Outcomes Most students should be able to: describe the
composition of the blood describe the structure of red blood cells
and their role in the blood describe how oxygen is transported from
the lungs to the other body organs by haemoglobin describe the
structure and functions of the white blood cells and the platelets
describe the functions of the blood plasma in the transport of
substances around the body. Some students should also be able to:
explain how red blood cells are adapted to carry out their function
describe the reversible reaction between haemoglobin and
oxygen.
Slide 3
Workbook homework p. 112
Slide 4
Which type of blood vessels?
Slide 5
What is blood made up of?
Slide 6
Name of part of blood Brief description /
diagramFunction(s)
Slide 7
Blood Plasma The liquid part of our blood is called plasma. It
transports red blood cells, white blood cells and platelets. Blood
plasma is a yellow liquid which transports all blood cells and
other substances around the body. Carbon dioxide produced as a by-
product of aerobic respiration is carried in the plasma back to the
lungs. It is the red blood cells which give blood its red
colour.
Slide 8
Red Blood Cells Red blood cells pick up oxygen from your lungs
and carry it to where it is needed for aerobic respiration. DID YOU
KNOW? One red blood cell contains about 250 million molecules of
haemoglobin which allow it to carry 1000 million molecules of
oxygen There are more red blood cells than any other type of cell
in your body about 5 million in each cubic millimetre of your
blood
Slide 9
A red blood cell has several features that help it do its job:
Biconcave disc-shaped, with a dent on each side, creates a large
surface area for gas exchange. A large surface area compared to
volume, so oxygen is always close to the surface. Short diffusion
distance How are red blood cells adapted to carry oxygen? It
contains haemoglobin, a special pigment that combines with oxygen.
It has no nucleus, so there is more space for haemoglobin and so
more oxygen.
Slide 10
Gases moving in and out of the blood
Slide 11
The reversible reaction between oxygen and haemoglobin
Slide 12
The reversible reaction between oxygen and haemoglobin WHAT
ORDER SHOULD IT BE? 1 Circulatory system transports the oxygen
bound to the haemoglobin 2 Tissues respire using oxygen up 3 Oxygen
diffuses from high to low concentration into the blood, and red
blood cells In the lungs 4 Oxygen leaves the haemoglobin and
diffuses from high to low concentration into the tissues 5
Haemoglobin binds oxygen in the blood
Slide 13
The reversible reaction between oxygen and haemoglobin Oxygen
diffuses from high to low concentration into the blood, and red
blood cells In the lungs Haemoglobin binds oxygen in the blood
Circulatory system transports the oxygen bound to the haemoglobin
Oxygen leaves the haemoglobin and diffuses from high to low
concentration into the tissues Tissues respire using oxygen up 3 5
1 4 2
Slide 14
White Blood Cells Much bigger than RBCs and there are fewer of
them. Have a nucleus and form part of the bodys self-defence system
against harmful microorganisms. Some WBCs form antibodies against
microorganisms. Other digest invading bacteria and viruses
(phagocytosis).
Slide 15
Blood clotting (Platelets) At the site of a cut or wound the
blood will clot. This prevents further blood loss, reduces the risk
of pathogens entering and forms a framework for repairing the
damaged tissue. Platelets will rapidly stick to a damaged area,
releasing chemicals that start a series of complex reactions. This
results in a network of protein threads that trap blood cells and
more platelets to form a jelly-like clot. The clot dries and
hardens to form a scab which protects the skin and stops bacteria
getting into your body
Slide 16
Which component?
Slide 17
Blood under the microscope Try and focus in high power to see
the cells
Slide 18
In your books match up the correct words and statements about
blood Component Function Plasma These cells form part of the bodys
defence system against microorganisms. There are many different
types. Red blood cells This liquid transports carbon dioxide from
the organs to the lungs, soluble products of digestion from the
small intestine to other organs, and urea from the liver to the
kidneys. White blood cells These are small fragments of cells. They
help blood to clot at the site of a wound. Platelets These cells
transport oxygen from the lungs to the organs. They have no
nucleus. They are packed with a red pigment called
haemoglobin.
Slide 19
Can I be a blood donor? Blood donors must be over 17 years old
and are always needed In small groups of 3 or 4, think of reasons
why a person should not donate blood After 5 minutes discussion,
produce a list of reasons as a class
Slide 20
Blood transfusions Blood is regularly donated by thousands of
people around the UK. The national blood service obtains,
transports and tests blood from donors before it is used. A blood
transfusion involves taking blood from one person and giving it to
another. Blood transfusions are used to replace blood lost in
accidents, after surgery and to treat blood conditions. Hospitals
will store a large amount of donated blood.
