M7: Animal responses to pathogens

Question 1

what is included in the first line of defence?

Answer 1

physical barriers, physical responses, chemical barriers

Question 2

What are physical barriers against infection?

Answer 2

passive innate barriers

• skin, mucous membrane, mucous, cilia, sphincters, peristalsis

Question 3

What are some examples of physical responses to infection?

Answer 3

• granuloma
• vomiting and diarrhea
• increased urination
• wound healing

Question 4

What are some chemical barriers against infection?

Answer 4

• urine
• sebum and sweat
• saliva
• tears
• gastric excretions

Question 5

what is involved in the second line of defence?

Answer 5

• antigens, chemical responses,

Question 6

what are antigens?

Answer 6

• protein markers that recognise things as foreign or belonging. If foreign, it activates the immune response.

Question 7

examples of chemical responses in the second line of defence?

Answer 7

inflammation, phagocytosis, complement system, cytokines, pyrogens

Question 8

what is the process of inflammation?

Answer 8

• triggers redness, swelling, pain, and heat through the release of chemicals - (histamine, serotonin, bradykinin). This acts as an alarm that causes capillaries to dilate.

Question 9

process of phagocytosis?

Answer 9

• phagocytes change shape to engulf pathogens, once done enzymes are released to destroy them. mostly macrophages.

Question 10

what is the complement system?

Answer 10

• a group of 20 soluble proteins that assist in destroying pathogens

Question 11

roles of complement system?

Answer 11

• attracts phagocytes to infection and stimulates them to be active
• destroys membranes of invading pathogens

Question 12

what are cytokines?

Answer 12

chemical messengers that are produced during an infection

Question 13

roles of cytokines?

Answer 13

• promote development of and differentiation of immune cells
• form a link between innate and adaptive immune system
• burst from infected cells causes nearby unaffected cells to release cytokines.

Question 14

what are pyrogens?

Answer 14

fever causing chemicals

Question 15

process of pyrogens?

Answer 15

• cytokines send signals to the brain to increase overall body temperature, increase white blood cells and limit the growth of pathogens.

Question 16

examples of cells involved in the second line of defence?

Answer 16

• neutrophil
• macrophage
• natural cell killer
• dendritic cell

Question 17

neutrophil?

Answer 17

release toxins to neutralise or inhibit the growth of bacteria or fungi

Question 18

macrophage?

Answer 18

phagocytosis of pathogens and cancer cells, antigen-presenting.

Question 19

natural killer cell?

Answer 19

kills tumour cells and virus-infected cells.

Question 20

dendritic cell?

Answer 20

an antigen-presenting cell that triggers an adaptive immune response.

Question 21

what is innate immunity?

Answer 21

1st and 2nd line of defence

Question 22

what is adaptive immunity?

Answer 22

3rd line of defence

Question 23

when is cell-mediated response used?

Answer 23

pathogens infect cells

Question 24

when is a humoral response used?

Answer 24

pathogens outside cells

Question 25

T cell? and types?

Answer 25

1. destroy intercellular pathogens
2. helper, killer, memory, suppressor

Question 26

B cells? and types?

Answer 26

1. produce antibodies and destroy extracellular pathogens
2. plasma, memory

Question 27

what is involved in cell-mediated immunity?

Answer 27

• intracellular bacteria
• macrophages/dedndrites present bacterial antigens on their surface
• helper cells stimulate cytotoxic T cells

Question 28

what is involved in humoral immunity?

Answer 28

• extracellular bacteria
• macrophage/dendrites present bacterial antigens on the surface
• helper T cell stimulates production or plasma b cells

Question 29

roles of memory cells?

Answer 29

primary immune response > antibody-producing plasma and cytotoxic cells are stored and stored for the next encounter

secondary immune response > when exposed again, more rapid and reproduces more antigens