Exam 1 Flashcards
list the skeletal muscle components from inner-most to outer-most structures
myofilament myofibril myofiber fascicle whole muscle
list the connective tissue within the skeletal muscle from inner-most to outer-most layers
endomysium
perimysium
epimysium
what is the muscle cell?
myofiber
name the neurotransmitter that is released into synapses between adjacent motor neurons
norepinephrine
explain one situation in which ATP is needed during a skeletal muscle contraction
ATP allows for the myosin head to achieve the cocked position needed for the power stroke to occur
a change in cell membrane potential of greater than 15-20mV is called a(n):
action potential
in comparison to type II muscle, type I fibers would have a higher concentration of:
isocitrate dehydrogenase
what accounts for the less forceful contraction from a type I muscle fiber?
myosin ATPase is less abundant than in type II
the sarcoplasmic reticulum is less developed than in type II fibers
fewer active sites for which the myosin head can bind are revealed per AP than in type II
during the propagation of the AP, potassium leaves the cell during:
repolarization
which neurotransmitter is required for proper activation of the skeletal muscle at the level of the neuromuscular junction?
acetylcholine (ACh)
describe the steps of the sliding filament theory in the correct order
- action potentials spread across the sarcolemma
- down t-tubules
- calcium is released
- the active site for the myosin head is revealed
- muscle shortens
which skeletal muscle fiber type is the most fatigue resistant?
type I
a motor neuron and all fo the muscle fibers it innervates is known as:
the motor unit
which skeletal muscle fiber type has the largest motor unit, and the most developed sarcoplasmic reticulum development?
type II
what is typically the most abundant energy substrate within the body?
fat
in which state does the muscle have the capacity to generate the greatest amount of force?
eccentric
proteins are broken down via oxidation and enter these processes at the level of the:
Krebs cycle
which energy system has a SLOWER rate of energy synthesis?
beta oxidation
at REST, the substrate utilized to provide the body with energy is determined by:
mass action effect
what can be considered a rate limiting enzyme for the breakdown of glucose?
(think about what enzymes are used in glycolysis)
hexokinase (HK)
phosphofructokinase (PFK)
when the ratio of CO2 expired to O2 utilized is at or above 1, an individual is utilizing __________ as their primary energy source.
glucose/glycogen
the PCr reaction takes place within:
the cytosol of the cell
the ETC reaction takes place within:
the mitochondria of the cell
an individual is performing HIGH INTENSITY running intervals. what happens to the lactic acid that is produced during this workout?
70-75% of lactate is utilized as an energy source
it is shuttled to the liver and concerted into glucose via the Cori cycle
