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147 Cards in this Set
- Front
- Back
Characteristics of smooth muscle tissue:
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Non-striated,
no sarcomeres, non-voluntary, has some motor neurons, good capacity for regeneration, has stretch/relaxation response (can stretch and relax at new length), calcium present No troponin |
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Characterisitics of Cardiac muscle tissue:
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Striated
Has Sarcomeres No regeneration No motor neuron Long refractory period No tetanus possible Can use lactic/fatty acids for energy Calcium in Sarcoplasmic reticulum/interstitial fluid |
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Characteristics of Skeletal muscle tissue:
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Striated
Sarcomeres Some regeneration Has motor neurons Calcium comes from Sarcoplasmic reticulum |
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Action potential
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Change in charge across membrane of cell.
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How many neurons responsible for muscle contraction?
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Two--one from brain to spinal cord, other from spinal cord to organ.
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Aponeurosis
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Flat, fibrous sheet of connective tissue similar to tendon but can connect muscle to bone or other tissues.
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Tendon sheath
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Layer of membrane around tendon.
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Entire muscle cell surrounded by connective tissue called:
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Epimysium
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Muscle fasicles
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bundles of muscle cells surrounded by perimysium
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Perimysium
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Connective tissue that surrounds muscle fasicles.
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One muscle cell also called___
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Muscle fiber
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Muscle would be considered ___ (tissue, organ, etc.)
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Organ (different tissues working together to perform function)
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Myofibrils
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Long cylinders that make up muscle fibers.
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Muscle fibers surrounded by connective tissue called____
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Endomysium
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Every muscle fasicle is made up of___
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Muscle fibers (extend entire length of muscle)
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Sarcolemma
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Cell membrane of muscle cell
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Sarcoplasm
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Cytoplasm of muscle cell
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Sarcoplasmic reticulum
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Smooth Endoplasmic reticulum of muscle cell that stores calcium.
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T-tubules
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"invaginations", indentations in membrane of muscle cell (place where sarcoplasmic reticulum sits--releases calcium when charge gets near)
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What is myofibril made up of?
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Myofilaments
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What makes up myofilaments?
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Actin, myosin
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Two types of myofilaments:
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Thick (myosin--A band)
Thin (Actin--I band) |
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Order of organization in muscle:
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Myofilament--> Myofibril --> Muscle fiber --> Muscle Fasicle --> Entire Muscle
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Sarcomere
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Unit of contraction in muscle cell
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Functions of myosin:
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"head" has ability to break down ATP
"Head" can pivot and bind to Actin |
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Three types of proteins in thin myofilament:
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Action, Troponin, tropomysoin
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Actin
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Has binding site for myosin "head"
Binds to myosin to begin muscle contraction |
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Troponin
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Attaches to tropomyosin, has binding site for calcium
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Tropomyosin
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Wrapped as spiral around actin and covers up binding sites.
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What happens to A band during contraction?
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Does not move
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What happens to I-band during contraction?
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Moves so that Z-lines move closer together, A bands "abut" each other.
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What causes relaxation of muscle
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Tropomyosin covering up binding sites
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Why is calcium normally low in concentration in sarcoplasm?
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Calcium pumped back into sarcoplasmic reticulum
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How is T-tubule involved in contraction?
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brings action potential near sarcoplasmic reticulum which has "voltage gated" protein channels that allow calcium to be released as they open up.
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How does troponin "pulls" tropomyosin off of binding site?
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Changes configuration when attached to calcium, this pull tropomyosin off.
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What allows myosin to "rachet?" What is this movement called?
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releasesADP & P allows it to swivel or tilt, causing rachet motion. Called the pwoer stroke.
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When does muscle contraction end?
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When calcium is no longer available
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Where does initial action potential come from?
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Motor neuron
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Neuromusclar junction
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Space between neuron and muscle cell (axon terminal, synaptic cleft, motor end plate)
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Sliding filament theory
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Explanation for how muscles shorten during contraction (thick and thin filaments within the sarcomere slide past one another, shortening the entire length of the sarcomere. In order to slide past one another, the myosin heads will interact with the actin filaments and, using ATP, bend to pull past the actin.)
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Sliding filament theory (steps)
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Calcium released into sarcoplasm when action potential travels down T-tubules.
Calcium binds to troponin (requires ATP) Troponin changes configuration when binding to calcium and slides tropomyosin off of actin binding sites. Myosin binds to actin--release of ADP allows myosin heads to swivel, moving sarcomere until it is maximally shortened. |
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Where in axon terminal is neurotransmitter stored?
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Inside vesicles
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What causes release of neurotransmitter in axon terminal?
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Calcium enters cell through protein channels, causing transmitter to be released by exocytosis.
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How does neurotransmitter move across synaptic cleft?
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Diffusion
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What does neurotransmitter bind to on other side of synaptic cleft?
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Receptors on motor end plate
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Choline esterase
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Enzyme that breaks down acetylcholine
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Motor unit
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a neuron and muscle fibers it innervates
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Which muscles have large motor units?
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Back muscles
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Which muscles have small motor units?
