muscle physiology II Flashcards
ATP supply depends on _____ supply
oxygen
what do you add to ADP to make it ATP
phosphate
what does anaerobic fermentation produce
lactate (lactic acid)
how many ATP per glucose molecule does the mitochondria produce
36
what are high energy phosphates that can be used to make ATP called
phosphagens
when are phosphogens used as an energy source
are they aerobic or anaerobic
around the 10 sec mark
anaerobic
when youre at work, creatine and ATP make energy, what is the reverse process when youre resting
phosphocreatine + ADP
what transfers one phosphate from ADP to another ADP to make ATP and AMP
myokinase
what is an enzyme that adds a phosphate to something else
a kinase
what gets used up during the first 3 seconds of working out
oxygen from myoglobin
what gets used around the 2 min mark for exercise
the glycogen lactate system (anaerobic, only produces 2 ATP/glucose, produces lactic acid so youre sore)
what respiration are you using when youre doing endurance training
aerobic respiration
rank the types of energy usage from:
3 sec
10 sec
10 sec- 2 mins
30 mins
beyond 30 mins
oxygen from myoglobin
phosphogen system
glycogen lactate system
aerobic respiration using glucose and FA
aerobic respiration just FA (glucose depletion)
in exercises lasting longer than 10 mins, ___% of ATP is produced aerobically
90
what is the term for when muscle growth is stimulated from cellular enlargement
happens in body builders
hypertrophy
does skeletal muscle undergo mitosis to get bigger
no
what 2 things do slow twitch muscles have more of than fast twitch muscles
what do they have less of
mitochondria
density of blood capillaries
sarcomeres
marathon runners have a higher ____ ____ ____ count than the average person
red blood cell
how do muscles get smaller with age or the cessation of exercise
contractual proteins get broken down
what is the term for age related muscle loss
sarcopenia
after age 30, how much muscle does one tend to lose per decade
3-5%
what accumulates in muscles that allows for fatigue during high intensity workouts
K
what releases calcium into skeletal muscle fibers
the sarcoplasmic reticulum
what 2 things being depleted lead to fatigue in slow twitch muscles/ duration training
fuel depletion
electrolyte depeltion
what part of the body can get fatigued during endurance training that isn’t muscles
the central nervous system
brain motor neurons inhibited by exercising muscles release ______, which is linked to fatigue
ammonia
what is the amount of oxygen the an individual can utilize during intense exercise called
what are its units
maximum oxygen intake (VO2)
kg/min
every muscle contains a ____ of fiber types
mix
slow twitch fibers are also called
slow oxidative fibers
slow twitch muscles have _____ myoglobin than fast twitch fibers
more
which muscle fibers are more red
slow twitch
which muscle fibers are recruited for movement first
why
slow twitch
size principle; theyre smaller so they go first
do most humans have fast glycolytic fibers or fast oxidative fibers
fast glycolytic
bigger muscles have more ______
sarcomeres
what do fast twitch muscles have more of (2)
sarcomeres
glycogen reserves
large motor units have more FG fibers/ power, but less _____
control
what 2 things do fast oxidative fibers have more of (think about it)
what color are they
myoglobin
blood vessels
red
what is the term for being able to contract rhythmically and independently of the NS
autorythmic
what two things does the autonautic NS control for the heart
heart rate
contraction strength
musle cells in a given heart chamber contract in _____
unison
what type of muscle fibers are shorter, thicker, and branched (relative to skeletal muscle)
cardiac
how many nuclei are in a given cardiomyocyte
1 or 2
what two types of facia do heart muscle cells lack
perimysium
epimysium
what type of respiration does the heart use
aerobic
heart muscle cells have large _______
mitochondria
what do heart muscle cells get replaced with after their loss
scar tissue
in heart muscle cells, what is less developed and what is larger (relative to skeletal muscle)
sarcoplasmic reticulum less developed
larger T tubules
what are tiny channels that allow the rapid passage of ions between cells in the heart
gap junctions
what are intercellular junctions in heart muscle cells that provide strong adhesion between cells
desmosomes
what joins cardiomyocytes together
intercalated discs
what layer is on the outside of a smooth muscle
what layer is on the inside of a smooth muscle
longitudinal
circular
how do smooth muscles modify pressure and flow of blood in the circulatory/ respiratory system
dilating or constricting
goosebump muscles and the iris contain _____ muscle
smooth
what shape are smooth muscles
fusiform
how many nuclei do smooth muscle cells have
1
how many nuclei do skeletal muscles have
many
how does smooth muscle regenerate
mitosis and hypertrophy
what type of muscle has a net like structure of myofilaments
smooth muscle
what type of muscle cels lack nerve supply
smooth muscle
what is the equivalent to a z disc in smooth muscle cells
dense bodies
in smooth muscles,
what filaments are attached to dense bodies
what filaments are dispersed throughout the cytoplasm
actin
myosin
what contain synaptic vesicles in smooth muscle that allow for ACh to be responded to
varicocities
what are the flask like invaginations on smooth muscle that increase surface area
caveolae
what does unitary mean in reference to smooth muscle
requires only 1 or 2 nerve fibers to activate an entire sheet of smooth muscle
what does multiunit refer to in smooth muscles
each myocyte contracts independently and has its own neuron
what type of smooth muscle contains gap junctions
unitary
what type of smooth muscle does not have gap junctions
multiunit
why is a smooth muscle contraction much slower than skeletal muscle
slow to break up ATP
what is it called when smooth muscles contract at regular intervals
audtorhythmicity
how does smooth muscle make most of its ATP
aerobically
what type of muscle does not contain myofibrils or sarcomeres
smooth muscle
where does smooth muscle get its calcium
extracellular fluid
sarcoplasmic reticulum
what type of muscle does not have T tubules
smooth muscle
what protein does calcium bind to on smooth muscle
CaM
after calcium binds to CaM in smooth muscle, what happens to it
it activates a myosin light chain kinase (MLCK)
what happens after CaM activates MLCK
it adds a phosphate group to the myosin and myosin can then break ATP up so that it can perform its action
for smooth muscle relaxation, what 3 things must happen
calcium must leave the cell
Ca dissociates from CaM
a phosphate is removed from myosin
what enables myosin to remain attached to actin for a prolonged time without consuming more ATP
what muscles do this
latch bridge mechanism
smooth muscle
what is tetanus tonic contraction
smooth muscle tone
what happens in the GI tract that causes Ca channels to open
mechanical stretching
what is it called when a smooth muscle is stretched and it briefly contracts and resists, but then relaxes again (happens in the urinary tract so you dont pee yourself when your bladder is stretched)
stress relaxation response
what are 2 reasons smooth muscle can contract even when its stretched
there are no z discs
myosin heads are everywhere in the muscle so they can attach anywhere and produce a strong response
what is a muscles ability to adjust its tension to the degree of stretch
plasticity
