CHAPTER 1. Quick Check and Active Learning Answer Keys QUICK CHECK

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1 CHAPTER 1 QUICK CHECK Page 9 1. Anatomy is the study of the structure of an organism and the relationships of its parts. Physiology is the study of the functions of living organisms and their parts. Pathology (scientific study of disease) uses the principles of anatomy and physiology to determine the nature of particular diseases. 2. The scientific method is a systematic approach to discovery. It includes the following: hypothesis, experimentation, and collecting and analyzing data (accept or reject). A hypothesis that has gained a high level of confidence is called a theory or law. 3. Chemical cellular tissue organ organ system organism 4. A tissue is an organization of many similar cells that act together to perform a common function. Organs are larger and more complex than tissues. An organ is a group of several different kinds of tissues arranged so that they can act together as a unit to perform a special function. Page Anatomical position is a reference position. The body is in an erect or standing posture with the arms at the sides and palms turned forward. The head also points forward, as do the feet, which are slightly apart. 2. Anatomical directions are listed in sets of opposite pairs to help understand them better. Page A section or plane describes how the body as a whole is subdivided or cut into smaller segments (e.g. sagittal, frontal, transverse). 2. Ventral and dorsal body cavities. 3. The lower part of the ventral cavity includes the abdominal cavity and pelvic cavity. Because no physical partition separates them, they actually form one cavity: the abdominopelvic cavity. Page The axial portion of the body consists of the head, neck, and torso or trunk. The appendicular portion consists of the upper and lower extremities. 2. Upper extremities: arm, forearm, wrist, and hand components. Lower extremities: thigh, leg, ankle, and foot components. 3. Atrophy is a degenerative process that is characterized by a generalized decrease in size or a wasting away of many body organs and tissues that affects the structure and function of many body areas. Page Homeostasis is what physiologists call the relative constancy of the internal environment. Because the activities of cells and external disturbances are always threatening internal stability or homeostasis, the body must constantly work to maintain that balance or stability. 2. A feedback loop is a basic type of control system in the body. It works to restore homeostasis. An example can be seen in how our body restores body temperature when we become chilled. A sensor (nerve endings) detects a change in temperature. Information from the sensor feeds back to a control center (brain) that compares the actual temperature to the normal temperature and responds by activating an effector (muscle shivering). 3. Negative feedback loops oppose or negate a change in a controlled condition. Instead of opposing change in the internal environment and causing a return to normal, positive feedback loops cause an ever-increasing rate of events to occur until something stops the process. Page 1 of 6

2 ACTIVE LEARNING Review Questions 1. Anatomy is the study of the structure of an organism and the relationship of its parts. Physiology is the study of the functions of living organisms and their parts. Pathology is the scientific study of disease. 2. Disease results from abnormalities of the body structure or function that prevent the body from maintaining the internal stability that keeps us alive and healthy. 3. First, one makes a tentative explanation called a hypothesis. After a hypothesis has been proposed, it must be tested (experimentation). If the results of experimentation support the hypothesis, it is tentatively accepted as true. If not, the researcher rejects the hypothesis. Initial experimentation results are published in scientific journals so that they can be verified by other researchers. If the hypothesis withstands this rigorous retesting and has gained a high level of confidence, it is called a theory or law. 4. The chemical level of organization consists of atoms and molecules that make up the organism. The existence of life depends on the proper levels and proportions of many chemical substances in cells of the body and other living things. Cells are the smallest living units of structure. The tissue level is composed of an organization of many similar cells that act together to perform a common function. The organ level is a group of several different kinds of tissues arranged so that they can act together as a unit to perform a special function. The system level is an organization of varying numbers and kinds of organs arranged to perform complex functions for the body. 5. The anatomical position is the reference position in which the body is in an erect or standing posture with the arms at the sides and palms turned forward. The head points forward, as do the feet, which are slightly apart. 