birth. Scent plays a role in guinea pig communication, and mother guinea pigs use it to identify their young. Guinea pigs
- 4. can hear sounds of up to 40,000 to 50,000 Hz, and some guinea pig vocalizations have ultrasonic components above 20,000 Hz. Coat The wild relatives of guinea pigs have ticked grey coats similar to that of Shadow. Breeding guinea pigs for research and show has produced many combinations of coat colour, length, and quality. Common colours include white, brown, black and combinations thereof. Guinea pig fur may be long or short, straight, frizzy or curly, soft and silky or rough and harsh, and it may lie smoothly or in rosettes. Activity Guinea pigs are most active at dawn and dusk, but they are active throughout the day. Under conditions of constant light and cool temperature, they do not appear to have fixed sleeping or eating patterns. Social Be havior As social animals, guinea pigs will seek contact with one another and tend to associate in groups of several to several dozen if given the opportunity to do so. They investigate unfamiliar guinea pigs by nose-to-nose contact and anogenital nuzzling. Guinea pigs interact and socialize with their caregivers when kept as pets. For example, they may chirp at their caregiver to ask for food. In groups of guinea pigs, males have a linear hierarchy. The alpha male has exclusive rights to mating with the females in his group, and will not tolerate other males attempting to mate with his females. Females are subordinate to their male, and they may have a loose social hierarchy among themselves.
- 5. Locomotion Guinea pigs are quadrupedal. They walk and run on the soles of their feet . Young guinea pigs play by "popcorning", that is, by jumping, bucking, and throwing up their heads. In response to danger or fright, guinea pigs will either freeze or run away. Groups of guinea pigs may respond by suddenly scattering in all directions. Communi catio n Guinea pigs communicate with one another by making sounds. They produce a variety of vocalizations that go along with certain activities. For example, a guinea pig will "chutt" when exploring, "whistle" when fed by a caregiver or when separated from a companion, and "purr" when seeking contact. Guinea pigs also use scent to communicate. Scent from adanal glands may be used to mark territory. In courtship, an unreceptive female will sometimes squirt a jet of urine at the persistent male, who then sniffs it. While the male investigates, the female escapes. Alternatively, the persistent male may squirt urine at the female, possibly in an attempt to mark her as part of his group. Fe e ding Guinea pigs are herbivores. They feed in groups with little competition for food. Unlike other rodents, guinea pigs cannot manufacture vitamin C; they must consume it in their diet. Sources of dietary vitamin C include fresh vegetable matter and supplements that caregivers add to food or water. To extract as much nutrition as possible from their cellulose-rich diet, guinea pigs use coprophagy. They cannot digest cellulose themselves, but bacteria in their cecum can. However, once food has reached the cecum, guinea pigs cannot absorb nutrients from it. So, they pass and eat special, soft fecal pellets containing bacteria-digested cellulose.
- 6. APPARATUS/MATERIALS: The following equipment and materials were used in the dissection: 1 live Guinea pig, 1 ruler, 1 dissecting kit including (1 scissors, 1 scapula, 1 forceps and1 probe, 8 pins), 1 dissecting tray, paper towel, 4 cm3 chloroform, 1 small carton box, 100 ml of bleach, 50 ml of liquid detergent, 1 pair of latex gloves, 1 lab coat, 1 digital camera, 2 blank papers, 2 sheets of newspaper, a sheet of cardboard and 1 pencil. PROCEDURE: Part A: Observing the Guinea Pig’s External Anatomy A Lab Coat and a pair of latex gloves were put on before the start of the practical. To allow for an undisturbed observation, the Guinea pig had to be subdued. The Guinea pig was placed in a small carton box, 4 cm3 of chloroform was soaked in a sheet of paper towel and placed over the nose of the mammal. The carton box was closed tightly to reduce the air in the box and to allow for the chloroform to be inhaled by the Guinea pig. After three minutes, no movement was detected by the Guinea pig. The guinea pig was then placed on its ventral side then on its dorsal side and observed on a piece of cardboard on the dissecting tray. Pins were pierced in the feet and hands of the Guinea pig to fix it onto the dissecting tray; this allowed for the easy observation of the external anatomy of the frog. Pictures and measurements were taken and a drawing made and labeled to represent its external anatomy. Part B: Observing the Guinea Pig’s Internal Anatomy The forceps was used to lift the skin while the scissors were used to make a vertical incision in the middle of the trunk, starting from above the cloaca to the neck. Horizontal incisions were made at the top and bottom of the vertical incision and the forceps were used to pull away the
- 7. skin to expose the chest cavity region of the Guinea pig. Having the chest cavity exposed, a scapula and scissors were used interchangeable to carefully repeat a vertical incision from above the anus to the neck of the Guinea pig. Horizontal incisions were made with the scapula at the top and bottom of the vertical incision. The forceps was used to pull the cavity apart and pin it to the cardboard to expose the internal organs. A probe was then you used to explore the internal organs exposing some structures that were located beneath. A picture was then taken and a drawing made with the structures labeled. Part C: Clean Up and Disposal Once the observing and identifying the structures of the Guinea pig were made, the pins were removed and it was disposed of safely. Excess fluids on the dissecting tray were cleaned off with plenty of water, bleach and liquid detergent. All of the mammal’s tissues were placed directly into the garbage bag provided by the lecturer. The dissecting instruments were washed off with bleach and liquid detergent and dried with a paper towel to prevent rusting. The dissecting instruments were placed back into the kit only when there were fully dried. The gloves were disposed of and hands were washed thoroughly.
