HSC 422/520 Physiology for the Clinical Sciences Exam #1, February 7, 2024 PDF

**HSC 422/520** **Physiology for the Clinical Sciences** **Exam \#1, Wednesday, 7 February 2024 Name: [ ]** **Fill in the bubble on the Scantron that corresponds to the correct answer. Be sure to use a \#2 pencil. 50 questions, two points each, 100 points total.** 1. Maintaining small fluctuati...

**HSC 422/520** **Physiology for the Clinical Sciences** **Exam \#1, Wednesday, 7 February 2024 Name: [ ]** **Fill in the bubble on the Scantron that corresponds to the correct answer. Be sure to use a \#2 pencil. 50 questions, two points each, 100 points total.** 1. Maintaining small fluctuations in the internal environment of a cell or a body, while the outside environment may have substantially larger fluctuations, is called: A. Homeostasis D. Positive feedback B. Diffusion E. Negative feedback C. Physiology 2. When an artery is broken or torn, platelets and clotting proteins gather at the cut edge of the blood vessel. This clump of platelets and proteins causes more clotting and clumping at the site of the injury, which in turn causes even more clotting until the broken blood vessel is sealed off and no longer bleeding. This is an example of: D. *Positive feedback* D. *Negative feedback* E. *Simple diffusion E. Facilitated diffusion* F. Osmosis 3. The process of ingesting large particles, like bacteria or viruses, into a cell is called: G. Phagocytosis D. Pinocytosis H. Active transport E. Facilitated diffusion I. Simple diffusion 4. Which of the following best describes the role of the lysosome? J. Synthesizing ATP molecules D. *Breaking down ingested material* K. Synthesizing messenger RNA E. Synthesizing new proteins L. Maintaining the structure of the cell 5. Why can cholesterol move directly through a phospholipid bilayer? M. It is a non-polar molecule D. It is a polar molecule N. It is an ion E. It has oxygen atoms O. It is a protein 6. Why are amino acids coded for by a sequence of three bases? P. Each amino acid must bind to three bases so that the amino acid can be activated Q. One or two bases would store insufficient energy to bind amino acids together R. One or two bases would not provide enough codes for 20 amino acids S. Only the first two bases code for the amino acid, the remaining base provides additional electrons T. Messenger RNA needs a three-base code to start the process of translation 7. The molecule that connects a particular amino acid to a particular codon is: U. Messenger RNA D. *Transfer RNA* V. Reticular RNA E. Thymine RNA W. Uracil RNA 8. Which of the following statements about the graph to the right is completely TRUE? X. Line B represents simple diffusion, whose rate increases as long as the concentration of substance increases Y. Line C represents facilitated diffusion, whose rate is constant regardless of concentration Z. Line A and C represent simple diffusion, whose rate does not change A. *Line A represents simple diffusion, whose rate increases as long as the concentration of substance increases* B. Line B represents facilitated diffusion, whose rate continues to increase as long as the concentration of substance increases 9. In the graph above: which of the following explains why Line B is shaped as it is? C. The rate of facilitated diffusion is limited by the concentration of substance, which has a limit on the extent to which it can increase D. The rate of simple diffusion is limited by the number of carrier proteins a substance can pass through, and the speed at which those carriers can operate E. Line C represents the rate of simple diffusion, which limits the rate of facilitated diffusion F. The rate of simple diffusion is limited by the rate constant, which is represented by Lines A and C G. *The rate of facilitated diffusion is limited by the number of carrier proteins a substance can pass through, and the speed at which those carrier proteins can operate* 10. Which of the following describes the role of messenger RNA (mRNA)? H. Delivers the appropriate amino acid to the ribosome to assemble a chain of amino acids I. Long term storage of the instructions for making proteins J. Incorporated into the structure of the ribosome K. Makes a chemical reaction occur faster and/or with less energy L. Provides instructions for assembling particular amino acids into a chain 11. Which of the following best defines