Exam 2 Flashcards
one advantage of using immediate energy sources?
able to get energy quickly (highest rate of energy transfer). 6-8x as fast as an aerobic pathway
one disadvantage of using immediate energy sources?
amount of storage is finite
after stored muscle glycogen and CP system is used, what is used to make ATP
glycogen (stored in the muscle). glycolysis…turning glycogen into ATP
during activities less than ____%of VO2 max lactate accumulation=lactate disappearance because lactate is being converted to pyruvate bc there is oxygen present
50%
between which time interval is lactate accumulation the highest in high intensity activities
60-180 sec (1-3 min)….during glycolysis
how long can we do exercises using stored reserves (Stored ATP and CP system)?
1 minute max
after 50% VO2 max, which pathway is mostly being used?
Anaerobic
describe tissue hypoxia and how it causes problems in the body
it is when the glycolytic mechanism predominates and we get too much NADH produced for the oxygen available. not enough oxygen available to accept the hydrogen being produced, so lactic acid forms.
___% of Lactic acid is used to create energy elsewhere (heart, other muscles, liver, etc)
70%
__% of Lactic acid is converted to glucose
20%
__% of Lactic acid gets converted to amino acids
10%
which type of muscle fiber has the most LDH
2b (fast glycolytic)
what does LDH do?
if converts lactic acid to pyruvic acid (removes the hydrogen to lactic acid)
what is the blood-lactate threshold
when lactate levels in the blood start to accumulate
how does the blood-lactate threshold increase through training? (3 things)
- ) training adaptations occur….endurance training increases the number of capillaries in the body, size of mitochondria, etc.
- ) Faster removal of lactate….neighboring cells respond to constant levels of high lactate levels during training by increasing their metabolites to remove the lactic acid
- ) some people may have a genetic endowment to have increased blood flow to the muscle or a greater number of mitochondria in the muscle)
do endurance or power athletes experience a 20-30% incr in the amount of lactic acid they can produce
power athletes
why do training people have the capacity to produce higher levels of lactic acid (3 things)
- ) improved motivation
- ) increased intramuscular glycogen stores…more glycogen in the muscle glycogen means larger muscle size
- ) increase in glycolytic enzymes
have to switch to aerobic pathway after how long maximum?
3 minutes max
why can’t steady state actually go on forever?
- ) because we would eventually deplete our energy supply (carbs, fats, proteins) needed for the energy production pathways
- ) loss of hydration…exercise duration shorter in hot climates
- ) the amount of stored glycogen is a limiting factor…muscle glycogen is the only type of glycogen that powers exercise
balance between energy production and energy demand=
steady state
why doesn’t steady state occur immediately?
anaerobic pathways are doing the work before going to steady state. (think: takes time for body to get oxygen into the cells, so have to rely on other ways to produce energy)
why does the shift to aerobic pathways occur
**the consumption of oxygen is proportional to the need for atp….production makes demand
do endurance athletes, power athletes, or both types reach a steady state faster (have less of an oxygen deficit)
endurance only!! endurance training allows one to almost go directly into the aerobic pathways
why do endurance athletes reach steady state faster (have less of an oxygen deficit)?——-3 things
- ) more rapid increase in bioenergetics…this means they have more enzymes that shift them toward aerobic cycle and away from lactate production
- ) increase in overall cardiac output….increase in blood flow means greater exchange happening at the lungs so oxygen can get into and around the body quicker
- ) get better at shunting the blood to the active tissues (tissue perfusion)
maximal aerobic power is the same thing as____
vo2 max
maximal oxygen consumption is____
vo2 max
what does vo2 max quantify?
person’s ability to produce energy via the aerobic pathway
does vo2 max incr or decr w/ age?
decr
do young men or young women have a higher vo2 max?
young men
do older women or older men have a higher vo2 max
older women (vo2 max become more similar as we age…between genders)
what are some physiological changes that contribute to an incr in vo2 max?
