BIO 210 TEST #3 EXAM | QUESTIONS & ANSWERS (VERIFIED) | LATEST UPDATE | GRADED A+

1 BIO 210 TEST #3 EXAM | QUESTIONS & ANSWERS (VERIFIED) | LATEST UPDATE | GRADED A+ CHAPTER 8 JOINTS AND ARTICULAR MOVEMENTS joint Correct Answer: articulation; the junction of two or more bones structural classification of joints Correct Answer: focuses on the material binding the bones together and whether or not a joint cavity is present (fibrous, cartilaginous, and synovial joints) functional classification of joints Correct Answer: based on the amount of movement allowed at the joint (synarthroses, amphiarthroses, and diarthroses) synarthroses Correct Answer: immovable joints syn=together, arthro=joint 2 amphiarthroses Correct Answer: slightly moveable joints amphi=on both sides, arthro=joint diarthroses Correct Answer: freely moveable joint dia=apart, arthro=joint fibrous joint Correct Answer: bones joined together by fibrous tissue; no joint cavity is present; connection made by hyaline cartilage or dense irregular connective tissue --TYPES-- -sutures -syndesmoses -gomphoses sutures Correct Answer: aka synostoses meaning "seams"; occur only between bones of the skull; exhibit interlocking edges filled with minimal amounts of very short connective tissue fibers continuous with the periosteum; synarthroses = immovable (ex. plated bones of skull) 3 syndesmoses Correct Answer: (syndesmos = ligament) bones that are exclusively connected by ligaments, cords, or bands of fibrous tissue; move-ability related to length of tissue band; amphiarthroses = slightly moveable, ranges (ex. radial-ulnar articulations) gomphoses Correct Answer: peg-in-socket fibrous joint; only found in the articulation of a tooth with its bony alveolar socket; uses periodontal ligaments for attachment; synarthroses = immovable (ex. teeth) cartilaginous joints Correct Answer: articulating bones are united by cartilage; lack a joint cavity and are not highly moveable --TYPES-- -synchondroses - symphyses synchondroses Correct Answer: bones united by a bar or plate of hyaline cartilage; virtually all are synarthroses = immovable (ex. epiphyseal plate in children's long bones) 4 symphyses Correct Answer: articular surfaces of bones are covered with articular hyaline cartilage that is fused to an intervening pad, or plate, of fibrocartilage, which is the main connecting material; amphiarthroses = slightly moveable (ex. intervertebral disc and pubic symphysis) synovial joints Correct Answer: articulating bones are separated by a fluid-containing joint cavity; permits substantial freedom of movement; diarthroses = freely moveable (ex. nearly all joints of the limbs) Synovial joint distinguishing features Correct Answer: 1) Ligament 2) Articular Capsule 3) Fibrous Layer 4) Synovial Membrane 5) Articular Cartilage 6) Joint Cavity ligaments of synovial joints Correct Answer: band-like ligaments reinforce and strengthen synovial joints; can be located on the outide or inside of the joint capsule 5 articular capsule of synovial joints Correct Answer: joint capsule; a two-layered membrane enclosing the joint cavity fibrous layer of synovial joints Correct Answer: the external layer of the articular capsule that is composed of dense irregular connective tissue, that is continuous with the periostea of articulating bones; serves to strengthen the joint and keep bones from pulling apart synovial membrane of synovial joints Correct Answer: the internal layer of the articular capsule composed of loose connective tissue; lines the fibrous capsule internally and covers all internal joint surfaces that are not hyaline cartilage articular cartilage of synovial joints Correct Answer: smooth hyaline cartilage covering opposing bone surfaces within the articular capsule; keeps bone ends from being crushed together joint cavity of synovial joints Correct Answer: synovial cavity; feature unique to synovial joints holding small amounts of synovial fluid synovial fluid 6 Correct Answer: slipper fluid derived largely from filtration of the blood through capillaries and then secreted as hylauronic acid by cells within the synovial membrane; made of hylauronic acid, lubricin, proteinases, and collagenases synovial fluid formation Correct Answer: Synovial fluid is a modified plasma component secreted by the joint tissues surrounding a synovial joint. The major difference between synovial fluid and other body fluids derived from plasma is the high content of hyaluronic acid (mucin) in synovial fluid. Both fibroblasts beneath the synovial membrane intima and synovial membrane-lining cells produce and secrete this mucous-like polysaccharide component of synovial fluid. Absense