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46 Cards in this Set

  • Front
  • Back
bundles of muscle cells
connective tissue around indiv. muscle fibers
around fasicles
around entire muscle
flat sheet-like layer of tendon
plasma membrane of a muscle cell
places where the sarcolemma extends inwards into sarcoplasm; important in triggering muscle contraction
contracting unit of skeletal & cardiac muscle
motor neuron & all the muscle fibers it innervates
motor unit
junction of axon w/ muscle fiber
neuromuscular junction
motor end plate
modified sarcolemma at neuromuscular junction
most popular neurotransmitter (the one we ALWAYS talk about)
what hydrolyzes acetylcholine?
what drives muscle contraction (i.e, where does the energy come from)?
ATP hydrolysis
how is contraction in cardiac muscle different from in skeletal muscle?
it is much more dependent on calcium ions in the external medium
how do muscles relax?
ATP-driven calcium pump in the sarcoplasmic reticulum pumps calcium ions from sarcoplasm back into sarco. retic.
what is calsequestrin involved in?
muscle relaxation
why can't muscles relax after death?
detachment step requires ATP to bind to myosin head; there is no ATP
rigor mortis
muscles contract when a person dies b/c calcium ions leak from extracellular fluid into muscle fibers, exposing myosin-binding sites on actin
name 3 misc. muscle proteins
what step in cellular metabolism produces the most ATP?
oxidative phosphorylation
creatine phosphate
helps produce energy for muscle by building up creatine phosphate, the major source of energy in the first 8-10 sec of a sprint
phosphagen system
creatine phosphokinase transfers phosphate from creatine phosphate to ADP => more ATP for immediate use
4 steps to burn glucose
formation of acetyl CoA
Krebs cycle
oxidative phosphorylation
what provides oxygen for oxidative phosphorylation?
hemoglobin or myoglobin (in cardiac & some skeletal muscle)
energy for exercise comes from where?
ATP already in cell
creatine phosphate
anaerobic energy from glycolysis
aerobic energy from oxidative phosphorylation
oxygen debt = enough oxygen to ?
-convert lactate => glucose
-replenish ATP & creatine phosphate stores
-replenish O in myoglobin
endurance fibers in muscle
red b/c of myoglobin
generate aerobic energy
fatigue resistant
many mitochondria
fast fibers in muscle
generate anaerobic energy
susceptible to fatigue
temp. to qualify as a heat stroke
>105 degrees C
actin & myosin are ?
what plays an important role in excitation-contraction coupling?
the sarcoplasmic reticulum (& t-tubules)
thick filaments in a myofibril
thin filaments in a myofibril
A band has?
actin & myosin
Z line found?
between sarcomeres
I band has?
H band has?
M line?
middle of myosins
how do curare & a-bungarotoxin work?
binds to acetylcholine receptors so that acetylcholine can't bind to them; results in paralysis
how does botulinum toxin work?
prevents release of acetylcholine
what happens in myasthenia gravis?
patients develop antibodies against acetylcholine receptors in the neuromuscular junction
how do nerve gases work?
block cholinesterase, thereby increasing the AcCh in the synapse & causing asphyxiation
how does black widow venom work?
explosive release of AcCh
calcium ions bind to ? which causes a change in ? so that myosin can bind to ?
calsequestrin is found where?
sarcoplasmic reticulum, where it binds calcium ions