BIOL 348 EXAM 2 PRACTICE QUESTIONS COMPLETE WITH 100% VERIFIED ANSWERS AND DETAILED RATIONALE

BIOL 348 EXAM 2 PRACTICE QUESTIONS COMPLETE WITH 100% VERIFIED ANSWERS AND DETAILED RATIONALE 1. Which type of muscle tissue is striated and involuntary? A. Skeletal muscle B. Smooth muscle C. Cardiac muscle D. Both skeletal and cardiac muscle Correct Answer: C. Cardiac muscle Rationale: Cardiac muscle is striated like skeletal muscle but is involuntary like smooth muscle. Skeletal muscle is striated but voluntary, while smooth muscle is nonstriated and involuntary. ________________________________________ 2. Where is cardiac muscle exclusively found? A. Throughout the circulatory system B. Only in the heart C. In the walls of blood vessels D. In both the heart and large arteries Correct Answer: B. Only in the heart Rationale: Cardiac muscle tissue is found exclusively in the heart. It is not found in blood vessels (which contain smooth muscle) or elsewhere in the body. ________________________________________ 3. What is the primary function of intercalated discs in cardiac muscle? A. Store calcium ions B. Produce ATP for contraction C. Join cardiocytes and ensure synchronized beating D. Attach cardiac muscle to bone Correct Answer: C. Join cardiocytes and ensure synchronized beating Rationale: Intercalated discs contain gap junctions and desmosomes that join cardiocytes together, allowing for coordinated, synchronized contraction of the heart muscle. ________________________________________ 4. Which components are found in intercalated discs of cardiac muscle? A. T-tubules and sarcomeres B. Gap junctions and desmosomes C. Myofibrils and mitochondria D. Actin and myosin filaments Correct Answer: B. Gap junctions and desmosomes Rationale: Intercalated discs contain gap junctions (which allow ions to pass between cells) and desmosomes (which hold muscle fibers together). These structures enable synchronized contraction of cardiac muscle. ________________________________________ 5. In which body systems does smooth muscle form? A. Only in the digestive and urinary systems B. Only in blood vessels and airways C. Integumentary, blood vessels, airways, reproductive, glands, digestive, and urinary systems D. Only in the reproductive and glandular systems Correct Answer: C. Integumentary, blood vessels, airways, reproductive, glands, digestive, and urinary systems Rationale: Smooth muscle is widely distributed throughout the body, forming in the integumentary system, blood vessels, airways, reproductive system, glands, digestive system, and urinary system. ________________________________________ 6. What is the function of smooth muscle in the integumentary system? A. Regulate blood pressure B. Produce goose bumps via arrector pili muscles C. Control airflow D. Produce digestive secretions Correct Answer: B. Produce goose bumps via arrector pili muscles Rationale: In the integumentary system, smooth muscle forms the arrector pili muscles, which contract to cause goose bumps in response to cold or emotional stimuli. ________________________________________ 7. What role does smooth muscle play in blood vessels and airways? A. Produces goose bumps B. Regulates blood pressure and airflow C. Produces movements for childbirth D. Prevents food from moving backward Correct Answer: B. Regulates blood pressure and airflow Rationale: Smooth muscle in blood vessels regulates blood pressure through vasoconstriction and vasodilation, while smooth muscle in airways regulates airflow by controlling bronchial diameter. ________________________________________ 8. What do sphincters do in the digestive and urinary systems? A. Produce involuntary contractions for substances B. Act as valves to prevent backward movement of materials C. Regulate blood pressure D. Produce secretions for digestion Correct Answer: B. Act as valves to prevent backward movement of materials Rationale: Sphincters act as valves that prevent food from moving backward in the digestive system and prevent urine from flowing backward in the urinary system. ________________________________________ 9. Which structural characteristic is NOT found in smooth muscle cells? A. Single central nucleus B. Scattered myosin fibers C. T tubules and sarcomeres D. Thin filaments attached to dense bodies Correct Answer: C. T tubules and sarcomeres Rationale: Smooth muscle cells do NOT have T tubules, myofibrils, sarcomeres, tendons, or aponeuroses. They are nonstriated and have a different structural organization than skeletal muscle. ________________________________________ 10. What is the shape of smooth muscle cells? A. Short and branched B. Long spindle-shaped C. Cylindrical and multinucleated D. Round with a single nucleus Correct Answer: B. Long spindle-shaped Rationale: Smooth muscle cells are long and spindle-shaped with a single central nucleus. This shape allows them to contract and relax effectively in hollow organs. ________________________________________ 11. What is the function of dense bodies in smooth muscle cells? A. Store calcium ions B. Produce ATP C. Transmit contractions from cell to cell D. Attach muscle to bone Correct Answer: C. Transmit contractions from cell to cell Rationale: Dense bodies in smooth muscle cells transmit contractions from cell to cell, similar to how Z-discs function in skeletal muscle, allowing for coordinated contraction of smooth muscle tissue.