Chapter 6: Exercise & the Immune System

Question 1

mechanisms of defense of the innate immune system

Answer 1

phagocytosis, apoptosis, complement, and acute inflammation

Question 2

define phagocytosis

Answer 2

ingestion of bacteria by macrophage and neutrophils

Question 3

define apoptosis (innate)

Answer 3

natural killer cells destroy tumor and virally infected cells by programmed cell death

Question 4

define complement

Answer 4

complement proteins tag surface of bacteria and destroy it by creating pores in surface

Question 5

define acute inflammation

Answer 5

pathogen activates immune cells within injured tissue, including “alarm” cells (macrophage , neutrophils)

Question 6

mechanism of acute inflammation

Answer 6

“alarm” cells trigger vasodilation and increased vascular permeability —> increased blood flow to injured area —> inflammation

Question 7

define sterile inflammation

Answer 7

inflammation in the absence of any pathogen

Question 8

define chronic inflammation

Answer 8

due to persistent infection or prolonged immune response

Question 9

what is low grade chronic inflammation caused by

Answer 9

inactivity, obesity, aging

Question 10

what is high grade chronic inflammation caused by

Answer 10

certain cancers and rheumatoid arthritis

Question 11

role of B cells (plasma cells)

Answer 11

secrete antibodies that tag pathogen for destruction

Question 12

role of cytotoxic T cells

Answer 12

kill virally infected cells

Question 13

role of helper T cells

Answer 13

secrete cytokines that enhance immune response

Question 14

role of regulatory T cells

Answer 14

prevent immune system from attacking normal body antigens

Question 15

what kind of exercise is shown to improve immunosurveillance

Answer 15

acute moderate exercise (40-60% VO2 max) < 60 mins
moderate intensity / short duration

Question 16

how does acute moderate exercise boost immunosurveillance? when does it return to normal?

Answer 16

boosts innate and adaptive immune system, returns to normal after about 3 hours

Question 17

what type of exercise has a depressive effect on immune system?

Answer 17

prolonged exercise (> 90 mins)
high intensity / long duration

Question 18

How does acute prolonged exercise depress the immune system?

Answer 18

decreases levels of B cells, T cells, and natural killer cells
decreases natural killer cell activity and T cell function
decreases nasal neutrophil phagocytosis
decreases nasal and salivary IgA
increases pro and anti inflammatory cytokines

Question 19

what is the relationship between chronic exercise workload and UTRI risk?

Answer 19

J curve model, too little is normal risk, too much is higher risk

Question 20

how does continuous moderate aerobic exercise protect against infection?

Answer 20

regularly boosts immunosurveillance, and has associative factors (less emotional stress, better nutrition, adequate sleep)

Question 21

describe the “open window” concept

Answer 21

window after high-intensity / long-duration aerobic exercises where an individual is at an increased risk of infection because of a depressed immune system

Question 22

does exercising in a hot environment impair immune function?

Answer 22

no, even though we see an increase in cortisol compared to a cold environment, it is not enough to elicit a depressive immune response

Question 23

does exercising in a cold environment have an effect on the immune system?

Answer 23

no

Question 24

does exercising at a high altitude have an effect on the immune system?

Answer 24

yes, we see increased levels of cortisol and in the field, increased risk of URTI

Question 25

when is it okay to exercise when you are sick?

Answer 25

when symptoms are above the neck (runny nose, nasal congestion, sore throat), just reduce intensity or duration

Question 26

when is it not okay to exercise when sick?

Answer 26

if symptoms are below the neck (chest congestion, cough, stomach pain)

Question 27

when is it definitely NOT okay to exercise when sick?

Answer 27

when you have a fever, fatigue, or widespread muscle aches