of large plasma proteins in synovial fluid Correct Answer: Almost all of the protein components of synovial fluid are derived from plasma. The passage of plasma proteins to synovial fluid is related to the size and shape of the protein molecule. synovial fluid vs plasma Correct Answer: synovial fluid -- fluid secreted by the synovial membrane and derived from plasma; lubricates joint surfaces and nourishes articular cartilages plasma -- the non-living fluid component of blood within which formed elements and various solutes are suspended and circulated 7 Interesting Synovial Fluid Fact Correct Answer: synovial fluid exhibits the qualities of a fluid called THIXOTROPHY; this is the property of certain colloids or gels to become fluid when shaken. At standing room temperature, normal synovial fluid may assume a gelatin-like appearance. When it is shaken is will "melt" and resume its normal fluid nature (not on class objectives sheet. just thought it was cool) arthritis Correct Answer: pertains to over 100 different types of inflammatory or degenerative diseases that damage the joints osteoarthritis Correct Answer: (Degenerative Joint Disease) the most common chronic arthritis; often called wear-and-tear arthritis; is associated with the aging process but some forms are genetic and can occur at younger ages; it is more prevalent in women than men but almost 85% of the population develops it gouty arthritis Correct Answer: occurs when the waste product uric acid, normally excrete in urine, builds up to excessive levels within the blood and crystallizes within soft tissues of joints. The shape urate crystals cause inflammation within the joints which in turn 8 causes pain; it is more prevalent in men than women due to estrogens effect of uric acid excretion; this type of arthritis is curable with medical attention and dietary measures source of uric acid Correct Answer: uric acid is derived the metabolism of natural breakdown of cells and foods high in purine. Excessive consumption of alcohol can promote over production of uric acid rheumatoid arthritis Correct Answer: a chronic inflammatory disorder with an insidious onset (usually by the time you realize you have developed this disease it is too late to reverse it) The exact trigger for this disease is unknown but bacteria and viruses have been suspected. The disease is classified as an autoimmune disease as the body's immune system begins to attack its own tissues, causing swellings within synovial joints, release of inflammatory chemicals by lymphycytes, neutrophils, and other inflammatory cells destroy the body tissues. This can eventually lead to ankylosis which is the twisting or bending of joints which causes disability and severe pain autoimmune disease Correct Answer: disease in which the body instructs its own immune system to treat its own tissues as a pathogen, eventually destroying its own tissues as though it were the cause of the disease 9 Type of arthritis classified as autoimmune disease Correct Answer: rheumatoid arthritis bursae Correct Answer: flattened fibrous sacs lined with synovial membrane and contain a thin film of synovial fluid; occur where ligaments, muscles, skin, tendons, or bones rub together tendon sheaths Correct Answer: an elongated bursa that wraps completely around a tendon subjected to friction; they are common where several tendons are crowded together within narrow canals (ex. in the wrist region) fatty pads and menisci Correct Answer: fatty pads -- located between the synovial membrane and bones of some joints such as the hips and knee menisci -- articular discs or wedges of fibrocartilage that extend inward from the articular capsule and partially or completely divide the synovial cavity in two (ex. knee, jaw) 3 factors that influence stability in synovial joints Correct Answer: 1) articular surfaces -- mainly affect movements but can affect stability. The larger and deeper the articulation the more stable 10 2) ligaments -- prevents excessive or undesireable motion. The more ligaments the stronger the joint 3) muscle tone -- muscle tendons crossing the joint are most important stabilizing factor which are kept taught by muscle tone; muscle tone = low levels of contractile activity in relaxed muscles that keep the muscles healthy and ready to react to stimulation) Tpes of Synovial Joints Correct Answer: 1) plane joints 2) hinge joints 3) pivot joints 4) condyloid joints 5) saddle joints 6) ball-and-socket joints plane joints Correct Answer: the articular surfaces are flat, and allow only shot nonaxial (nonrotating) gliding movement (ex. intercarpals, intertarsals, vertebral joints) hinge joints 11 Correct