Cardiorespiratory Physiology Notes
Respiratory zone (where gas exchange occurs) : alveoli (epithelial cells of alveoli)
Conductive zone (warms and moistens air): mouth, nose, trachea, larynx, bronchus,
Inspiration: external intercostals contract/relax?, rib cage moves up, diaphragm moves
Expiration: internal intercostals contract/relax?, rib cage moves down, diaphragm moves
Tidal volume: amount of air breathed in or out under normal resting conditions.
Inspiratory reserve volume: amount of air that can be forcefully inhaled after a normal
Expiratory reserve volume: amount of air that can be forcefully exhaled after normal
Residual volume: the amount left in lungs after expiratory reserve volume is out. This air
that’s left is what stops the lungs from collapsing.
Total lung capacity = TV + IRV + ERV + RV. All the air in the lungs.
Vital capacity: amount of air that can be exhaled after a max inspiratory effort.
Inspiratory capacity: amount of air that can be inspired after normal expiration.
Functional residual capacity: what’s left in the lungs after normal expiration
Minute ventilation: breaths/min x tidal volume
P wave: activation of atria
QRS wave: activation of ventricles
T wave: recovery
Cardiac Output = heart rate x stroke volume
Arteries carry blood away from the heart Veins carry blood towards the heart
Dead air space and gas exchange?
Oxygen is carried in the hemoglobin (carries 4 O2 molecules at a time)
Oxygen unattaches from hemoglobin based on the concentration gradient. High
concentration of oxygen in blood travels to low concentration in muscles.
An increased heart rate means faster blood flow so less time for oxygen to get off and
A short transit time is desirable for elite athletes.
Q (oxygen deliver) = heart rate X stroke volume
Fick’s Equation: VO2 = Q x (CaO2 – CvO2)
Stroke volume (amount of blood pumped per beat) increases with exercise.
This increases VO2.
O2 carrier free space is a barrier to diffusion. Greater O2 carrier free space = less oxygen
delivered to muscles. (I think?)
How to increase VO2: deliver more oxygen AND extract a greater proportion of it
The heart pumping more blood per minute (stroke volume) would increase VO2.
What increases VO2: higher stroke volume (more oxygen delivered), delivering more
oxygen, and a greater proportion of oxygen extracted.
Q, Stroke volume and blood volume limit maximal exercise.
Anaerobic system: does not produce lactate, uses ATP and creatine kinase
Oxidative/Glycolytic system: lactic acid is produced, ETC, krebs cycle.
Plateau in VO2 indicates that VO2 max has been reached.
Respiratory Exchange Ratio
RER = VCO2 (expired) /VO2 (consumed)
If 0.7, fat is the main energy source used. Lower number = fat used
If 1.0, carbs is the main energy used. Higher number = carbs used Respiratory quotient (RQ) is theoretical because it stops at 1.0 whereas RER can go
above that due to bicarbonate and CO2 being produced.
RER increases with exercise since more CO2 is produced when lactic acid is buffered by
bicarbonate when exercise becomes intense after a long time.
T Vent is the point at which the ventilation increases disproportionately to the oxygen
uptake. High amount of CO2 in blood causes you to breath at a faster right
Above the T vent, there was very high lactate levels in blood which causes the person to
slow down and stop. Higher % T vent is better.
Lactate can be converted into glucose using the liver, but too much increases pH of blood
and lowers enzyme activity causing you to slow down.
Bicarbonate from the kidneys is used to buffer lactic acid and lower pH. This produces
Aerobic activities: rhythmical, continuous, uses large muscle groups.
3-5 days of exercise per week is necessary to increase VO2. Good time is 20-60 minutes.
VO2 max can only be improved by 20-25%.
High intensity, high frequency, long duration exercise causes the greatest increase in
Adipose tissue is the most abundant energy source.
Long aerobic exercises uses the most glycogen, short intense exercise uses very little
glycogen since it uses mainly ATP and PCr.
It is beneficial to carb-load for events longer than 90 minutes. No benefit if less than that.
Disadvantages: extra water weight, bloating.
Carb-loading delays fatigue by 20%
Improves times to go a certain distance by 2-3%
Classic carb loading: eat little or no carbs for a few days (gradually decrease the amount
of exercise), which causes muscle glycogen levels to be depleted. Then eat a lot of carbs
to saturate muscles with glycogen (more than before).
Carb loading encourages body to use more glycogen rather than fat or glucose.
500g of carbs is recommended after exercise. Both carb loading and fat loading work, but fat loading only works well for athletes. Carb
loading is best for non-trained.
For a fat loading to work, one must train high fat. With carb loading you can do it in 1
Baking soda increases power by 2% by buffering acid, but it causes GI discomfort.
Caffeine increases endurance time by 10-15% but it needs to be taken in pill form
Leading causes of death: 1 cancer, 2 heart disease, 3 stroke.
Females have a higher death rate from CVD because they perceive it differently and they
do not think they are having a heart attack when they are, so they die.
Male pattern baldness connection to CVD ?? MPB is caused by increased testosterone
HDL is good Comes from unsaturated fat
LDL is bad. Comes from saturated fat
Cholesterol comes from food and liver.
The #1 most popular rick factor of CVD is lack of fruits and vegetables.
Triglycerides are carried by a protein called albumin
White blood cells engulf LDL cholesterol and become foam cells, after growing it bursts
and releases plaque. Plaque accumulates in the arteries and makes them narrow.
Blood pressure numbers: less than 130 Systolic is normal
Less than 85 Diastolic is normal
Above 140 Systolic is bad
Above 90 Diastolic is bad
High blood pressure can cause: eye damage, kidney damage, heart attack, stroke, arterial
wall damage. Thrombosis: blockage in the local artery area caused by thrombus travelling thru and by
plaque that’s stuck in artery.
