Muscle and Tissue Organization

______ is when the angle between articulating bones decreases and the opposite is _____
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_____ is movement of the thumb across the palm toward the fingers to permit grasping and holding an object and the opposite is ______Opposition, repositionWhat are the properties of muscle tissue?Excitability, contractility, elasticity, extensibilityThe excitability or responsiveness of a muscle cell to input from stimuli is whereThe stimulus (electrical charge) initiates electric change that sweeps across the entire plasma membrane of the cell that leads eventually to muscle contractionWhen electrical change within muscle cells generations tension within them, contraction happens which isThe shortening of the fibersThe elasticity of a muscle is its ability toReturn to original length, NOT stretchThe extensibility of a muscle isThe capability of it to extend in length in response to contraction of opposing muscle cellsEach skeletal muscle is an organ composed of what tissue types?All four; epithelial, connective, muscle, neuralA muscle _____ is an individual muscle cellFiberHow do muscles contribute to temperature regulation in the body?ATP is used for muscle contraction, heat is a byproduct of energy usage, heat from normal muscle contraction maintains our normal body temp.What is the breakdown of the anatomy of a muscle?A muscle is composed of fascicles, fascicles are bundles of muscle fibers (cells), muscle fibers are composed of myofibrils, myofibrils are made of myofilaments (actin and myosin)The dense irregular connective tissue covering of the entire muscle is called theEpimysiumThe dense irregular connective tissue covering of the fascicle and supporting the neurovascular bundles that branch to innervate each fascicle is thePerimysiumThe primary areolar connective tissue covering each muscle fiber providing it with electrical insulation is theEndomysiumThe thick proteins of myofilaments are made ofMyosinThe thin proteins of myofilaments are made ofActin, tropomyosin, troponinWhat fibers of the endomysium help keep capillary beds and other fibers in place?ReticularThe deep/visceral/muscular fascia includes what?Endomysium, perimysium, epimysiumThe _____ fascia separates individual muscles and binds those with similar functions togetherDeep/visceral/muscularThe ______ fascia is deep to the dermis and is considered the subcutaneous layerSuperficialWhat is the sueprficial fascia composed of and what does it do?Areolar and adipose CT, separates muscle from skinWhat merge to form a tendon at the end of the muscle?The connective tissue layers/deep fasciaWhat is it called when a tendon forms a flattened, thin sheet?AponeurosisThe less mobile attachment of a muscle is called theOriginThe more mobile attachment of a muscle is called theInsertionThe extensive network of blood vessels and nerve fibers of muscle are found where?In the epi and perimysiumSkeletal muscle are classified as voluntary muscles because they are controlled by theSomatic nervous systemNeurons that stimulate muscle contraction are calledMotor neuronsThe axon/nerve fiber of a motor neuron travels through epi and perimysium and penetrated the _____ and transmits a nerve impulse to the muscle fiberEndomysiumWhat is the junction between an axon and muscle fiber called?Neuromuscular junctionThe _____ is the plasma membrane of the muscle fiberSarcolemmaThe ____ is the cytoplasm of a muscle fiberSarcoplasmThe ______ is the smooth ER of a muscle fiberSarcoplasmic reticulumWhat does the sarcoplasmic reticulum of a muscle fiber store?Calcium needed for contractionThe ______ is the perpendicular expanded ends of sarcoplasmic reticulum that are in contact with the transverse tubulesTerminal cisternaeWhat is the site of calcium ion release to promote muscle contraction?Terminal cisternaeThe _______ are narrow, tubular invaginations of the sarcolemma into the sarcoplasm contacting terminal cisternae and wrapping around myofibrilsTransverse tubules/T-tubulesWhat is the function of T-tubules?Quickly transporting muscle impulse from sarcolemma through the entire fiberThe thick filament is bundles of _____ that bind to the thin filament to cause contractionMyosinThe thin filament is composed of _______ and thick filaments bind to it to cause contractionsActin, troponin, tropomyosin_____ is the contractile protein binding site for myosin on the thin filament to shorten the sarcomereActin______ is the regulatory protein that covers the active sites on actin to prevent myosin from binding when the muscle is at restTropomyosin_______ is the regulatory protein that holds tropomyosin in place and anchors to actinTroponinWhat happens when calcium ions bind to one of troponins subunits?It changes shape, causing tropomyosin to fall off actin active site and permitting myosin to bind (to contract)How do skeletal muscle fibers become multinucleated?Groups of embyronic myoblasts fuse during development but their nuclei remainWhat happens to the myoblasts that do not fuse with other cells during development?They remain in adult skeletal muscle as satellite cells (stem cells) that can be stimulated to differentiate and assist in repair and regenerationThe sarcoplasm of a muscle cell contains hundreds of thousands of _______ which components change position to cause their shortening, resulting in muscle