- 8. OBSERVATION AND RESULTS: The pictures below show the external and internal structures of the Guinea Pig
- 9. DISCUSSION: Like other mammals the Guinea pigs have characteristics which show evolutionary development that has placed them on top of the class of animals. They have numerous adaptations that enable them to survive in a wide range of environments. Guinea pigs have hair which grows from skin cells called follicles. Hair can take on several different forms including thick fur and long whiskers. Hair serves a variety of functions for guinea pigs; it provides insulation, protects the skin, serves as camouflage and provides sensory feedback. Mammals such as guinea pigs differ from other vertebrates such as reptiles, birds and amphibians in that they have a single lower jaw bone that attaches directly to the skull. This bone is referred to as the dentary, due to the fact that it holds the teeth of the lower jaw. In other vertebrates, the dentary is one of several bones in the lower jaw and does not attach directly to the skull. The structure of the lower jaw and the muscles that control it provides mammals with a powerful bite and enables them to use their teeth to cut and chew their prey. Mammal species have specialized teeth adapted to their particular diet. Cats, for example, have sharp teeth that enable them to tear meat while herbivores such as bison have broad teeth, well-suited for grinding plant material. Mammals have a unique arrangement of three bones in the middle ear. These bones—the incus, malleus and stapes, commonly referred to as the hammer, anvil and stirrup—are unique to mammals, no other animal group has them. The middle ear bones transmit sound vibrations from the tympanic membrane or eardrum to the inner ear and transforms them into neural impulses. The malleus and incus are derived bones that were once part of the lower jaw in mammal ancestors. Mammals are endothermic which means they are capable of regulating their own body temperature so that it remains at a relatively constant temperature regardless of the temperature
- 10. of the surrounding environment. Like all vertebrates, mammals have a muscular heart that contracts repeatedly to pump blood throughout the body's blood vessels. The heart serves to deliver oxygen and nutrients throughout the body and remove waste products. In general, the heart consists of multiple chambers (the number of chambers differs for the various animal groups). Two to four chambers may be present and there are two types of chambers, the atrium and ventricle (the atrium receives the blood returning to the heart while the ventricle pumps blood from the heart to the rest of the body).
- 11. CONCLUSION: Guinea pigs serve as a useful tool in understanding the anatomy of mammals as its body systems were easily identified and related to structures of humans normally viewed in books and on pictures or diagrams. Their behavioral patterns, anatomy and morphology showed evolutionary development of the class which has helped them to adapt to their surrounding maintaining their dominance among the life forms. Due to their similarity not only in their body system arrangement but also in their physiological processes, they can be used by scientist to test for cure or treatment of different illnesses. This investigation has proved worthwhile as due to the close examination of the anatomy of the guinea pig and a study of its behavioral patterns it has been proven that mammals are among the most intelligent creatures and have a more complex body system to sustain life.
- 12. REFERENCES Johnson, George B. (2003). The Living World (Third Edition). McGraw-Hill Higher Education Miller, Stephen A. & Harley, John P. (2007). Zoology (Seventh Edition). McGraw Hill Higher Education Mack, L. (2006). Animals. New York, NY.: DK.