Heart does not regenerate after being damaged by heart attack.
If one has chest pain (angina), doctors do: ECG, stress test, angiography.
Hyperacute phase = immediately after a heart attack
Fully Fully evolved phase = a few hours to days after a heart attack evolved phase = a
few hours to days after a heart attack
Resolution phase = a few weeks after a heart attack
Stabilized chronic phase is the last phase and typically has permanent
pathological changes compared to a normal ECG tracing.
Angiography: used to visualize inside of arteries by inserting a catheter tube. Dye is also
inserted and x-rayed to view blood flow in arteries.
Medication for angina: nitrates to open up blood vessels to lower blood pressure.
Angioplasty: balloon inserted into artery and blown up to widen artery and increase
blood flow to the heart. Plaque also gets compressed.
Coronary Graft Bypass: vein is taken from leg and is used to replace the coronary artery.
CABG (coronary artery bypass graft) – bypasses arteries in front of the heart. This is
TECAB (total endoscopy coronary artery bypass) – a robot with a video camera is
inserted into artery
Deep vein thrombosis: blood clot in leg. Leg appears swollen.
Caused by: stagnant blood, hypercoagulability (clotting), cancer, trauma to leg.
Treatment: anti-coagulants, vena cava filter, compression stocking.
Pulmonary Embolism: a clot that has travelled to pulmonary artery and caused a
blockage there. This can kill.
*Thrombus is local. Embolus travels somewhere away from where it was formed.
A thrombus can become an embolus if it moves.
2 types: hemorrhagic (caused by ruptured blood vessel leaking into tissue) and ischemic
(caused by blockages in brain blood vessels) Hemorrhagic can be fatal because it can develop into an aneurism (ballooned area of
Ischemic stroke can cause part of brain to die due to lack of blood.
Cerebral Aneurism: ballooned blood vessel on brain. 3 types: secular, fusiform, giant.
These do not show symptoms until they are big or when the burst.
Ruptured aneurism is called haemorrhage (bleeding between skull and brain).
How it is diagnosed: CTA, Angiogram, MRA.
Treatment: -clipping (cutting it off). -Occlusion (clamping it off to stop blood flow there)
-Bypass (using another blood vessel to allow blood flow instead of ballooned aneurism).
-Endovascular therapy (coiling to allow flow inside aneurism without letting it get bigger.
Stroke FACE test: face arm speech time
Risk Factors for Stroke: age, hypertension, high RBC count, heart disease, blood fats,
Exercise is the best way to prevent the development of plaques.
2000-2999 calories of exercise per week is the most effective for reducing risk of Heart
Moderate exercise is better than vigorous exercise for preventing CHD.
5-6 hours of exercise per week can REVERSE the effects of coronary atherosclerosis.
Exercise is more effective in preventing artherosclerosis than diet alone.
Pulmonary circulation diseases: affect the blood vessels through clotting, scarring,
inflammation. Ex: pulmonary embolism, pulmonary arterial hypertension, pulmonary
Restrictive lung diseases: affect the structure of the lungs. Causes lungs to be stiff,
increases O2 demand, reduced tidal volume, causes increased respiratory rates.
Ex: pulmonary fibrosis, sarcoidosis, severe obesity.
Airway Diseases – narrowing or blockage of airways. Ex: asthma, bronchitis,
emphysema, COPD. Scoliosis causes limited chest movement, and reduces lung volume.
Cystic Fibrosis causes lots of fluid, mucus to be in the lungs, this reduces the gas
exchange at alveolar-capillary level.
Sarcoidosis is an immune disease that causes lumps on organs.
Restrictive lung disease patients require 4 times the normal amount of O2 to do exercise.
Stroke volume is also reduced.
5% of popular has asthma. At rest the airways are normal. Once something triggers it,
Asthma treatment (3): relievers (bronchodialators), controllers (anti-inflammatory),
Many elite athletes have asthma.
Exercise can not be used to improve/get rid of asthma.
COPD = bronchitis + emphysema
COPD is caused by smoking.
Exercise prescription for COPD patients: interval training, small muscle weight training.
Pursed Lip breathing: breath in with lips tightly closed, breath out for twice as long as
when you breathed in. This allows for less frequent breathing and increased tidal volume.
Hypoxia (less oxygen reaching tissues) is caused by COPD. It can lead to right ventricle
Chronic Bronchitis – inflamed bronchial tubes, damaged cilia mucus in lungs.
Acute bronchitis (short lasting) occurs after a cold/flu, but it goes in a few weeks.
Smokers that get this, have it for a much longer time because their cilia is damaged so the
mucus will be harder to remove.
Emphysema – damaged lung tissue caused by irritation such as smoke. It takes more
work to push air out of lungs.
-Reduced alveolar surface area, O2 uptake, CO2 offtake
Lung capacity, inspiratory reserve and expiratory reserve is lowered with emphysema.
Oxygen desaturation is assessed to test for lung function. Normal saturation is 95-100%.
If lower than 86%, they will need supplemental O2. Cystic Fibrosis – hereditary disease that causes the body to produce thick, sticky mucus.
The later it is diagnosed, the better.
-Symptoms: salty sweat, coughing, fatigue, pneumonia, shortness of breath.
Testing for CF: blood test for the CF gene, sweat chloride test for salty sweat.
CF can lead to lung infection and lung damage, nose polyps, enlarged heart, fat in poo,
infertility, trouble digesting food, sinus problems, gallstones.
Causes respiratory problems that can lead to death. High levels of fitness can extend a CF