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Eye and finger muscles (large varying degrees of contraction/movement)
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Recruitment
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increasing number of active motor units (increases strength of contraction)
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All or none law
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There is no partial contraction of fibers--each muscle cell will contract to its maximum ability every time.
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Muscle tone
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Some motor units are active at any given time and some are not. (important so posture cells do not fatigue)
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Hypotonic/flaccid
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Decreased muscle tone/muscles are "limp."
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Hypertonic/spasticity
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Increases muscle tone/ Muscles are "rigid."
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Atrophy
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Loss of muscle myofibrils (caused by inactivity and denervation--muscle cells replaced by fibrous tissue)
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Hypertrophy
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Increased diameter due to increased muscle myofibrils (build up muscle protein)
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What requires ATP in muscle contraction?
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Myosin to detach from actin, power stroke, binding of actin/swiveling of myosin head, active transport of calcium, Na+/K+ pump to keep action potential going
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Anaerobic
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produces lactic acid and two ATP (fast glcolytic fibers)
*Sprinter would need this type of energy |
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Aerobic
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Produces CO2, 38ATP, water & heat
Slow oxidative fibers (cross country runner or jogger would need this type of energy) |
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myoglobin
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protein that binds oxygen and can hold O2 inside muscle cells
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How does neurotransmitter binding to receptors affect charge on motor end plate?
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binding causing protein channels to open up allowing sodium to rush into cell, which changes charge and start action potential.
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What is acetylcholine?
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Neurotransmitter involved in muscle contraction.
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How is acetylcholine removed from synaptic cleft?
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broken down by enzyme
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Events at neuromuscular junction:
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Action potential travels down neuron
opening channels in membrane which allow calcium to enter This causes release of neurotransmitter (Acetlycholine) out of vesicles in axon terminal by exocytosis Neurotransmitter diffuses across synaptic cleft And then binds to receptor on motor end plate |
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Synergists/antagonists of elbow flexion?
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Brachialis, Biceps Brachii/ Triceps brachii
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Prime mover of elbow extension?
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Triceps brachii
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Synergists/antagonists of elbow extension?
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Triceps Brachii (elbow extension)
Brachialis/Biceps Brachii (antagonists) |
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Prime mover of shoulder adduction?
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Pecoralis major
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Synergists/antagonists of shoulder adduction?
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Latissimus dorsi, Pectoralis major, Triceps Brachii/ Deltoid muscle, Subscapularis
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Prime mover of shoulder abduction?
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Deltoid muscle
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Synergists/antagonists in shoulder abduction?
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Subscapularis, Biceps Brachii (Synergists)
Latissimus Dorsi, Pectoralis major, Triceps Brachii (antagonists) |
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Prime mover in hip flexion?
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Iliopsoas muscle
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Synergists/anatgonists in hip flexion?
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Iliospoas, rectus femoris, Gracilis, Sartorius (Synergists)
Gluteus Maximus, Hamstrings (Antagonists) |
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Prime mover in hip extension?
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Gluteus maximus, Hamstrings
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Synergists/antagonists in hip extension?
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Gluteus Maximus, Hamstrings (Biceps femoris, Semitendinosus, Semimembranosus)
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Prime mover in knee flexion?
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Biceps femoris
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Synergists/Antagonists in knee flexion?
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Semimembranosus, semitendinosus, sartorius/ vastus lateralis, vastus medialis, vastus intermedius
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Prime mover in knee extension?
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Biceps femoris
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Synergists/antagonists in knee extension?
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Vastus medialis, intermedius, medialis/ Biceps femoris
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Prime mover in plantar flexion (ankle extension)?
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Gastrocnemius
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Synergists/antagonists in plantar flexion (ankle extension)?
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Soleus, Gastrocnemius (Synergists)
Tibialis anterior (Antagonists) |
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Prime mover in dorsi flexion (ankle flexion)?
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Tibialis anterior
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Facial muscles insert into:
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Skin
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Facial muscles are innervated by?
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Nerve VII (7)
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Bells palsy
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Sudden paralysis of facial nerves on one side
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Would muscle would cause extension of neck?
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Contraction of Trapezius muscle
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What three movements is pectoralis major responsible for?
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Flexion, adduction, and medial rotation of shoulder.
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Latissimus dorsi does what three movements to shoulder?
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Extends, adducts, and medially rotates
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Latissimus dorsi and Pectoralis major are synergists in what movements?
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Adduction of shoulder, medial rotation of shoulder
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What movements make latissimus dorsi and pectoralis major antagonists?
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Flexion (pectoralis), extension (latissimus)
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Muscles that make up rotator cuff:
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Supraspinatus, Infraspinatus, Subscapularis, Teres minor
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Which muscle of rotator cuff abducts shoulder?
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Supraspinatus
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Major function of deltoid muscle is:
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Abduction
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Major function of Biceps brachii is:
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Elbow flexion
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Brachialias muscle
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Flexes elbow
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Is triceps brachii a synergist or antagonist of the brachialis muscle? Why?
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Triceps brachii extends elbow--brachialis flexes elbow, so they are antagonists because of opposite movement.
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Abdominal muscles:
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Rectus abdominis, external olblique, internal oblique, transverse abdominis
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Which muscle helps flex the spinal column?
