Environmental and nutritional pathology

Question 1

Nutritional disorders

Answer 1

occur when there is a lack of essential nutrients in the body

Question 2

Seven different groups of substance essential in the diet

Answer 2

water
carbohydrates
proteins
fats
vitamins
minerals
fibre

Question 3

Primary nutritional deficiency

Answer 3

occurs when a person does not have enough nutrients in their diet
This condition is reversible if the person begins to eat sufficient nutritious food
Examples: Kwashiokor and marasmus arise in famine or inadequate food supply
More specific nutritional deficiencies can also occur if a particular nutrient is missing e.g vitamin A deficiency which results in night blindness
vitamin C results in scurvy

Question 4

Marasmus

Answer 4

when insufficient total calories are consumed

Question 5

Kwashiorkor

Answer 5

result of insufficient protein consumption

Question 6

Secondary nutritional deficiency

Answer 6

occurs when the body’s ability to absorb nutrients is restricted by a disorder or illness.
E.g celiac disease, cystic fibrosis and some cancers

Question 7

Cachexia

Answer 7

loss of body mass that cannot be reversed by correcting diet. Will continue to lose weight
Seen in patients with cancer, AIDS, congestive heart failure, tuberculosis and other serious illnesses
Amphetamine addiction is another cause

Question 8

Obesity

Answer 8

person is defined as obese if they have a body mass index of over 30kg/m2
Obesity is generally due to consumption of excessive calories that exceed the calories used.

Question 9

Obesity increases the probability of a number of diseases including

Answer 9

heart disease
osteoarthritis
insulin resistance
obstructive sleep apnea
certain types of cancer

Question 10

Metabolic syndrome

Answer 10

a cluster of biochemical and physiological abnormalities of energy utilization and storage. Metabolic syndrome increases a persons risk of heart disease, diabetes, stroke and hypertension and is linked to obesity and lack of exercise

Question 11

Harmful agents in the environment include

Answer 11

electrocution
radiation injury
chemical exposure ( air pollution
medications)
personal exposures
physical injury
infectious agents

Question 12

Thermal changes

Answer 12

Many cellular reaction in the body are highly temperature sensitive. Because of this the body is maintained at a fairly constant temperature by the hypothalamus. Changes in the body temperature die to excess heat or cold (Hypothermia) can be dangerous

Question 13

Burns

Answer 13

occur when the body is exposed to extreme heat. Can be classified as first degree, second and third degree depending on the depth of the tissue damage. The area of the body that has been burnt is given as a percentage on the body. Inhalation of heat and smoke causes significant damage. Survival after severe burns will depend on all these factors including the age of the patient

Question 14

Substances in the environment can enter into the body through different portals including

Answer 14

ingestion
inhalation
injection
skin contact

Question 15

Exposure to strong acids or alkalis causes

Answer 15

rupture of cell membranes causing cell and tissue necrosis and capillary damage. Blood then leaks into the tissues and the damage may be similar to that caused by burns

Question 16

Tobacco smoke

Answer 16

is a complex mixture that contains nicotine and many other harmful substances and is therefore dangerous, Many of the chemicals found in cigarettes are highly toxic and exposure to tobacco is extremely damaging to the body. Tobacco is addictive due to the presence of nicotine.

Question 17

Long term causes of tobacco use

Answer 17

cancer 70% causes and 30% related to usage
cardiovascular disease
respiratory disease

Question 18

Gaseous and elements from tobacco are toxic including

Answer 18

carbon monoxide
nicotine
chemical carcinogens
irritant substances

Question 19

Alcohol

Answer 19

Ethanol ( found in alcoholic beverages) is a general depressant of the central nervous system, It affects the brain therefore it is considered a psychoactive drug.

Question 20

Blood alcohol content

Answer 20

measure used to determine a person’s level of intoxication. Intoxication occurs at a blood alcohol (%v/v) of less that 0.1 % and death if the level exceeds 0.5%

Question 21

Effects of blood alcohol content on the body

Answer 21

0.05% chattiness, relaxation
0.1% central nervous system depression impaired motor function reduced sensory function queasiness potential vomiting compromised cognition
> 0.14% decreased blood flow to brain
0.3% confusion disorientation possible unconsciousness
0.4% possible death
>0.55% death

Question 22

Long term use of alcohol

Answer 22

most organ systems in the body may be damaged
As alcoholism can harm liver, pancreas and intestines, secondary malnutrition can result. Developing foetal brain is also susceptible to the toxic effects of alcohol and foetal alcohol syndrome may result if pregnant mothers drink excessive amounts of alcohol.

Question 23

Why methanol and ethyl alcohol are toxic if consumes

Answer 23

They are metabolized to foam toxic carboxylic acid and aldehyde products respectively ethanol can be used to treat poisoning by these alcohols as the ethanol will compete with the other alcohols for the alcohol dehydrogenase enzyme and therefore may be cleared from the body before being metabolized