the term [charge] (for physiology)? M. Atoms or molecules that typically move very fast N. Substance which tends to be relatively elongated (rather than relatively spherical) O. *Having one or more extra electrons or extra protons* P. A substance that has many electrons in its electron shells Q. Substance in which electrons spend more time at one end of the molecule than at other parts 12. RNA molecules use \_\_\_\_\_\_\_ instead of \_\_\_\_\_\_\_, which is used by DNA molecules: R. Uracil instead of thymine D. Adenosine instead of Adenine S. Tungsten instead of gold E. Sodium ions instead of potassium ions T. ATP instead of ADP 13. When a substance travels from an area where it is highly concentrated to where its concentration is low, creating an even distribution, and it goes through a phospholipid bilayer or channel proteins, it is called: U. Primary active transport D. Simple diffusion V. *Facilitated diffusion* E. Secondary active transport W. Osmosis 14. Why is it that sodium ions cannot travel across a phospholipid bilayer? X. Sodium ions are non-polar, and cannot cross the polar phospholipid bilayer Y. Sodium ions can only cross the phospholipid bilayer when they are bonded to water Z. Sodium ions are repelled by the positively charged interior of the cell A. Sodium ions are charged, and cannot cross the non-polar phospholipid bilayer B. Sodium ions have too many electrons to cross the phospholipid bilayer 15. What two molecules form the backbones of the DNA double helix? C. Arginine and phenylalanine D. *Deoxyribose and phosphate* D. Guanine and cytocine E. Adenine and Thymine E. Uracil and Ribose 16. Which of the following best describes secondary active transport? F. *Already existing concentration gradient used to pump a different molecule across a cell membrane* G. ATP is used to pump a molecule across a cell membrane against the concentration gradient H. A molecule passes across the cell membrane from high concentration to low I. A molecule passes through a channel protein from high concentration to low J. Water moves from an area of low concentration of a substance to a high concentration of a substance 17. When water moves through a semi-permeable membrane from a region with low concentrations of dissolved substances to a region of high concentrations, this is known as: K. Active transport D. Facilitated diffusion L. Simple diffusion E. Osmosis M. Sodium-potassium pump 18. Which of the following statements about active transport is TRUE? N. It requires no energy, but carrier proteins must be used O. Substance is transported from high concentration to low concentration P. Occurs across the phospholipids bilayer, with no channels necessary Q. Requires energy, and transport occurs across the phospholipids bilayer with no channels necessary R. *Substance is transported from low concentration to high concentration* 19. Where is hyaline cartilage found? S. External ear D. Epiglottis T. Laryngeal cartilages E. Intervertebral joints U. Joint surfaces of bone 20. A cell needs to concentrate an ion by a factor of 100,000 (one hundred thousand). Calculate how much energy is needed (in calories per osmole). V. 1400 B. 2800 C. 4200 D. 5600 E. 7000 21. Which of the following is NOT a way that bone can be placed under stress? W. Torsion B. Compression C. *Cortical* D. Tension E. Shear 22. Which of the following is a rope-like protein in bone that allows it to resist being stretched? X. Enzymes B. Osteoblast C. Osteoclast D. *Collagen* E. Hydroxyapatite 23. Which of the following statements about primary bone is TRUE? Y. *It is stronger than secondary bone, but it is all replaced within about the first year of life* Z. It is made from woven bone, and it is the first bone formed after a fracture A. It is made from lamellar bone, and it forms during bone remodeling B. It is made entirely from collagen molecules C. It is made entirely from hydroxyapatite crystals 24. The purpose of the inflammatory phase of bone repair after a fracture is: D. Begin remodeling process D. Generate a provisional callus E. Replace woven bone E. Remove provisional callus F. Immobilize the broken ends 25. Which of the following statements about woven bone is TRUE? G. It forms slowly compared to lamellar bone H. It is found at the end of long bones, whereas lamellar bone is found in the shaft I. It is stronger and more organized than lamellar