ASC Quiz 1 fully solved & updated.

Anatomy and physiology are two distinct disciplines within animal science, but they are often discussed together. Which of the following statements correctly describes the difference between anatomy and physiology? - ANSWER-Anatomy focuses on animal form, whereas physiology focuses on animal function Horses are an athletic animal and need to be able to produce large amounts of ATP aerobically in their muscles. If you were to compare the muscle cells of a fit, athletic horse to those of a less athletic animal such as a pig, which organelle would you expect to be present in greater amounts in the muscle cells of the horse? - ANSWER-Mitochondria When many individual phospholipids are put into an aqueous solution, such as water, what would you expect to happen? - ANSWER-They will form a phospholipid bilayer with the polar regions facing outwards and in contact with the water and the non-polar regions clustered together in the middle In veterinary medicine, a 0.9% saline solution is considered to be isotonic (isosmotic) and can be infused into the blood stream of an animal without fear that it will damage the blood cells. If pure water were accidentally infused into an animal instead of the 0.9% saline solution, what would you expect to happen to the blood cells? - ANSWER-The blood cells will gain water and expand and possibly burst Lactase is the enzyme used to digest the lactose found in milk. You have just adopted an adult cat from the humane society and decide that you would like to feed her milk as a treat. The first day you feed your cat milk, she seems to get a little sick and has very soft, loose feces. However, you keep feeding her milk every day and over time her feces return to normal. You decide that this is because her body has started to make more lactase so she is able to digest the milk better. This is an example of what type of enzyme regulation? - ANSWER-Chronic Cats and rabbits are both non-ruminant mammals of a similar size. The main ingredient in cat food is usually a meat such as chicken, which is high in protein. In rabbits, the main ingredient is often a type of hay, which is high in cellulose. Based on the types of diets that each of these animals consumes, what differences in gastrointestinal structure would you predict? - ANSWER-The cat will have a larger stomach, while the rabbit will have a larger cecum Why are horses more predisposed to gastric ulcers than other non-ruminant species? - ANSWER-The stomach of horses has a large non-glandular region where no mucous is produced The digestion of which of the following nutrients would be negatively impacted if an animal had a pancreas that was not adequately functioning? - ANSWER-Fat, protein and starch The digestive secretions of which of the following organs are regulated by both the endocrine and nervous systems? - ANSWER-Stomach and pancreas Why is bicarbonate secretion by the pancreas into the small intestine so important? - ANSWER-It neutralizes the hydrochloric acid released in the stomach Ruminants produce much more saliva on a daily basis than similarly sized non- ruminants. Which of the following is not a benefit of this large amount of saliva production that is unique to the ruminant? - ANSWER-Contains amylase which can be used to digest starch Which of the following statements correctly describes how the rumen microbes produce the volatile fatty acids? - ANSWER-Microbesreleaseanenzymethatisabletodigestcellulose,themicrobesabsorb the resulting glucose and use it to make ATP, generating the volatile fatty acids as a byproduct When cattle eat a high forage diet, a substantial amount of the gas methane is produced by the rumen microbes and must be released from the rumen. What is the name of the process whereby this gas is liberated from the rumen? - ANSWER-Eructation When comparing a dog and a beef cow, which of the animals will require more feed each day on a g feed/kg body weight basis and why? - ANSWER-The dog because it has a greater weight-specific metabolic rate Which of the following is not one of the conditions that must be met when determining an animal's basal metabolic rate? - ANSWER-The animal must be breathing in pure oxygen The thermoneutral zone for most adult dogs is between 20 0C and 30 0C. As the environmental temperature increases from 22 0C to 28 0C, which of the following describes a physiological response that the dog will have to help maintain its body temperature? - ANSWER-The dog will dilate the blood vessels on the surface of its body (vasodilation) The lower critical temperature for a sheep with 10 cm of fleece is -3 0C (Sheep A), whereas for a sheep that was recently shorn it is 22 0C (Sheep B). Based on this information, which of the following statements is true? - ANSWER-When the environmental temperature falls from 15 0C to 5 0C, Sheep A can increase the degree of piloerection to stay warm, whereas Sheep B will shiver to stay warm The inside of the cell has a ______________ concentration of sodium ions than the outside