Download Year 7 Science Homework

Year 8 Science Homework
Name: ___________________
Form: ________
Homework No: _______
Due date: ________________
Grade: _______
Title: Structure of the Heart
Read the Information and answer questions.
All the cells in the body need OXYGEN and FOOD to produce Energy for the body to stay alive
and it is the CIRCULATORY SYSTEM which transports them, along with many other things,
around the body.
Ques 1. Oxygen + Food  __________ + carbon dioxide + water
a) Complete the equation.
b) What does Food refer to? __________________________________
c) What is the name of the above LIFE PROCESS? _________________
The parts of the Circulatory System:
o
o
o
o
o
o
o
The
The
The
The
The
The
The
HEART
ARTERIES
VEINS
CAPILLARIES
RED and WHITE BLOOD CELLS
PLATELETS
PLASMA
Ques 2: There are 3 main parts of the Circulatory System:
a) The Pumping organ = _____________
b) The Blood = ____________ (liquid) 55%
+ 45% Blood cells: __________________ + ____________________ + _______________
c) The Blood Vessels: ___________________ + __________________ + ___________________
The functions of the Circulatory System:






To carry OXYGEN to all the cells in the body ________________
To carry FOOD to all the cells in the body
________________
To remove WASTE from the cells of the body ________________
To distribute HEAT around the body ________________
To form a part of the DEFENCE the body has against microbes
________________
To REPAIR itself and prevent blood loss by clotting ________________
Ques 3: The above information is about the functions of the Circulatory System: write
down the parts of blood which is responsible for the individual function.
ie. Choose from PLASMA, WBC, RBC, PLATELETS
Ques 4: Draw the diagrams of white blood cell, red blood cell and platelet.
The 'DOUBLE' pump of the
Human Heart
RIGHT Side
LEFT Side
1. Deoxygenated blood FROM
THE BODY entering the
heart
2. The RIGHT ATRIUM
3. The VALVES prevent blood
flowing the wrong way
when the atria and
ventricles contract
4. The RIGHT VENTRICLE
5. The thicker walled LEFT
VENTRICLE
6. The LEFT ATRIUM
7. Oxygenated blood FROM
THE LUNGS entering the
heart
8. Oxygenated blood leaving
the heart and flowing TO
THE BODY
9. Deoxygenated blood
leaving the heart and
flowing TO THE LUNGS
Ques 5: Label the above diagram with the following words:
Right Atrium, Left Atrium, Right Auricle, Left Auricle (4 chambers of the heart), Valves
Pulmonary (Lung) Artery, Pulmonary Vein, Vena Cava, Aorta (4 blood vessels in the heart)
Ques 6: Why is the Left Ventricle THICKER than the Right Ventricle?
______________________________________________________________________________
______________________________________________________________________________
Ques 7: What is the function of Valves in the heart?
______________________________________________________________________________
How blood moves through the heart.



A Vein takes blood to the heart where it enters an Atrium.
This contracts and forces the blood into a Ventricle.
This then contracts and forces the blood out of the heart and into an Artery
Remember: Vein -> Atrium -> Ventricle -> Artery i.e. V A V A
Ques 8: Briefly describe the internal structures of the heart:
______________________________________________________________________________
______________________________________________________________________________
The following information is about the 3 different types of blood vessels our body:

Arteries always carry blood away from
the heart. (Remember: AAA)
All arteries carry OXYGENATED blood
except the one carrying blood from the
heart TO THE LUNGS.
Arteries have:
o
o
o
o

Veins always carry blood towards the heart. (VAT).
All veins carry DEOXYGENATED blood except the one carrying blood FROM THE
LUNGS to the heart.
Veins have:
o
o
o
o

THICKER WALLS
SMALLER LUMEN
MORE ELASTIC and MORE MUSCLE FIBRES
NO VALVES
THINNER WALLS
LARGER LUMEN
LESS ELASTIC and LESS
MUSCLE FIBRES
VALVES to help blood return to the heart
Capillaries are microscopic and their walls are only ONE CELL THICK.
They have NO VALVES and they LINK ARTERIES to VEINS.
FOOD and OXYGEN pass out through the thin walls into the cells and WASTE and
CARBON DIOXIDE enter the blood and are carried
away.
Ques 9: What is an artery? - AAA
______________________________________________________________________________
Ques 10: What is a vein? - VAT
______________________________________________________________________________
Ques 11: Give 2 differences between a vein and an artery.
______________________________________________________________________________
______________________________________________________________________________
Ques 12: Why capillaries are very thin?
______________________________________________________________________________
Ques 13: What types of substances are carried away from cells into the capillaries?
______________________________________________________________________________