exam 2 Flashcards
energy expenditure equation
fuel+O2= energy+heat+CO2+h2o
heat
direct calorimetry
O2 and CO2
indirect calorimetry
40% of substrate energy from
ATP
60% of substrate energy from
heat
direct calorimetry
measures energy expenditure directly t
indirect calorimetry
measures metabolic gases to indirectly measure energy expenditure
measuring energy expenditure =
estimates the total body energy expenditure based on O2 used and CO2 produced
O2 used in
ETC
CO2 is produced in
Krebs and PDH
VO2
volume of O2 consumed per minute
calculating VO2=
volume of inpsired O2 -volume of expired O2
why does venous blood have lower O2
tissues have consumed the oxygen out of it
VCO2
volume of CO2 consumed per minute
calculating VCO2=
volume expried -volume inpsired
whis is CO2 breathed out larger than CO2 breathed in
CO2 production in bioenergetics and the extra CO2 enters the blood as a waste product
venous blood CO2 content is
high
arterial blood CO2 content is
lower
(A-V) O2 difference
subtracting arterial from Venous and getting O2 difference
lowest VO2 =
resting or RMR
highest VO2 =
VO2 max
everytime RER =0.80
RER eq. = 4.80 kcals/ L O2
everytime RER= 0.95
RER eq. = 4.99 kcals/ L O2
Maximal VO2 uptake (VO2 peak)
point at which O2 consumption doesnt increase with further increase in intensity
aterial blood O2
highest because blood has just gone through the lungs
venous blood O2
lowest because blood has passed through the tissues
Vo2 max best measures
fitness
adaptions that can increase VO2 peak
- increase mitochondria
- increase hemoglobin
- increase mypglobin
- add capillaries
absolute VO2 peak
L/min
better used in non weight bearing actiives
relative Vo2 peak
ML/kg/min
most accurate when comparing
-body sizes
-body composition
-sexes
criteria for reaching VO2 max
- plataue in O2 uptake
-< 2 ml/kg/min difference during last 2 minutes - HR
->95% max HR - RER > 1.10
2 of 3
how to find predicted HR
220-AGE
VT
Point at which VE/Vo2 begins to rise disproportionately and without a corresponding increase in VE/VO2
-follows lactate threshold
when ventilation begins to increase disproportionately
ventilatory threshold equivalents
VE/VCO2
VE/VO2
lactate threshold
when lactate begins to appear in the blood
mitochondria consumes
pyruvate but all of it that cannot be consumed spills over into the blood
fatigue after VT and LT
increase acidity (decrease in Ph)
increase in H
buffering capacity is overwhelmed
acidity inhibits which bioenergetic pathways
glycolysis, krebs and ETC
VT and LT indicate
performance
indirect calorimetry limitations
- CO2 production may not =CO2 exhalation
- RER inaccurate for protein oxidation
- lactate use a fuel produces RER about 1.0 due to CO2 exhalation
- gluconeogenesis produces RER <0.70
1 L O2/min =
5 kcals
1 met =
3.5 ml/kg/min
light intnesity =
< 3.0 mets
medium intensity =
3.0-5.9 Met
high intensity =
> 6.0 met
metabolic rate =
rate of energy used by body
RMR
rate of energy used at rest and to sustain life
steady state
when the work is constant
VO2 consumption, metabolic rate, and VO2 increase with
exercise
O2 deficit
O2 demand is greater than O2 consumed
pathways that supply energy during O2 deficit
PCR and glycolysis
EPOC
represents that difference between O2 consumption and O2 demand
-O2 consumed is greater than demand
reasons for EPOC
- elevated hormones
- oxidizing lactate
- thermoregulation
- ion redistribution
- elevated breathing and HR
anaerobic sports
high intensity
short duration
bioenergetics - PCr, glycolysis (incomplete)
successful endurance athletes have
High Vo2 max
high LT
high economy of effort
high % of type 1 fibers
high LT =
better endurance performance
fatigue
decrements in muscular performance with continued effort
2. inability to maintain required power output to continue muscular work at given intensity
fatigue causes
- inadequate energy delivery
- accumulation of metabolic pathways
- heat
- altered neural control of muscle contraction
inadequate energy delievery
Phosphocreatine depletion
PCr is used for short term intensity
glycogen depletion =
hitting a wall
fiber type recruitment
Type 1 first
type 2a (moderate-high Intensity)
type 2x recruited last (maximal intensity)
H+ accumulates during a brief high intensity exercise causes