Answer: the cylindrical end of one bone conforms to a trough-shape surface of another; motion is along a single plane; uniaxial hinge joints permit flexion and extension only (ex. being and straightening the elbow and fingers) pivot joints Correct Answer: the rounded end of one bone conforms to a sleeve or ring composed of bone or ligaments for another; only allows uniaxial rotation or one bone around its own axis (ex. radioulnar joint where the head of the raidus rotates within a ringlike ligament secured to the ulna) condylar joints Correct Answer: (ellipsiodal joints) oval articular surface of one bone fits into a complimentary depression in another; biaxial condyloid joints allow for all angular motions: flexion, extension, abduction, adduction, and circumduction) saddle joints Correct Answer: resemble condyloid joints but allow greater range of movement; each articular surface has both concave and convex areas that fit together, shaping them like saddles (ex. carpometacarpal joints of the thumbs, allowing for twiddling action) 12 ball-and-socket joints Correct Answer: the spherical or hemi-spherical head of one bone articulates with the cuplike socket of another; multiaxial and the most freely moving of the synovial joints (ex. shoulder and hip are only examples) Movement from Synovial Joints and Skeletal Muscles Correct Answer: all skeletal muscles are attached to bone or connective tissue structures at no fewer than two points; the origin of the muscle is attached to the less moveable bone; the insertion is attached to the moveable bone; body movement occurs when muscles contract pulling the insertion to the origin General Types of Movements Correct Answer: 1) gliding movements 2) angular movements 3) rotational movements flexion Correct Answer: decreases the angle of a joint and brings the articulating bones closer together extension Correct Answer: increases the angle of a joint and takes the articulating bones further apart 13 hyperextension Correct Answer: increasing the angle of a joint beyond 180 degrees abduction Correct Answer: movement of a limb away from the midline of the body ( adduction Correct Answer: the opposite of abduction, movement of a limb toward the midline of the body circumduction Correct Answer: moving a limb so that is describes a three-dimensional cone shape in space rotation Correct Answer: turning of a bone around its own long axis supination Correct Answer: denotes movement of the radius around the ulna; rotational movement of the forearm laterally faces the palm anteriorly or superiorly; in supination the radius and ulna are parallel 14 pronation Correct Answer: denotes movement of the radius around the ulna; rotational movement of the forearm medially faces the palm posteriorly or inferiorly; in pronation the radius and ulna are crossed dorsiflexion Correct Answer: lifting the foot so that the superior surface approaches the shin plantarflexion Correct Answer: depressing the foot (pointing the toes) away from the body inversion Correct Answer: the sole of the foot turns medially eversion Correct Answer: the sole of the foot faces laterally protraction Correct Answer: nonangular anterior movement elevation Correct Answer: lifting a body part superiorly 15 depression Correct Answer: moving the elevated body part inferiorly opposition Correct Answer: the action taken when touching the thumb to the tips of the fingers CHAPTER 9 Correct Answer: MUSCLES AND MUSCLE TISSUES Types of Muscle Tissue Correct Answer: 1) skeletal muscle tissue 2) cardiac muscle tissue 3) smooth muscle tissue muscle fibers Correct Answer: elongated muscle cells of the skeletal and smooth muscle varieties word part references to muscle Correct Answer: myomyssarcoskeletal muscle tissue 16 Correct Answer: packaged into skeletal muscle; composed of elongated cylindrical multinucleated cells with obvious striations; the muscles attach to the body's skeleton; voluntary control (skeletal, striated, voluntary) cardiac muscle tissue Correct Answer: packaged into cardiac muscle occurring only in the heart walls; cells are mostly single nucleated with faintly noticeable striations; involuntary control; (cardiac, striated, involuntary) **branching cardiac muscle cells are connect by INTERCALATED DISC [specialized connections between myocardial cells containing gap junctions and desmosomes] smooth muscle tissue Correct Answer: packaged into smooth muscle; composed of elongated spindle-shaped cells with a centrally located nucleus that are non-striated; mainly found in the walls of hollow organs (smooth, non-striated, involuntary) Functions of Muscles 17 Correct Answer: 1) Producing movement (skeletal) 2) Maintaining Posture and Body Position (skeletal) 3) Stabilizing Joints (skeletal) 4) Generating Heat (all, but 40% skeletal) 5) Protect fragile organs (skeletal) 6) Form Regulatory Valves (smooth) 7) Form Fluid Pumps (cardiac) Characteristics of Muscle Tissue Correct Answer: 1) Excitability 2) Contractility 3) Extensibility 4)Elasticity excitability Correct Answer: (responsiveness) the ability of muscle tissue to receive and respond to stimulus contractility Correct Answer: the ability of muscle tissue to shorten forcibly when adequately stimulated extensibility 18 Correct Answer: the ability of muscle tissue to be stretched or extended when relaxed elasticity Correct Answer: the ability of muscle tissue to recoil and resume its resting length after being stretched Anatomy of a Skeletal Muscle Correct Answer: Connective tissue sheaths --1) epimysium --2) fascicles --3) perimyisum --4) endomysium Muscle Fibers --5) sarcolemma --6) sarcoplasm --7) myoglobin --8) myofibers --9) myofibrils --10) mitochondria --11) myofilaments (thick and thin) epimysium 19 Correct Answer: means "outside the muscle" -- the overcoat of dense irregular connective tissue that surrounds the whole muscle fascicles Correct Answer: means "bundles" - groups of muscle fibers bound by perimysium permysium Correct Answer: means "around the muscle" -- a layer of fibrous connective dense surrounding each fascicle endomysium Correct Answer: means "within the muscle" -- a whispy sheath of connective tissue that surrounds each individual muscle fiber consisting of fine areolar connective tissue sarcolemma Correct Answer: means "flesh husk" -- the plasma membrane surface of a skeletal muscle sarcoplasm Correct Answer: the cytoplasm of a muscle cell, which is similar to cytoplasm of other cells, but it contains larges amounts of glycosomes and myoglobin glucosomes 20 Correct Answer: granules of stored glycogen that provide glucose during periods of muscle cell activity myoglobin Correct Answer: a red pigment that stores oxygen within muscle cells, similar in function to hemoglobin of blood sarcomere Correct Answer: smallest contractile unit of a skeletal muscle fiber myofibrils Correct Answer: rod-like bundles of contractile filaments (myofilaments) found in muscle fiber cells; consist of long chains of sarcomeres myofibers Correct Answer: skeletal muscle cell or fiber; filament that constitutes of myofibrils; two types: myosin, actin thick myofilaments Correct Answer: bundles of myosin filaments composed of the protein myosin; each myosin molecule contains a 2-head region providing both an actin & ATP bind sites, a flexible hinge region, and a tail 21 thin myofilaments Correct Answer: composed primarily of the protein actin but also contain regulatory proteins tropomyosin and troponin tropomyosin Correct Answer: protein found on actin myofilaments; blocks actin's myosin-binding sites so contraction cant take place due to lack of cross-bridge formation troponin Correct Answer: protein found on actin myofilaments; after calcium ions bind to troponin, it moves tropomyosin out of the myosin binding site and contraction can occur due to cross-bridge formation Sarcomere structure Correct Answer: 1) A-band 2) I-band 3) H-zone 4) Z-discs 5) Thick myofilaments 6) Think myofilaments A-band 22 Correct Answer: form dark bands within skeletal muscle striation; each A-band has a lighter H-zone within its borders I-band Correct Answer: form light bands with skeletal muscle striation H-zone Correct Answer: a lighter region in the midline of each A-band; appears lighter because thin filaments do not extend into this region Z-discs Correct Answer: a darker region in the midline of each I-band; anchors thin filaments myofilaments Correct Answer: causes the banding patterns on skeletal muscle cells, which arises from the ordered arrangement of actin and myosin filaments thick filaments Correct Answer: containing myosin, extend the entire length of the A-band thin filaments Correct Answer: containing actin, extend the entire I-band and part way into the A-band 23 Arrangement of Sarcomeres Correct Answer: 1) A-bands contain darker thick (myosin) filaments and intruding thin (actin) filaments; [light midline H-zone = (A-band minus actin-filament intrusion)] -- [darker M-line = bisects H-zone as basis pf attachment for thick filaments] 2) I-bands contain lighter thin (actin) filaments [darker midline Z-disc = basis of attach for actin filaments] 3) Each thick filament is surrounded by a hexagonal arrangement of six thin filaments, and each thin filament enclosed by three thick filaments Physical change that occurs to shorten a sarcomere (contraction) Correct Answer: THE SLIDING FILAMENT MODEL OF CONTRATION -- During contraction the thin actin filaments (I-bands) slide past the thick myosin filaments (A-bands) 1) Muscle fibers stimulated by the nervous system 2) The myosin heads form a cross bridge with myosin-binding sites on the actin in the thin filaments 3) This cross bridge cause the flexible hinge below the myosin heads to flex sliding the actin filaments into the H-zone (disappears), causing a pull upon the Z-disc 4) Each successive sarcomere performs this action causing the muscle to ultimately shorten and contract 24 FROM CHAPTER 11 Correct Answer: MEMBRANE POTENTIAL membrane potential Correct Answer: voltage difference harnessed across the plasma membrane of a cell resting membrane potential (RMP) Correct Answer: the voltage that exist across the plasma membrane during the resting state of an excitable cell; ranges from -90 to -20 millivolts depending on cell type Four Factors Causing Negative RMP Correct Answer: 1) the membrane of the resting cell is more permeable to K+ than to any other ions present 2) there is more K+ inside the neuron than outside, which contains sodium, potatssium, and calcium 3) large, negatively charge particles inside the cell cannot permeate through the membrane, helping to hold a (-) charge 4) protein ion pumps transport three (Na+) ions out while bringing in two (K+) ions creating a cycle of -1 charges Protein export out of cell? Correct Answer: Large proteins that are within the cell are transported via exocytosis 25 anion vs cation Correct Answer: anion - negatively charged ion (-) cation - positively charged ion (+) concentrations of ions Correct Answer: -- [Na+] -- ExCF = high ... InCF = low -- [K+] -- ExCF = low ... InCF = high -- [Cl-] -- ExCF = equal ... InCF = equal Simple diffusion of ions Correct Answer: - slightly permeable to Na+ - 75x more permeable to K+ than Na+ - Cl- is freely permeable - leakage (non-gated channels) - ion channels that are always open -- K+ loss through abundant leakage channels establishes a negative membrane potential; K+ flows down its large concentration gradient because the membrane is highly permeable to K+. As positive K+ ions, the negative voltage that develops on the membrane interior counteracts the concentration gradient 26 -- Na+ entry though the leakage channels reduces that negative membrane potential slightly. Na+ flows down its large concentration gradient but the membrane is only slightly permeable to Na+. As a result, Na+ entering the cell makes the membrane potential slightly less negative than if there were only K+ channels Primary active transport of Na+ and K+ Correct Answer: Sodium-potassium pumps; Na+ K+ ATPase; a primary active transport system that simultaneously drives three Na+ out of the cell against a steep gradient and pumps two K+ back in Membrane potential change when: Correct Answer: 1) anions enter the cell -- more negative 2) anions exit the cell -- less negative 3) cations enter the cell -- less negative 4) cations exit the cell -- more negative excitable cells Correct Answer: a cell is considered excitable if it has the ability to respond to stimuli (neurons and muscle cells are excitable) 27 resting potential voltage Correct Answer: resting potential = -70 mV What happens to ion flow when: Correct Answer: o) voltage-gated Na+ channels open = Na+ ions flow into the cell (Depolarization = less negative) o) voltage gates K+ channels open = K+ ions flow out of the cell (Hyperpolarization = more negative) voltage-gates channels Correct Answer: open and close in response to changes in the membrane potential ligand-gates channels Correct Answer: open when the appropriate chemical binds to an active site threshold potential Correct Answer: the critical level to which the membrane potential must be depolarized in order to initiate an action potential threshold potential voltage Correct Answer: threshold potential = -55 mV 28 Cause of threshold Correct Answer: depolarization of the cells membrane potential shifts the potential to a less negative value depolarization Correct Answer: a reduction in membrane potential; the inside of the membrane becomes less negative (moves closer to zero) than the resting potential; increases the likelihood of an action potential voltage-ion gate channel that opens at threshold Correct Answer: Voltage-gates Na+ channels -- allow influx of Na+ ions into the cell, making it less negative ,shifting its membrane potential toward zero; DEPOLARIZATION (3 different states) - closed -- at resting state; no Na+ enters the cell through these channels - open -- by depolarization; allows Na+ to enter the cell - inactivated -- channels automatically blocked by inactivation gates soon after the open action potential 29 Correct Answer: a large transient depolarization event, including polarity reversal, that is conducted along the membrane of a muscle cell or a nerve fiber (cells membrane potential depolarizes from -70 mV to +30 mV) repolarization Correct Answer: a change in polarity following depolarization [(-) to (+) = less negative] cause by the opening of voltage-gates K+ channels, allowing K+ to flow out of the cell causing an action potential voltage-gates ion channel opened at peak of depolarization causing repolarization Correct Answer: Voltage-gates K+ channels -- allow exflux (outflow) of K+ ions from the cell, making it more negative ,shifting its membrane potential back toward zero after depolarization; REPOLARIZATION (2 different states) - closed -- at the resting state; no K+exits the cell through these channels - open -- at peak of depolarization, allowing K+ to exit the cell action potential upstroke Correct Answer: depolarization action potential downstroke 30 Correct Answer: repolarization hyperpolarization Correct Answer: when the membrane potential increase, becoming more negative than the resting potential; decreases the likelihood of an action potential; occurs during downstroke after repolarization has occured (aka undershoot) voltage-gates ion channels during downstroke Correct Answer: - All of the voltage-gated Na+ channels are closed and resetting at the end of the downstroke (no Na+ in) - Some of the voltage-gated K+channels are still open at the end of the downstroke (allows K+ flow out = more negative past resting potential) absolute refractory period Correct Answer: - period following stimulation during which no additional action potential can be evoked (Na+ channels open to reset during depolarization) - voltage-gated Na+ channels are open, the neuron cannot respond to another stimulus, no matter how strong relative refractory period Correct Answer: - interval following the absolute refractory period (includes repolarization and hyperpolarization) 31 - most Na+ channels have returned to their resting state, some K+ channels are still open, and repolarization is occurring all-or-none phenomenon Correct Answer: an action potential either happens or it doesn't happen at all motor neuron Correct Answer: efferent nerve fibers that carry impulses leaving the brain and spinal cord, and destined for effectors - motor dendrites -- short, tapering, diffusely branching extensions used as input regions; usually hundreds clustered near the neural cell body - motor axons -- long single axon for each neural cell arising from the cell body; used to transmit stimuli to a muscle or effector Propagation of the action potential down the motor neuron axon Correct Answer: - refers to the transmission of a signal down an axons entire length; the influx of Na+ caused by depolarization establishes local currents that depolarize adjacent membrane areas in the forward direction toward the axon termial, which opens voltage-gates ion channels and triggers an action potential there; triggers onset of absolute refractory periods 32 sarcoplasmic reticulum Correct Answer: smooth endoplasmic reculum in skeletal muscle fibers that surrounds each myofibril; stores calcium ions; releases stored calcium ions, when necessary, for skeletal muscle contraction; also located in cardiac and smooth muscle transverse tubules Correct Answer: also called T-tubles; extensions of the sarcolemma that surround the myofibrils; carries the action potential deep inside the myofiber neuromuscular junction Correct Answer: region where a motor neuron comes into close contact with a skeletal muscle fiber; where action potential is transmitted from motor neuron to skeletal muscle fiber; also found in multi-unit smooth muscle motor-end plate Correct Answer: trough-like portion of a skeletal muscle cell's sarcolemma that forms part of the neuromuscular junction; specific portion of the sarcolemma that contains receptors for acetylcholine and ligand-gated ion channels SKELETAL MUSCLE FIBER CONTRACTION STEPS (KNOW ALL IN ORDER FOR TEST) Correct Answer: 1) Action potential propagates down the motor neuron axon and reaches synaptic end bulbs 33 2) Action potential opens voltage-gates Ca2+ channels on the synaptic end bulbs. Ions diffuse through open-gate into synaptic end bulbs 3) Synaptic vesicles containing acetylcholine migrate towards synapse end due to increase in intracellular Ca2+, fusing with the plasma membrane of the bulb and releasing acetycholine into the synaptic cleft via exocytosis 4) Acetylcholine binds with receptors on