Topic 13: Exercise and Immunity (HL)

Question 1

Pathogen

Answer 1

Any organism or substance capable of causing disease

Question 2

Self

Answer 2

Particles, such as proteins and other molecules, that are a part of, or made by, your body

Question 3

Non-self

Answer 3

• Refers to particles that are not made by your body
• Sometimes called foreign bodies

Question 4

13.1.1. State the function of the immune system

Answer 4

• Protects body from infectious disease.
• Involved in tissue repair and protection against potential pathogens
• Looks for and remove pathogens

Question 5

13.1.2. Outline the mechanisms the body uses in response to damage or an infectious agent

Answer 5

• Physical: skin, epithelial linings, mucosal
  secretions
• Chemical: pH of bodily fluids, hormones and
  other soluble factors
• Leucocytes: white blood cells that fight
  disease
• Inflammation
• Clotting
• Lymphocyte and antibody production

Question 6

Characteristics of the INNATE IMMUNE SYSTEM

Answer 6

• Quick response
• First line of defense
• More primitive, it targets everything perceived to be a foreign threat
• Non-specific immune system / In-born immune system
• Does not provide long-lasting immunity to the host

Question 7

Characteristics of the ADAPTIVE IMMUNE SYSTEM

Answer 7

• Delayed response
• Second line of defense
• More complex, it targets specific threats that it recalls from past memory
• Specific immune system / Acquired immune system
• Creates immunological memory after an initial response to a specific pathogen

Question 8

Barriers of Innate Immune Sytem (A)

Answer 8

A.1. Physical Barrier

A.2. Chemical Barrier

A.3. Leukocytes: Macrophages

Question 9

A.1. Physical Barrier

Answer 9

• Skin
• Tears in the eyes; mucous membranes; mucus secretions
• Epithelial surfaces, such as the linings of the lungs and stomach.
• Eyelashes and other body hair.

Question 10

A.2. Chemical Barrier

Answer 10

• Low pH of the stomach, which inhibits the growth of pathogens.
• Urination
• Tears: contain lysozymes (an enzyme that destroys bacteria on eyes)
• Salivary enzymes
• Vaginal secretions
• Hormones

Question 11

A.3. Leucocytes: Macrophages

Answer 11

• leukocyte = WHITE blood cells
• part of the innate immune system
• responds to inflammation, clotting

Question 12

Barriers of Adaptive Immune System (B)

Answer 12

B.1. Inflammation

B.2. Clotting

B.3. Lymphocyte and antibody production

Question 13

B.1. Inflammation

Answer 13

• The body’s localized response to tissue damage or infection
• Marked by increased blood flow, histamine release
• Symptoms: pain, heat, redness, swelling, and possible loss of function.

Question 14

B.2. Clotting

Answer 14

• Platelets form a mesh that traps red blood cells to create a clot and stop bleeding
• The clot dries into a scab, blocking pathogen entry

Question 15

Lymphocyte and antibody production

Answer 15

Lymphocytes destroy pathogens or produce antibodies to target them.

Type of white blood cell include:

• Natural killer cells (innate immune system)
• T cells (adaptive immune system)
• B cells (adaptive immune system)

Question 16

T CELLS

Answer 16

• lymphocytes
• produced in stem cells in bone marrow
• contain receptors which allow them to bind to pathogens

Question 17

B CELLS

Answer 17

• Produced in the bone marrow
• Contain B cell receptors that bind to antigens.
• Produce antibodies
• Activated by T cells or directly by antigen
• Memory B cells persist in the body to quickly produce antibodies

Question 18

ACUTE EFFECTS OF EXERCISE ON IMMUNE FUNCTION

Answer 18

• increase in the number of circulating leukocytes
• Increase in plasma concentration of hormones

Question 19

13.1.3. Describe the effects of intense and long-term training on the immune system.

Answer 19

When training loads are high and prolonged:

• Decrease in innate and adaptive immune function
• Cortisol and adrenaline suppress the immune system
• Leucocyte numbers drop compared to sedentary people
• High load and long training = decrease in leucocytes
• Short intense = increase in leucocytes

Question 20

13.1.4. Discuss the relationship between exercise and susceptibility to infection.

Answer 20

Athletes are more susceptible to infections than their sedentary peers because of:

• lower leukocyte numbers caused by the stress of the exercise
• inflammation caused by muscle damage
• greater exposure to airborne bacteria and viruses because of an increased rate and depth of breathing.

Question 21

13.1.5. Describe strategies for minimizing risk from infection among athletes.

Answer 21

• Incorporation of sufficient recovery time into training programmes.
• Avoid close contact with people with infections.
• Maintain oral hygiene.
• Maintain hydration status.
• Ensure water is pathogen-free.
• Maintain good personal hygiene (for example, washing hands, avoiding hand-to mouth contact).
• Maintain a suitable and varied diet.
• Ensure sufficient sleep.

Question 22

Explain the J curve in relation to exercise and susceptibility to infection

Answer 22

• as one’s exercise levels increase → their susceptibility to infection decrease, but only to a certain point
• past this point, the body’s immune response will decrease
• susceptibility to contracting disease increase