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111 Cards in this Set
- Front
- Back
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What is external lamina?
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conn tissue
surrounds each muscle fiber delicate tissue |
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What is endomysium?
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conn tissue
surrounds each individual fiber thick layer |
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What are tendon aponeurosis?
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tough conn tissue merging of ends of cylindrical muscle fiber connecting to bone
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What are three types of aponeurosis?
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epimysium
perimysium endomysium |
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What are fasica?
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more general term for conn tissue that covers, supports, seperates muscle. Also unites with hypodermis(superficial fasica)
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What is a motor neuron?
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transmits directly to muscle
motor unit one motor unit controls thousands of muscle fibers |
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What is a neuromuscular junction?
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presynaptic terminal
neuromuscular cleft postsynaptic terminal |
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Describe the presynaptic terminal?
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thousands of synaptic vesicles
Aceytlcholine when AP initiated (ach) Action potential(ap) electrical impulse voltage gated ca channels |
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Describe neuromuscular cleft
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ACH released into cleft
Sodium ions in the cleft |
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Describe the postsynaptic terminal.
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motor end plate
ACH receptor sites Sodium rushes into sarcolemma(AP) Beginning of contraction when threshold is met |
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What is the aftermath of ap in muscle?
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ACH is broken down by esterase
acetic acid and choline reabsorbed by synaptic vesicle |
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What is the neuromuscular junction summary?
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AP--ACH released into cleft--AP on sarcolemma
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What is action potential of muscle called?
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excitation-contraction coupling
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If you want more muscle tension...
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Then you turn on more motor units
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What does exitation-contraction coupling involve?
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ca
neuromuscular junction sarcolemma sarcoplasmic reticulum T-tubules tropomyosin/troponin |
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What do T-tubules do in muscle contraction?
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extension of sarcolemma
extends into muscle fibers and conveys nerve signal that cause ca release from SR |
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What is sarcoplasmic reticulum of muscle contraction?
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Holds 2000 times more ca than sarcoplasm
releases ca |
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Describe muscle contraction by action potentional
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AP spreads like wave away from motor end plate in all directions over the sarcolemma to the t-tubules
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What does muscle impulse cause?
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ca to be released from sarcoplasmic reticulum to be released into sarcoplasm (ICF)
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When Ca is released what does it bind to?
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troponin of actin myofilaments
exposes actin |
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What happens after actin is exposed by ca?
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myosin heads bind to actin and contraction begins
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Is Atp used for myosin heads?
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yes
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What are energy sources that create atp?
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creatine phosphate(in muscle)
Glucose from glycogen(liver) Fatty acids (fats) Amino acids(body proteins) |
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Why does muscle fatigue occur?
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ATP depletion
cross bridges cannot function tension of muscle declines |
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What causes muscle soreness?
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Inflammation of muscle fibers
Edema of in extracellular fluid microscopic injury lactic acid accumulation |
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What is oxygen debt?
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oxygen taken in by body above what is required for resting metabolism after exercise
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How is the oxygen debt paid back?
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creatine to creatine phosphate
removal of lactic acid to glucose depends on intensity and time of exercise homeostasis returns |
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What are different type of muscle fibers?
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Slow twitch Type I
Fast Twitch Type IIa Fast twitch Type IIx |
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Describe slow twitch type I
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high oxidative red
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Describe fast twitch type IIa
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low oxidative white
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Describe fast twitch type IIx
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low oxidative white
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What is slow twitch type I for?
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contract slower
more blood supply fatigue resistant more mitochondria aerobic respiration |
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What does slow twitch muscle fiber contain?
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myoglobin
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What does myoglobin do?
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binds to oxygen as a reservoir and enhances aerobic respiration
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Where is slow twitch type I muscle fiber located?
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postural muscles and lower limbs
marathon running, swim, bike |
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What is fast twitch type IIa for?
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break down atp rapidly
cross bridges break and form rapidly Less blood supply low myoglobin/mitochondria anerobic respiration-glycogen |
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Where is fast twitch type IIa located?
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lower limbs
contracts shorter time-higher fatigue weight lifting |
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What is fast twitch type IIx for?
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lowest myoglobin
fewest mitochondria lowest blood supply highest anerobic respiration |
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What is fast twitch type IIx located?
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upper/lower limbs
has fastest atp breakdown |
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What is a muscle twitch?
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stimulus-contaction-relaxation sequence
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What are the three phases of muscle twitch?
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lag phase
contraction phase relaxation phase |
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What is the lag phase in muscle contraction?
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stimulus to motor neuron and the beginning of contraction
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What is the contraction phase of muscle contraction?
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contraction occurs
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What is the relaxation phase of muscle contraction?
