immune system

Question 1

where did intial links with sport and the immune system come from?

Answer 1

athletes complaining of illness following intensitive competition higher than the rate of the population or at any other time in their season

Question 2

what is the difference in % in URTI symptoms in marathon runners compared to control group of runners who didn’t run it?

and what factor increases the %?

Answer 2

urti - upper respiratory tract infections (minor illnesses)

13% of marathon runners
2% of controls

more likely the more km run in the weeks leading up to marathon

Question 3

what is the difference in % of urti incidence of older women doing moderate, low and sedentary activity?

Answer 3

50% of sedentary
% much lower in low and even lower in moderate

(contradicts marathon runners results)

Question 4

what does the J shaped curve explain?

Answer 4

risk of urti dependent on exercise and intensity

end of J at low intensity at average/low risk

middle of J at moderate insensity at low risk

high intensity at end of J and much higher risk

Question 5

how do we defend against pathogens innately/’frist line of defence’?

Answer 5

1. anatomical barriers - mucus, skin and low pH in stomach
2. chemical barriers
3. immune cells - granulocytes, monocytes and natural killer (destroy infection by killing host cells but non-specific killing anything foreign)

Question 6

how do we defend against pathogens acquired?

Answer 6

specific and previous exposure required

cells - develop immune cells to destroy illness e.g cytotoxic t cells

humoral - atnibodies

Question 7

which WBCs engage in which functions?

Answer 7

phagocytosis (engulf and destory) - neutrophil & monocyte

destory parasites - eosinophil

inflammation - basophil

immune response - lymphocyte

Question 8

effect of exercise on circulating white blood cells/leukocytes?

and specifically neutrophils and lymphocytes

Answer 8

exercise produces increase in leukocytes (leukocytosis)

after exercise falls to resting levels

lymphocytes - go below baseline level after exercise so open to infection

2 hours later rise in neutrophil

difference in response (straight after vs dalyed) = biphasic response

Question 9

what is meant by ‘demargination’?

and what does it explain?

Answer 9

during exercise, increase in shear stress and catecholamines meanes adherence of WBCs to walls of vessels decreases

therefore more immune cells in blood as come away from walls

Question 10

what are the 2 response after exercise by WBCs?

Answer 10

immediate & delayed

Question 11

what is involved in the immediate response of WBCs after exercise?

Answer 11

increased catecholamines and shear stress

decreased endothelial adherence (demargination)

so increased circulating lymphocytes and neutrophils

Question 12

what is involved in the delayed response of WBCs after exercise?

Answer 12

cortisol levels might not reach peak until following exercise

cortisol increases release of neutrophils from bone marrows but lag when doing this as transport etc.

Question 13

what is lymphocytopemia and what is the result of it?

Answer 13

fall in levels of lymphocytes following exercise which can lead to ‘open window hypothesis’ meaning vulnerability to infection

Question 14

what is the function of neutrophil?

how to check if working properly?

Answer 14

part of innate immune system

open up, absorb antigen, digest and get rid of - phagocytosis

degranulation and respriatory burst gives idea of whether doing correct function

Question 15

what is the response of neutrophil to acute exercise?

Answer 15

increase immediate and after 2 hours

fall in function after exercise and 2 hours after so more but not as good at their job - function inhibited

Question 16

what is the response of neutrophil to different types of training?

explanations for this?

Answer 16

intensified training - decrease in neutrophil function as more release of neutrophils from bone marrow due to higher cortisol levels and mature ones run out (depleted stores after chronic training) and new naive cells aren’t as good

Question 17

what is selective proliferation?

Answer 17

when well have immune cells with specific surface antigen receptor

foreign agents when ill and need specific surface antigen receptor to fit it

make lots more of certain immune cell which has that antigen to get rid of all forgein agents - selective proliferation

Question 18

describe lymphocyte proliferaton during exercise?

Answer 18

way at looking at lymphocyte function

proliferation doesn’t change in controls

marathon runners - for 3 hours after decline in ability to selectively proliferate lymphocytes
due to increased cortisol levels inhibiting

Question 19

how do lymphocytes start out and what will be formed in the case of viral or bacterial infections?

Answer 19

t or b cell always start as naive t helper cells

either go to t helper 1 to t (viral) or 2 to b (bacterial) lymphocytes

Question 20

response of lymphocytes to viral infection?

Answer 20

increase in t helper 1 cells and increased t lympocytes

produce ifn, il2 and tnf beta

known as cell-mediated immunity - intracellular pathogens - receptors to detect antigens

Question 21

response of lymphocytes to bacterial infection?

Answer 21

t helper 2 cells increasing b lymphcytes

creating antibodies of il4, il10 and il13 increasing

known as humoral immunity - extracellular pathogens - antibodies

Question 22

what is the cell mediated response to severe exercise?

how is cell mediated repsonse measured?

Answer 22

decline in cell mediated immune response after exercise

measure by seeing how many pricks which have gone in skin inflame - larger inflammation if good immune response as ‘fighting infection’

Question 23

effect of cycling to fatigue and cytokine production?

Answer 23

ifn increased after exercise (t)

no change in il4 (b)

Question 24

what is the il6 response to exercise?

Answer 24

marker of inflammation

increase following exercise

Question 25

are you more likely to produce t or b lymphocytes during exercise?

Answer 25

b lymphocytes from t helper 2 sites due to catecholamines increasing levels of e.g il10
which counter regulates t helper 2 sites which produce t lymphocytes

why getting stressed may decrease immunity due to increase level of adrenaline which is a catecholamine which limits t lymphocytes

Question 26

what is the difference between humoral and cell-mediated immunity?

Answer 26

humoral - produces antibodies to destroy extra-cellular antigens/pathogens and involves B cells for bacterial infections

cell mediated - produces immune cells e.g phagocytes to destory intra-cellular antigens/pathogens and involves T cells for viral infections