(6 things)
- ) Incr pulmonary ventilation
- ) incr hemoglobin concentration
- ) incr blood volume
- ) affecting cardiac output (stronger heart)
- ) changes in peripheral blood flow
- ) incr in aerobic enzyme concentration
low myoglobin content in found in______fibers which is _______muscle
fast glycolytic (2b), white
red muscle means what?
high myoglobin content (and oxidative)
stop and go sports would use what muscle fiber type a lot?
type 2a (maintain both types of fibers for most sports)
rate of recovery for light aerobic exercise?
rapid recovery because there was a rapid attainment of steady state, so not much oxygen deficit and not much lactic acid being produced….fast component is the only thing seen here
rate of recovery for moderate to heavy exercise?
both fast and slow component seen bc lactic acid does accumulate. longer recovery time because it took a bit longer to reach steady state
rate of recovery for maximal exercise?
no steady state is ever produced, there is lots of lactic acid accumulation so a large slow component to remove the LA from the body
recovery time is dependent on both intensity and duration but MAINLY
Intensity
what are some other factors aside from intensity that influence recovery time?——5 things
- ) Body temperature….the more we heat up during exercise, the longer it takes to recover.
- ) Reloading lungs….have to get air back into the lungs in the same proportion as before exercise
- ) Reloading myoglobin
- ) Elevated Heart Rate…heart needs to have energy consumption to make it beat
- ) Tissue repair…need oxygen to repair damaged tissues
active recovery good for??
non-steady state things (done to remove the lactic acid)
passive recovery good for??
steady state—bc we want a process that will resynthesize phosphate and replenish oxygen in the body. so doing nothing is ideal to allow oxygen to be replenished in the body
what is Dalton’s law?
percent contribution of gas in a mixture makes up the total pressure
how does Dalton’s law relate to gas exchange at the lungs?
this shows that not all gases will be able to reach the lungs equally/not all gases have the same effect
describe H20, N2, and O2 levels of air in the trachea compared to the atmosphere
H20….incr
N2….decr
O2….decr
hydration of the air occurs____
in the trachea
describe H20, O2, and CO2 levels in alveoli compared to trachea
H20…constant
O2….decr again
CO2….gained LOTS
how does the composition of the air in the alveoli stay constant
functional residual capacity (air that always stays in the lungs)
Henry Law says what
the amount of gas dissolved in solution varies depending on the pressure
what two things affect movement of gases into and out of the lungs?
pressure differential and solubility of the gas
net movement of gas goes from…
high to low pressure
which is more soluble co2 or o2
co2 (25x more soluble)
which is at a higher pressure co2 or o2 (thus wants to move to a lower pressure0
o2
why is partial pressure of oxygen in the blood lower than that of the alveoli (lungs)?
venous admixture
factors that impair gas transfer? (2 things)
- ) thickened alveolar membrane (particulate matter)
2. ) reduction of surface area of alveoli (emphysema caused by smoking)
why do we always maintain co2 levels in the blood?
ventilation is controlled by co2 levels, so co2 tells us how hard we need to breathe. if co2 levels are high the pons/medulla oblongata are activated to stimulate the respiratory center
how many HEMES total in hemoglobin
4
endurance athletes can suffer from what type of anemia?
Iron deficiency
why does endurance training cause one to suffer from fe deficiency anemia?
long distance training reduces fe content so they have to make sure they consume lots of iron in their diet
what is cooperative binding?
the binding of one oxygen to hemoglobin promotes binding of more and more hemoglobin. hemoglobin wants to be fully saturated with 4 oxygen total
hemoglobin will not give up oxygen until the partial pressure of oxygen gets below what %?
60%
what is the Bohr effect?
an increase in plasma acidity (or an increase in body temperature) that causes hemoglobin to give up oxygen to the tissue more easily (this shifts the curve down and to the right). note: the change in pH is caused by the accumulation of lactic acid
hemoglobin doesn’t give off more than ____% of what it has
70%
why does hemoglobin stay 70% saturated even after offloading oxygen at tissues
because it needs to have a reserve….just in case
what are the 2 methods to change the amount of perfusion happening?