contractionMyofibrilsEach strand of myosin has a free _____ that forms crossbridges when binding with thin filaments and an elongated tailFree globular headThin filaments are composed of two helical strands of _____ that have strings of tropomyosin surround them that may or may not block their binding sites depending on _______Actin, troponinCaclium binds to ______ to move it off of tropomyosin, freeing up the actin sites to attach to those of thick filamentsTroponinThe functional contractile unit of a skeletal muscle fiber is theSarcomere, aka one z disc to the nextWhat gives skeletal muscle its striated appearance?Multiple sarcomeres lined up end to end on myofibrilsWhat are thick and thin filaments doing when a muscle contracts?Sliding past each other to shorten the sarcomere (their length does NOT change)Each muscle fiber is controlled by how many motor neurons?OneThe ______ is the expended tip of an axon that covers a large surface area of the sarcolemmaSynaptic knobThe synaptic knob contains ______ that are filled with ________Synaptic vesicles, acetylcholineThe _____ is the specialized region of the sarcolemma that has an abundance of folds and indentation to increase surface area for the synaptic knobMotor end plateThe motor end plate contains what to receive Ach from synaptic vesicles?Ach receptorsWhat resides in the synaptic cleft to break down molecules of ACh to prevent continuous stimulation (contraction) of the muscle fiber?AcetylcholinesteraseWhat is Hirschsprung disease?A genetic abnormality resulting in the failure of ganglion (or death of) cells that innervate the walls of the colon. This makes it unable to undergo peristalsis causing the proximal region to become distended with fecesExplain the steps of skeletal muscle contraction1) ACh released in vesicles from the synaptic knob into cleft, received by ACh receptors on the motor end plate, initiating a muscle impulse in the sarcolemma 2) Impulse spreads along sarcolemma through T-Tubules, causing calcium ions to release from terminal cisternae into sarcoplasm 3) Calcium binds to troponin, troponin changes shape and moves tropomyosin off of actin active sites, myosin heads of thick filaments attach to active sites and form crossbridges 4) Myosin heads pivot and move thin filaments toward sarcomere center. ATP binds the myosin heads and they deatch and cycle repeats as long as calcium stays bound to troponin, sliding the filaments past each other and causing contraction of the muscle 5) Calcium ions are transported back into the sarcoplasmic reticulum by ATP driven ion pumps when the impulse stops and tropomyosin recovers active sites. Filaments slide back into original positions and muscle relaxesWhat causes rigor mortis?ATP supplies run out, myosin is unable to detach from actin sites on thin filaments, muscles are not able to relaxRigor mortis usually begins in 2 hours and takes 6-12 ours to fully develop, what can speed this up?Violent exercise causing depleted ATP or high body tempInstantaneous rigor mortis or _______ is rare and happens instantly after death, usually from very high body temp or violent exertionCadaveric spasmA motor unit consists ofA single motor neuron and all the muscle fibers it controlsAn _____ relationship exists between the size of the motor unit and the degree of control providedInverse, the smaller the motor unit the finer the controlMuscle fibers obey the all or none principle meaningThey contract completely or not at allWhen a motor unit is stimulated, how many of its fibers contract?All of them at the same timeThe total force generated by a muscle is entirely dependent onThe total number of motor units activatedMuscle tone isThe resting tension in a skeletal muscleWhat creates the muscle tone of a muscle?Motor units randomly being stimulated to maintain constant tension on tendonsWhat are the two types of muscle contraction?Isometric and isotonicIn _____ contraction the length of a the muscle does not changeIsometricIn isometric contraction the tension produced by contraction is not enough toExceed the resistance, ie. a plank or a flex that doesnt move the angle of the jointIn _____ contraction the tension produced from the contraction is equal to or greater than the resistance, and the muscle fiber length changes resulting in movementIsotonicWhat are the two types of isotonic contraction?Concentric and eccentric_____ isotonic contractions actively shorten a muscleConcentric, ie. biceps during flexion____ isotonic contractions lengthen the muscleEccentric, ie. biceps during extensionWhat are the three types of skeletal muscle fibers?Slow oxidative (Type I), fast oxidative (type IIa), fast glycolytic (type IIb)Whats the difference between fast and slow muscle fibers?Fast have higher myosin ATPase activity (ATP-splitting) so its able to make energy available for cross-bridge cylcing quicker. Able to produce a fast twitch compared to slow fibers_____ is an oxygen binding pigment found in skeletal muscle fibers that stores oxygen released from capillary bedsMyoglobin_____ fibers have half the diameter of other skeletal muscle fibers and contain slow working ATPaseSlow oxidative (type I)What are the pros and cons to slow oxidative (type I) fibers?They contract slower and less powerful, but can remain contracted for a long time without fatigueATP of slow and fast oxidative fibers is primarily supplies throughAerobic