2.2 Animal Tissues, Organs and Systems

Question 1

What substance carries the different components of blood around the body?

Answer 1

Plasma

Question 2

What substances are transported by plasma ?

Answer 2

• Red blood cells
• White blood cells
• Platelets
• Carbon dioxide
• Urea
• Products of digestion

Question 3

What is plasma ?

Answer 3

A yellow liquid within blood that transports substances around the body

Question 4

What is the purpose of red blood cells in blood ?

Answer 4

Transport of oxygen around the body

Question 5

How are red blood cells adapted for their function?

Answer 5

• Biconcave shape - increased surface area to volume ratio.
• No nucleus - more room for haemoglobin to bind to oxygen.
• Contain haemoglobin - binds to oxygen.

Question 6

What is the purpose of white blood cells in blood ?

Answer 6

They form part of the immune system , which protects the body from invading pathogens

Question 7

How are white blood cells adapted for their function ?

Answer 7

• Have a nucleus - contains DNA which codes for proteins
• Can produce antibodies
• Can produce antitoxins
• Can engulf and digest pathogens (phagocytosis)

Question 8

What is the purpose of platelets in blood ?

Answer 8

Platelets are small cell fragments which aid the clotting of blood at the site of a wound.

Question 9

Why is the function of platelets inportant ?

Answer 9

• Platelets aid in the process of blood clotting .
prevents bacteria from entering the wound.

Question 10

What is coronary heart disease ?

Answer 10

Coronary heart disease occurs when the coronary arteries that supply the heart muscle become blocked with a buildup of fatty material.
This restricts the supply of oxygen to the heart, possibly leading to a heart attack or death.

Question 11

What is a stent and how does it work ?

Answer 11

A stent is a metal mesh tube that is inserted into a blocked artery so that it remains open.
The stent is inflated using a balloon, which is later removed to allow blood to flow freely.

Question 12

What are the adv and disadvantages of stents ?

Answer 12

Advantages
• Insertion can be carried out without general anaesthetic
• Quick recovery time
• Lower the risk of a heart attack
Disadvantages
Risk of postoperative infection
• Risk of blood clots at site of stent

Question 13

What are statins ?

Answer 13

Statins are drugs which reduce the level of LDL (bad) cholesterol which contributes to the development of coronary heart disease.

Question 14

What are the adv and disadvantages of statins ?

Answer 14

Advantages
• Reduce risk of strokes, coronary heart disease and heart attacks
• Increase level of HDL (good) cholesterol
Disadvantages
• Have to be taken continuously
• May have side effects
• Effect may not be immediate

Question 15

What is a heart bypass surgery ?

Answer 15

A surgery where blocked coronary arteries are replaced with sections of veins taken from other parts of the body.

Question 16

What are the consequences of leaky heart valves?

Answer 16

Blood flows in the wrong direction, causing the heart to become less efficient. Patients may become breathless and die as a result.

Question 17

What type of valves can replace leaky valves?

Answer 17

• Mechanical - made of metal or polymers
• Biological - taken from animals (pigs, sometimes humans)

Question 18

What are the adv and disadvantages of mechanical valves?

Answer 18

Advantages
• Last for a very long time
Disadvantages
• Need to take medication to prevent blood clotting around valve

Question 19

What are the advand disadvantages of biological valves?

Answer 19

Advantages
• Work very well - no medication required
Disadvantages
• Only lasts 12-15 years

Question 20

What is the purpose of an artificial heart ?

Answer 20

Artificial hearts are intended to support a patient’s heart while they wait for a suitable donor heart.

Question 21

What are the adv and disadvantages of artificial hearts ?

Answer 21

Advantages
• Less likely to be rejected by immune system
• Allows damaged heart to rest to help recovery
Disadvantages
• Risk of infection due to surgery
• Risk of blood clots
• Have to take blood-thinning drugs

Question 22

What is health ?

Answer 22

Health is the state of physical and mental wellbeing

Question 23

What is a communicable disease?

Answer 23

A disease caused by a pathogen which can be transmitted from one person to another eg. The flu

Question 24

What is a non-communicable disease?