of the cell - ANSWER-Lower The ______________ is the digestive organ in the poultry gastrointestinal tract where acid is secreted. - ANSWER-Proventriculus In the small intestine of both ruminants and non-ruminants, the major propulsive motility pattern is ______________ , whereas the major retentive motility pattern is ______________. - ANSWER-Peristalsis; segmentation The secretion of the enzyme ______________ in the abomasum is essential in order for ruminants to be able to digest and absorb microbial protein - ANSWER-Lysozyme In land mammals, an increase in the speed that the animal runs will result in a(n) ______________ in the rate of energy expenditure - ANSWER-Increase The term ______________ refers to animals which maintain a constant body temperature by using physiological means to regulate how heat is gained, produced and dissipated - ANSWER-Homeotherm True or False? Homeostasis refers to the ability of an animal to change its internal environment in response to changes in its external environment. - ANSWER-False True or False? Because poultry do not chew their feed to any large extent, the gizzard plays an important role in reducing the particle size of ingested feed. - ANSWER-True True or False? Species lacking a gallbladder are not able to digest dietary fat. - ANSWER-False True or False? Although the enteric nervous system is contained entirely within the walls of the gastrointestinal tract, it also receives inputs from the central nervous system through the sympathetic and parasympathetic branches of the nervous system. - ANSWER-True True or False? If the forage to concentrate ratio in a diet fed to beef cattle changes from 80:20 to 40:60, there will be no effect on the ratio of acetate to propionate produced by the rumen microbes. - ANSWER-False True or False? Glucose, fat and protein can all be used to make ATP aerobically - ANSWER-True True or False? The part of the brain that is critical for thermoregulation is the hypothalamus - ANSWER-True Pair the enzyme with the nutrient that it digests: Pepsin - ANSWER-Protein Pair the enzyme with the nutrient that it digests: Lipase - ANSWER-Fat Pair the enzyme with the nutrient that it digests: Cellulase - ANSWER-Fiber Pair the enzyme with the nutrient that it digests: Trypsin - ANSWER-Protein Pair the enzyme with the nutrient that it digests: Amylase - ANSWER-Starch The plasma membrane of cells is considered to be semi-permeable, meaning some molecules are able to pass directly through the membrane while other molecules cannot and need an alternate method to cross the membrane. Give an example of a molecule that can cross freely through the plasma membrane. - ANSWER-Small, non-polar molecules (gases, fatty acids, cholesterol); also water The plasma membrane of cells is considered to be semi-permeable, meaning some molecules are able to pass directly through the membrane while other molecules cannot and need an alternate method to cross the membrane. Give an example of a molecule that cannot cross freely through the plasma membrane. - ANSWER-Large macromolecules such as proteins; charged molecules (ions); polar molecules (glucose, amino acids) The plasma membrane of cells is considered to be semi-permeable, meaning some molecules are able to pass directly through the membrane while other molecules cannot and need an alternate method to cross the membrane. There are two types of membrane proteins that can be used to move these molecules (that cannot freely cross the membrane) across the plasma membrane. Name these types of proteins and explain the major differences in how these proteins function. - ANSWER-Channels and transporters. Transporters require binding and channels do not. Channels always allow movement towards equilibrium and are therefore passive, whereas transporters may be either passive or active. Not all organs that are essential for digestion are part of the continuous tube known as the gastrointestinal tract. These organs are known as the accessory organs. Name the three accessory organs. - ANSWER-Salivary glands, pancreas, liver/gallbladder Not all organs that are essential for digestion are part of the continuous tube known as the gastrointestinal tract. These organs are known as the accessory organs. Explain how these organs can play an essential role in digestive function, despite the fact that digesta does not actually travel through any of these organs. - ANSWER-They contribute to essential secretions into the lumen of the GIT Both non-ruminants and ruminants eat diets containing protein and need to be able to break down the protein to the amino acids that can be absorbed. In as much detail as possible (including the names of organs, enzymes, secretions, etc.), describe how protein is digested to amino acids in non-ruminants. - ANSWER-Stomach- HCl and pepsinogen are released; HCl unwinds protein and activates pepsinogen, which is then able to start cleaving the protein chain into smaller pieces Small intestine - pancreatic zymogens (trypsinogen, chymotrypsinogen, proelastase, procarboxypeptidase) are