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Rectus abdominis
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Which muscles help compress abdomen?
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All four abdominal muscles
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Which muscles make up iliopsoas? What movement do they cause?
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Iliacus and psoas muscles--work together to flex hip.
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Parts of quadriceps muscle:
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rectus femoris, vastus lateralis, vastus medialis, vastus intermedius
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What does "Triceps" mean? Quadriceps?
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three & four "heads."
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Which of quadriceps muscles causes hip flexion? knee extension?
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Rectus femoris/ Vastus intermedius-lateralis
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Which nerve innervates quadriceps muscles?
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Femoral nerve
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Which of thigh muscles causes movement at both hip and knee?
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Gracilis & sartorius
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Iliotibial tract
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Stabilizes knee in extension and partial flexion
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Which thigh muscle only spans one joint?
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Tensor fasciae latae
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Difference between gluteus maximus and medius:
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Maximus laterally rotates hip, medius abducts hip
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Which one (of gluteus medius and maximus) is primary extender?
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Gluteus maximus
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Muscles of hamstrings?
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Semimembranosus, Semitendinosus, biceps femoris
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What two movements do hamstrings cause?
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Flexion of knee and extension of hip.
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Which of hamstring muscles is located on side of hip?
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Semitendinosus
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Gastrocnemius ___ the knee and _____ ankle.
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flexes/plantar flexes
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Muscles of triceps surae:
(both of these muscles form what?) |
Soleus, gastrocemius/ forms achilles tendon that inserts in calcaneal bone.
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Tibialis anterior causes what movement?
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Flexes ankle (dorsi flexion)
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Prime mover
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Major muscle that produces desired action.
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Antagonist
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Action opposite of prime mover
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Synergist
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Assists prime mover
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Fixator
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Stabilizes point of origin of prime mover
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Why would cadaver develop muscle contraction?
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Because of myoson still attaching to actin (using ATP but not having enough to detach, so gets "Stuck" in contraction phase)
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Which way does the Na+/K+ pump Na+?
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Outside the cell
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What are all possible energy sources in anaerobic contraction?
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Phospocreatine, Lactic acid, glucose
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How do muscle cells get oxygen?
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Myoglobin
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Primary energy source for aerobic contraction?
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Glucose--blood flow needs to be increased to muscles to produce more oxygen so that more ATP can be produced.
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What happens if muscle does not get enough ATP or oxygen?
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Fatigue results from low oxygen, low ATP, increased lactic acid.
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What do we do after fatigued?
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Pant!
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Oxygen debt
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Not enough oxygen can be taken in or pumped to meet body's needs.
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What will muscle cell do during recovery?
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replinish oxygen (build up myoglobin stores)
Get rid of lactic acid build up, replinesh glycogen, make new phosphocreatine |
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What is muscle twitch?
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One motor unit's response to one action potential.
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What is a myogram? Three parts?
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Graph of a twith (tensions v. Time)
Latent period/contraction period/ relaxation period |
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Refractory period
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Period where nerve is unable to respond to another stimulus after having been previously stimulated.
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Summation
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If muscle is stimulated right after refractory period but before it has completely relaxed, the second contraction is greater than the first.
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Why is second contaction greater than first in summation if muscle cell always contracts to maximum ability (all or none law)?
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Because it contracts maximally with whatever amount of calcium available.
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Tetanus
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Sustained muscle contraction with no relaxation.
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Treppe
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If the same stimulus is used, muscle will contract more forcefully after it has contracted several times.
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What factor leads to better contraction?
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Higher temperature
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Similarities between summation, treppe, tetanus?
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All due to increased calcium availability.
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Differences between treppe, summation, tetanus?
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Muscle not completely relaxed in summation, muscle not relaxed at all in tetanus, muscle completely relaxes in treppe.
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Isotonic contraction--example?
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Constant tension, muscle shortens
Ex. Picking up table |
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Isometric contraction--example?
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Tension increases, but muscle does not shorten.
Ex. Attempting to push or pull something vert heavy but not actually being able to move it. Force increases, but object is not actually moved, so muscle does not shorten. |
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How are skeletal and cardiac muscle similar?
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They both have alot of mitochondria for energy (ATP production)
They both have sarcomeres (they are striated) |
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Why is longer contraction and refraction important in cardiac muscle?
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Allows for steady heart beat, heart is completely relaxed before contaction again (no tetanus possible). Cardiac muscle also has no motor units, beats on its own.
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Why is it important that cardiac muscle can use lactic acid for energy?
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Lots of lactic acid is produced during exercise /activities and although muscles cells might be fatigued, heart can still use sources available for energy to keep heart pumping.
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What is cardiac muscle's capacity for regeneration and does it undergo mitosis?
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Does not undergo mitosis, very poor.
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How is smooth muscle unique and similar to skeletal muscle?
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It has no striations and better capacity for regeneration, and involuntary unlike skeletal, but has motor units similar to skeletal.
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Does smooth muscle have sarcomeres? What about its contraction time?
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No, non-striated/longer contraction time, begins slower.
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Does smooth muscle have myosin and actin?
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Yes, but no troponin
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