Learning Outcomes On completion of this chapter students should be able to: OB13 describe the...
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Transcript of Learning Outcomes On completion of this chapter students should be able to: OB13 describe the...
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