Week 6 - Cardiovascular Physiology Flashcards
What is the basic function of the CV system?
Delivery of O2 Removal of waste products Support thermoregulation and control body fluid balance Hormone transport Regulation of immune function
Name the system parts and functions
Heart - pressure creation
Arteries and arterioles - carry blood away from heart
Capillaries - exchange of gases
Veins and venules - carry blood towards the heart
What happens to the right side of the heart throughout a complete cycle?
Receives blood returning from throughout the body
Pumps deoxygenated blood to the lungs
What happens to the left side of the heart throughout a complete cycle?
Receives oxygenated blood from the lungs
Pumps oxygenated blood to all other tissues in the body
What type of valves are bicuspid and tricuspid?
Atrioventricular valves
What is the function of semilunar valves?
Stops pumped blood returning back into the ventricle
What are the two types of semilunar valves?
Pulmonary (right side)
Aortic (left side)
On an ECG, what does the P wave represent?
Atrial, depolarisation
On an ECG, what does the QRS comples represent?
Ventricular depolarisation (masks atrial repolarisation)
On an ECG, what does the T wave represent?
Ventricular repolarisation
What is Henry’s Law?
When a mixture of gas is in contact with liquid each gas dissolves in the liquid in proportion to its partial pressure and solubility until equilibrium is achieved and the gas partial pressure are equal in both locations.
What pressure gradient do gases diffuse to?
From high to low areas of pressure
What is systolic blood pressure the measure of?
The pressure exerted by blood on vessel walls during ventricular systole (contraction phase)
What is diastolic blood pressure the measure of?
The pressure exerted by blood on vessel walls during ventricular diastole (relaxation phase)
How is mean arterial pressure calculated?
2/3 DBP + 1/3 SBP
What is cardiac volume and how is it calculated?
Total volume of blood pumped by the ventricle per minute
Q(L) = HR x SV
Q(L) = HR x (ESV - EDV)
What is stroke volume and how is it calculated?
Total blood pumped out of the left ventricle per beat
SV = ESV - EDV
What does EDV and ESV stand for and mean?
EDV - end diastolic volume, at the end of the relaxtion phase how much blood is there
ESV - end systolic volume, at the end of the contraction phase how much blood is there
How is heart rate variability measured using ECG?
Assessing R-R variability, (the R from the QRS complex)
What type of control is sympathetic and parasympathetic?
Autonomic control
What does the sympathetic system do to the CV system?
Increase HR Increase inotropism (contractions)
What does the parasympathetic system do to the CV system?
Decrease HR Decrease inotropism (contractions)
Regarding HR variability, what is a sign of a healthier heart?
More variability, shows our body can quickly respond to stimulus.
What has higher HR variability been associated with?
Good emotional regulation
Well being
Information processing
What has lower HR variability been associated with?
Depression, anxiety, poor emotional regulation
IBS
Aging
Cardiac mortality
What is VO2 and how is it calculated?
The difference between volume of gas inhaled and volume of gas exhaled per unit of time
= [(V1 x F1O2) - (V2 x F2O2)]/T
What are the determinants of VO2?
Blood flow and oxygen extraction
What is maximal oxygen uptake?
The integrated functioning of the pulmonary, cardiovascular and muscle systems to uptake, transport and utilise O2
Who two athletes had the same VO2max but differing lactate thresholds, who would perform better in an endurance event?
The athlete with the lower lactate threshold
What happens to BP during exercise and why?
Increases due to increase in Q thus more blood flows harder and faster
What happens to Q during exercise and why?
Q increases
HR increases
SV increases
What happens to O2 extraction during exercise and why?
Increased extraction of O2 from the blood
Because affinity to Hb decreases
What conditions lead to a decrease of O2s affinity to Hb?
Increase in acidity
Increase in PCO2
Increase in temp
Increase in 2-3 BPG
What is ‘A-VO2 difference’?
The difference in oxygen saturation of the blood going to the tissues (in the arteries) and of the blood returning to the heart (in the veins).
How are rates of oxygen utilisation increased?
Increased extraction of O2 from the blood
Dilation of peripheral vascular beds (increased gas exchange)
Increased Q
Increase in pulmonary blood flow (lungs)
Increased ventilation
