Cardiovascular Physiology Flashcards
Oxygenated blood goes to –
the body
Deoxygenated blood goes to –
the lungs
Arteries carry blood –
Away from the heart
Veins carry blood –
Towards the heart
Which node emits spontaneous electrical impulses
The sinoatrial node
Is atrial systole or diastole stimulated by the first wave of excitation
Atrial Systole
Which node speeds down the speed of electrical transmission
Atrioventricular Node
What is systole
period of contraction of the ventricles of the heart that occurs between the first and second heart sounds of the cardiac cycle
What is diastole
when the heart muscle relaxes and allows the chambers to fill with blood.
Why is AV delay important?
Allows the atria to complete their contraction before the ventricles begin to contract.
When does ventricular systole occur
At the end of the conduction cycle, when the electrical impulses spreads across the ventricles
What are the 5 elements of an ECG trace
P Q R S T
QRS complex represents what
Ventricular systole
P wave represents what
Atrial Systole
T wave represents what
Ventricular diastole
An elevated ST section indicates
Heart attack
A small or unclear P wave represents what
Atrial fibrilation
A deep S wave represents what
abnormal ventricular hypertrophy
what is Henry’s law
when a mixture of a gas is in contact with a liquid, each gas dissolves in the liquid in proportion to its partial pressure and solubility, until equilibrium is achieved + gas pp are equal in both
How much O2 is there roughly per litre of blood
3ml/l
What are the male and female haemoglobin values
M- 150g/l
F-130g/l
1 g of Hb = approximately —- O2
1.34ml
What is the equation for the oxygen carrying capacity of the blood?
[O2] ml/l =([Hb] x 1.34 x 0.97) + (PO2 x 0.003)
What are the 3 ways CO2 can be transported in the body
- 7% dissolved CO2
- 23% carbamino compounds e.g. carbaminohaemoglobin
- 70% bicarbonate ions (in plasma as HCO3)
What is the first equation for the chloride shift
H2O + CO2 –> H2CO3
What is the second equation for the chloride shift
H2CO3 –> H+ + HCO3-
Describe the 6 steps of chloride shift
- CO2 in plasma diffuses into the RBC and binds with water
- carbonic anhydrase catalyses the conversion into H2CO3
- This then converts into H+ and HCO3
- HCO3 diffuses into the plasma as chloride comes into the RBC
- H joins with HBO8 and forms HHb and 4O2
- O2 diffuses out into plasma
Define blood pressure
pressure exerted by blood on vessel walls
What is the equation for Mean Arterial Pressure (MAP)
MAP = DBP + 0.33(SBP-DBP)
What is Q
total volume of blood pumped by ventricle per minute
What is the equation for cardiac output
Q(l)=HR(bpm) x SV(ml)
How can we work out Stroke Volume
End Diastolic Volume – End Stroke Volume
What is EDV
end of relaxation (how much blood is left)
WHat is ESV
blood pumped out
What is heart rate variability
variation in time interval between heart beats
How does the sympathetic NS affect HR and Ionotropism
increases HR and ionotropism
How does the parasympathetic NS affect HR and Ionotropism
decreases HR and ionotropism
Is it better for the heart to have lower or greater variability
A high heart rate variability is good as shows the body can respond quickly from 1 stimulus to another
What is the oxygen consumption equation
VO2 = [(V1 x FeO2) - (V2 x FeO2)] / time
WHat is VO2
The difference between volume of gas inhaled and volume of gas exhaled per unit of time
What is the fick equation
VO2 = Q X (CaO2 – CVO2)
Lactate is converted from what by LDH
Pyruvate
What is the lactate threshold
the highest workload a person can work without a dramatic increase in blood lactate levels.
What is the lactate turnpoint
When there is an unsustainable increase in lactate levels
Why is having a higher lactate threshold better?
in a race that person could hold a higher pace without lactic acid build-up than previously. This translates to a faster race pace and times.
An increase in PH and a decrease in DPG and temperature shifts the dissociation curve which way
Left
A decrease in PH and a increase in DPG and temperature shifts the dissociation curve which way
Right
Better oxygen utilisation is caused by what 4 things
• Increased extraction O2 o Dilation of peripheral beds • Increased Q • Increased pulmonary blood flow • Increased ventilation
