Download Anatomy and Physiology - Muscle - University of Arizona PSIO 201 Lecture Exam 3 Questions and more Exams Anatomy in PDF only on Docsity!
of Arizona PSIO 201 Lecture Exam 3 Questions
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Three Types of Muscle - correct answer ✅Skeletal, Cardiac, and Smooth Basic function of all three muscle types - correct answer ✅Generate Tension Functions of skeletal muscles - correct answer ✅Locomotion, Facial Expression, Posture and body position, Regulation of Body Temperature Skeletal muscle contraction is... Voluntary or Involuntary - correct answer ✅Voluntary - requires nervous system input. 1 skeletal muscle (diaphragm) is automatic but we have the power to change their activity (take a deep breath/hold breath) Origin - correct answer ✅Place where muscle starts on a bone, remains stationary
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Insertion - correct answer ✅Place where muscle ends on a bone, moves toward origin Flexion versus extension - correct answer ✅Flexion: movement to reduce angle between articulating bones at a joint, extension: to increase angle between articulating bones at a joint Abduction versus Adduction - correct answer ✅Abduction: movement away from midline, Adduction: movement toward midline Forearm: muscle action, origin, insertion - correct answer ✅Muscle action: flexion, origin: scapula, insertion: radius Reverse muscle action (RMA) - correct answer ✅When the insertion is anchored and the origin moves toward the insertion, ex: pull-ups
of Arizona PSIO 201 Lecture Exam 3 Questions
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Abduction of the arm: agonist, antagonist, synergist, fixator - correct answer ✅Agonist: deltoid, Antagonist: latissimus dorsi, Synergist: supraspinatus, Fixator: trapezius Flexion of forearm: agonist, antagonist, synergist, fixator - correct answer ✅Agonist: brachial, Antagonist: triceps brachii, Synergist: biceps brachii, Fixator: pectoralis minor First Class Lever - correct answer ✅Scissor or seesaw, fulcrum is in middle with load and effort on either side, example: neck and head Second class levers - correct answer ✅Wheelbarrow - Fulcrum on one side, load in the middle, effort on the opposite side. Example: foot and leg Third class lever - correct answer ✅Tweezers - Fulcrum and load on opposite sides with effort in the middle, example: arm and hand
of Arizona PSIO 201 Lecture Exam 3 Questions
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(Groups of muscles/Muscle/Fasicle/Muscle Fiber) covered by... - correct answer ✅Deep Fascia/Epimysium/Perimysium/Endomysium Diameter/Length of Muscle Cells - correct answer ✅100 um in diameter, many cm long Cellular and subcellular skeletal muscle structure - correct answer ✅Muscle cells are called fibers, can be very large -- typically multinucleate Muscle development: prior and post-birth - correct answer ✅Prior: myoblasts fuse into muscle fiber, Post: muscle fibers grow through hypertrophy (increase in size) rather than hyperplasia (increase in number). Satellite cells have the ability to undergo mitosis after birth to aid in muscle regeneration 3 Function Units of Organization - correct answer ✅1) Conduction of electrical signals - sarcolemma
- Control of muscle contraction - sarcoplasmic reticulum
- Contraction - myofibrils inside muscle fibers
of Arizona PSIO 201 Lecture Exam 3 Questions
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Contractie Proteins - correct answer ✅Actin and myosin Regulatory proteins - correct answer ✅Troponin and tropomyosin Structural proteins - correct answer ✅Titin, dystrophin, a-actin, myomesin, nebulin Tropomyosin - correct answer ✅Found in thin filaments, covers the myosin binding sites on actin when the muscle is relaxed Troponin - correct answer ✅Found in thin filaments, holds tropomyosin in place when the muscle is relaxed, binds to calcium during contraction which helps to expose binding sites for cross bridge formation
of Arizona PSIO 201 Lecture Exam 3 Questions
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Sliding filament model of muscle contraction - correct answer ✅1. Myosin heads bind to actin to form a crossbridge
- Conformational change, energized by ATP hydrolysis causes thin filaments to slide along thick filaments
- Myosin head groups release, form new cross bridges, cycle repeats... Result: Z-lines move toward one another, sarcomere length decreases, myofibril shortens, muscle fiber shortens As thick/thin filament overlap increases... - correct answer ✅I band length decreases, A band length remains constant, H zone length decreases, Zone of overlap increases Dystrophin - correct answer ✅Cytoskeleton protein that links thin filaments to the sarcolemma, attached to the extracellular proteins in the connective tissue surrounding the muscle fiber, helps transmit tension from the sarcomeres to the tendons
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The conduction of electrical signals toward the interior of a muscle fiber is aided by the presence of ___ along the sarcolemma - correct answer ✅T-tubules During arm abduction, the latissimus dorsi is considered an: - correct answer ✅Antagonist, because it adducts the arm Whih of the following supports the sliding filament theory of muscle contraction? - correct answer ✅The distances between the z-lines decreases during concentric contraction Which of the following acts as an ATPase during the contraction cycle of skeletal muscle? Actin, creatine phosphate, the motor unit, myosin head groups, the z-disc - correct answer ✅The myosin head groups Cardiac muscle is characterized by all except: Long, multinucleate, cylindrical cells
