Unit 2 - Module 2 - Health And Disease Flashcards
(88 cards)
0
Q
What is disease?
A
A departure from good health.
It is a malfunction of the body or mind which causes symptoms, these may be physical, mental or social.
1
Q
What does it mean if you are in good health?
A
Free from disease Able to carry out normal physical and mental tasks Well fed, with a balanced diet Usually happy, with a positive outlook Suitably housed with proper sanitation Well integrated into society
2
Q
What is a parasite?
A
An organisms that lives in or on another living thing causing them harm?
3
Q
How to parasites cause the host harm?
A
Usually by taking their nutrient from host.
If they become too numerous they may become a huge burden to the host.
They also may cause harm that means they cause secondary infections.
4
Q
What is a pathogen?
A
Organisms that cause disease.
5
Q
How do pathogens harm their host?
A
Thy live by taking nutrition from their host, but also cause damage in the process. This can be considerable.
6
Q
What must a pathogen be able to do in order to cause a disease?
A
Travel from one host to another
Get into the hosts tissues
Reproduce
Cause damage to the host’s tissues
7
Q
What are the most common forms of transmission?
A
By means of a vector
By physical contact
By droplet infection
8
Q
What causes malaria?
A
A eukaryotic organism from t genus Plasmodium Plasmodium falciparum P. vivax P. ovale P. malariae
9
Q
How is malaria spread?
A
A vector. The female Anopheles mosquito
10
Q
Describe this transmission of malaria?
A
If host already has malaria, mosquito will suck gametes into its stomach
Gametes fuse and zygote develops in stomach
Infective stages are formed and move to salivary glands
When bites someone inject saliva as anticoagulant
In human host, infective stages enter liver, where they multiply
Pass into blood where they enter RBC, feed of haemoglobin and gametes are produced
11
Q
What causes HIV/AIDS?
A
Th human immunodeficiency virus
12
Q
What happens once the HIV virus becomes active?
A
It attacks and destroys the T helper cells in the immune system.
This means your ability to resist infection is reduced.
So unable to defend yourself against any pathogen that enters the body and May contract a range of opportunistic infections.
13
Q
What does AIDS stand for?
A
Acquired immune deficiency syndrome
14
Q
How can HIV be transmitted?
A
Exchange of body fluids Unprotected sexual intercourse Unscreened blood transfusions Use of unsterilised surgical equipment Sharing hypodermic needles Accidents such as needle-stick Across the placenta or during child birth From mother to baby during breast feeding
15
Q
What cause tuberculosis?
A
Mycobacterium tuberculosis
Mycobacterium bovis
16
Q
How is Tab transmitted?
A
Droplet infection
17
Q
What conditions make the contraction and spread of TB more likely?
A
Overcrowding Poor ventilation Poor health Poor diet Homelessness Living or working with people who have migrated from areas where TB is common
18
Q
Other than droplet infection, how else can TB be contracted?
A
From milk of meat of cattle
19
Q
In less economically developed countries what aspects may contribute to poor health?
A
Poverty Lack of proper shelter Lack of purified water Poor nutrition Poor hygiene Lack of investment by government Poor or inadequate health services Inadequate education Civil unrest of warfare Inadequate transport facilities that prevent reaching medical assistanc
20
Q
What is th global impact of malaria?
A
Kills about 3 million people each year
About 300 million people are affected worldwide, and the number is increasing
Of all people with malaria 90% live in sub-Saharan Africa
21
Q
Where is malaria found?
A
Where the vector mosquito, Anopheles, can survive. Currently th tropical regions.
Global warming means it may be able to survive further north
22
Q
What is the global impact of HIV/AIDS?
A
At the end of 2005 approximately 45 million people were living with it
More than half of these were in sub-Saharan Africa
Every year 5 million people are newly infected.
By end of 2005, nearly 39 million had dies from related diseases.
23
Q
What is the distribution of HIV/AIDS?
