Circulatory system Flashcards
Name the path of blood from the body to the lungs
Body - vena cava - RA - tricuspid valve - RV - semi lunar valve - pulmonary artery - Lungs
Name the path of blood from the lungs to the body
Lungs - pulmonary vein - LA - bicuspid valve - LV - semi lunar valve - aorta - Body
Describe the conduction system
- SA node generates electrical impulse and fires it through the wall of the atria causing them to contract
- The AV node collects and delays impulse. Atria finishes contracting and releases impulses
- The Bundle of His splits the impulse into 2
- The bundle branches carries the impulse to the base of each ventricle
- The Purkinje fibres distributes the impulse through the ventricle walls causing them to contract
What are the 3 stages of the cardiac cycle?
Diastole (0.5 seconds)
Systole (0.3 seconds)
- atrial systole
- ventricular systole
What happens during the diastole stage?
The atria and ventricles relax decreasing the pressure.
Blood passively flows through atria into ventricles
AV valves = open
SL valves = closed
What happens during atrial systole?
Atria contracts
Blood flows into ventricles
AV valves = open
SL valves = closed
What happens during ventricular systole?
Ventricles contract
Blood leaves heart
AV valves = closed
SL valves = open
Define heart rate
Number of times the heart beats per minute
What is the resting heart rate for trained and untrained individuals?
Trained = 50bpm
Untrained = 72 bpm
What is the sub maximal heart rate for trained and untrained individuals?
Trained = 95 - 120 bpm
Untrained = 100-130 bpm
What is the maximal heart rate for trained and untrained individuals?
220 - age
Define stroke volume
Volume of blood ejected from left ventricle per beat
Increased venous return results in an increased stroke volume (increased stretch of ventricles results in an increased contraction force)
What is the resting stroke volume for trained and untrained individuals?
Trained = 100ml
Untrained = 70ml
What is the sub maximal stroke volume for trained and untrained individuals?
Trained = 160-200ml
Untrained = 100-120ml
What is the maximal stroke volume for trained and untrained individuals?
Trained = 160-200ml
Untrained = 100-120ml
Define cardiac output
Volume of blood ejected from left ventricle per minute
Heart rate X Stoke volume = cardiac output
What is the resting cardiac output for trained and untrained individuals?
Trained = 5 l/min
Untrained = 5 l/min
What is the sub maximal cardiac output for trained and untrained individuals?
Trained = 15-20 l/min
Untrained = 10-15 l/min
What is the maximal cardiac output for trained and untrained individuals?
Trained = 30-40 l/min
Untrained = 20-30 l/min
What regulates heart rate?
Cardiac control centre
How is heart rate increased?
Increases stimulation of the sympathetic nervous system via the cardiac accelerator nerve
How is heart rate decreased?
Vagus nerve sends impulse to the parasympathetic nervous system
What tells the CCC what to do?
Control mechanisms
Name and explain neural control mechanisms
Proprioceptors = detect movement
Chemoreceptors = detect chemical changes (pH, oxygen, carbon dioxide & lactic acid)
Baroreceptors = detect stretch of blood pressure walls and blood pressure