6. The sagittal plane is a lengthwise plane running from front to back that divides the body or any of its parts into right and left sides. The midsagittal plane divides the body into two equal halves. The frontal plane is a lengthwise plane running from side to side. It divides the body or any of its parts into front and back portions. The transverse plane is a horizontal or crosswise plane that divides the body or any of its parts into upper and lower portions. 7. Organs in the mediastinum include the trachea, heart, and blood vessels. Organs in the abdominal cavity include the liver, gallbladder, stomach, spleen, pancreas, small intestine, and parts of the large intestine. Organs of the pelvic cavity include the colon, rectum, urinary bladder, and reproductive organs. 8. The nine abdominopelvic regions are left hypochondriac, epigastric, right hypochondriac, left lumbar, umbilical, right lumbar, left iliac (inguinal), hypogastric, and right iliac (inguinal). 9. The dorsal cavity includes the cranial cavity, which contains the brain, and the spinal cavity, which contains the spinal cord. 10. Lower extremity refers to the hip and all structures below the hip: hip, thigh, leg, ankle, and foot. The thigh refers to the area between the hip joint and the knee. The leg refers to the area between the knee and the ankle. 11. Temperature, salt content, acid level (ph), fluid volume and pressure, and oxygen concentration must be kept in homeostatic balance. Other vital conditions must remain within acceptable limits. 12. The sensor detects the change in the regulated condition and feeds information to the control center, which responds by initiating certain changes that are then sent to the effector, which influences the controlled condition. For example, when you ride a bike, your eyes are the sensors, your brain is the control center, and your muscles are the effectors. Page 2 of 6

3 Critical Thinking 13. (A) Inferior to the heart any structure below the heart (e.g., stomach) (B) Superior to the heart any structure above the heart (e.g., mandible) (C) Anterior to the heart any structure in front of the heart (e.g., sternum) (D) Posterior to the heart any structure behind the heart (e.g., thoracic vertebrae) (E) Lateral to the heart any structure on either side of the heart (e.g., arms) Note: Refer to Figure 1-3 on pg. 9 in the text. 14. The maintenance of body temperature is a negative feedback loop. A negative feedback loop opposes or negates a change in the controlled condition. In maintaining body temperature, the nerve endings act as temperature sensors that feed information to a control center in the brain that compares actual body temperature to normal body temperature. In response to a chill, the brain sends nerve signals to the muscles, which then begin to shiver. Shivering produces heat that increases body temperature; shivering stops when feedback tells the brain that the body temperature is normal. The birth of a baby is a positive feedback loop. A positive feedback loop temporarily amplifies or reinforces the change that is occurring. The events that cause rapid increases in uterine contractions before the birth of a baby is an example of a positive feedback loop. A negative feedback loop tends to restore homeostasis; a positive feedback loop does not. 15. The organs that occupy most of the epigastric region are the stomach and liver. Chapter Test 1. Anatomy 2. Physiology 3. Pathology 4. theory, law 5. Chemical, cells, tissues, organs, systems 6. Supine, prone 7. transverse 8. frontal 9. sagittal 10. midsagittal 11. axial 12. appendicular 13. c. dorsal and ventral 14. b. diaphragm 15. d. none of the above 16. d. both a and c 17. b. Contractions of the uterus during childbirth 18. d. Both a and c 19. e. inferior 20. d. proximal 21. a. posterior 22. c. medial 23. b. superficial Case Studies 1. Mrs. Miller s mole is on the anterior (front) surface of her trunk, inferior to (below) the rib cage, and superior to (above) and left (lateral) of the navel. With the choices given, it is best to ask Mrs. Miller to assume a supine (belly-up) position. Mrs. Miller s occipital mole is on the back of her head. This is best examined if she rolls to a prone (belly-down) position or sits up and tilts her head forward. 2. Mr. Sanchez s injury was at the end of his ring finger. A typical response to a sudden drop in blood pressure is to increase pumping of blood by the heart. Under normal circumstances, this response would bring the blood pressure back up to its average value. In this case, however, increased pumping by the heart will increase blood loss causing a further drop in blood pressure and threatening Mr. Sanchez s homeostatic balance even more. If the blood loss is not stopped soon, Mr. Sanchez could lose a large volume of blood. Because this response amplifies the drop in blood pressure rather than returning it to its normal value, it is a case of positive feedback. Page 3 of 6

