1.2.2 Lesson 1 - immediate effects on the cv system

GCSE PE

Unit 1.2.2

The Cardiovascular System

Exercise has a number of immediate effects upon the cardiovascular system:

Increased Heart Rate

Increase in Blood Pressure

With a partner, create a mind map of everything that you know about

the CV system using task 1

The Cardiovascular system is made up of 3 parts…

3. The Heart1. Blood

2. Blood Vessels

Heart rate (or pulse rate) is the number of times your heart beats every minute.

It is expressed in beats per minute (bpm).

Resting heart rate varies from individual to individual and is affected by fitness.

The fitter you are, the lower your resting heart rate will be.

A normal resting heart rate is between 60-80 bpm.

The average resting heart rate is about 70–75 bpm.

You can measure how fast your heart is beating by taking your pulse.

This can be done at the wrist or the neck.

Count how many times your heart beats in 6 seconds and then multiply

by 10.

Lets do it………

Using the …… on page…… of your book to record your result for the following activities:

1.Sitting in a chair

2.Jogging on the spot for 1 min

3.Running as fast as you can for 30 seconds

You can measure how fast your heart is beating by

taking your pulse. This can be done at the

wrist or the neck. Count how many times your

heart beats in 6 seconds and then multiply by 10.

The four chambers of the heart have special names:

A lower chamber is called a ventricle.

An upper chamber is called an atrium (plural: atria).

rightatrium

rightventricle

leftatrium

leftventricle

The heart as a pump

There are three types of blood vessels, as shown in this magnified part of the circulatory system.

Why are there different types of blood vessels?

blood from the heart

blood to the heart

arterycarries blood

back intothe heart

carries blood away fromthe heart

carries blood to and from the body’s cells

vein

thick outer wall

thick inner layer of muscle and elastic fibres

narrow central tube (lumen)

thin outer wall

thin inner layer of muscle and elastic fibres

wide central tube (lumen)

wall only one cell thick

ARTERY

VEINCAPILLARY

When blood is flowing against gravity, or when a vein is squeezed by muscle action, there is a risk that blood will flow in the wrong direction. Veins have valves to prevent backflow.

blood to the heart

backflow prevented

vein valve open

vein valve closed

The valves allow blood to flow in the correct

direction…

…but close if blood starts to flow in the wrong

direction.

• Blood pressure is the force exerted by blood on the walls of the arteries.

• It increases during exercise as more blood is pumped around the body.

• You use a blood pressure meter to measure both systolic and diastolic blood pressure

Systolic PressureThe maximum pressure in the

arteries when the heart contracts (beats) and pushes

blood out through the aorta into the body.

Increases during exercise.Decreases during rest.

Diastolic PressureThe pressure of the blood during

the relaxation phase between beats (when the heart is at

rest).Pulse Pressure

The difference between systolic and diastolic blood pressures.

Lets do it…….

Get into a group of 4

Task 3 in your book - you need to take the readings of all the people in your group.

The heart as a pump

thick outer wall

thick inner layer of muscle and elastic fibres

narrow central tube (lumen)

thin outer wall

thin inner layer of muscle and elastic fibres

wide central tube (lumen)

wall only one cell thick

ARTERY

VEINCAPILLARY

• Check your weight• Limit alcohol consumption

• Don’t smoke• Eating too much salt

• Avoid stress and anxiety• Regular exercise

Complete the following:

1. Update any missed notes from today’s lesson.

2. To do Homework 1 on page 3.