Cardiovascular system
Describe the pathway of the blood in the heart
Vena cava, Right atrium, tricuspid valve, right ventricle, semi-lunar valve, pulmonery artery, lungs, pulmonery vein, left atrium, bicuspid valve, left ventricle, aortic semi-luna valve, aorta, body
Define heart rate, stroke volume, and cardiac output
HR - amount of beats per minute
SV - Volume of blood pushed out the heart per beat
CO - The volume of blood pumped around the body per minute
How do you calculate HR and what is the average value
Ave - 70BPM
220 - age
Explain the HR response to exercise
1.HR remains steady at rest (60-70 bpm)
2.The anticipatory rise just before exercise is caused by the early release of adrenaline.
3.HR increases rapidly as exercise starts to meet increased demand for O2
4.HR Plateaus when a steady state is reached and O2 demand is met during submaximal intensity exercise
OR
5.HR continues to rise until max is reached (anaerobic) during maximal intensity exercise.
Post-exercise:
6.Immediate drop due to less oxygen demand.
7.Then gradual drop to repay oxygen debt.
Name the 5 blood vessels
arteries
veins
capillaries
venules
arterioles
Name the components of blood
Red blood cell
White blood cell
Platelets
Plasma
Describe the roles of the components of blood
RBC - Carries oxygen around the body via haemoglobin
WBC - fights of bacteria and infections
Platelets - prevents bleeding when cut
Plasma - 50% of blood
Explain the structure and role of Arteries
Carries blood away from the heart
Thick, muscular walls
High Pressure
Large amounts of elastin
Explain the structure and role of Arterioles
Connect arteries to caapillaries
Have Pre-capillary sphincters that contract to change blood flow
Explain the structure and role of Capillaries
One cell thick
Low pressure to allow diffusion
Site where O2, CO2 and Nutrients pass from the blood to the tissues
Explain the structure and role of Venules
Venules connect capillaries to veins; they are smaller versions of veins, without valves.
They collect the blood, drawing it together before emptying into the veins.
Pressure is much less than in arteries.
Pressure in the venules relies on the flow of blood to keep it moving.
Explain the structure and role of Veins
Vessels with a large lumen, with valves inside to prevent the backflow of blood.
The veins contain pocket valves to prevent backflow of blood.
The flow of blood back to the heart is called venous return.
What is Venous Return
The volume of blood that returns to the right side of the heart via veins
What 5 mechanisms aid venous return
Pocket valves
Muscle pump
respiritory pump
smooth muscles
gravity
State and explain what Vascular shunt is, and how it works
VS is when the flow of blood is redistributed towards working muscles when exercising and away from inactive organs
As CO2 increases in the blood, the way the blood is distributed is altered.
The body activates the arterioles and precapillary sphincters to either increase or reduce blood flow.
Muscles are the main beneficiary of the vascular shunt mechanism.
This increased volume to the muscles is accounted for mostly by increased cardiac output.
What's Vasoconstriction and Vasodilation
Constriction - When the sphicnter contract to reduce the flow of blood
Dilation - When the sphincters relax to increase the flow of blood to an area
What are the short term effects of exercise on the cardiovascular system
Increased Heart Rate (HR)
Increased Stroke Volume (SV)
Increased Cardiac Output (Q)- due to increase in SV and HR
Increases in HR and SV are linked to intensity of exercise, higher intensity = greater rise.
Intensity is related to fitness (If you are fitter your HR goes up slower).
Vascular shunt mechanism activated
Increased blood pressure/flow
Decreased blood viscosity
Increased blood temperature
Increased Blood Pressure
What are the Long term effects of exercise on the cardiovascular system
Increased resting and exercising SV of the left ventricle.
Resting HR reduced (resting Q stays the same).
Maximum Q increased.
Cardiac hypertrophy
Decreased risk of cv disease
Decreased blood pressure
How do cool downs help c-v system
Maintain respiratory and muscular pump mechanisms - increased venous return
Prevents blood pooling - due to skeletal muscle pump
Maintain venous return
Maintain Q and SV - Starling’s Law
Keeps capillaries dilated to flush out lactic acid and supply oxygen (vascular shunt mechanism continues for longer)
How do Warm-ups help the CV system
1.Increases HR which increases venous return then increases stroke volume. This results in increased cardiac output.
2.Reduced viscosity of blood
3.Vascular shunt activated
4.Decreased production of lactic acid (delays OBLA)
5.More oxygenated blood to muscles due to increased blood flow
6.Reduced build up on lactic acid/ Reduces DOMS/muscle soreness
7.Increases blood temperature
8.Reduces risk of injury - muscle strains
9.Increased speed/strength of contraction due to increased muscle temperature
10.Increased enzyme/metabolic activity