- ) change the amount of blood to certain place that need it (shunting)
- ) hemoglobin more likely to give up oxygen to active than inactive tissues
why is hemoglobin more likely to give up oxygen to active over inactive tissues?
active tissue is using up its oxygen, so the gradient is greater.
what is 2,3 dpg?
a byproduct of lactic acid being produced in the rbc
what does 2,3 dpg do?
it binds to hemoglobin, and lowers hemoglobin’s affinity to oxygen…..it makes oxygen more available to the tissues
do women or men have higher levels of 2,3 dpg?
women
describe myoglobin and why it can pull oxygen off of hemoglobin
myoglobin is the muscles way of storing oxygen and it has a 240x greater affinity for oxygen than hemoglobin, so that is why is can pull oxygen off of hemoglobin
What does it mean that there is no Bohr effect with myoglobin?
the binding affinity of oxygen to myoglobin is not affected by changes in pH or temperature
co2 binds to the _____part of hemoglobin
globin (the amino acid)
60-80% of the co2 in the body functions as________
bicarbonate ions
what percentage of co2 is carried via carbaminohemoglobin?
15-25%
what is the Haldane effect
as oxygen binds to hemoglobin at the lungs, this removes co2
how does the Haldane effect increase exchange at the lungs?
as oxygen move on, co2 moves off
what are the three ways in which the rate and depth of breathing are regulated
- ) neural controls
- ) humoral controls
- ) neurogenic effects
where are the inspiratory centers located?
medulla oblogata
how do neural controls regulate breathing?
stretch in the lungs is monitored and each time they are activated, inspiration is shut off and expiration is shut on
what is the primary regulator in the breathing cycle?
stretch
name 4 rhythm modulators of breathing
- ) chemoreceptors
- ) muscles and joints
- ) irritation receptors
- ) emotional responses like pain or a cramp
how do chemoreceptors modify breathing rhythm
by monitoring the concentration of co2
how do muscles and joints modify breathing rhythm
incr breathing when muscles and joints are activated bc more co2 released and more o2 needed
how do irritation receptors modify breathing
turn off breathing when cough or sneezing happens to prevent irritants from getting into the body
when at rest, what controls pulmonary ventilation the most?
blood concentration (co2 is the most important AT REST)
describe how neurogenic factors modify breathing rate
signals from the motor cortex telling the muscles to contract (or prepare to contract) can increase ventilation or sensory inputs from joints, tendons, and muscles can adjust ventilation
describe cortical influence on breathing rate
nerve signals from the motor cortex causing us to breathe faster
describe peripheral influence on breathing rate
sensory inputs from muscles causing us to breathe faster
do we incr breathing when we get slightly hotter?
no, breathing rate will only change when temp gets super high
offloading of oxygen out of the lungs is due to_____
pressure
offloading of co2 from body to lungs is due to_____
solubility
does depth, rate, or both change with steady state activities
depth
describe ventilation in non-steady state
not linear relationship between oxygen consumption and ventilation
why isn’t there a proportional increase between oxygen consumption and ventilation in non-steady state activities
some of the oxygen taken in is being used to remove the lactic acid accumulating and NOT being used to fuel the active muscles
ventilation threshold=
the highest exercise intensity/oxygen consumption without producing 1mmol of lactic acid
will you reach vent threshold in steady state and why?
no, because no lactic acid is being produced
VT is a product of
exercise intensity
VT is a good indicator of______
endurance performance
lactate threshold=
point at which blood lactate levels increase rapidly. lactate production becomes greater than lactate clearance
is there a big cost to breathing during rest
no
is there a big cost to breathing during exercise
yes, a 15% increase in blood flow from rest
does exercise causing respiratory system adaptations
no
exercise induced arterial hypoxia=
associated w/ endurance athletes. as we breathe deeper and panting we are not getting as much air into the alveoli, and less gas exchange occurs in the lungs with distance training
bicarbonate buffers where
plasma
phosphate buffers where
inside cells (intracellular fluids)
proteins buffer where
in the plasma AND in the cells
what has the greatest impact on buffering?
hemoglobin (a protein)
why is maintaining pH important
to maintain proper exchange in the blood
prevent changes in pH
chemical buffers
act once the pH of the blood has been changed
physiological buffers
what has a larger effect chemical or physiological buffers?
physiological buffers
which physiological buffer has the greatest effect
ventilatory
what is the goal of increasing the rate of breathing
to remove more co2
what does the renal physiological buffer do?
remove other acids other than co2 via urine for excretion
how do resistance exercises affect bp?