the motor end plate of the skeletal muscle fiber; this binding opens ligand-gated ion channels on the motor end plate 5) Ions diffuse through the opened channels, and ions flow across the mote end plate to reach threshold and an action potential is generated at the motor end plate 6) Action potential propagates from the motor end plate to the sarcolemma of the muscle fiber and down the T-tubules. From the T-tubules the action potential propagates to the sarcoplasmic reticulum 7) MEANWHILE, the acetycholine is broken down by acetylcholinesterase- an enzyme located in the motor end plate 8) Action potential reaches the sarcoplasmic reticulum, opening voltage-gates Ca2+ channels in the sarcoplasmic reticulum 34 9) Calcium ions diffuse through open voltage gates out of the sarcoplasmic reticulum, into the sarcoplasm 10)These calcium ions bind to troponin on actin myofilaments, removing myotroposin from the myosin-binding sites on thin myofilaments, allowing for mysoin to bind with actin 11) Myosin head can then form crossbridges with myosin bindin sites on actin filaments as longa s the myosin head have been activated by the energy released from the breakdown of ATP. 12) Myosin heads attach forming a crossbridge and pull the actin myofilament (I-band) toward the center of the sarcomere (A-band). Myosin heads detach when a new ATP m excitation - contraction coupling Correct Answer: coupled reactions are two different reactions that go together to achieve a common result. Sometimes one reaction causes the second reaction to take place acetylechoinesterase 35 Correct Answer: enzyme that degrades released acetylcholine into acetic acid and choline for reuptake; located in the synaptic cleft on postsynaptic membranes; without breakdown muscle spasm occur; closes ligand-gated Ca2+ channels myosin ATPase Correct Answer: enzyme that catalyses the chemical reaction ATP + H2O <==> ADP + phosphate; ATP hydrolysis provides energy for actomyosin contraction body's main source of Ca2+ Correct Answer: foods that are digested and metabolized ATP storage in skeletal muscle cells Correct Answer: muscle cells store very limited reserves of ATP; about 4-6 seconds worth or just enough to get you going Methods for Making ATP Correct Answer: 1) Direct phosphorylation = coupled reaction of creatine phosphate and ADP 2) Anaerobic pathway = glycolysis and lactic acid formation 3) Aerobic pathway = aerobic cellular respiration 36 Direct phosphorylation Correct Answer: - coupled reaction of creatine phosphate and ADP by Creatine kinase - Energy source = creatine phosphate (CP) - Oxygen used = none - Products = 1 ATP per CP, creatine - Duration of energy = 15 seconds CP + ADP ==> ATP + Creatine (used in resting activities, maintainence; fastest production; 6 seconds) Anaerobic pathway Correct Answer: - glycolysis and lactic acid formation - Energy source = glucose - Oxygen used = none - Products = 2 ATP per glucose, lactic acid - Duration of energy = 60 seconds or slightly more Glucose ==> Glycolysis = 2 ATP =(No O2)=> Pyruvic acid =(No O2)=> Lactic acid ==> released into blood 37 (used in burst of strenuous activity; breaks down glycogen or glucose without oxygen to generate ATP; slow but not slowest) Aerobic pathway Correct Answer: - aerobic cellular respiration - Energy source = glucose; pyruvic acid; free fatty acids form adipose; amino acids from protein catabolism - Oxygen used = Required - Products = 34 ATP per glucose, CO2, H2O - Duration of energy = hours Glucose =(No O2)=> Pyruvic acid =(O2 present)=> aerobic respiration in mitochondria ==> CO2 + H2O + 32 ATP (used in prolonged strenuous activity; breaks down several nutrient fuels using oxygen; slowest due to # of steps) muscle movement from direct phosphorylation Correct Answer: ATP is formed from creatine phosphate by creatine kinase after about 6 seconds of vigorous activity glycolysis 38 Correct Answer: refers to the conversion of glucose to ATP and pyruvic acid or lactic acid reversibility of ATP reactions Correct Answer: Direct phosphorylation = reversible Anaerobic pathway = irreversible Aerobic pathway = reversible glycogen Correct Answer: main carbohydrate stored in animal cells for conversion to glucose in ATP production release of glucose into blood Correct Answer: only liver cells can release glucose into the bloodstream liver conversion of lactic acid Correct Answer: converts lactic acid in blood to glucose or glycogen - blood glucose level = low ==> liver breaks down glycogen for metabolism - blood glucose level = high ==> liver catabolizes glycogen from glucose for storage 39 main source of glucose in glycolysis Correct Answer: glucose from blood or