bone J. *It is disorganized and less strong than lamellar bone* K. It is found in the shaft of long bones, whereas lamellar bone is found in the ends 26. Which kind of cell is responsible for breaking down bone tissue during bone remodeling? L. *Osteoclast* B. Lamellar C. Osteoblast D. Trabecular E. Sarcomere 27. The point at which a substance stops undergoing elastic deformation and begins undergoing plastic deformation is called the: M. Brittleness D. Ultimate strength N. Yield strength E. Rigidity O. Ductile property 28. Which of the following substances is important in the formation of hydroxyapatite? P. *Phosphate* B. Sodium C. Chlorine D. Potassium E. Nitrogen 29. The long, thin proteins that move when they are pulled on during muscle contraction are called: Q. Titin D. Tropomyosin R. Troponin E. Myosin S. Actin 30. What is the role of acetylcholine in skeletal muscle contraction? T. Causes sodium ions to be released from the motor axon end plate, which then pass across the muscle cell membrane to propagate the action potential U. Causes calcium ions to be released from the sarcoplasmic reticulum V. Crosses the synaptic cleft, connects to and opens a sodium ion channel on a muscle cell membrane, allows action potential to propagate through a set of muscle fibers W. Crosses the synaptic cleft, connects and opens a sodium ion channel on the axon, allows action potential to propagate through the axon X. Causes potassium ions to be released from the muscle cell membrane 31. Why does skeletal muscle appear striated in a microscope? Y. The multiple nuclei in muscle fibers line up and give it a striated appearance Z. *Sarcomeres line up, with rows of myosin appearing darker than the rows of actin* A. The muscle fibers run at angles to each other B. The fibers receive a rich blood supply, which gives them a striated appearance C. The parts of the fibers that require the most oxygen appear darker 32. Which type of protein covers the binding sites on actin, preventing myosin from binding to it? D. Titin D. Acetylcholine E. Troponin E. Tropomyosin F. Synapse 33. Which of the following describes one of the roles of ATP in the cross-bridge cycle? G. Causes myosin to bind to actin H. Causes myosin to pull on actin, which shortens the sarcomere I. Changes shape of myosin so that a phosphate can be released J. Changes shape of myosin so that it is under tension and storing energy K. Strengthens the bond between myosin and actin 34. What forms the "I-band" in a sarcomere? L. Actin molecules lined up and connected to a Z-disc (or "Z-line") M. Band of dark colored filaments comprised only of myosin N. Band of filaments where myosin and actin overlap O. Portion of sarcomere where titin molecules line up P. Portion of sarcomere where myosin molecules are attached to each other 35. What is the name of the connective tissue that covers a muscle? Q. Perimysium D. Endomysium R. Epimysium E. Sarcomysium S. Sarcoplasmic reticulum 36. Which of the following statements about slow twitch muscle fibers is TRUE? T. Rapid contraction speed U. Poorly developed oxidative energy pathway V. Fatigue resistant W. Few mitochondria, and they are small X. Low myoglobin level 37. Which of the following occurs once an action potential is no longer spreading through a motor unit? Y. Tropomyosin uncovers binding sites on actin Z. Ca^2+^ binds to Troponin A. Na^+^ is pumped into the muscle cells B. *Sarcoplasmic reticulum pumps Ca^2+^ back into itself* C. Acetylcholine is released from the axon into the synaptic cleft 38. Which of the following best describes an action potential? D. An electric charge that causes myosin to pull on actin in a repeated manner E. A change in voltage in just one part of the cell F. A wave of Na^+^ flowing into the cell followed by a wave of K^+^ flowing out of the cell G. The cycle of myosin binding to actin, pulling on it, letting go, and repeating H. The binding of Ca^2+^ to troponin, allowing binding sites on actin to be uncovered 39. When a sarcomere is stretched as long as it can be, which of the following statements is TRUE? I. The actin runs out of space, and cannot move any further; therefore less tension is generated J. Ca^2+^ can no longer bind to troponin K. The myosin proteins sometimes break, which weakens the sarcomere L. The actin fibers break, causing the sarcomere to weaken M. *Fewer cross bridges connect myosin to