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relaxation occurs
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What is the refactory period with regards to muscle contraction?
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insensitivity to other stimulus it cannot receive new stimulus during contraction
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What is the difference between a twitch and contraction?
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twitch accomplishes nothing and contraction needed for daily life
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What unit of time is a muscle contraction measured in?
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ms
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When a muscle fiber is given a minimal stimulus what will occur?
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the fiber with contract maximally (threshold stimulus)
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What is different with whole muscles when they receive a stimulus?
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They have a graded effect or staircase effect
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What is graded fashion?
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varying degress of contraction demonstrated by whole muscle
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What is a motor unit?
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single motor neuron and all the muscle fibers it controls
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What is stimulus? strength
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increase in strength=more motor units (muscles) contract
"motor unit recruitment" |
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What is stimulus frequency?
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increasing the frequency(#times/sec)of a threshold stimulus increases strength of contraction
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What is it call when individual waves begin to merge?
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summate
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What is tetany?
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continued contraction do to constant stimulus (summate) muscle will eventually fatigue
increase ca in myofibrils |
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WHat is isotonic?
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same tension
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WHat is isometric?
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same length of muscle
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characteristics of healthy muscle
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partially contracted like back legs head
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What is hypertrophy?
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muscle fibers increase in size, strength
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WHat is origin?
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muscle attachment to immovable bone
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What is insertion?
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muscle attachment to moveable bone
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What is flexion?
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decreased joint angle
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What is extension?
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increased joint angle
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What is abduction?
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move limb laterally away from median plane
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What is adduction?
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move limb medially toward median plane
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WHat is rotation?
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movement around the axis
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WHat is circumduction?
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movement of distal end of limb in wide circle
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What is dorsiflexion?
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bending top of foot upward
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What is plantar flexion?
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bending bottom of foot downward
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What is supination?
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turn palm/thumb upward and outward
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What is pronation?
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turn thumb/palm downward and inward
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WHat is inversion?
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turn bottom of foot medially
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What is eversion?
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turn bottome of foot laterally
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What is opposition?
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touching thumb to finger(s) on same hand
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what are muscles attached to?
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bone
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What do muscles maintain?
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tone
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How do muscle stabilize joints?
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muscle/tendon attachments across synovial joints
supports poorly fitting articulations |
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what muscles are used for respiration?
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thorax-moves rib cage
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how does muscle produce body heat?
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ATP is used in contraction of muscle By-product of atp synthesis is heat/body movement with contraction
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What communication in muscular system?
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nervous---> muscle
biocommunication |
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How do organs/vessels constrict?
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smooth muscle aids in digestion, secretions from organs, hear beat, blood flow
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What are four functional properties of muscle function?
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contractility
excitability extensibility elasticity |
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What are three types of muscle tissue?
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skeletal
smooth cardiac |
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What is muscle tissue specialized to do?
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contract
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HOw much body weight does muscle make up?
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40%
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What are fibers made of?
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cells
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What is skeletal muscle?
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long cylindrical fiber
several nuclei |
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What is skeletal muscle formed by?
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myoblasts
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What is skeletal muscle controlled by?
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single motor neuron
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How do fibers of skeletal muscle contract?
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some slow, others fast
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Where is smooth muscle located?
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organs, eyes, blood vessels, glands, skin
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How many nuclei does smooth muscle have?
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one
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Describe cardiac muscle?
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cylindrical/branched
one nuclei intercalated discs joining one another contracts to pump blood |
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What is whole muscle?
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organ of muscular system that can be isolated, identified
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What is whole muscle made of?
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fasicles
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What are some examples of whole muscle?
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biceps, gluteu maximus, pectoralis
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WHat is a muscle fasicicle?
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bundle of muscle fibers
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What is a muscle fiber?
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unit of many myofibrils
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What is a myofibril?
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elongated, striated contractile structure within muscle fibers
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What is a myofibril composed of?
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sarcomeres
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What is a sarcomere composed of?
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myofilaments
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What is a myofilament?
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actin/myosin used for contraction
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WHat wraps around thin protein filament actin?
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troponin and tropomyosin
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WHat is a thick protein filament?
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myosin
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What is a sarcolemma?
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Plasma (cell) membrane of muscle fiber
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What is sarcoplasm?
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Cytoplasm of muscle fibers (myofibrils)
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What is mitochondria in muscle?
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max. production of atp
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What is the nuclei of muscle fiber?
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single skeletal muscle fiber contains many nuclei
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What are two forms of conn tissue?
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epimysium
perimysium |
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Describe epimysium?
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tough conn tissue covering entire muscle
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describe perimysium?
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tougher conn tissue surrounding a muscle fascicle
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