glycogen stored in the muscle normal glucose levels Correct Answer: 100 g / 1 L oxidative phosphorylation Correct Answer: another term for aerobic respiration; process of ATP synthesis during which inorganic phosphate group is attached to ADP; occurs in the presence of oxygen; uses pyruvic acid, fatty acids, amino acids, and glycogen/glucose products of oxidative phosphorylation Correct Answer: 32 ATP + CO2 + H2O -- occurs in mitochondria motor unit Correct Answer: motor neuron + all the skeletal muscle fibers it stimulates; each motor unit has only one motor neuron but may contain only a few skeletal muscle fibers (small motor unit; functions in fine muscle movements) or many skeletal muscle fibers (large muscle unit; functions in gross muscle movements) myogram 40 Correct Answer: a graphic record of skeletal muscle contraction; may be produced in the laboratory attaching an isolated muscle to an apparatus that measures muscle contraction muscle twitch Correct Answer: the response of an isolated skeletal muscle to one threshold stimulus; one threshold stimulus causes the muscle to contract once, then relax; myogram of a muscle twitch = latent period + period of contraction + period relaxation muscle tension Correct Answer: the force exerted by a contracting muscle on an object; muscle tension increases when a skeletal muscle contracts muscle fatigue Correct Answer: when a skeletal muscle is physiologically inable to contract; occurs when ATP production fails to keep up with ATP use skeletal muscle fiber types Correct Answer: 1) slow oxidative 2) fast oxidative/glycolytic 3) fast glycolytic 41 slow oxidative muscle fiber Correct Answer: - contracts slowly because its myosin ATPases are slow - depends on oxygen delivery and aerobic pathways (high oxidative capacity) - high endurance; fatigue resistant - thin in shape - relatively little power - many mitochondria - rich capillary supply - red color; rich in myoglobin (best suited for endurance) fast oxidative/glycolytic muscle fiber Correct Answer: - contracts rapidly because its myosin ATPases are fast - does not use oxygen/unless needed - depends on glycogen reserves - tires quickly - large diameter - few mitochondria - red to pink (lack of myoglobin) fast glyolytic muscle fiber Correct Answer: - contracts fast because myosin ATPases are fast 42 - does not use oxygen - high in glycogen reserves - very fatigable - white (lack of myoglobin) Substances necessary for muscle contractions: Correct Answer: 1) Ca2+ 2) ATP 3) Acetylcholine muscle load Correct Answer: ... small vs large motor units Correct Answer: ... components of muscle twitch Correct Answer: ... wave summation Correct Answer: ... incomplete (infused) tetanus 43 Correct Answer: ... complete (fused) tetanus Correct Answer: ... ion responsible for increased muscle tension Correct Answer: ... Why must threshold stimulus be applied to a muscle in order for muscle tension to increase? Correct Answer: ... Why increase in stimulus increases muscle tension: Correct Answer: ... maximal stimulus Correct Answer: ... recruitment Correct Answer: ... order of recruitment Correct Answer: ... 44 isotonic muscle contractions Correct Answer: ... isometric muscle contractions Correct Answer: ... excess postexercise oxygen consumption (EPOC) Correct Answer: ... skeletal muscles before and after exercise Correct Answer: ... EPOC differences (high or low, young or old, fit Correct Answer: high vs low: young vs old: fit vs unfit: smoker vs non-smoker: Describe how the following affect contractile force 45 Correct Answer: number of muscle fibers stimulated recruitment size of muscle fibers sarcomere length stretch of connective tissue wrappings how the following affect contractile velocity and contractile duration Correct Answer: predominance of fast glycolytic fibers; predominance of slow oxidative fibers; size of load. single unit smooth muscle Correct Answer: ... multi-unit smooth muscle Correct Answer: ... Smooth muscles Correct Answer: body location: 46 cell shape and appearance: connective tissue: presence of sarcomeres: presence of actin and myosin presense of elaborate sarcoplasmic reticulum presence of gap junctions presence of individual neuromuscular junctions involuntary calcium ion source site of calcium regulation presence of pacemakers speed of contraction 47 response to stretch stress-relaxation response origin Correct Answer: ... insertion Correct Answer: ... main divisions of nervous system Correct Answer: CNS = central nervous system = brain and spinal cord PNS = peripheral nervous system = cranial and spinal nerves and nerves arising from them cranial vs spinal nerves Correct Answer: ...