they incr bp bc the muscle is straining and the artery is compressing
how do resistance exercises affect blood flow
decr blood flow due to peripheral resistance
how does the sympathetic nervous system respond to less blood flow going to an active muscle
it incr Cardiac Output which incr MAP as well
what is the bp adaptation to resistance work
as we do more resitance work our blood pressure will decrease
what do the blood vessels do during steady state exercises
they dilate and decr peripheral resistance to allow more blood to flow in
does bp still incr during steady state exercises
yes bc muscles are still having to contract
is there a change in systolic, diastolic, or both during steady state exercises
only systolic
why does bp go up to 140-160 and then decline after first few min
declines due to peripheral resistance
how does graded exercise affect bp
systolic incr w intensity….diastolic can actually drop a little
why does using the arms and legs affect bp?
larger bp when using arms bc muscles in arms are smaller than muscles in legs and this increase the peripheral resistance
true or false: diastolic and systolic increase when using arms and legs
true
when do both systolic and diastolic bp incr
when using both arms and legs
what is the hypotensive response
reduction in blood pressure below pre exercise levels
why does the hypotensive response occur
bc blood is still in the muscles and not back to heart yet. there is less blood in circulation (blood volume is changing)
___% of blood in the chambers supplies the heart
5%
does heart have more or less oxidative capacity of skeletal muscles
more (3x more)
what makes the heart have more oxidative capacity than skeletal muscles
more mitochondria
what does RPP measure
how hard the heart is working
how is RPP determined
peak systolic bp x HR.
what is used for energy by the heart at rest
glucose/glycogen and fatty acids
describe functional synctom in the heart
once we have depolarization in one cell in the heart it spreads over the adjacent cells and lets the heart contract as one. this occurs bc of the leaky cells
p-wave
depolarization of the atra
QRS complex
depolarization of ventricles and repolization of atria
t-wave
repolarization of atra
describe the heart’s role in dual innervation
sympathetic and parasympathetic fibers go to the same parts of the body but usually have antagonistic effects
parasympathetic fibers mostly run to______
atria
sympathetic fibers mainly run to_____
ventricles
what is the ionotropic effect?
an incr in the heart’s contractility due to the release of catecholamines
what is the chronotropic effect?
an incr in HR due to the release of catecholamines
what effect does Ach have on strength of contraction
NONE
What effect does ach have on HR
decr it
the amount of incr in hr is dependent on what two things
duration and intensity of exercise
what area of the brain provides us with the greatest control over HR
somatosensory portion of brain
why is checking bp on the carotid artery a problem
bc putting pressure on the artery changes pressure of blood inside the artery and this can cause HR to be reduced (vagal tone incr)
factors that can affect preload of heart?
venous return and filling time
factors that can affect contractility of heart
hormones (epinephrine and norepinephrine) and autonomic innervation
factors that can affect afterload
vasodilation or vasoconstriction
3 factors that affect SV
preload, contractility, and afterload
SV =
EDV-ESV
describe direct fick
stick a needle in artery and vein to determine the difference in oxygen concentration to measure cardiac output (arterial-venous oxygen levels in the denominator)
how does direct spirometry work
it measures o2 consumption by how much oxygen they consume (still measures cardiac output)
describe indictor dilution
a known quantity of inert dye is injected into a vein. then samples are drawn from the arterial side to see how dilute the dye is. the dilution represents the outflow from the heart (more dilute= higher cardiac output)
describe co2 rebreathing
someone keeps rebreathing the same air to look find the point when co2 reaches equilibrium in the alveoli
why is cardiac output lower in women
smaller body size
what is the HR for an average person
70 bpm
what is the average stroke volume
50, 60 mL for female and 70mL for male
why does the training adaptation for a lower HR occur for endurance athletes
because of the release of Ach. Ach lowers HR (since the HR decr, SV incr)
Is max hr higher or lower in athletes vs sedentary
lower
is max SV lower or higher in athletes vs sedentary
higher
why is exercise SV greater in athletes than the sedentary?
- ) enhance cardiac filling followed by more systolic contraction (intrinsic to cardiac muscle)
- ) normal ventricular filling with a subsequent forceful ejection during systole (sending more sympathetic signals to ventricles)
- ) training adaptation that incr blood volume (training causes an incr in blood volume)