respirationSlow oxidative muscle fibers have an extensive vascular supply to supply oxygen and appear dark red because of the presence of large amounts ofMyoglobin______ fibers are the least numerous, intermediate in size, and have fast ATPaseFast oxidative (type IIa)How are fast oxidative (type IIa) different that slow oxidative?They produce fast powerful contractions and their vascular network is not as extensive. Also less myoglobin so less color_____ fibers are the most prevalent skeletal muscle fiber type, contain fast ATPase, and are the largest in diameterFast glycolytic (type IIb)What is the difference in fast glyoclytic and oxidative fibers?Fast glycolytic provides power and speed, gets ATP through anaerobic respiration, lacks myoglobin (are white), and fatigue quick so only contract in short burstsTrue/False: within a single motor unit, different fiber types may be presentFalseThere are no ______ fibers in the muscles of the eye and handSlow oxidativeThe ratio of fiber types in muscle determines an individuals endurance capabilites and is determined by what?GeneticsIndividuals with an increased number of fast glycolytic fibers will be able to excel at what types of activities?Sprinting or weight liftingThe proportion of what kind of muscle fibers can change with physical conditioning?Fast oxidative, can develop characteristics and mimic functionality of SO or FGWhat are the four types of muscle fascicle arrangement?Circular, parallel, convergent, pennateWhat kind of fascicle arrangement makes a sphincter where fibers are concentrically arranged around an opening?CircularContraction of circular muscle does what to the opening?Closes it off/decreases diameterParallel muscle fibers run parallel to their long axis and have a central body called aBelly/GasterWhat happens when a parallel muscle contracts?Muscle shortens, body increases in diameterParallel muscles have high endurance at the expense of what?They are not as strong as other muscle typesWhat are examples of parallel muscles?Rectus abdominis, biceps brachii, masseterWhat kind of muscle is often triangular in shape and the fibers converge on a common attachment site? Whats an example?Convergent muscles, pectoralis majorWhat are advantages and disadvantages to convergent muscles?They are versatile and the direction of pull can be modified, the force generated by contraction of all fibers is not as forceful as a parallel muscleWhat kind of muscles resemble a large feather and may have one or more tendons extending through the body?PennateHow are the fascicles arranged in a pennate muscle? What is an advantage of this?An oblique angle to the tendon, creating pull at an angle to the tendon, they can generate more tension than a parallel muscle of the same size (but dont pull teh tendon as far)What are the types of pennate muscles?Unipennate (all fibers on one side of the tendon, extensor digitorum), bipennate (muscle fibers on both sides, palmar interosseous), multipennate (branches of tendon within the muscle, deltoid)How are skeletal muscles named?Action, body region, attachments, orientation of fibers, muscle shape and size, heads/tendonsDescribe the form of cardiac myocytesStriated, short/thick, 1-2 nuclei, bifurcated (Y shaped)Cardiac muscles are _____ meaning individual cells can generate muscle impulse without nervous stimulation/involuntaryAutorhythmicWhat ion are cardiac muscle cells dependent on for contraction? What is less developed and able to store less of it?Calcium, sarcoplasmic reticulum, calcium is found in interstitial fluidWhat kind of respiration does cardiac muscle use almost exclusively?Aerobic, they contain an abundance of mitochondriaDescribe the form of smooth muscleFusiform shaped, single central nucleus, no specific alignment of thick/thin filaments so no striations or sarcomeresFilaments of smooth muscle attach to ______ cytoskeletal attachments located throughout the cell adjacent to sarcoplasmDense bodiesSmooth muscle also gets its calcium from interstitial fluid and uses it toCytoplasmic levels of calcium are used to regulate contractile activity______ are proteins made by plasma cells that are the integral component of the humoral immune responseAntibodiesAntibodies bind to ______ which areAntigens, anything perceived as foreignWhat is it called if a protein is seen as foreign but is actually self?AutoantibodyIf an antigen is self and is perceived as non-self it is called aAutoantigenAutoantibodies binding to autoantigens, is a ________ hypersensitivity reactionAntibody-mediated type IIWhat can autoantibodies binding to autoantigens result in?Destruction of cells, inflammation, interference with normal tissue functionWhat happens in the antibody-mediated disease of the neuromuscular junction myasthenia gravis?In most cases autoantibodies against postsynaptic Ach receptors degrade the receptors and damage the postsynaptic membrane, leaving myofibers unable to respond to Ach. Clinically patients present with fluctuating weakness that worsens with exertion and throughout the day. Extraocular muscle involvement is commonWhat happens in the antibody-mediated disease of the neuromuscular junction Lambert-Eaton myasthenic syndrome?Antibodies inhibit presynaptic calcium channels and block Ach release. In this case, rapid repetitive stimulation increases muscle response. Clinically patients usually have weakness of the extremities