Topic 13: Exercise and Immunity (Not Finished) (HL)

Question 1

Pathogen

Answer 1

Any organism or substance capable of causing disease

Question 2

Self

Answer 2

Refers to 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
• The non-self particles that are infectious or pathogenic, like bacteria, viruses, and parasites, make proteins called antigens that allow the human body to know that they intend to cause damage

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 is the physical barrier between inside and outside of the body.
• Tears in the eyes; mucous membranes; mucus secretions that trap and rinse away pathogens; and cilia in the nasal passages and respiratory tract
• 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 is a term for all WHITE blood cells that fight off diseases
• 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 response to any tissue irritation, injury, or infection; a localized protective reaction involving increased capillary blood flow and capillary permeability, triggered by histamine release from tissue mast cells, and characterized by pain, heat, redness, swelling, and sometimes loss of function.

Question 14

B.2. Clotting

Answer 14

• Platelets in the blood react, changing shape, to form a mesh like structure that can also trap red blood cells, creating a blood clot and preventing bleeding.
• This structure dries and forms a scab, which also acts as a physical barrier, preventing entry by pathogens

Question 15

Lymphocyte and antibody production

Answer 15

Lymphocytes are white blood cells which will either destroy pathogens or produce antibodies to mark the pathogens for destruction

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

• They are 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