Cardiovascular physiology Flashcards
What does a dot over a letter indicate?
That there is a time element. So if you see a V with a dot over it in eg VO2, it means volume of oxygen (probs in ml) per minute
What is VO2max?
the maximum or optimum rate at which the heart, lungs, and muscles can effectively use oxygen during exercise
What are the two ways you can measure VO2 max?
- absolute VO2max is the maximum amount of oxygen you can breathe (in eg ml) per minute
- relative VO2max measures that volume of oxygen (eg in ml) per minute, per kilogram of body weight
Give 2 differences between the aerobic and anaerobic energy systems?
(1) Your aerobic energy system needs oxygen to convert muscle glycogen into fuel; your anaerobic system does not
(2) Your aerobic energy system can deliver fuel for hours and hours; your anaerobic system can deliver fuel for a short window of time (ie minutes)
Which energy system does your body use first, aerobic or anaerobic?
Aerobic energy system is what muscles first use for fuel
When would the body switch between energy systems?
- amount of fuel aerobic system can provide is limited by how much oxygen it receives from CV system
- when body is working so hard that muscles need more fuel than aerobic energy system can produce, anaerobic energy system takes over (and body’s ability to hold that effort level is limited to relatively short duration)
How does VO2max relate to your aerobic and anaerobic energy systems?
- VO2max is oxygen limit that caps fuel production capabilities of your aerobic energy system
- higher VO2max = more oxygen your cardiovascular system can deliver to muscles
- more oxygen available to muscles = more fuel aerobic energy system can provide
- more fuel muscles have, the harder they can work and the longer they can last
What is relative VO2 max useful for?
It’s VO2 max relative to an athlete’s body weight, so allows us to compare fitness between individuals
How might you improve relative VO2 max?
You could lose weight (so there’s more 02 per kg of you), or do endurance or interval training
What percentage of your blood flow goes to your skeletal muscles during maximal exercise?
about 85%
What are the approximate maximums for male and female athletes VO2max ever recorded?
Male = just under 100ml/kg/min, Female = just under 80ml/kg/min
What are average untrained female and male VO2max rates?
Female = around 25-30 ml/kg/min
Male = around 35-40 ml/kg/min
Is there much difference in VO2Max between the genders in sedentary people?
No
What are mitochondria?
- Membrane bound organelles within cells that generate ATP (the cell’s main source of energy) to power the cell’s biochemical reactions
What is the name of the portion of your circulatory systems that moves blood between the heart and the lungs?
Pulmonary circuit
What is the name of the portion of your circulatory systems that moves blood between the heart and the rest of the body?
Systemic circuit
What are the two portions of cardiac cycle events?
Diastole and systole. Diastole represents ventricular filling, and systole represents ventricular contraction/ejection.
What is normal untrained adult blood pressure and what do those numbers mean?
120 over 80. 120 is the systolic pressure in the arteries when the heart beats; 80 is the diastolic pressure ie that in the arteries in between beats
What are the two sides of the heart responsible for?
- Left side receives oxygenated blood from pulmonary circuit and pumps it around systemic circuit
- Right side receives deoxygenated blood from systemic circuit and pumps it to the lungs-
- it’s left/ right as if it’s your heart, not as you look at it
What are the main parts of the blood flow circuit?
- right atrium (towards the top)
- right ventricle (towards the bottom - remember bottom of heart is kind of pointy like a V)
- left atrium (towards the top)
- left ventricle
- superior and inferior vena cava (carry deoxygenated blood from body to heart)
- aorta (carries oxygenated blood from heart to body)
pulmonary arteries (carry deoxygenated blood from the right side of the heart to the lungs) - pulmonary veins (carry oxygenated blood from lungs to left side of heart)
- pulmonary arteries (carry oxygen-poor blood from the right side of heart to lungs) 🫁
why do we measure blood pressure in the upper arm?
because when you’re upright it’s about the same level as your heart
what blood vessels is blood pressure measured in?
arteries. pressure in your veins is v low (so their walls are much thinner than arteries) and there isn’t the same diastolic/ systolic range in veins
if someone’s heart is bigger than average, is that a sign of training or disease?
either! endurance athletes’ hearts can grow bigger as a normal and beneficial response to exercise. or an enlarged heart can be eg if someone has high blood pressure, every time the heart beats it’s trying to send blood through a relatively thin tube so remodels through hypertrophy due to this extra work
what is the relative structure of veins and arteries?
Vein has a larger lumen and less elasticity; veins work at a much lower pressure than arteries. The lumen in arteries is smaller but can change more than that of a vein. Arteries are more elastic and made of more layers than veins
Which type of blood vessels facilitate gas exchange in and out of muscle, and what can you say about their diameter?
Capillaries - diameter is smaller than the diameter of red blood cell. Makes the cells get slowly squeezed through to give time for 02 to diffuse out into the interstitial space
What is coronary circulation?
With every heart beat about 20-25% of blood is redirected back into the heart because it’s a muscle with huge energy requirements. This is coronary circulation
In a graph, which variable would you tend to put on the x axis (horizontal)?
x-axis (horizontal) = independent y-axis (vertical line) = dependent
The independent variable is the cause. Its value is independent of other variables in your study. The dependent variable is the effect. Its value depends on changes in the independent variable
What is the cardiac cycle?
It is the time taken for the heart to go through one round of diastole and systole. Measured in seconds
If you know someone’s heart rate how do you work out their cardiac cycle?
Divide 60 by their heart rate.
So for a heart rate of 74bpm, divide 60 by 74 to give you 0.81sec
What proportion of resting cardiac cycle is spent in systole and diastole?
At rest, about 1/3 systolic and 2/3 diastolic
what effect does training have on diastole?
for most untrained people the heart doesn’t fill completely during diastole. training can mean the heart fills more completely
How do you calculate cardiac output?
Cardiac output (Q) is the amount of blood pumped from the heart around the systemic circuit every minute and can be calculated by multiplying heart rate (HR) by stroke volume (SV). So Q = HR × SV
What is heart rate, and what is the average adult resting heart rate?
The number of times the heart beats (or the ventricles pump blood out) in one minute. Average resting HR is approx 70 beats per minute (bpm)
What is stroke volume, and what is the average adult resting stroke volume?
Stroke volume is the amount of blood pumped out of the heart each time it beats. The average resting SV is 70-80ml, which translates to 5litres per min