ch 12 Flashcards
majority of our activities utilize which system?
oxidative
(lower intensity, lower power output)
Cardiovascular respiratory system is broken up into
- Pulmonary circulation (deoxygenated blood pumped from heart to lungs: oxygenated blood returns to heart)
- Systemic circulation (oxygenated blood is pumped from heart to cells: deoxygenated blood is pumped back to heart)
how many gallons of blood circulate our body every day?
2000 gallons
Path of blood flow starting with deoxygenated blood
deoxygenated blood comes back into heart through the superior vena cava, into the right atrium, through the tricuspid valve, into the right ventricle, blood is sent to lungs through the pulmonary artery
In the lungs the blood releases CO2, picks up O2, returns oxygenated blood in our pulmonary veins, to left atrium, through bicuspid (mitral) valve, to the right ventricle, leaves heart via aorta, goes to rest of body
Blood is flowing into the ventricles during the — phase
diastolic
When ventricles contract, that is
systole
Ejection fraction
amount of blood pumped/circulated per heart beat
Does the ejection fraction increase during exercise?
Yes!!!!!
Cardiac output (Q) equation
Q= HR x SV
Cardiac output (Q)
the amount of blood pumped by either the right or left ventricle of the heart PER MINUTE
Stroke volume (SV)
the amount of blood pumped by the left or right ventricle PER BEAT
Heart rate
beats per minute
The skeletal muscle pump
muscles relaxed= valves closed
muscles contracted= valve above muscle opens
Why is aerobic/rhythmic exercise preferred over isometric exercise?
alternating contraction/relaxation= allows blood to push past valves
isometric= does not allow blood to push past valves (can increase blood pressure, not good for beginners)
What are the two types of respiration?
External respiration= exchange of O2 and CO2 in the lungs
Internal respiration= exchange of O2 and CO2 at the cell/tissue level
mechanics of breathing
air moves from high to low pressure
Inspiration: active
–> diaphragm and external intercostals contract
–> increases volume in thoracic cavity
–> low pressure= air flows in
Expiration: passive
–> relaxation of inspiratory muscles
–> decreases volume (increases pressure) in lungs
–> air flows out
Most endurance based (skeletal) muscle in body?
diaphragm!!!
(not heart bc that is cardiac muscle)
minute ventilation (Ve)
the volume of air inspired or expired in one minute
tidal volume (Vt)
the volume of air ventilated per breath
respiratory frequency (Fr)
number of breaths per minute
minute ventilation= (equation)
tidal volume x respiratory frequency
Typical minute ventilation during rest vs heavy exercise
rest= 6L/min
Heavy exercise= 150 L/min
Components of blood
plasma= 55% of tot, liquid component, protein, blood glucose, electrolytes, hormones
buffy coat= 1% of tot, leukocytes, platelets
erythrocytes= 45% of tot blood, erythrocytes
Hematocrit
portion of blood composed of RED blood cells
plasma is –% water
90-95
total blood volume of an average man is
approx 8% of his body weight
oxyhemoglobin=
hemoglobin + oxygen
–> hemoglobin binds to oxygen but can also be dissociated from it
do males or female have more hemoglobin?
males
–> performance enhancer
Systolic blood pressure
pressure against the arterial walls when the left ventricle contracts (systole)
-normal range 100-140mm Hg
(120mm Hg= average)
Diastolic blood pressure
pressure in the arteries between ventricular contractions (diastole)
-normal range 60-90mm Hg
(80mm Hg= average)
Pulse pressure
systolic pressure minus diastolic pressure
(driving force of the heart)
Hypertension:
and when are you classified as having it?
high blood pressure
–> no symptoms: “silent killer”
bp higher than 145/95 (normal= 120/80 and ideal is 110/70)
decades of long distance endurance training can result in
with coronary artery calcification, diastolic dysfunction and large-artery wall stiffening
changes in blood flow
-at rest
-during maximal exercise
at rest, 15-20% of systemic blood flow goes to the skeletal muscles
during maximal exercise, 85% of total blood flow (cardiac output) can be diverted to the muscles
3 methods that blood gets diverted to the working muscles
increased BP
dilation of arterioles
decreased blood flow to other tissues
VO2 max formula
VO2= SV x HR x (a-v)O2diff
(a-v)O2 diff= atrial venous O2 difference
trained vs elite differences in aerobic capacity
HR doesn’t really change
SV increases
a-vO2 diff increases
Exercises HR vs workload
untrained= HR goes up faster for lower workload
SV during exercise
SV reaches maximum at approx. 40% of VO2 max
–> the plateau response
Four main types of stroke volume responses with increasing exercise (in a VO2 vs. SV graph)
-progressive increase
-plateau with a secondary increase
-plateau
-plateau with a drop/dip
VO2 max
the highest oxygen use an individual can attain during exercise
-to quantify aerobic fitness
Factors to determine VO2 max
-the ability of the heart to pump blood
-the oxygen carrying capacity of the blood (haemoglobin content)
-the ability of the working muscles to accept a large blood supply
-the ability of muscle cells to extract O2 from capillaries and use it to produce energy
after age 25, VO2 max declines by – per decade
10%
–> high intensity training can reduce loss for males but not for older/middle-aged females
which athletes have the highest VO2 max?
cross country skiers
endurance performance depends on
-VO2 max
-anaerobic/lactate threshold
-individual variation in mechanical efficiency
-belief and focus
-diet
-training and recovery cycles
can genetics account for VO2 max?
yes!!
what is the best thing to train to reach your genetic potential for VO2 max?
endurance
The specificity of VO2 max
VO2 max is different for different exercises
Systemic cardiorespiratory changes from aerobic exercise (generall)
-improved CR capacity, hormonal changes, improved cellular aerobic mechanisms, improved emotional well-being
“Systemic”= changes in DELIVERY of O2 to muscles: not at the cellular level
Systemic cardiorespiratory changes AT REST due to aerobic exercise
-heart mass and volume increase
-decrease in HR, increase in SV with no change in cardiac output
-increase in blood volume and total body haemoglobin content (concentration does not change)
Systemic cardiorespiratory changes during SUB-MAXIMAL exercise
-decrease in HR and SV
-slight decrease in cardiac output
-slight decrease/no change in O2 consumption
-decrease in amount of air breathed
Systemic cardiorespiratory changes during MAXIMAL exercise
-no change/slight decrease in maximal HR
-increase in max SV
-increase in max cardiac output
-increase in max (a-v)O2diff
–> incr in max O2 consumption
-incr in endurance performance
-incr in max minute ventilation