4 CHAPTER 2 QUICK CHECK Page Matter is anything solid, liquid, or gas that occupies space and has mass. Atoms are considered the basic units of matter. 2. A compound is a substance whose molecules are made of several atoms of the same element. An element is a pure substance, composed of only one of more than a hundred types of atoms that exist in nature. 3. Energy levels (shells) are regions outside the nucleus of the atom where electrons in their orbitals are arranged. The farther an orbital extends from the nucleus, the higher its energy level. Page An ion is formed when an atom donates or accepts an electron from another atom. 2. Electrolytes dissociate when they are dissolved in water. Free ions are then formed from this dissociation. 3. Hydrogen bonding does not result in the formation of a new molecule. Hydrogen bonds weakly bond neighboring molecules. Ionic bonds are formed when an atom donates or receives an electron to complete its outer shell. Covalent bonds are formed when atoms share electrons. Ionic and covalent bonds create new molecules. Page An organic compound is composed of molecules that contain carbon-carbon (C-C) covalent bonds or carbon-hydrogen (C-H) covalent bonds or both kinds of bonds. 2. In dehydration synthesis, reactants combine only after hydrogen and oxygen atoms are removed. Dehydration synthesis is a reaction in which water is lost from the reactants. As in any kind of synthesis reaction, the reactants combine to form a larger product. Hydrolysis is virtually the reverse of dehydration synthesis. Water disrupts the bonds in large molecules, causing them to be broken down into smaller molecules. 3. The presence or absence of H + determines whether a solution is acidic or alkaline. If a solution has an excess of H + then it is acidic. Solutions with an excess of OH (or a decrease in H + ) are alkaline. When a solution has an equal amount of H + and OH, the solution is neutral. 4. Buffers adjust the body s ph by preventing sudden changes in the H + concentration. Buffers do this by forming a chemical system that neutralizes acids and bases as they are added to a solution. Page Carbohydrates are made of monosaccharides. Lipids are made of fatty acids. Proteins are made of amino acids. Nucleic acids are made of nucleotides. 2. The structure of the protein is important because the shape of the protein determines its role in body chemistry. 3. DNA is the master code for assembling proteins and other nucleic acids. This code ultimately directs the living chemistry of the body. 4. ATP plays an important energy transfer role in the body. It picks up energy from nutrients and then quickly makes the energy available to cellular processes. Page 4 of 6

5 ACTIVE LEARNING Review Questions 1. An element is a substance composed of only one type of atom that cannot be broken into simpler constituents by chemical means. A compound is a chemical combination of two or more elements. An atom is the fundamental unit of an element. It consists of the nucleus, which contains protons and neutrons, and surrounding electrons. A molecule is formed when two or more atoms are joined. 2. At the core of each atom is a nucleus composed of positively charged protons and uncharged neutrons. Electrons inhabit the outer regions called electron shells. 3. Energy levels are regions surrounding the atomic nucleus that contain electrons, which are negatively charged particles. Each level may contain up to eight electrons. Energy increases with distance from the nucleus. 4. A chemical bond is formed to make atoms more stable. This can take place when two or more atoms share, donate, or borrow electrons, which enhances their stability. 5. The major types of chemical bonds are ionic, covalent, and hydrogen. 6. An electrolyte is a substance that ionizes in a solution, rendering the solution capable of conducting an electric current. An ion is an electrically charged atom or group of atoms. 7. Organic compound refers to chemicals that contain covalently bound carbon and hydrogen atoms and are involved in metabolic reactions. Inorganic compounds have chemical constituents that do not contain both carbon and hydrogen. 8. A solvent is a substance in which other substances are dissolved. A solute is a substance that is dissolved in a solution. 9. The term ph is a symbol used to mean hydrogen ion (H + ) concentration of a solution. As the concentration of H + increases, the solution becomes more acidic and the ph value decreases. As the OH concentration increases, the ph value also increases and the solution becomes more basic or alkaline. 