Cardiovascular System Flashcards
What does myogenic mean?
The capacity of the heart to generate its own impulses
What is the sinoatrial node (SAN)?
A small mass of cardiac muscle found in the wall of the right atrium that generates the heartbeat. It is more commonly called the pacemaker
What does atrioventricular node (AVN) do?
This node relays the impulse between the upper and lower section of the heart
What does systole mean?
It’s when the heart contract
What is the Bundle of His?
A collection of heart muscle cells that transmit electrical impulses from the AVN via the bundle branches to the ventricles
What are purkinje fibres?
They are muscle fibres that conduct electrical impulses in the walls of the ventricles
The heart muscle is described as being myogenic. What does this mean and discuss how the cardiac conduction system works?
The heart is said to be myogenic because it has the ability to generate its own electrical impulses which originate in the heart muscle itself, with an electrical signal in the SAN. This impulse spreads across the heart like a wave of excitation. This causes atrial systole or the atria to contract. The impulse then passes to the AVN where it is delayed for approximately 0.1 second to fill up with blood. The impulse then travels through the bundle of his which then divides into two branches and then again into the purkinje fibres. This allows the impulse to spread throughout the ventricles causing them to contract. This is known as ventricular systole.
What is the diastole phase?
When the heart relaxes to fill with blood
What is stroke volume?
The volume of blood that leaves the heart during each contraction
What does heart rate mean?
The number of times the heart beats per min
What does the anticipatory rise mean?
The slight increase in heart rate usually before an activity starts due to the expectation of exercise
What does the cardiac output mean?
Is the amount of blood the heart pumps out. Measured in litres per minute (L/min)
What is the formula for cardiac output?
Q=SV x HR
What happens to your resting heart rate after continuous training?
Your resting heart rate decreases
What happens to your muscles after continuous training?
Your muscles become stronger
What happens to your lungs after continuous training?
Your lungs become stronger
What happens to the number of red blood cells after continuous training?
The amount of red blood cells increases
What are the reduced risks of continuous training?
. Reduced risk of cardiovascular disease
. Reduced risk of metabolic syndrome
. May lower risk of some cancers
How does continuous training influence your life span?
It can increases your life expectancy
How does continuous training affect your metabolic rate?
It increases your metabolic rate
What happens to your bones after continuous training?
It improves the bone health
How would the red blood cells differ in a trained v untrained individual?
The trained individual will have more red blood cells delivered to the working muscles whereas the untrained individual have less
How would the heart rate differ for a trained individual compared to a untrained individual?
The heart rate for the trained individual will be lower than the untrained
What does regular training do to heart rate (HR)?
It lowers your resting heart rate, lowers your HR sub-max, slower HR increases, lower HR during exercise, faster return to resting HR
What would the stroke volume in an untrained individual be?
112mL
What would the stroke volume be in a trained individual be?
130mL
What would the stroke volume be for an endurance athlete?
180mL
What happens to the muscles around your heart when you train often and what are the effects of it
The muscles around your heart get bigger. This is known as cardiac hypertrophy. The chambers become larger and more blood will be ejected out of the heart with each beat
What is bradycardia?
A heart rate below 60bpm