released into the SI; trypsinogen is activated by enterokinase and then trypsin activates the other zymogens; the pancreatic enzymes continue to cleave the protein chains into smaller pieces and then brush border enzymes (aminopeptidase, dipeptidases) will make the final cleavages Both non-ruminants and ruminants eat diets containing protein and need to be able to break down the protein to the amino acids that can be absorbed. In as much detail as possible, explain how the process of protein digestion is different in ruminants than in non-ruminants. - ANSWER-In the Rumen: microbes digest dietary protein and use it, along with urea, to make microbial amino acids and microbial protein In the Abomasum: lysozyme is released, along with the acid and pepsinogen secretions, and lyses the bacteria, exposing the microbial protein; microbial protein can then be digested in a manner similar to dietary protein in non- ruminants In non-ruminants, the major product of starch digestion that is absorbed from the gastrointestinal tract is different from what results from starch digestion in ruminants. In as much detail as possible, explain why the same nutrient (starch) can have different digestive end products, depending on whether it is fed to a ruminant or a non-ruminant. In your answer, make sure to include the major starch digestive end-product for both ruminants and non-ruminants. - ANSWER-Non-ruminant end product: glucose Ruminant end product: Volatile fatty acids (may also say lactic acid) Explanation: In non-ruminants, starch is digested enzymatically, primarily by amylase released by the pancreas into the small intestine (perhaps also a small amount of salivary amylase). In ruminants, starch passes through the rumen prior to its major sites of enzymatic digestion and therefore the microbes are able to digest it. When microbes digest starch, they are able to metabolize the resulting glucose and VFA (and lactic acid) are produced as a metabolic byproduct. If a broad spectrum antibiotic designed to kill all bacteria were fed to a lamb eating a mainly hay (cellulose) diet, what effect would you expect that antibiotic to have on the lamb's growth rate and why? In your answer make sure to provide details about the specific roles that bacteria play in the digestive tract of ruminants. - ANSWER-Growth rate would decrease or stop altogether Cellulose is not digestible by the lambs own enzymes and requires microbes to release cellulase to digest it If the microbes in the rumen were all killed off, there would be no cellulose digestion and so no VFA for the lamb to absorb and so it would not have enough energy to do things such as grow (or likely even survive Your pet pot belly pig has gotten to be very overweight. You do not believe in restricting how much feed he gets on a daily basis, so have decided that you will try to increase your pigs metabolic rate. Define the term 'metabolic rate.' - ANSWER-Rate (speed) at which an animal consumes energy (or produces energy or produces heat) Your pet pot belly pig has gotten to be very overweight. You do not believe in restricting how much feed he gets on a daily basis, so have decided that you will try to increase your pigs metabolic rate. Give 2 specific examples of things that could be done to increase your pigs metabolic rate and explain how/why they would work to increase metabolic rate. - ANSWER-Need 2 of the following: - Increase exercise: increased activity increases the metabolic rate as muscles need to contract more to allow for movement - Put animal in a temperature outside of its thermoneutral zone: homeotherms want to keep a constant body temperature, so when placed in an environment that is too hot/too cold, they will consume energy to actively warm or cool their body - Increase the energy expenditure associated with feeding: the consumption of a meal is associated with an increase in energy expenditure, so feeding the same number of calories but divided between more meals could increase the metabolic rate as they are using energy to eat more often or feeding the same number of calories but in a harder to digest feed (more fiber needs more chewing, etc) could also increase energy expenditure There are four major methods that an animal can use to dissipate heat (or prevent its body from gaining too much heat). Name these 4 methods and provide an example for each one (using the animal of your choice). - ANSWER-- Conduction: must state something that involves the animal coming into physical contact with a colder object (ie. placing an ice pack on an animal) - Convection: must state something that involves cooler air or cooler water flowing over the animal (ie. standing in the wind, standing in a cool, running stream) - Evaporation: sweating, panting, putting water on an animal and allowing it to evaporate off - Radiation: must involve the animal either radiating heat to a cooler object, without physical contact (ie. tree nearby) or preventing the acquisition of more heat from radiation (ie. standing in the shade)