A
By 2006-07 it was spreading rapidly in China, Russia and other Eastern European countries
24
How many people are infected with TB?
Approximately 1% of the population is newly infected each year, and 10-15% of those go on to develop the disease.
In 2005 about 8.8 million new cases were recorded and about 1.6 million people died from it.
Up to 30% of the population may be infected
25
Where is Tb common?
South East Asia and sub-Saharan Africa
| It is rising in Eastern Europe
26
What are the body's main primary defences?
Skin
| Mucous membranes
27
How does the skin work as a primary defence?
The epidermis consists of layers of cells, mostly keratinocytes.
They are produced at the base of the epidermis and migrate out to the surface.
A they migrate the dry out and they cytoplasm is replaced by keratin
When cells reach surface they are no longer alive, and slough off.
28
How do mucous membranes work as a primary defence?
The epithelial layer contains goblet cells.
In airways mucous traps any pathogens and the cilia waft the mucous along to the top of the trachea, where is can enter the oesophagus.
It is swallowed and passes down the digestive system, killed by acidity in stomach.
29
What other primary defences are there?
Eyes are protected by antibodies in tear fluid
Ear can is lined by wax, which traps pathogens
Vagina is protected by maintaining relatively acidic conditions
30
What are neutrophils?
Most common phagocyte
Multilobed nucleus
Manufactured in bone marrow
Travel in blood and squeeze out into tissue fluid.
Also found in epithelial surfaces, such as the lungs
Short lived but releases in large numbers as a result of an infection
31
Describe macrophages?
Larger than neutrophils
Manufactured in bone marrow
Travel in blood as monocytes
Settle in body organs, particularly lymph nodes, where they develop int macrophages
32
How do phagocytes work?
They engulf and destroy pathogenic cells
Pathogen attached to phagocyte by antibody and surface receptors
Pathogen engulfed by unfolding of phagocyte membrane
Pathogen trapped inside a vacuole called a phagosome
Lysosomes fuse with phagosome and release lysis that digest the pathogen
Harmless end products of digestion are absorbed
33
What are antigens?
Molecules that can stimulate an immune response.
Usually large and have a specific shape.
Usually a protein or glycoprotein in or on the plasm membrane
34
What is the structure of an antibody?
Four polypeptide chains hod by disulphide bridges
A constant region
A variable region
Hinge region
35
What is the function of the constant region on an antibody?
It is the same on all antibodies which enable they to attach to phagocytic cells and helps in the process of phagocytosis.
36
What is the function of the variable region on antibodies?
Has a specific shape and differs from one antibody to another.
It ensure the antibody can attach onto to the correct antigen.
It is complementary to that shape of the antigen and can bind to it.
37
What is the function of the hinge regions?
Allow flexibility.
| These allow branches of the Y-shaped molecule to move first apart on order to attach to more than one antigen.
38
How do antibodies work?
Either by neutralisation or agglutination?
39
What is neutralisation?
Antibodies covering the pathogen binding sites prevent the pathogen from binding to a host cell and entering the cell.
40
How does agglutination work?
One large antibody can bind many pathogens together. This means it is too large to enter a host cell
41
What are the stages involved with B cells and humoral immunity?
The surface antigens of invading pathogen are taken up by B cells
B cells process antigens and present them on their surface.
T helper cells attach to the processed antigens on the B cells
B cells are now activated to divide by mitosis to give a clone of plasma cells
The cloned plasma cells produce antibodies complementary to antigen
The antibodies attach to antigens and destroy pathogens
Some B cells develop into memory cells
42
What are the states in cell mediated response?
Pathogens invade body or are taken in by phagocytes
The phagocyte places antigens on it cell surface membrane
Receptors on certain T helper cells fit exactly onto antigens. The receptors on each T cell respond to a single pathogen
This activates other T cells to divide rapidly by mitosis to form clones
43
What can cloned T cells do?