a decrease in muscle PH
Altered neural control of muscle contraction
failure may occur at the neuromuscular junction, preventing muscle activation
endocrine system
message delivery system
hormone-producing tissue
glands and pancreas
target cells
cells that a hormone communicates with
non steroid hormones communication
binds to an exterior cell membrane
-stimulates secondary messengr
non steroid hormones are made from
amino acids and not lipid soluble
protein/peptide hormones
insulin, glucagon, growth hormone
amino acid derived hormone
thyroid hormones, adrenal hormones, epinephrine and norepinephrine
steroid hormone communication
all hormones deliver a message inside the cell
steriod hormones are made from
cholesterol
lipid soluble
examples of steroid hormone
adrenal hormone (cortisol) , sex hormones
homeostasis and feedback system
- stimulus
- receptor
- control center
- effector
- stimulus reduced
the primary role of the endocrine system is to maintain body homeostasis
-blood sugar
-body temp
-metabolism
-blood calcium
-blood pressure
-hydration
negative feedback loop
increased output from system; inhibits system output
stimulus
homeostasis deviation from set point
control center
trigger whatever can fix it
effector
resolving the problem
more hormone means greater
action
hormone action is dependent on
the number of working receptors
receptor amount can change due to
up and down regulation
upregulation
increase number of receptors
downregulation
decreases number of receptors
steroid receptors are found
inside the cell
steroid hormone binds to
DNA and regulates mRNA to transcription and translation
Nonsteroid hormone receptors are
second messengers
common secondary messenger
cAMP
anterior pituitary gland located
inferior to hypothalamus
___ causes anterior pituitary glands to secrete
exerecise
GHRH releases
GH from anterior pit gland
GH
anabolic
-promotes muscle growth
-stimulates fat metabolism via lipolysis
thyroid gland located in
neck and trachea
thyroid gland releases
T3 and T4
order of how thyroid gland releases hormones
- hypothalamus is stimulated by exercise
- that releases TRH
- anterior pituitary releases TSH
- travels to thyroid and stimulates T3 and T4 release
T3 and T4 lead to increases in
Metabolic water, protein synthesis, # and size of mitochondria, glucose uptake by cells
Exercise increases TSH release which increases
T4 releases
Adrenal gland releases
catecholamines (fight or flight)
-epinephrine
-norepinephrine
-Cortisol
epinephrine and norepinephrine are released by
nervous system
catecholamine release increases
HR, Contractile force, BP, glycogenolysis, lipolysis, blood flow
once the hypothalamus is stimulated it releases CRH which causes the Anterior pituitary to
release ATCH which then releases cortisol
functions of cortisol
increase protein catabolism
-decrease in protein synthesis
-decrease in muscle mass
pancreas
releases insulin to correct blood sugar
insulin is a ___ hormone
anabolic
-helps store excess energy from a meal
inhibits catabolic processes
glucago is a ___ hormone
catabolic
-helps makes energy available for muscles
anabolic and inhibits catabolic
glycogenolysis, proteolysis, lipolysis
glucagon
raises blood glucose
target cells for glucagon
liver and skeletal muscle
catabolic hormones
liberates stored nutrients
catabolic hormones are released during
exercise
hormones that help maintain available glucose via glycogenolysis and/or gluconeogenesis
-glucagon
-epinephrine
-norepinephrine
-cortisol
glycogenolysis
glycogen breaks down into glucose
lipolysis is stimulated by
-decrease in insulin
-increase in epinephrine
-increase in norephrphine
-increase cortisol
-increase GH
stimulate lipolysis via
HSL
respiratory system purpose
to bring O2 into and remove CO2 from the body
respiratory system is carried out by
- pulmonary diffusion
- pulmonary ventilation
- gas exchange
exchange zone
alveoli and capillaries
gase diffuses from
high to low concentrations
arterial blood
high PO2
low PCO2
venous blood
low PO2
high PCO2
pulmonary gase exchange 2 major functions
- replenish blood oxygen
- removes carbon dioxide
blood path =
right ventricle to pulmonary arteries to pulmonary capillaries to pulmonary veins to left atrium