actin, and less tension can be generated* 40. Which of the following statements about motor units is TRUE? N. Consists of varying muscle types (fast and slow twitch) O. All the muscle fibers connected to a single axon must contract at the same time P. Consists of all the muscle fibers within an entire muscle Q. Consists of all the contractile proteins within a single muscle fiber R. Every muscle has around 10 motor units 41. Which of the following statements about the dense body is true: S. In skeletal muscle, it allows the axon to communicate with the muscle fibers T. In smooth muscle, it attaches the myosin molecules to the cell membrane U. *In smooth muscle, it holds together a group of actin molecules* V. In skeletal muscle, it manufactures ATP W. In smooth muscle, it covers the binding sites on actin molecules 42. When troponin changes shape as a result of Ca^2+^ binding to it, what then happens? X. Tropomyosin uncovers binding sites on actin Y. Myosin unbinds from actin Z. Troponin pulls on actin A. Action potential spreads across sarcoplasmic reticulum B. Na^+^ channels open on the sarcolemma 43. Which of the following is a description of the sarcolemma? C. Tubules containing Ca^2+^ D. Location of the motor end plate D. Protein fibers responsible for contraction E. Vesicles containing acetylcholine E. Cell membrane of a muscle cell 44. When a muscle generates force and elongates, this is known as: F. Concentric contraction D. Motor unit contraction G. Isometric contraction E. All or nothing contraction H. Eccentric contraction 45. What is the effect of Ca^2+^ and K^+^ channels being open simultaneously in an action potential in ventricular tissues of the heart? I. The cell membrane depolarizes very quickly J. The myosin and actin molecules unbind, and the heart relaxes K. The cell membrane repolarizes very quickly L. The action potential spreads across the entire heart simultaneously M. The cell membrane remains depolarized for 1-2 tenths of a second 46. Define "threshold" as it occurs in a sinus node N. The membrane voltage that initiates an action potential O. The membrane voltage that delays an action potential or makes it less likely to occur P. The maximum number of depolarizations per second Q. The maximum voltage that can exist across a cell membrane R. The maximum speed of an action potential across cardiac tissue 47. What happens that makes a sinus node self-stimulate? S. Hydrolyzing ATP provides the energy to pump Na^+^ out and K^+^ into the cell T. K^+^ diffuses into cell, causing it to repolarize, which triggers an action potential U. Osmosis causes water to follow the greatest concentration of dissolved substances, which triggers an action potential V. Ca^2+^ and Na^+^ slowly diffuse into cells, causing them to gradually depolarize and trigger an action potential W. Ca^2+^ and Na^+^ slowly diffuse out of cells, causing them to gradually repolarize and trigger an action potential 48. Which of the following statements about smooth muscle is TRUE? X. Smooth muscle is controlled voluntarily Y. Fibers are stimulated only by nerves Z. Fibers contract faster and more strongly than skeletal muscle A. Fibers can contract more strongly and for a longer time than skeletal muscle B. Fibers use actin, but not myosin, to cause shortening and generation of tension 49. Parasympathetic stimulation of the heart causes which of the following to happen? C. Increased contraction strength D. Decreased contraction strength D. Increased heart rate E. More rhythmic contractions E. Decreased heart rate 50. What causes the change described above? F. Decreased permeability of the membrane to Na^+^ causes membrane to become depolarized G. Increased permeability of the membrane to Na^+^ causes membrane to become hyperpolarized H. Increased permeability of the membrane to K^+^ causes membrane to become hyperpolarized I. Decreased permeability of the membrane to K^+^ causes membrane to become depolarized J. Increased permeability of the membrane to Na^+^ and K^+^ causes membrane to become hyperpolarized 51. Which kind of muscle fiber can be stimulated to contract by stretching it? K. Skeletal B. Smooth C. Excitatory D. Conductive E. Syncytial 52. The portions of cardiac tissue that allow ions to travel almost completely freely between cells are called: L. Striations D. Action potentials M. Synapses E. T-tubules N. Intercalated discs