Diseases

Question 1

What is a disease?

Answer 1

the condition in which the normal state of an organism is modified or damaged.
Types of diseases:
Pathogenic Diseases
Deficiency Diseases
Physiological Diseases
Hereditary Diseases

Question 2

Cause of Pathogenic diseases

Answer 2

pathogens..microscopic organisms. a pathogen is a parasite that causes diseases in its host e.g. viruses, bacteria, fungi protozoans.

Question 3

cause of deficiency diseases are

Answer 3

shortage or lack of a particular nutrient in the diet

Question 4

causes hereditary

Answer 4

an abnormal gene passed on from one generation to the next

Question 5

physiological cause

Answer 5

malfunctioning of a body organ or a change in the structure of certain body cells over time causing them not to function properly

Question 6

communicable (pathogenic) and non communicable (every other disease type)

Answer 6

communicable/infectious diseases can be passed on from one person to person whereas non-communicable diseases cannot be passed on from person to person

Question 7

vector- rats transmit lepto fleas the bubonic plague etc

Answer 7

an organism that carries pathogens in or on its body. it transmits the pathogen from one person to another and is usually not harmed by the pathogen.

Question 8

the life cycle of the mosquito

Answer 8

has for distinct stages
egg
larva
pupa
adult

Question 9

control of mosquitoes

Answer 9

to control any vector, its life cycle must be understood to work out at which stage or stages control would be most effective.

larvae and pupae control-
draining stagnant water
adding insecticides to breeding areas to kill larvae and pupae
introducing fish like tilapia into breeding areas to feed on the larvae and pupae
spraying oil and kerosene onto still water breeding areas to stop the larvae from breathing

adult control-
spraying with insecticides
removing dense vegetation to reduce protection for adults during daylight hours

Question 10

Treatment

Answer 10

The aim of treating a disease is to relieve the symptoms experienced by persons suffering from the disease and cure the disease if possible.

Question 11

Control

Answer 11

The aim of controlling a disease is to prevent further development and spread of the disease so that the incidence of the disease in the population is reduced.

The ultimate goal of treating and controlling any disease is to totally eradicate it from the human population.

Question 12

Examples of pathogenic diseases

Answer 12

AIDS, common cold, influenza, dengue and yellow fever are caused by viruses. MOSQUITOES

Gonorrhoea, syphilis, tuberculosis (TB) and cholera are caused by bacteria.

Athlete’s foot, thrush and ringworm are caused by fungi.

Malaria, amoebic dysentery and sleeping sickness are caused by protozoans

Question 13

Examples of deficiency diseases

Answer 13

Scurvy is caused by deficiency of vitamin C.

Anaemia is caused by a deficiency of iron.

Kwashiorkor is caused by a deficiency of protein.

Question 14

examples of hereditary diseases

Answer 14

sickle cell cystic fibrosis and Huntingdon’s

Question 15

Examples of physiological diseases

Answer 15

Diabetes, hypertension, cancer and Alzheimer’s disease.

Question 16

The role of diet in controlling physiological diseases

Answer 16

Diabetes and hypertension can both be controlled by eating a healthy, balanced diet

Question 17

Social, environmental and economic implications of disease

Answer 17

Disease within human populations can cause loss of earnings as persons with the disease are unable to work. Businesses then become less productive due to a reduction in hours of labour, and this leads to a reduced economy. Demands on health services increase as more people have to seek treatment. Ultimately, human resources are lost and standards of living are reduced.

Question 18

Diabetes type 1

Answer 18

caused by the pancreas not producing any insulin. It is treated by regularinjections of insulin. Blood glucose levels of people with type 1 diabetes can suddenly drop toolow, in which case an injection of glucagon can be given

Question 19

type 2 diabetes

Answer 19

caused by the pancreas not producing enough insulin or by the body cells notresponding to the insulin. It is usually treated by taking tablets to lower blood glucose levels.

Question 20

Hypertension

Answer 20

a condition in which the pressure of the blood in thearteries is higher than normal. Factors that contribute to its development include being overweight orobese, smoking, too much salt or too much fat in the diet, consumption of too much alcohol, lack of physical exercise and stress. It is treated by taking drugs to lower blood pressure.

Question 21

There is a tendency for babies fed on powdered milk to gain weight morerapidly than breast fed babies. Suggest TWO reasons for this.

Answer 21

higher protein contet when compared to the protein content in females