The heart worsheet answrs

Science Department
April 2015
Grade 7
Name _________________________________
The Cardiovascular (circulatory) System
(Revision sheet)
Complete the statements below
1. The ___circulatory___ system transports oxygen, carbon dioxide, food molecules,
hormones, and other material to and from the cells of the body.
2. The blood vessels that connect the arteries to the veins are ____capillaries______.
3. The major function of ____platelets_____ is to assist in the blood-clotting process.
4. The primary role of hemoglobin in the blood is to carry ___oxygen______.
5. The iron-containing molecule in red blood cells is called ____haemoglobin____.
6. Defending the body against bacterial infection and invasion by other foreign
substances is the function of ____white_______ blood cells.
7. Antigens determining blood type are carried on the surface of ______________red
blood__________ cells.
8. The flow of blood from the heart to all parts of the body except the lungs is part of
the system of circulation called the _____systemic_____ circulation.
9. The largest vein in the human body is the _______vena cava________
10. The ___SA_________ node starts each contraction of the heart.
11. Systolic pressure is caused by contraction of the heart’s ____ventricles______.
Label the parts of the heart below
Pulmonary artery
Superior vena cava
Pulmonary arteries
Pulmonary veins
Left atrium
Right atrium
Left valve
Right valve
Left ventricle
Right ventricle
Match the keywords in column A to the statements in column B
__2___ Arteries
1) pumps blood to entire body
__6___ Veins
2) carry blood away from the heart
__14__ Capillaries
3) stop you from bleeding to death
_18___ Pulse
4) red blood cells-white blood cells-platelets
__12__ Aorta
5) pumps blood to lungs
__16_ Plasma
6) carry blood to the heart
__13___red blood cells
7) delivers oxygen rich blood to every cell in body
__3___ Platelets
8) force blood into vessels
__19___white blood cells
9) divides heart into two sides
__8___ blood pressure
10) receives oxygen poor blood
__1___ Heart
11) connects atriums to ventricles
12) branches off the heart and then divides into
__10___right atria
smaller arteries
13) carry oxygen and carbon dioxide through
__17___left atria
__5___ right ventricle
14) tiny vessels
__15__ left ventricle
15) most powerful part of heart
__7___ left ventricle
16) made mostly of water
17) receives oxygen rich blood
___9__ Septum
18) number of beats per minute
___4__ Blood cells
19) keeps you from getting infections
Answer the questions below:
1. Why do we need blood?
Blood carries ____oxygen____ and __nutrients______ to all _body cells_____.
Cells burn ___food____ in the presence of ___oxygen___ to release
____energy_____. This is a process called cellular___respiration________ .
Cellular respiration:
___energy___+___CO2___+_water vapor_
___CO2____ and ___water vapor____ are wastes that the body needs to get rid of.
They are carried by the __blood____ to the ___lungs____ to be excreted during
2. What is the importance of the heart?
It pumps blood to all body cells it also receives blood that will be sent to the lungs
for gaseous exchange
3. What is the importance of blood vessels?
They carry blood throughout the body
4. Mention the function of each of the following structures:
a. Septum
Prevents mixing of oxygenated and deoxygenated blood together.
b. Valve
Prevents the backflow of blood into atria or veins.
c. Artery
Carries blood away from the heart.
d. Vein
Carries blood into the heart.
e. Cardiac muscles
They help the blood pump the blood.
f. Capillaries
They connect arteries with veins
5. What is a valve and where are the two places where it is present?
It is a structure found in veins and in the heart between the atria and ventricles, it
allows blood to move in one direction only.
6. Mention the origin (where it starts) of each blood vessel and where it is
heading to:
Blood vessel
Heading to
Left ventricle
All body cells
Pulmonary vein
Left atrium
Pulmonary artery
Right ventricle
Vena cava
All body cells
Right atrium
7. What is the difference between the blood on the right side of the heart and
the blood on the left side of the heart?
Right side of the heart carries deoxygenated blood which Is blood rich in
CO2_while the left side of the heart carries oxygenated blood which is blood rich
in O2.
8. Compare between the two types of circulation in our body:
Blood circulating
Blood circulating
between the heart and
between the heart and
all body cells except
the lungs
the lungs