SECTION 1.1.2f

LESSON TWENTY ONETHE 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 system1.2.2b : 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.

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

•When exercising muscles need more O2 - so the heart needs 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

Definitions

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

BLOOD PRESSUREThe 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 number is 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• Heart Rate increase• Cardiac output increases

Heart rate x stroke volume = cardiac output

• Blood pressure increase• Blood is shunted to the working muscles• Digestive system are by-passed by the blood• Oxygen and Haemoglobin (Oxyhaemoglobin)

combine and are transported to the working muscles.

• Amount of exercise influences the heart rate• Cardiac centre controls and regulates the heart

rate• Blood vessels dilate at skin surface, to release

heat, causing skin to redden• Waste products such as salt and water exit

body via pores and capillaries at skin surface (sweat)

• The endothelium (internal space of arteries) of arteries automatically widens to let more blood through.

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

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

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.

Complete past paper questions

http://www.bhf.org.uk/heart-health/conditions/high-blood-pressure.aspx