Slide 21
Real blood Blood is vital to life if you lose too much you can
die. Patients can be given blood plasma or saline to restore blood
volume, but using real blood for transfusions presents several
problems can you think of any?
Slide 22
Draw a table like the one below to input your notes during the
next few slides TopicBrief descriptionAdvantagesDisadvantages Real
Blood Artificial Blood Haemoglobin- based products Perfluorocarbons
(PFCs) Artificial mechanical heart
Slide 23
Disadvantages of using real blood It has to be kept
refrigerated It has a shelf life of only 42 days People have
different blood groups that need to be matched Real blood may be
contaminated by viruses e.g. HIV There is often a shortage of blood
donors Some people cannot accept blood transfusions for religious
reasons
Slide 24
Artificial blood Contains no cells. 2 main types are on
trial:
Slide 25
Advantages of artificial blood (currently being trialled in
Europe) Shelf life of a year or more It does not need refrigeration
It can be sterilised so does not carry disease It is safe
regardless of blood type as does not contain any cells But it cant
do all the work of real blood
Slide 26
Haemoglobin based products Based on haemoglobin taken from
human or animal blood Can be made synthetically or by genetic
engineering This haemoglobin carries even more oxygen than normal
blood Disadvantage: it is broken down quickly and only lasts in the
body for 20-30 hours
Slide 27
Perfluorocarbons (PFCs) These are very non- reactive chemicals
that can carry oxygen around your body Oxygen dissolves very
readily in PFCs Disadvantage: PFCs dont dissolve in water, so
getting them into the blood is difficult
Slide 28
Use the data in the graph on p.240 and the next slide to help
you explain why there is so much interest in developing artificial
blood products Activity 1
Slide 29
Slide 30
Artificial Hearts Scientists are also trying to develop
artificial hearts, since there are not nearly enough donors and it
is difficult to find a donor with the right tissue type In 2010, a
43 year old American was the first person to leave hospital with a
completely artificial heart He carried it in a back-pack!
Slide 31
Artificial hearts work by pumping deoxygenated blood from the
body to the lungs. The device then pumps oxygenated blood through
the body. The newly approved device, called AbioCor, made by
Massachusetts-based Abiomed, uses an implanted hydraulic pumping
system to simulate a natural heart beat. But an alternative design,
conceived by O.H. "Bud" Frazier, a prominent heart surgeon and
pioneer in the development of cardiac devices at the Texas Heart
Institute in Houston, pumps blood through the body continuously,
rather than with the periodic beat of the normal heart. Extension:
How do they work?
Slide 32
Problems with artificial hearts? Expense Problems with blood
clotting Size
Slide 33
Questions Answer q.1 and 2 p.240 Workbook p.113
Slide 34
Plenary: How science works which one should I have? Scientists
are working on developing an artificial heart that can be fitted
into patients Read the information about this and think about the
ethical issues involved Complete the task questions
Slide 35
Homework Choose from: A. Make a poster encouraging people to
give blood. Include information about the need for blood and the
advantages and limitations of the artificial bloods developed so
far (the NHS Blood and Transport website is useful) B. Make a
poster or presentation about the history of heart transplants and
the benefits of artificial hearts
Slide 36
Extension - ABO blood grouping Cells contain markers on their
surface, called antigens. Red blood cells can contain two types of
antigens called antigen A and antigen B. These form the basis of a
type of blood grouping called the ABO blood system. blood group O
cells do not contain antigens A and B Blood groups can be
classified by the presence or absence of these antigens: blood
group A cells contain antigen A only blood group B cells contain
antigen B only blood group AB cells contain antigens A and B
Slide 37
Who can receive what type of blood? The immune system will
contain antibodies against the antigens that are not present in the
blood. For example group A blood will contain antibodies against
antigen B. If a recipient's anti-B antibodies come in contact with
blood cells containing antigen B this will cause clotting. This
affects blood donation, e.g. a person with group A blood can only
receive blood group A or O, as these dont contain B antigens. Blood
groupAntigensAntibodies Can receive O A B AB None A B A and B
anti-A, anti-B anti-B anti-A None O A and O B and O All groups