W22 Body defences and immunity

Question 1

What are some First line body defences against pathogens?

Answer 1

Skin, tears, mucus in nasal cavity and trachea, stomach acid, saliva

Question 2

What are the roles of the lymphatic system in terms of body defence?

Answer 2

• Transports WBC’s to fight infection

- Filters out microbes and waste in lymph nodes

Question 3

What is lymph?

Answer 3

filtered interstitial fluid (filtered from plasma)

Question 4

What are innate and adaptive defence? Give examples of each.

Answer 4

Innate: Second line defence
Non-specific interior defence, existing from birth.
Examples: Phagocytic WBC’s, antimicrobial proteins, inflammatory response

Adaptive: Third line defence
Specific defence, can adapt depending on pathogen.
Examples: lymphocytes (T and B), antibodies

Question 5

What is an antigen?

Answer 5

Antigens = all foreign molecules that trigger specific immune response

Question 6

What are antibodies? what are their role?

Answer 6

Antibodies are proteins produced by lymphocytes

They bind to antigens & trigger a response to eradicate them

Question 7

What happens during automimmunity?

Answer 7

If T-cells fail to recognise self from non-self, you get autoimmunity

Question 8

What are the primary lymph organs?

Answer 8

Bone marrow, thymus

Question 9

What are the secondary lymph organs?

Answer 9

Tonsils, spleen, lymph nodes

Question 10

What is a microbiota?

Answer 10

A population of microbes

Question 11

What is a biofilm? Where can they be found?

Answer 11

Bacteria form a biofilm , where they stick to eachother and a often a surface. Like a living clingfilm.
Found on TEETH, GI tract, the lung
Makes them more resistant to antimicrobials (like antibiotics)

Question 12

How is a normal microbiota beneficial to us?

Answer 12

Protects against potentially harmful organisms BY competing for binding sites with pathogenic microorganisms

Question 13

Describe the 3 symbiotic relationships

Answer 13

Mutualism: both parties benefit
Commensalism: one party benefits, but the other is unharmed
Parasitism: microbe benefits at the expense of host

Question 14

Which two types of T-cells are there? What are their specialties?

Answer 14

CD4: Activates B-cells, T-cells, macrophages
CD8: Kills foreign cells, and body cells with foreign antigens

Question 15

What are the different forms of immunity?

Answer 15

Natural Active: immunity from infection of pathogen
Natural Passive: immunity passed from mother to fetus

Artificial Active: vaccine with virus
Artificial Passive: injection of immune serum (someone elses antibodies)