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Intercalated discs Numerous large mitochondria Striations - correct answer ✅Long, multinucleated, cylindrical cells Smooth muscle: Is largely under voluntary control Is located in the coverings of solid organs Is striated Moves blood through the heart Is regulated by the autonomic division of the nervous system - correct answer ✅Is regulated by the autonomic division of the nervous system In a concentric reaction... - correct answer ✅The effort is greater than the load Aerobic metabolism... - correct answer ✅Converts fatty acids into ATP, occurs in the
of Arizona PSIO 201 Lecture Exam 3 Questions
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- ACh is released into the synaptic cleft and binds to ACh receptors on the sarcolemma
- ACh receptors open and allow Na+ to enter the muscle fiber, generating an action potential on the sarcolemma
- ACh is quickly broken down into acetate and chlorine by AChE Excitation-Contraction Coupling - correct answer ✅1. AP Runs along sarcolemma, continues into T- tubules
- Triggers release of Ca2+ from SR
- Ca2+ diffuses into sarcoplasm and myofibrils
- Ca2+ binds to troponin on thin filament Myosin binding site on actin is exposed
- Crossbridges form -> tension is generation, contraction is started Relaxation - correct answer ✅1. When APs stop arriving at the NMJ, the trigger to release Ca2+ from the SR stops
- Active Ca2+ transporters in the SR membrane pump Ca2+ back into the SR
of Arizona PSIO 201 Lecture Exam 3 Questions
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- Cytoplasmic concentration of Ca2+ decreases
- As Ca2+ concentration in the cytoplasm falls, Ca2+ comes off troponin, the myosin binding sites on actin get covered by tropomyosin
- Crossbridge cycling stops and tension drops
- Titin brings the sarcomere back to resting position 3 periods of muscle twitch - correct answer ✅Latent, contraction, relaxation Tetanus/Tetanic contraction - correct answer ✅Summation over time (temporal summation) of individual twitches Motor Unit - correct answer ✅a motor neuron and all the muscle fibers it innervates
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Eccentric contraction - correct answer ✅Type of isotonic contraction, load > effort, muscle lengthens Length-Tension Relationship - correct answer ✅Tension generated is proportional to the number of cross bridges formed, peak tension is developed at an intermediate sarcomere length Immediate sourced of energy to support development of tension - correct answer ✅ATP Cell 'pool' of ATP - correct answer ✅ATP is not stored, only enough to support ~ 2 secs of maximal force Creatine Phosphate pool - correct answer ✅Stores high energy phosphate, has enough high energy phosphate to support ~ 15 sec of maximal contraction
of Arizona PSIO 201 Lecture Exam 3 Questions
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Where does ATP come from? - correct answer ✅Glycogen -used anaerobically in glycolysis, occurs in cytoplasm, occurs rapidly, can support ~2 min contraction -used aerobically in oxidative phosphorylation, occurs slowly in mitochondria, can support 40 mins to several hours of contraction depending on intensity Cori Cycle - correct answer ✅Lactic acid from muscle is converted into glucose in the liver and returned back to the muscle O2 debt - correct answer ✅cost of resetting system after exercise Reasons for elevated O2 consumption after exercise - correct answer ✅1. Lactic acid conversion back to glycogen in the liver during cori cycle
- Resynthesize CP
of Arizona PSIO 201 Lecture Exam 3 Questions
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Intermediate fibers - correct answer ✅Relatively fast, primarily anaerobic Within a motor unit, all fibers are ____. - correct answer ✅The same type. Cardiac muscle function - correct answer ✅To pump blood Cardiac muscle structural features - correct answer ✅Smaller branched cells, less extensive t-tubule and SR system, myofibrils organized into sarcomeres, extensive cell-to- cell interactions (called intercalated discs) containing gap junctions and desmosomes Cardiac muscle functional issues - correct answer ✅SR Ca2+ is not sufficient to support contraction, so there is an obligatory need for extracellular Ca2+ Nervous input influences rate & strength of contraction -- acts on pacemaker cells and Ca2+ delivery
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Cardiac muscle contractions - correct answer ✅Not initiated by electrical signals from nervous system, electrical activity is stared by pacemaker cells, or a spontaneous generation of action potentials. No motor units, so every cell contracts with every beat due to the electrical signal moving cell-to-cell through gap junctions. Every contraction is a twitch -- no tetanus Cardiac action potential - correct answer ✅Lasts 300 milliseconds, 30+ times longer than skeletal muscle action potential Smooth muscle has no sarcomeres and no extensive t-tubule/SR system -- True/False - correct answer ✅True Composition of smooth muscle - correct answer ✅Thick and thin filaments with rudimentary overlapping organization, so crossbridges can form Single nucleus and small