Stimulate B cells to divide
Develop into memory cells
Stimulate phagocytes to engulf pathogens by phagocytosis
Kill infected cell (T killer cells)
44
What forms can the antigenic material in vaccines be?
```
Whole, live microorganisms
A harmless or attenuated version
A dead pathogen
A preparation of the antigens from a pathogen
Some harmless toxin, called toxoid.
```
45
What. Herd vaccination used for?
To provide immunity to all or almost all of the population at risk. Once enough people are immune, the disease can no longer spread.
46
What is an example of her vaccination being used?
To eradicate smallpox
| It was necessary to vaccinate 80-85% of the population
47
What is ring vaccination?
It is used when a new case of a disease is reported.
| It involves vaccinating all the people in the immediate vicinity of the new cases.
48
When is ring vaccination often used?
In many parts of the world to control the spread of livestock disease.
49
In the UK who is vaccinated against influenza?
Over 65s
| At risk groups, often ones with respiratory tract problems, such as asthma
50
Why do people need the flu vaccine every year?
The virus mutates so you no longer have immunity.
| Research is undertaken to determine which of the strains of flu are most likely to spread that year
51
What is active immunity?
Immunity that is achieved by activation of the immune system.
52
What is passive immunity?
It is where antibodies have no been manufactures by stimulating the recipients immune system.
53
What is an example of natural passive immunity?
Antibodies provided via the placenta or via breast milk
54
What is an example of natural active immunity?
Antibodies due to infection.
| E.g. Immunity to chicken pox
55
What is an example of artificial passive immunity?
Antibodies provided by injection of antibodies.
| E.g. Tetanus injections
56
What is an example or artificial active immunity?
Immunity provided by antibodies made in the immune system as a result of vaccination.
E.g immunity to TB and influenza
57
Why are new drugs needed?
New diseases are emerging
Many diseases for which there are no effective treatments
Some antibiotics are becoming less effective
58
How are new drugs discovered?
```
By accident
Traditional medicines
Anaesthetics
Observations of wildlife
Modern research
```
59
What are possible sources of new medicines?
Tropical plants
60
What are harmful substance in cigarette smoke?
Tar, a mixture of chemicals including carcinogens
Carbon monoxide
Nicotine
61
What are the short term effects of tar?
Allergic reaction - smooth muscle contracts lumen gets smaller
Paralyses or destroys the cilia - unable to waft mucus away
Stimulates goblet cells to enlarge and release more mucus
Bacteria and viruses get trapped and are not removed, multiply and may block bronchioles
Presence of bacteria and viruses lungs more susceptible to infection
62
What are the longer term effects of tar?
Smokers cough - an attempt to remove mucus
Cough means delicate lining of airways and alveoli become damaged. Replaced by scar tissue, less flexible and thicker.
Layer of smooth muscle thickens reduces lumen restrict flow of air
63
What do the frequent infections in the lungs cause?
Inflames lining of airways, damages the lining of the airways
Attracts WBC, in order to get into airways release enzymes.
They digest parts of the lining of the lungs in order to pass into air spaces.
Elastase is used. Reduces elasticity of alveolus walls. Do not recoil, bronchioles collapse trapping air in alveoli- burst due to pressure
64
How does cigarette smoke cause lung cancer?
Tar Contains carcinogens, that lies on delicate surface of lungs .
Enter cells, then nucleus, have a direct effect upon genetic material.
If mutation affects genes that controls cell division, then uncontrolled cell division takes place. This is cancer.
65
Where doe lung cancer often start?
At the entrance to the bronchi, as the smoke hits this fork in the airway and deposits tar.
66
What is chronic bronchitis?
It is the inflammation of the lungs, accompanied by damage to cilia and overproduction of mucus so it collects in the lungs.
67
What are the symptoms of chronic bronchitis?
Irritation of the lungs
Continual coughing
Coughing up mucus that is often filled with bacteria and WBC
Leads it an increased risk of lung infection
68
What is emphysema?
