Learning OutcomesOn completion of this chapter students should be able to:

• OB13 describe the function and composition of blood, and know that blood contains white blood cells, red blood cells and platelets in a liquid called plasma

• OB14 understand the structure and function of the heart, identify the four chambers of the heart, and explain the difference between the left and right ventricles

• OB15 describe the passage of blood through the heart and lungs via arteries and veins, identify the pulmonary artery and vein, aorta and vena cava, and distinguish between arteries, veins and capillaries

Learning Outcomes contd..

• OB16 demonstrate the effect of exercise and rest on pulse rate and understand that a balance of each promotes good health

• OB17 recall that the average pulse rate for an adult at rest is 70 beats per minute, and explain why exercise results in increased pulse and breathing rates

Lesson 1

Composition of Blood

What is the circulatory system?

The Circulatory System is responsible for transporting materials to and from different places in the body.

It is made up of:

Blood consists of:

Red Blood Cells

Most numerous cell in the body

Small doughnut shape

Contain haemoglobin which transports oxygen around the body

White Blood CellsLarger than red

blood cells but also much fewer in number

Fights infection by destroying bacteria and viruses that have invaded the body

Platelets

Tiny fragments of cells

Cause blood to clot by producing tiny fibrinogen fibres

These stretch across a cut to stop bleeding

Plasma

A straw-coloured liquid that carries the cells and the platelets which help blood clot.

• carbon dioxide

• glucose

• amino acids

• proteins

• minerals

• vitamins

• hormones

• waste materials

It also contains useful things like:

Functions of Blood

To transport food, oxygen and wastes

To transport heat to the skin to keep the body temperature at 37°C.

To fight infection

Lesson 2

Blood Vessels

Blood vessels

There are 3 types of blood vessels found in our body:

Veins

Veins carry blood towards the heart

They have thin walls and a wide inner cavity which allows blood flow to the heart easily

They also contain valves which stops the blood flowing backwards

Wide inner cavity (lumen)

veins with valves

Arteries

Arteries carry blood away from the heart

They have thick elastic walls which allows them to stretch and recoil at each heartbeat

These muscles contract to push the blood along

No valves present Narrow inner cavity (lumen)

Thick muscular walls

CapillariesCapillaries link arteries and veins

Have very thin walls-just one cell thick

Materials can be exchanged from the blood to other body cells and vice versa via capillaries

Wall just one cell thick

Lesson 3

The Structure of the Heart

The Heart

The heart is a muscular pump that transports blood around the body

It consists of 4 chambers:

Right atrium Left atrium

Right ventricle Left ventricle

YouTube video

The Heart

Ventricles The lower chambers Receives blood from the

atria Pumps blood out through

arteries Left ventricle has thick

walls (more strength required to pump blood around the body)

Atria The upper chambers Receives blood from

veins Pumps blood into

ventricles Have thin walls

Structure of the Heart

Right Ventricle

Right AtriumLeft Atrium

Left Ventricle

Vena Cava

Pulmonaryartery

Aorta

Pulmonary vein

How does the heart work?

1. Deoxygenated blood enters right atrium via vena cava

2. Blood is pumped to right ventricle and then to the lungs via the pulmonary artery

3. Oxygenated blood enters left atrium via pulmonary vein

4. Blood is pumped to left ventricle where it leaves via the aorta

Pulmonaryartery

Vena cava

Aorta

Pulmonary Vein

Tips for remembering

VEAL

Veins Enter, Arteries Leave

LORD

Left=Oxygenated, Right=Deoxygenated

Pulmonary = related to lungse.g. Pulmonary vein enters from lungs

Lesson 4

The Pulse&

How to demonstrate the effect of exercise on the pulse

The PulseEvery time the heart contracts, the blood surges forward in the arteries. By placing your fingers

over an artery, you can feel this pulse

The Pulse

For an adult the average pulse rate is 70 beats per minute (b.p.m.).

Children have faster heartbeats than adults.

What happens to our pulse rate when we exercise?

Mandatory Practical

Title: to demonstrate the effect of exercise on the pulse rate

Beats per minute at rest

vs.

Beats per minute after exercise

Results

Beats per minute

Person 1 Person 2

At rest

Immediately after exercise

3 minutes after exercise

6 minutes after exercise

Conclusions

When a person exercises, the muscles need more oxygen to get more energy from food. A faster heartbeat delivers oxygen to the muscles quicker.

Exercise increases the pulse rate.

Why we need exercise

Exercising the heart makes it stronger and reduces the likelihood of heart disease.

To prevent heart disease we should:Take regular exerciseNever smokeEat only small amounts

of saturated (animal) fats

Assessment

The circulatory system is made up of blood, blood vessels and the _____.

Arteries _____ the heart and ______ enter the heart.

The capillaries ______ arteries and veins.

Blood is made up of red blood cells which carry _____, white blood cells which fight _______, platelets which causes blood to _____ and ______ which is the liquid part of blood.

The heart is made up of _____ chambers, 2 atria and 2 ventricles.

SolutionsThe circulatory system is made up of blood, blood vessels and the heart.

Veins enter the heart; arteries leave the heart and

The capillaries link arteries and veins.

Blood is made up of red blood cells which carry oxygen, white blood cells which fight infection, platelets which causes blood to clot and plasma which is the liquid part of blood.

The heart is made up of four chambers, 2 atria and 2 ventricles.

Bibliography

http://library.thinkquest.org/5777/images/circulatory.gif

http://images.encarta.msn.com/xrefmedia/sharemed/targets/images/pho/35a5c/35A5C297.jpg http://www.fi.edu/learn/heart/blood/images/blood-platelets.gif

http://www.worldofteaching.com/

http://www.clarian.org/ADAM/doc/graphics/images/en/19432.jpg

http://www.artie.com/valentines_day/arg-beating-heart-sfx-url.gif

http://www.bradfitzpatrick.com/character_design/images/full/DancingHeart.gif

http://whttp://www.son.jhmi.edu/images/content/blood.jpgww.pamf.org/images/shutterstock/HM_SH001-W.jpg

http://www.bbc.co.uk/schools/ks2bitesize/science/revision_bites/keeping_healthy2.shtm l

http://www.clipartheaven.com/clipart/outdoor_recreation/cycling/mountain_biking_-_cartoon.gif