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102 Cards in this Set
- Front
- Back
The three types of muscle tissue are
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1. Skeletal
2. Cardiac 3. Smooth |
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What is a sarcolemma?
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thin plasma membrane that encloses a striated muscle fiber
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What is sacoplasm?
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cytoplasm of a muscle cell
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What are striations?
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obvious stripes in skeletal muscle tissue
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___________ Muscle is controlled voluntarily.
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skeletal muscle
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___________ Muscle is responsible for overall body motility.
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skeletal muscle
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___________ Muscle occurs only in the heart.
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Cardiac Muscle Tissue
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___________ Muscle is striated but is not voluntary.
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Cardiac Muscle tissue
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What mechanism is rhythmically controlled by a sinoatrial node and located in the heart?
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pacemaker
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What type of muscle is found in the walls of hollow visceral organs?
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Smooth Muscle Tissue
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_______________ Muscle forces food and other substances through internal body channels.
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Smooth Muscle Tissue
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Muscle found in the stomach urinary bladder and respiratory passages is?
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Smooth Muscle Tissue
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What type of muscle is voluntary but is not striated?
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Smooth Muscle Tissue
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What are four functional characteristics of muscle tissue?
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1. Excitability or irritability
2. Contractility 3. Extensibility 4. Elasticity |
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What is excitability / irritability of muscle tissue?
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the ability to receive and respond to stimuli
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What is contractility of muscle tissue?
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the ability to shorten forcibly
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What is extensibility of muscle tissue?
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the ability to be stretched or extended
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What is elasticity of muscle tissue?
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The ability to recoil and resume the original resting length
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What are the three connective tissue sheaths?
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1. Endomysium
2. Perimysium 3. Epimysium |
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What is the endomysium?
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a fine sheath of connective tissue composed of reticular fibers surrounding each muscle fiber
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What is the perimysium?
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a fibrous connective tissue that surrounds groups of muscle fibers called fascicles
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What is the epimysium?
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an overcoat of dense regular connective tissue that surrounds the entire muscle
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Each skeletal muscle is a organ composed of what four things?
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muscle tissue
blood vessels nerve fibers connective tissue |
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Most skeletal muscles span joints and are attached to bone in at least _______ places.
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2
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When muscles contract the movable bone (AKA the muscle’s ________) moves toward the immovable bone (AKA the muscle’s __________).
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the insertion / the origin
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When skeletal muscles attach directly the_____________ of the muscle is fused to the __________ of the bone
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epimysium / periosteum
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What are the three types of skeletal muscle attachments?
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1. Directly
2. tendon to muscle 3. indirectly |
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When skeletal muscles attach _________ the connective tissue wrappings extend beyond the muscle as a tendon or aponeurosis.
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indirectly
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Each skeletal muscle fiber is a long, cylindrical cell with mutiple ______ just beneath the sarcolemma (cell membrane).
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nuclei
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T/F Skeletal muscle fibers are up to hundreds of centimeters long.
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True
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Each skeletal muscle cell is a syncytium (unit) produced by fusion of __________.
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embryonic cells
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__________ are densely packed rod-like contractile elements.
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myofibrils
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What elements make up most of the muscle volume?
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myofibrils
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The arrangement of____________ creates a repeating series of dark A- bands and light l-bands.
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myofibrils
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What are the smallest units of a muscle?
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Sarcomeres
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Sarcomeres are composed of _____________ made up of contractile proteins.
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myofilaments
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What are the two types of myofilaments?
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thick and thin
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____________ filaments are composed of the protein myosin and extend the entire length of an A band.
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thick filaments
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____________ filaments extend across the I band and partway into the A band.
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thin filaments
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____________ is a coin-shaped sheet of proteins that anchors the thin filaments and connects myofibrils to one another.
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Z-disc
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Each myosin molecule has a rod-like tail and ________ globular heads.
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two
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____________ filaments have two interwoven heavy polypeptide chain tails and two smaller
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light polypeptide chains called cross bridges that make the head., myosin
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___________ myosin filaments are chiefly composed of the protein actin.
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thin
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T/F The thick myosin filament subunits contain the active sites to which myosin heads attach during contraction.
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False Thin filaments
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T/F Tropomyosin and troponin are regulatory subunits bound to myosin.
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False actin
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What is the movement provided by the ankle? (anterior and posterior)
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dorsiflexion = (ant. Compartment)
plantar flexion = (post. Compartment) |
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The movement provided by the Intertarsal joints is?
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inversion and eversion of the foot
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The movement of the toes is?
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flexion and extension
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What are the four muscles in the anterior compartment of the calf that are the primary toe extensors and ankle dorsiflexors?
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1. tibialis anterior
2. extensor digitorum longus 3. extensor hallucis longus 4. fibularis tertius |
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What are the two main muscles of the lateral compartment in the calf that plantar-flex and evert the foot?
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1.fibularis longus
2. fibularis brevis muscles |
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What five muscles of the Posterior Compartment in the calf flex the foot and the toes.
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1.gastrocnemius
2. Soleus 3.Tibialis posterior 4. Flexor digitorum longus 5. flexor hallucis longus |
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___________ compartment flexes leg and extends the thigh.
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posterior compartment
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___________ compartment of the thigh extends the leg.
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anterior compartment
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___________ compartment adducts the thigh.
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medial compartment
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__________ compartment of the leg plantar flexes and everts foot.
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lateral compartment
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___________compartment plantar flexes the foot and flexes the toes.