The loss of elasticity in the alveoli, which causes them to burst.
Lungs have reduced surface area as larger air spaces are formed
69
What are the symptoms of emphysema?
Shortness of breath, especially when extorting them selves
Breathing becomes shallow and rapid
Fatigue as blood is less well oxygenated.
70
What is COPD?
Chronic obstructive pulmonary disease
| A combination of disease including, chronic bronchitis, emphysema and asthma
71
What effects does nicotine have on the body!
It mimics action of transmitter substances at synapses between nerves. Nervous system more sensitive and smoker feels more alert
Release of adrenaline, increase heart rate and breathing rate and constriction of arterioles, raises blood pressure
Constriction of arterioles to extremities. Reduces blood flow
Affects platelets to make them sticky, increases risk of thrombus
72
What are the effects of carbon monoxide!
Enters RBC combines with haemoglobin. Combines more readily to form carboxyhaemoglobin. Reduces oxygen carry capacity of blood
Feel it when they exercise
Can also damage lining of arteries.
73
What is the effect of damaging the endothelium of arteries?
Carbon monoxide amd high blood pressure
| Repaired by WBC these encourage growth of smooth muscle and deposition of fatty substance.
74
What do the deposits consist of?
Cholesterol from LDLs
Also may include fibres, dead blood cells and platelets.
This process is atherosclerosis
75
What happens with the build up of atheromas?
Occur under the endothelium
It may grow enough to break through inner lining of the artery
Eventually forms a plaque, which sticks out into the lumen
Artery wall is rougher less flexible and lumen is smaller, so blood flow is reduced
76
What is thrombosis?
Blood flowing past plaque cannot flow smoothly.
Increases chance blood will clot
Also stickiness of platelets increases chance
Clot in artery may stop blood flow
77
What three forms can CHD take?
Angina - severe pain in chest
Heart attack - death of heart muscle
Heart failure - cannot sustain pumping action, due to blockage of coronary artery but also other causes
78
What are the two causes of a stroke?
Thrombus floating in blood blocks a small artery leading to part of the brain
An artery leading to brain bursts ( haemorrhage)
79
What are cardiovascular diseases?
Atherosclerosis
CHD
Stroke
Arteriosclerosis
80
What is arteriosclerosis?
The hardening of artery walls, which makes them less flexible.
Caused by deposition of calcium
81
What are the symptoms of cardiovascular disease?
High blood pressure and hypertension are usually first signs
82
What are the symptoms of stroke?
Sudden numbness or weakness of the face arm or leg
Sudden confusion and difficulty speaking or understanding
Sudden difficult with seeing
Sudden difficulty with walking
Sudden severe headache with no known cause
83
What factors increase the risk of developing CHD?
```
Age
Sex
Cigarette smoking
Obesity
High blood pressure
High blood cholesterol concentration
Sedentary lifestyle
Diet- high salt, absence of healthy fats, high level of animal fats, absence of antioxidants
Genetic factors
Diabetes stress
```
84
What epidemiological evidence is there linking smoking and increased risks of early death?
Regular smoker three times more likely to die prematurely
50% of regular smokers are likely to die of smoking related diseases
More cigarettes person smokes per day more likely they will die prematurely
85
What are the links between smoking and lung cancer?
A smoker 18 times more likely to develop lung cancer
25% of smokers dies of lung cancer
Heavy smoke is 25 times more likely to die of lung cancer
Chance of developing lung cancer reduces as soon as they stop smoking
86
What are the links between smoking and lung diseases?
COPD is rare in none smokers
98% of people with emphysema are smokers
20% of smokers have emphysema
87
What experimental evidence is there for smoking?
Dogs forced to breath smoke developed changes similar to those of COPD and early signs of lung cancer
Paint tar on bare skin of mice, they develop cancer in skin celd covered by tar
