Microbiology ll

Question 1

Lymphatic and defense system: Immunity

How is immunity to a disease achieved?

Answer 1

Through the presence of antibodies to that specific disease in a person’s system

Question 2

Lymphatic and defense system:

What are antibodies?

Answer 2

Proteins produced by the body to neutralise or destroy toxins/disease carrying organisms

are disease specific**

e.g Measles antibody will protect a person who is exposed to measles disease but will have no effect if he or she is exposed to mumps.

Question 3

Lymphatic and defence system: How many types of immunity are there? What are they?

Answer 3

• 2
• Active and passive immunity

Question 4

Lymphatic and defence system: Active immunity

How does active immunity occur?

Answer 4

Active immunity occurs when exposure to a disease organism triggers the immune system to create antibodies for that disease

Question 5

Lymphatic and defence system: Active immunity

What are the ways that active immunity can be acquired?

Answer 5

• Either through natural or artificially vaccine-induced immunity
• Natural immunity: is acquired from exposure to to the disease organism through infection with the actual disease
• Vaccine induced immunity: is acquired through the introduction of a killed or weakened form of the disease organism through vaccination
• Either way, if an immune person comes into contact with that disease in the future, their immune system will recognise it and immediately produce the antibodies needed to fight it.
• Active immunity is long lasting, sometimes life long

Question 6

Lymphatic and defence system: How is passive immunity acquired?

Answer 6

Passive immunity is provided when a person is given antibodies to a specific disease, rather than producing them through their own immune system

Question 7

Lymphatic and defence system: Passive immunity

What are the ways that natural immunity can be acquired?

Answer 7

• Natural or artificially
• Naturally: A newborn baby acquires natural immunity from the mother though the placenta, and after birth during breastfeeding
• Artificially: A person received antibody containing blood products such as immune globulin, which may be given when immediate protection from a specific disease in needed

Question 8

Lymphatic and defence system: Passive immunity (artificially acquired type)

When is gamma globulin administered?

Answer 8

After exposure to hepatitis

Question 9

Lymphatic and defence system: Passive immunity (artificially acquired type)

When is other immune sera e.g antivenom, anti toxin administered?

Answer 9

When exposed to their specific diseases… These diseases will kill a person before acquired immunity can be established

Question 10

Lymphatic and defence system: Passive vs Active immunity…

What are some of the benefits/disadvantages of passive vs active immunity and vice versa?

Answer 10

• Passive:
• protection is immediate (benefit)
• Usually only lasts a few weeks/months
• Active:
• Active immunity takes time to develop (usually several weeks to develop)
• Only active immunity is long lasting (benefit)

Question 11

Lymphatic and defence system: Passive + active immunity (extra note*)

• passive immunity has no immunological memory where active does

Question 12

Immune system: Define

Answer 12

The immune system is a complex network of specific immune cells and protein that work in synergy (together) to protect the body against foreign invaders (antigens) and harmful toxic materials coming from the environment

Question 13

Immune system: What are the two ways the immune system can be activated (by immune responses)?

Answer 13

• Innate: non specific responses
• Acquired: specific adaptive response

Question 14

Immune response: DEFINE -

• Antigens

Answer 14

• Any substance/molecule capable of mobilising our immune system and provoking an immune response
• Foreign substances that trigger an immune response include:
• Microbes: Virus, fungi, bacteria etc
• Allergens: pollen, animal dander, food, chemicals etc

Question 15

Immune response: DEFINE

• Antibodies

Answer 15

• Specialised proteins that help immune cells destroy antigens
• Antibodies = often called immunoglobulins
• Bind to the antigen to stop further damage to the cells
• Remain in the body

Question 16

Immune system: Lines of defence

• How many lines of defence are there in the body?
• What is each line of defence made up of?

Answer 16

• There are three lines of defence in the body
• The first two = innate (non-specific defence mechanisms), the last/third line = Adaptive (specific defence mechanisms)
• First line of defence: (innate) - Skin, mucous membranes, secretions of skin and mucous membranes
• Second line of defence: (innate) - Phagocytic cells, natural killer cells/NK cells, antimicrobial proteins, the inflammatory response, fever
• Third line of defence: Lymphocytes, antibodies, macrophages and other antigen-presenting cells

Question 17

Immune System: 2nd line of defence - (non-specific innate responses)

NOTES

Answer 17

• Inflammation
• Natural killer cells (NK cells): recognise and eliminate infected cells
• Phagocytes: consumer infected cells, debris and pathogens
• Antimicrobial proteins (cytokines and the complement system - cell signalling)
• Fever: inhibit microbial multiplication

Question 18

Immune system: Adaptive immune system (third line of defence) usually involves two types of WBC…
- What are they?
- Function?

Answer 18

• B lymphocytes: developed in the bone marrow, produces antibodies and react with antigens
• T lymphocytes: developed in the thymus, attack antigen directly
• A system of recognition and response, reacting to a range of specific microbial and non-microbial substances
  Slow acting – days to weeks
  Specific
  Adaptive – capable of memory

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