Physiology Exam 3
the center of the a band is
H zone
what is the resting membane potential of a skeletal muscle?
-90
what is the resting membrane potential of a skeletal muscle fiber?
-90
cardiac muscle has how many nuclei
1-2
a thin filament contains
actin, troponin, tropomyosin
gluose is catabolized to generate
atp
glucose passes from the
blood
myoglobin is a red oxygen binding proteins only found
in muscles
where is creatnine synthesized
in the liver, kidneys, pancreas
when muscle fibers are relaxed do they produce more or less ATP?
more
when muscle fibers are relaxed they produce ______ atp than needed for resting metabolism.
more
myosin functions as what kind of protein
motor
after creatnine is synthesized it is transported where
muscle fibers
help switch the contraction process on and off
rgulatory proteins
the sarcoplasm is sorrounded by the
sarcolema
the plasma membrane of a muscle fiber is called
sarcolemma
the storage of calcium in a relaxed muscle is
sarcoplasmic recticulum
which muscle is multi-nucleated?
skeletal muscle
filamnets are
smaller structures within myofibrils
give myofibril extensibility and elasticity
structure
M line is formed by
supporting proteins holding thick filaments together
What causes repolarization in skeletal muscle?
the opening of potassium channels
what causes the depolorizing phase in skeletal muscle
the opening of sodium channels
ability of muscle fibers contract forcefully when adequately stimulated
contractibility
what proteins generate force during contractions
contractile proteins
excess ATP is used to synthesize
creatnine phosphate
what is the first source of energy when muscle contraction begins
creatnine phosphate
z discs are narrow plate shaped regions of
dense proteins
ability of muscle to return to its original length and shape after contraction or extension
elasticity
ability to respond to stimuli by producing action potentials that trigger movement
electrical excitability
ability to stretch without being damaged
extensibility
glucose passes from the blood into contracting muscle fibers via
facilitated diffusion
true or false: glycolosis requires oxygen
false
what are the roles of contractile proteins and an example?
generate force during contraction actin and myosin
what are the roles of regulatory proteins
help switch contraction process on and off troponin and tropomyosin
myosin is made of what kind of filaments?
thick
Myosin is made up of what?
thick filaments
h zone contain only
thick filaments
actin is made up of wat kind of filaments?
thin
the myofibiril contains
thin and thick filaments
a triad is formed by
transverse tubules and two terminal cisternae
myosin has thick filaments
true
the formation of ATP from creatnine occurs slowly, or rapidly
very rapidly
where is the flexible hinge is located
where the myosin head joins myosin tail
each myosin head contains how many bindingsites
2
a thick filament contains how many myosin molecules
300
calcium ions move tropomyosin away from the ____ on the actin molecules
myosin
what are the two types of contractile protein?
myosin, actin
the repolarizing phase in skeletal muscle is caused by the opening of
potassium channels