SECTION 1.1.2f LESSON TWENTY ONE THE CARDIOVASCULAR SYSTEM 1.2.2a:Understand the immediate and short-term effects of exercise and physical activity on the cv system 1.2.2b : Understand the long-term effects of exercise and physical activity on the cv system

LESSON OBJECTIVES WALT 1.2.2a:Understand the immediate and short-term effects of exercise and physical activity on the cv system 1.2.2b : Understand the long-term effects of exercise and physical activity on the cv system

LESSON OUTCOMES All of you – will understand the immediate and short-term effects of exercise and physical activity on the cv system and the long-term effects of exercise and physical activity on the cv system Most of you– will understand the immediate and short-term effects of exercise and physical activity on the cv system and the long-term effects of exercise and physical activity on the cv system and be able to answer exam questions/complete worksheets with help from teacher Some of you - – will understand the immediate and short-term effects of exercise and physical activity on the cv system and the long-term effects of exercise and physical activity on the cv system and be able to answer exam questions/complete worksheets independently.

starter What are blood pressure, cardiac output, heart rate, stroke volume ?

answer Blood pressure = the force exerted by circulating blood on the walls of the blood vessels Cardiac output = the amount of blood ejected from the heart in one minute Heart rate = the number of times the heart beats per minute Stroke volume = the volume of blood pumped out of the heart by each ventricle during one contraction

The cardiovascular system The heart is a muscular pump that pumps blood away from the heart around the body through a system of arteries which take oxygen rich blood and nutrients to the muscles to allow them to work Blood then picks up CO2 as a waste product from the muscles and carries this back to the heart in veins. From there it is pumped to the lungs where it is breathed out and in exchange O2 is breathed in = gaseous exchange. This happens because muscles need energy in the form of O2 and nutrients to produce movement. CO2 is produced when we exercise. The CV system helps us get rid of waste products and supplies muscles with the O2 and nutrients needed to keep working

THE IMMEDIATE AND SHORT TERM EFFECTS OF PARTICIPATION IN EXERCISE AND PHYSICAL ACTIVITY ON THE CV SYSTEM

When exercising muscles need more O2 - so the heartneeds to beat stronger and quicker Heart rate rises because of adrenaline This means more blood is pumped to the lungs so that more O2 and nutrients can be circulated and waste removed Training helps body to cope better when exercising A fit person has a bigger and stronger heart

BLOOD PRESSURE The heart beats more strongly during exercise, causing blood pressure (bp)to rise. BP has 2 parts Systolic = high pressure measured when blood is pumped out of heart – this high number higher when exercising Diastolic =pressure when heart relaxes between beats – the lower number

Effects of regular exercise on the cv system Regular exercise cv system becomes stronger. Changes are: Stroke volume increases Cardiac output increases Heart rate x stroke volume = cardiac output

3. Resting HR decreases – as heart can pump more blood per beat 4.size of heart increase - larger and stronger 5.CO increases 6.time taken to return to resting heart rate decreases 7. blood pressure reduces – as reg. exercise strengthens heart so more blood pumped per beat so less stress on arteries. 8. regular exercise leads to weight loss and so lower blood pressure 9.veins and arteries are healthier as they become more flexible and efficient – and so lower risk of coronary heart disease

Test yourself Complete questions 1 a, b, c, d and 2 on page 57

The effects of lifestyle on the cv system 1.2.2c – understand the impact of rest on the cv system 1.2.2d -– understand the impact of diet on the cv system 1.2.2e -– understand the impact of recreational drugs on the cv system

REST REST and RECOVERY are 2 principles of training that allow body to adapt to training. The same applies to the CV system as rest allows the heart to increase in size and the number of capillaries to increase

DIET – CHOLESTEROL HIGH CHOLESTEROL LEVELS CAN INCREASE THE RISK OF CHD CHOLESTEROL = Fatty substance carried in blood by lipoproteins HDL ( High density lipoprotein ) LDL (Low density lipoprotein ) HDL = good cholesterol because it takes cholesterol away from blood vessels. LDL = bad cholesterol – builds up in arteries, makes them less flexible and more difficult for blood to pass through – so heart attack or stroke can occur. Combination of high blood pressure and high blood pressure = risk of heart attack/stroke

Recreational drugs. NICOTINE – found in tobacco Smoking increases heart rate and BP – which leads to high blood pressure Nicotine also reduces amount of HDL – so smoking combined with diet high in LDL – higher risk of heart disease. ALCOHOL – drinking too much causes high blood pressure.

Test yourself P.58 questions 3 and 4.

Complete past paper questions