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posterior compartment
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___________ compartment dorsiflexes the foot and extends the toes.
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anterior compartment
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The________ muscles of the foot help flex,extend, abduct, and adduct the toes.
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intrinsic
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What is the single dorsal foot muscle, which extends the toes?
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the extensor digitorum brevis
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The plantar muscles occur in how many layers?
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four
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What does the interossei group of muscles in the hand do?
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abduct and adduct the fingers
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What three groups are enclosed by the fascia lata?
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1.anteriormuscles of the hip and thigh
2.posterior compartments 3.medial compartments |
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The __________ hip joint permits –Flexion, Extension, Abduction, Adduction, Circumduction and, Rotation.
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ball-and-socket
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What are the most important thigh flexors? (3)
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1. iliopsoas (prime mover)
2. Tensor fasciae latae 3. Rectus femoris |
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The medially located adductor muscles and _________ assist in thigh flexion.
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sartorius
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Thigh extension is primarily effected by what three hamstring muscles?
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1.biceps femoris
2. Semitendinosus 3.semimebranosus |
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Forceful extension of the hamstring muscle is aided by what muscle?
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the gluteus maximus
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Abduction and rotation of the thigh is assisted by ____________ & ______________ and antagonized by the ______________.
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-Gluteus medius and gluteus minimus
antagonized by the lateral rotators |
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What are the five adductor muscles that assist in adduction of the thigh?
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1.adductor magnus
2.adductor longus 3.adductor brevis 4.the pectineus 5.gracilis |
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What muscle is the sole extensor of the knee?
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quadriceps femoris
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What group of muscles is used to flex the knee and acts as antagonists to the quadriceps femoris?
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hamstring muscles
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During flexion the thumb bends __________ along the palm and during extension the thumb points _________.
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-medially
-laterally |
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During flexion the fingers bend _________________ and during extension the fingers move ______________.
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-anteriorly
-posteriorly |
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There are ______ groups of intrinsic hand muscles.
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3
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The thenar eminence and hypothenar eminence each have a flexor, an abductor, and an opponens muscle. Where is this group of muscles located on the body?
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the hand
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What do the mid-palm muscles (the lumbricals and interossei) do?
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extend the fingers
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____________ is smooth endoplasmic reticulum that runs longitudinally and surrounds each myofibril.
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sarcoplasmic reticulum (SR)
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What controls regulation of intracellular calcium levels?
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sarcoplasmic reticulum (SR)
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_____________ are continuous with the sarcolemma and they conduct impulses to the deepest regions of the muscle.
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t tubules
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The impulses from the T tubules signal for the release of ____________.
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Ca+2
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Thin filaments slide past the thick ones so that the actin and myosin filaments overlap to a greater degree. In the relaxed state thin and thick filaments overlap only slightly. Upon stimulation myosin heads bind to actin and sliding begins. What does this represent?
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sliding filament model of contraction
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In the sliding filament model each myosin head binds and detaches several times during contraction acting like a ratchet to generate tension and propel the thin filaments to the center of the____________. As this event occurs throughout the sarcomeres the muscles _____________.
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sarcomere
the muscles shorten |
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What three things must happen in order for a skeletal muscle to contract?
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1. Stimulation by a nerve ending
2. Production of an electric current/ action potential along its sarcolemma 3. Rise in Ca2+ to trigger the contraction |
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Skeletal muscles are stimulated by the motor of the ______________.
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somatic nervous system
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__________ of the neurons travel in nerves to muscle cells as well as branch profusely as they enter muscles.
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axons
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Each axonal branch forms a ______________ with a single muscle fiber.
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neuromuscular junction
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What is “cross bridge formation”?
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myosin cross bridge attaches to actin filament
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What is the working (power) stroke in contraction?
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myosin head pivots and pulls actin filament toward M line
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What is the “cross bridge detachment”?
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ATP attaches to myosin head and the cross bridge detaches
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What is “Cocking” of the myosin head?
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energy from hydrolysis of ATP “cocks” the myosin head into the high-energy state
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Contraction refers to the activation of what?
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myosin cross bridges
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What are the two types of muscle contractions?
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Isotonic and isometric
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_____________ contraction decreases muscle length.
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isotonic
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Isometric contraction increases muscle __________ and does not shorten during contraction.
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tension
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Iso=_______________ / tonic=___________________/ metric=_______________
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same / tone / length
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A _____________ is a neuron and all the muscle fibers it supplies.
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motor unit
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The number of muscle fibers per motor unit varies from ___________ to __________ hundred.
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four to several hundred
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What forms the neuromuscular junction?
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axonal ending
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The axonal endings have small membranous sacs (synaptic vesicles) that contain what neurotransmitter?
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acetylcholine (ACh)
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What is the motor end plate of a muscle?
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a specific part of the sarcolemma that contains ACh receptors and helps form the neuromuscular junction
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What is the space called between the axonal ends and muscle fibers?
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the synaptic cleft
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When a nerve impulse reaches the end of an axon at the neuromuscular junction: Voltage regulated calcium channels open and allow Ca2+ to enter the ___________. Ca2+ causes axonal vesicles to fuse with the axonal membrane. This fusion releases __________into the synaptic cleft. ACh diffuses across the synaptic cleft to ACh receptors on the sarcolemma. Binding of ACh to its receptors initiates an ____________ in the muscle.
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enter the axon / releases ACh / initiates an action potential
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