Answer 24

A disease the can not be transmitted from person to person eg. Cancer

Question 25

How can diet affect health ?

Answer 25

• Too little food / lack of nutrition - anaemia, vitamin deficiencies.
• Too much food / too much unhealthy food - obesity, type 2 diabetes.

Question 26

How can stress affect health ?

Answer 26

Prolonged stress is linked to a wide range of health problems including heart diseases, cancers and mental health issues.

Question 27

How can life situations affect health ?

Answer 27

Many life factors such as location, gender, financial status, ethnic group and healthcare provision can impact a person’s mental and physical health.

Question 28

Give examples of how health problems can interact

Answer 28

• Infection with certain viruses can lead to cancer eg. hepatitis infections can lead to liver cancer.
• A compromised immune system (eg. due to cancer) can lead to a higher risk of infection with communicable diseases.
• Immune reactions caused by a pathogen can trigger allergic reactions.
• Problems with physical health can lead to mental health issues.

Question 29

What is a risk factor ?

Answer 29

A risk factor is an aspect of a person’s lifestyle or a substance found in the body or the environment which can increase the risk of a disease.

Question 30

What is a casual mechanism ?

Answer 30

A mechanism which demonstrates how one factor boilogically influences another

Question 31

How do diet , smoking and exercise affect the development of cardiovascular disease?

Answer 31

• Diet: high levels of LDL cholesterol causes arteries to become blocked, increasing blood pressure and the risk of a heart attack.
• Smoking: nicotine increases heart rate; other chemicals damage the artery lining and increase blood pressure.
• Exercise: lowers blood pressure, reducing strain on the heart.

Question 32

How does obesity affect the development of Type 2 diabetes ?

Answer 32

• Obesity is strongly linked with the onset of type 2 diabetes - a disease in which the body stops responding to insulin.

Question 33

How does alcohol affect liver and brain function ?

Answer 33

• Excessive long-term alcohol use may lead to liver cirrhosis (scarring of the liver).
• Increases risk of liver cancer.
• Damages brain tissue and nerve cells.

Question 34

How does smoking affect the development of lung disease and lung cancer?

Answer 34

• Tar in tobacco can damage the alveoli of the lungs, leading to chronic obstructive pulmonary disease (COPD).
• Tar also damages the cells which line the lungs, leading to lung cancer.

Question 35

How do smoking and alcohol affect unborn babies ?

Answer 35

• Carbon monoxide from tobacco smoke reduces the amount of oxygen the foetus receives, which can lead to premature birth or stillbirth.
• Alcohol passes across the placenta and damages the developing foetus. Once born, the baby may have a number of deformities and health problems as part of foetal alcohol syndrome.

Question 36

How do carcinogens affect the development of cancer ?

Answer 36

lonising radiation is a type of carcinogen which can cause mutations in DNA, potentially leading to cancer.

Question 37

What is cancer ?

Answer 37

Cancer is the development of a tumour as a result of uncontrolled cell division.

Question 38

What is a benign tumour ?

Answer 38

• A tumour that is contained in one location, usually within a membrane.
• They are not cancerous and do not invade other parts of the body.
• Can grow large very quickly - may cause damage to another organ.

Question 39

What is a malignant tumour ?

Answer 39

• A tumour that can spread around the body via the blood and lymphatic system.
• Can invade other tissues (metastasis).
• Cells divide more rapidly and have a longer lifespan.
• Disrupts healthy tissues and may lead to death.

Question 40

Give examples of factors which can lead to cancer

Answer 40

• Genetics - certain genes increase the risk of breast and ovarian cancer
• Smoking
• Obesity
• lonising radiation - UV light and X-rays
• Viral infections - HPV and cervical cancer

Question 41

What are villi ?

Answer 41

Villi are cells in your small intestine which absorb nutrients into the bloodstream.
Their hair-like shape means they have a large surface area, maximising the rate of absorption.

They contain microvilli which increases the surface area of the cell, usually for absorption

Question 42

What is carcinogens ?

Answer 42

Chemicals and other agents that can cause cancer