only 1/3 of lungs is filled due to
vascular shunting
top 2/3 of the lungs open during
exercise
vascular shunting releases because
relaxing of arteriole smooth muscle
gas exchange at the muscles =
capillary diffusion
myoglobin transports within
muscle
-protein with one Heme (FE)V
hemoglobin transports O2 from
lungs to muscle
loading
hemoglobin binding to O2
unloading
hemoglobin letting go of O2
hb has a tight group on O2 in the
lungs
hb has a weak group on O2 in the
muscle
myoglobin has a ____ for PO2
high affinity
myoglobin does not have
cooperative binding
factors influencing O2 delivery and uptake by the muscle
- O2 content of blood -higher O2 content of blood creates a larger gradient for tissue exchange
- blood flow - decrease blood flow =decrease in opportunity to deliver O2 to tissue
- local conditions (ph, temperature, PCO2)
transport O2 into blood by
hemoglobin
cooperative binding
the more HB binds to O2 the higher its affinity for all 4 O2
Hb is loaded with O2
at the lungs and pumped to the systemic circulation
hemoglobin unloading
decrease in PO2 causes HB to unload
bohr effect
increased affinity=less unloading (Left shift)
decreased affinity= more unloading (right hift
more acidic =
more unloading
increase temperature
promotes tissue O2 unloading during exercise
PCO2 increase =
increased blood CO2= HB curve shifts to right = more unloading
transport of CO2 in the blood in 3 ways
- as bicarbonate ions
- dissolved in plasma
- bound to Hb (carbaninohemoglobin)-
O2 binds to the ___ portion of HB
heme
CO2 binds to the ___ portion of HB
protein
acid
high PH
low H
basic
low PH
high H
buffering
soak up all the H
cardiovascular system purpose
- transportation -O2 and nutrients
- Removes CO2
- transports hormones
- enables homeostasis
5.immune function
3 major circulatory elements
- a pump
- pipes and tubes
- a fluid
arterial circulation
blood moving away from heart
-oxygenated
venous circulation
blood is moving towards the heart
-deoxygenated
all arteries but ___ have oxygenated blood
pulmonary Artery
All veins but the ____ have high levels of CO2
pulmonary viens
pressure is low in the
capiallries
arterioles
control blood flow and feed capillaries
-resistance vessels
capillaries
site of nutrient and waste exchange
venules
collect blood from capillary beds
contraction =
systole
relaxation =
diastole
highest pressure in the
aorta and arteries
lowest pressue in the
capillaries and veins
site of most potent vasoconstriction and vasodilation
arterioles
right heart
venous return and to the pulmonary circulation
-receives blood from the body
-pumps deoxygenated blood from veins to lungs
left heart
pulmonary return and aorta and systemic circulation
-receives oxygenated blood from lungs
-pumps oxygenated blood to body
intrinsic blood flow
coming from within in the vessel
3 types of intrinsic control
- metabolic
- endothetial
- myogenic
baseline sympathetic activity
vasomotor tone
increase sympathetic activity
increase vasoconstriction
decrease sympathetic activity
decrease Vasocontrstiction
top chambers receive from
vena cava and pulmonary vein
bottom chambers pump to
pulmonary artery and aorta
myocardium
heart muscle
-type 1
-high number of mitochondria
cardiac muscle connected by
intercalated disks and desomones and gap junctions
what side has the most myocardium
left ventricle
SA node
initiates contraction signal
-pacemaker cells
-stimulates Right atrium and left atrium
Av node
delays, relays signals to ventricles
av bundle
relays signal to Rv and LV
-divides into right and left branches
-sends signal to apex
Purkinje fibers
send signal into RV and LV
extrinsic parasympathetic nervous system
reaches the heart via vagus nerve
-creates vagal tone
-carries the impulse to SA and AV node
-decrease HR
extrinsic sympathetic nervous system
-carries impulse to SA and Av nodes
-increase Hr
-releases norepinephrine = depolarization
p wave
atrial depolarization
QRS complec
ventricular depolarization
T wave
ventricular repolarization
heart sound 1 “lub”
atrial valve closes
reaming blood in the ventricle after contraction
end-systolic volume
heart sound 2 “dub”
aortic valve closes
maximum volume of blood in the ventricle
end-diastole volume
stroke volume
volume of blood pumped in one heart beat
