2022/2023 ACADEMIC
SESSION
SUBJECT: BASIC SCIENCE
TOPIC: CIRCULATORY
SYSTEM
CLASS: GRADE 8
NUMBER OF STUDENTS: 22
AVERAGE AGE: 12+ YEARS
GENDER: MIXED
PERIOD: 7th
AND 8th PERIOD ON TUESDAY AND FRIDAY RESPECTIVELY
TIME: 1:20-2:00
DURATION: 40 MINUTES
PER PERIOD
DATE: 07/11/2022
SPECIFIC OBJECTIVES: By
the end of the lesson the students should be able to;
1.
state the meaning of the circulatory system and its parts (e.g. blood, hearts,
blood vessels);
2.
explain blood and its composition and functions. Blood vessels (artery, vein,
capillaries);
3.
discuss blood groups (A, B, AB, O) and blood test
ENTRY BEHAVIOUR: The
students are familiar with the heart and pulse.
INSTRUCTIONAL TECHNIQUE: Visual,
questions, simulation.
INSTRUCTIONAL MATERIALS: Textbook,
lesson note, laptop, projector, marker, whiteboard.
DEVELOPMENT:
STEP 1: MEANING OF THE
CIRCULATORY SYSTEM AND ITS PARTS
The
organs that are responsible for blood circulation in the body are together
called the circulatory system. Circulation is the process by which absorbed
food materials are carried through arteries, capillaries and veins to all parts
of the body where they are utilized for body functioning. Materials which are
transported by the blood in human body are water, salts, hormones, oxygen,
digested food, etc, waste materials also removed from the body through blood
circulation. The circulatory system consists of the blood, blood vessels and
the heart.
PARTS OF THE CIRCULATORY SYSTEM:
THE HEART: The
heart pumps blood to all part of the body through the circulatory system. The
heart is a muscular organ that lies in the chest cavity and is almost conical
in shape. It is made up of four chambers. These four chambers include two upper
chambers which are the right auricle and left auricle, and two lower chambers,
the right ventricle and left ventricle. Blood enters the heart at the auricles
and leaves from the ventricles. The heart is constantly beating, contracting
and relaxing. There are about 70-75 beats per minute although this beating rate
may vary with individuals. Beating rate is faster in children than in adults.
BLOOD VESSELS: These
are channels or routes through which blood passes to different parts of the
body. There are three types of blood vessels; the arteries, veins and
capillaries.
1. Arteries: These
are blood vessels that carry blood away from the heart to all parts of the body
except the pulmonary artery.
2. Veins:
These are blood vessels that carry blood to the heart from all parts of the
body except the pulmonary vein.
3. Capillaries: These
are tiny networks of blood vessels that connect arteries to veins. Blood flows
out from the heart through arteries to all parts of the body, through
capillaries and then into veins, and back to the heart where circulation
continues.
STEP 2: BLOOD AND ITS
COMPOSITION AND FUNCTIONS
BLOOD: Blood
is a body fluid in the circulatory system of humans and other vertebrates that
delivers necessary substances such as nutrients and oxygen to the cells, and
transport metabolic waste products away from those same cells.
COMPOSITION OF BLOOD: Blood
is composed of blood cells suspended in blood plasma which contains proteins,
glucose, mineral ions, hormones, carbon dioxide and blood cells themselves. The
blood cells are mainly red blood cells (erythrocytes) which contain
haemoglobin, white blood cells (leukocytes) and platelets (thrombocytes).
FUNCTION OF BLOOD
1.
Supply of oxygen to tissues (bound to haemoglobin, which is carried in red
cells).
2.
Supply of nutrients such as glucose, amino acids and fatty acids.
3.
Removal of waste such as carbon dioxide, urea and lactic acid.
4.
Immunological functions, including circulation of white blood cells.
5.
Coagulation.
6.
Messenger functions, including the transport of hormones and the signaling of
tissue damage.
STEP 3: BLOOD GROUPS
AND BLOOD TEST
Blood
typing is a method to tell what type of blood you have. Blood typing is done so
you can safely donate your blood or receive a blood transfusion. It is also
done to see if you have a substance called Rh factor on the surface of your red
blood cells.
Your
blood type is based on whether or not certain proteins are on your red blood
cells. These proteins are called antigens. Your blood type (or blood group)
depends on what types your parents passed down to you.
Blood
is often grouped according to the ABO blood typing system. The 4 major blood
types are:
·
TYPE A
·
TYPE B
·
TYPE C
·
TYPE D
BLOOD TEST:
How
the test is performed: A blood sample is needed. The test to determine your
blood is called ABO typing. Your blood sample is mixed with antibodies against
type A and B blood. Then, the sample is checked to see whether or not the blood
cells stick together. If blood cells stick together, it means the blood reacted
with one of the antibodies.
The
second step is called back typing. The liquid part of your blood without cells
(serum) is mixed with blood that is known to be type A and type B. People with
type B blood have anti-A antibodies. Type O blood contains both types of
antibodies.
The
2 steps above can accurately determine your blood type.
Rh
typing uses a method similar to ABO typing. When blood typing is done to see if
you have Rh factor on the surface of your red blood cells, the results will be
one of these:
·
Rh+(positive), if you have this cell
surface protein.
·
Rh-(negative), if you do not have this
cell surface protein.
EVALUATION: Oral
questions
1.
Meaning of the circulatory system and its parts (e.g. blood, hearts, blood
vessels);
2.
Blood and its composition and functions. Blood vessels (artery, vein,
capillaries);
3.
Blood groups (A, B, AB, O) and blood test
SUMMARY/CONCLUSSION: The
organs that are responsible for blood circulation in the body are together
called the circulatory system. Part of the circulatory system includes; blood,
heart, blood vessels.
ASSIGNMENT:
1.
State the meaning of the circulatory system and its parts (e.g. blood, hearts,
blood vessels).
2.
Explain blood and its composition and functions. Blood vessels (artery, vein,
capillaries).
3.
Discuss blood groups (A, B, AB, O) and blood test.
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