Science Focus 4.3

Question 1

What is blood?

Answer 1

Blood carries water, oxygen and the nutrients to cells around the body. It also removes carbon dioxide and waste material from those cells and maintains our body temperature.

Question 2

How much blood does the average human body contain?

Answer 2

About 5.5 litres

Question 3

What is blood made up of?

Answer 3

red and white blood cells, platelets and plasma.

Question 4

Where are red blood cells made?

Answer 4

in bone marrow

Question 5

Red blood cells have no nucleus, allowing them to carry more of a substance called what?

Answer 5

haemoglobin

Question 6

Haemoglobin attracts and carries ______ and contains ____, which gives blood its red colour.

Answer 6

oxygen; iron

Question 7

Blood containing oxygen is what colour?

Answer 7

Bright red. (Blood without oxygen is a much duller red (blue).)

Question 8

Red blood cells last for about ___ days.

Answer 8

100

Question 9

One drop of blood contains about how many red blood cells?

Answer 9

5 million

Question 10

White blood cells are _____ than red blood cells, and have a ______.

Answer 10

bigger; nucleus

Question 11

Our bodies have far fewer white blood cells that red ones. A drop of blood contains about ____ white cells.

Answer 11

3000

Question 12

White blood cells help rid the body of harmful _______ and _______ by surrounding and destroying them, or by producing chemicals to kill them.

Answer 12

bacteria; viruses

Question 13

Platelets have no nucleus, and help trigger formation of ______ strands, which help blood to ____.

Answer 13

fibrin; clot

Question 14

What is Plasma?

Answer 14

Plasma is a clear, yellow liquid in which red and white cells and platelets are suspended.

Question 15

Plasma is 90 per cent _____.

Answer 15

water (The rest is dissolved food, waste products and body chemicals called hormones.)

Question 16

Blood Type. Blood contains, at most, two types of ______, known as ________ and ________.

Answer 16

antigen; antigen A; antigen B. (Antigens are special chemicals involved in fighting microorganisms in the blood.)

Question 17

Type A blood contains ______, type B blood contains _______, type AB blood contains _____ and type O blood contains _____.

Answer 17

antigen A; antigen B; both; neither

Question 18

What is the most common type of blood?

Answer 18

type O positive

Question 19

Rhesus factor. Rhesus is another type of ______.

Answer 19

antigen

Question 20

Blood that contains the Rhesus antigen is classified as ___________. Blood without the Rhesus antigen is classified as ___________.

Answer 20

Rhesus positive (or Rh positive); Rhesus negative

Question 21

For a blood transfusion to be safe, the donor blood must not contain any _______ that are not already in the patient’s blood, otherwise blood cells may clump together and form deadly blockages.

Answer 21

antigens (The Rhesus factors must also match.)

Question 22

The human heart is really two pumps joined together that do separate jobs. One pump sends blood to the _____ to pick up oxygen. The other receives the oxygen-carrying blood and pumps it to the _____ and around the ____.

Answer 22

lungs; head; body

Question 23

Blood that is rich in oxygen is said to be _______, while blood that has had most of its oxygen removed is _______.

Answer 23

oxygenated; deoxygenated

Question 24

Each half of the heart, or each pump, has two main sections or chambers: the ______, where blood enters, and the ________, where blood is pumped out.

Answer 24

atrium; ventricle

Question 25

What are the three types of blood vessels?

Answer 25

arteries, capillaries and veins.

Question 26

Which blood vessels carry blood away from the heart to the organs, such as the kidneys and liver, and to tissues, such as the skin and muscles.

Answer 26

Arteries

Question 27

The arteries divide and connect with smaller tubes which eventually connect with fine tubes called ________, which are only one cell thick.

Answer 27

capillaries

Question 28

Capillaries then join with wider tubes called _____, which allow blood to return to the heart, ready to be pumped to the lungs for another load of oxygen.

Answer 28

veins

Question 29

The heart, arteries, veins and capillaries all combine to form the ________ system,

Answer 29

circulatory

Question 30

Bruises are caused by blood leakage from ruptured (broken) _____ _______.

Answer 30

blood vessels

Question 31

What is hypertension

Answer 31

High blood pressure

Question 32

When blood pressure is measured, two readings are taken. One is taken when the heart contracts (called ______ blood pressure), the other when the heart relaxes (called ______ blood pressure).

Answer 32

systolic; diastolic (A typical pair of readings for adults is around ‘120 over 80’ (systolic = 120 and diastolic = 80))

Question 33

Name five things the circulatory system transports around the body.

Answer 33

oxygen, carbon dioxide, digested food, chemicals and heat

Question 34

Which arteries branch off the aorta and supply the heart muscle itself with blood?

Answer 34

Coronary arteries

Question 35

Coronary arteries can become narrow due to a build-up of fat and a chemical called ________ that is transported in the blood.

Answer 35

cholesterol

Question 36

If narrowing of the coronary arteries reduces blood flow enough, it may lead to a condition known as...

Answer 36

angina (insufficient supply of oxygen and glucose to the heart)

Question 37

When a coronary artery becomes blocked, the region of heart muscle it supplies dies. This is called a _____ ______.

Answer 37

heart attack

Question 38

A dangerously narrowed artery can be treated by various medical procedures. Name 1 of 4,

Answer 38

It can be widened by inflating a special balloon in the affected area.

Question 39

A dangerously narrowed artery can be treated by various medical procedures. Name 2 of 4,

Answer 39

A special titanium alloy sleeve (called a stent) can be inserted to keep the artery walls apart.

Question 40

A dangerously narrowed artery can be treated by various medical procedures. Name 3 of 4,

Answer 40

The blockage can be destroyed with a laser beam.

Question 41

A dangerously narrowed artery can be treated by various medical procedures. Name 4 of 4,

Answer 41

The blockage can be bypassed by connecting a section of vein (taken from the leg) to the artery, on each side of the blockage.

Question 42

A heart valve may become defective and not allow enough blood to flow when open, or allow blood to leak back the wrong way when shut, and may be heard by a doctor as a _____ ______.

Answer 42

heart murmur

Question 43

Faulty heart valves can be replaced by:

Answer 43

artificial valves or valves taken from a deceased human donor or a pig

Question 44

The heartbeat originates from special __________ cells at the top of the heart in the wall of the right atrium which produce electrical impulses that spread to the atria and ventricles.

Answer 44

pacemaker

Question 45

The electrical impulses can be shown as an ____________ on a special detector.

Answer 45

electrocardiogram (ECG)

Question 46

An irregular heart beat may be treated by implanting an artificial _________,

Answer 46

pacemaker