Physiology Test 2 Set C Flashcards
(57 cards)
the plasma membrane of a single muscle cell
sarcolemma
muscle cells are created by
myoblasts
single muscle fibers contain many
myofibrils
act as stem cells which can develop into myoblasts
satellite cells
invagination into the muscle cells that allows depolarizing current to reach interior of the cell
T-tubules
functional unit of the muscle
sarcomere
repeating pattern of crosswise light and dark stripes
myofibrils
light region with a dark Z line at its center
I band
darker region separating 2 I bands
A band
the position where the thin filaments of one sarcomere join onto those of the neighboring sarcomere
Z line
thick filaments consist of a long fibrous tail connected to a globular head
myosin
thin filaments made of a long string of these molecules contain a myosin binding site
actin
two types of thin filaments
troponin and tropomyosin
represents the middle of the sarcomere
M line
neither thick nor the thin filaments change in length during a contraction, shortening occurs because filaments slide with respect to each other
sliding filament theory
elastic properties, span distance between M and Z line
titin
not elastic, associated with thin filaments and stability
nebulin
what forms the actin filaments
g-actin
moving actin closer to M line
Power stroke
if no ATP is present, actin, and myosin get stuck together and a rigid muscle results
rigor mortis
the signal that initiates the contraction
the binding of calcium to troponin
the source of calcium in muscle cells
sarcoplasmic reticulum
calcium channels on the SR
ryanodine receptors
two components of muscle contraction
contractile components
elastic components