immune system

Question 1

2 branches of the immune system

Answer 1

Innate (non-specific)
Adaptive (specific).

Question 2

what is the immune systems primary role

Answer 2

body defends against foreign pathogens including viruses (cold, flu), bacteria (pneumonia) & fungi, by recognising the difference between self and nonself

Question 3

cells of the innate immune branch

Answer 3

• Monocytes/ Macrophages - 0.2-1.0 x 10(9) /l
• Neutrophils - 2.5-8 x 10(9) /l
• Natural Killer Cells - 0.1-0.3 x 10(9) /l

Question 4

cells of the adaptive immune branch

Answer 4

• Lymphocytes (T-cells and B-cells) - 1.5-3 x 10(9) /l

Question 5

cells of the adaptive and innate immune system

Answer 5

• White blood cells (or leukocytes) - 5-10 x 10 to the power of 9 /l

Question 6

physical barriers
- what are they
- examples

Answer 6

• physically prevent substances from infecting
• eg. hair, mucus, skin, saliva, coughing, vomit, urine, tears, diarrhoea

Question 7

2 types of innate immunity

Answer 7

cell-mediated and humoral

Question 8

what is innate cell-mediated immunity

Answer 8

recognises pathogens non specifically

Question 9

what is a monocyte

Answer 9

• type of phagocyte that engulfs microbes and dead cells by phagocytosis

Question 10

what is a neutrophil

Answer 10

• type of phagocyte that engulfs microbes and dead cells by phagocytosis and also kills via the release of toxic molecules (respiratory burst)

Question 11

what is a natural killer cell

Answer 11

• Enters and Destroys virus-infected & cancerous cells by producing proteins to kill the host cell

Question 12

what is innate humoral immunity and how does it work (compliment proteins)

Answer 12

• Certain complement proteins can bind to antibodies or patterns on microbes (e.g., bacteria) or dead cells. They label and recruit phagocytes to the site via chemical gradients (complement cascade).

Question 13

what cells bridge innate and adaptive immunity and how

Answer 13

• dendritic cells/antigen presenting cells process parts of foreign bodies and present the antigen to cells of the adaptive immune system (T and B cells) in lymph nodes.

Question 14

what is adaptive immunity

Answer 14

• When the body re-encounters the same antigen – T and B cells action an immune response based on memory

Question 15

adaptive cell mediated immunity
- what cells

Answer 15

• helper t cells activate b cells to divide into antibodies and stimulate cytoxic t cells
• cytoxic t cells reognise antigens on cells and release toxins and cytokines that result in host cell death

Question 16

what cells are used in adaptive humoral immunity and what do they do

Answer 16

• b cells divide into plasma cells which produce antibodies which bind to and recruit phagocytes to destroy infected cells

Question 17

how can we measure immune function

Answer 17

• ask about how often someone has been ill
• concentration of immune cells
• measure antibody/enzyme responses to infection
• speed of recovery from a cut

Question 18

what is the open window for infection hypothesis

Answer 18

• increase in immune cells seen during exercise, then a drop below rest in hours after
• theory is that in this period you are vulnerable to infection

Question 19

why the open window for infection hypothesis is wrong

Answer 19

• cells are mobilised from endothelial wall which show an increase but not really
• immune cells are redistributed to sites of damage/infection where they are needed, eg. muscles

Question 20

how do t cells use metabolism to provide ATP to move and produce molecules to destroy infected cells

Answer 20

use glycolysis

Question 21

theory why individuals become susceptible to illness post exercise

Answer 21

• immune cell activation is impaired as oxygen and nutrient demands cannot be met so cannot initiate an appropriate immune response

Question 22

how long after exercise do immune cells migrate to tissues to address damage
- benefits of this migration

Answer 22

• 2 hours
• reduce inflammation, faster wound healing, faster muscle healing, reduced number of infections at the site

Question 23

what is better for immune function (as we currently know), moderate or heavy-intensity exercise

Answer 23

• Moderate - More antibodies and immune cells, reduced inflammation, better function of immune cells and vaccine response
• Heavy- Less antibodies and responsive immune cells, reduced immune cells and function of immune cells, poorer redistribution of immune cells

Question 24

impact of exercise on older and clinical populations’ immunity

Answer 24

• can improve and delay the decline in immune function
• may inhibit tumour growth