10. An acid is a concentration of hydrogen ions. As the concentration of H + ions increases, the solution becomes more acidic and the ph value decreases. Base, or alkaline, occurs when OH concentration increases, as does the ph, making the solution more basic. 11. Proteins are large molecules formed by linkage of amino acids by peptide bonds; one of the basic building blocks of the body. Lipids are organic compounds composed of hydrogen, carbon, and oxygen. The building blocks that make up lipids are glycerol and fatty acids. The types of lipids are triglycerides, phospholipids, and steroids (cholesterol). Carbohydrates are organic compounds such as carbon, hydrogen, and oxygen. They are made up of six-carbon subunits called monosaccharide units (e.g., sucrose, lactose) and polysaccharides, which are made up of many monosaccharide units (e.g., glycogen, made up of many glucose units). Nucleic acids are a group of high-molecular-weight substances found in cells of all living things. They consist of (1) nucleotide units, (2) DNA, and (3) RNA. 12. Proteins participate in chemical processes of the body. Functional proteins include some of the hormones. Most hormones are proteins, growth factors, cell membrane channels, receptors, and enzymes. Triglycerides (lipids) are a major source of stored energy. They also function to insulate and protect body organs. Carbohydrates store energy for later use. Nucleic acids direct overall body structure and function. Critical Thinking 13. Ionic bonds form when an atom gains or loses electrons in its outer energy level. The atoms donate or receive electrons to become stable. Covalent bonds form to make atoms more stable as the outermost energy level of each atom becomes full. The atoms share electrons to become stable. Page 5 of 6

6 14. The statement refers to any enzyme that speeds up the rate of chemical reaction (catalyzes), such as the catabolic reaction that uses water to break down large molecules into small molecules or subunits. Enzymes are chemical catalysts. This means they participate in chemical reactions, but are not changed by the reaction. No reaction in the body occurs fast enough unless the specific enzymes needed are present. 15. Blood ph is slightly alkaline. 16. Functional proteins, including hormones, participate in chemical processes of the body. 17. Proteins play a vital role in the body s structure and function. In a real sense, we are what our proteins are. Protein synthesis constructs an exact arrangement of amino acids in a specific sequence that produces a protein-synthesizing mechanism in each cell. The cell knows the exact pattern and assembly of the amino acid because it is coded and stored within the deoxyribonucleic acid (DNA) molecule. 18. Hydrogen has three isotopes: 1 H, 2 H, and 3 H. Each isotope has only one proton, but different numbers of neutrons (Clinical Application, p. 28, Figure 2-4, p. 30). One atom of hydrogen may bond with another atom of hydrogen to form a molecule of hydrogen, H 2, or two atoms of hydrogen bond with one atom of oxygen to form water, H 2 O. Chapter Test 1. Matter 2. atoms 3. protons 4. energy 5. compounds 6. covalent 7. ion 8. electrolyte 9. organic 10. solvent 11. dehydration synthesis 12. Acids 13. buffers 14. d. carbohydrate 15. f. protein 16. g. nucleic acid 17. e. lipid 18. a. salt 19. c. base 20. b. acid 21. c. electrons are gained or lost 22. a. CO d. deoxyribose 24. b. ph c. lipids Case Studies 1. A ph of 7.57 is significantly higher than the maximum (7.45) of the normal blood plasma ph range ( ). Grania may be suffering from alkalosis, a condition in which the blood ph is higher than normal. 2. A high-carb diet is one in which a person eats a higher proportion of carbohydrates than usual. The primary dietary carbohydrates are those based on the saccharide group (C 6 H 12 O 6 ) and include monosaccharides, disaccharides, and polysaccharides. Monosaccharides in Baraka s diet may include glucose, fructose, or galactose. Disaccharides in his diet may include sucrose, maltose, and lactose. Polysaccharides in Baraka s food are known as glycogen and various starches. One of the main roles of carbohydrates in Baraka s body is to provide energy for cellular work. For example, the energy from carbohydrate molecules is transferred to ATP and then transferred to the fibers that power the contraction of muscles. Therefore, carbohydrates must be present in relatively large amounts for athletic use of muscles. 3. Although high overall cholesterol levels are associated with increased risks of health problems, such as atherosclerosis and heart disease, there are different types of cholesterol with different roles in the body. HDL (high-density lipoprotein) cholesterol is associated with a lower risk of such health problems. Because Shane s HDL proportion has increased, he is now at a lower risk of health problems than before. Page 6 of 6