Cardiovascular system Flashcards
Pulmonary Circuit
Carries deoxygenated blood to lungs and oxygenated blood to heart
Systematic circuit
Carried oxygenated blood to body and deoxygenated to the heart
Structure of heart
-Double pump protected by ribs
-Left side gas thicker wall for larger force of contraction so O2 blood flows through systematic circuit to organs/ muscles
-Right side contracts to send deoxygenated blood through pulmonary system to lungs
-Atrioventricular and semi lunar valves
Path of blood- left side
-Oxygenated blood comes from lungs to heart in pulmonary vein
-Blood moves from LA to LV through AV (bicuspid) valve
-Contraction forces blood into aorta- to muscles and organs
Path of blood- right side
-Deoxygenated blood carried through vena cava to right atrium
-RA to RV through atrioventricular (tricuspid) valve
-RV to pulmonary artery
-Pulmonary artery to lungs
Myogenic
Heart creates its own impulse in order to contract
Cardiac cycle
Contraction of cardiac muscle and movement of blood through chambers
Diastole
-Relaxation phase of heart
-Fills with blood
Systole
-Contraction phase of the heart
-Blood moves into aorta and Pulmonary Artery
Cardiac cycle- diastole
-Chambers relax and expand as they fill with blood
-Pressure in atria increases- forcing Atrio Ventricular valve open
-Ventricles fill
-Semilunar valve closed to prevent blood leaving
Cardiac cycle- atrial systole
-Atria contract to force remaining blood to ventricles
Cardiac cycle- ventricular systole
-Ventricles contract- closing AV valve
-SL valve forced open
-Blood ejected into aorta and PA
Heart Rate
-Number of time heart beats per minute (72bpm)
-Lower it is = more efficient
-HRmax= 220-age
-> affected by age, gender, genetics + fitness
Bradycardia
Resting HR below 60bpm
Stroke volume
-Volume of blood ejected from left ventricle per beat
-Usually 70ml
-Occurs during ventricular systole
Cardiac output
-Volume of blood ejected from the left ventricle in one minute
-CO (L/MIN) = HR X SV
HR for trained and untrained
Untrained - 70-72 bpm
Trained - 50bpm
SV for trained and untrained at rest
Untrained - 70ml
Trained- 100ml
Cardiac Output for trained and untrained at rest
5l/min for both
Sub- maximal
-Low/ moderate intensity
-Below anaerobic threshold
-Aerobic work
Maximal
-High intensity
-Above aerobic capacity
-Fatigue + anaerobic work
HR response to sub maximal exercise
-Increases in line with intensity
-Plateaus as HR reaches steady state
->demand for O2 delivery and waste removal met
HR response to maximal exercise
-Increases in line with intensity
-Does not plateau as HR continues to increase
->demand for O2 and waste removal not met
HR response to exercise- sub max graph
-Initial anticipatory rise due to adrenaline
-Rapid increase in HR to increase blood flow and O2 delivery
-Steady HR throughout as demand met
-Initial rapid decrease in recovery
-More gradual decrease to resting level
HR response to exercise- max graph
-Initial anticipatory rise due to adrenaline
-No plateau as demand not met
-More gradual decrease during recovery
HR response to dynamic sports
-Fluctuates as intensity varies
SV response to exercise
-Increases in proportion to intensity until 40-60% of working capacity- plateaus
-Plateau during sub max due to:
->increase HR toward max doesn’t allow enough time for ventricles to fully fill- Limits Frank Starling mech
-SV maintained in early stages of recovery to maintain blood flow and decrease stress of cardiac muscle
->because HR rapidly decreases
SV able to increase during exercise due to…
-Increased venous return (volume of blood that returns to heart)
-Frank starling mechanism
Frank Starling Mechanism
-Increased venous return= increased end diastolic volume
-Therefore, increase stretch of ventricle walls
- Increased force of muscular contraction = larger vol of blood ejected from heart
-> lower HR = more time to maximise effect
Cardiac Output response to exercise
-Combination of HR and SV
-Increases with intensity but plateaus during maximal
-Rapid then slower decrease during recovery
HR for untrained performer rest, sub max and max
Rest - 70-72
Sub Maximal - 100-120
Maximal - 220-age
SV for untrained performer rest, sub max and max
Rest - 70ml
Sub Maximal - 100-120ml
Maximal - 120-200ml
Cardiac Output for untrained performer rest, sub max and max
Rest - 5l/min
Sub Maximal -10-15l/min
Maxima l- 20-30l/min
