Topic 13: Exercise and Immunity (HL) Flashcards
Pathogen
Any organism or substance capable of causing disease
Self
Particles, such as proteins and other molecules, that are a part of, or made by, your body
Non-self
- Refers to particles that are not made by your body
- Sometimes called foreign bodies
13.1.1. State the function of the immune system
- Protects body from infectious disease.
- Involved in tissue repair and protection against potential pathogens
- Looks for and remove pathogens
13.1.2. Outline the mechanisms the body uses in response to damage or an infectious agent
- 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
Characteristics of the INNATE IMMUNE SYSTEM
- 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
Characteristics of the ADAPTIVE IMMUNE SYSTEM
- 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
Barriers of Innate Immune Sytem (A)
A.1. Physical Barrier
A.2. Chemical Barrier
A.3. Leukocytes: Macrophages
A.1. Physical Barrier
- 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.
A.2. Chemical Barrier
- 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
A.3. Leucocytes: Macrophages
- leukocyte = WHITE blood cells
- part of the innate immune system
- responds to inflammation, clotting
Barriers of Adaptive Immune System (B)
B.1. Inflammation
B.2. Clotting
B.3. Lymphocyte and antibody production
B.1. Inflammation
- 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.
B.2. Clotting
- 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
Lymphocyte and antibody production
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)
T CELLS
- lymphocytes
- produced in stem cells in bone marrow
- contain receptors which allow them to bind to pathogens
B CELLS
- 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
ACUTE EFFECTS OF EXERCISE ON IMMUNE FUNCTION
- increase in the number of circulating leukocytes
- Increase in plasma concentration of hormones
13.1.3. Describe the effects of intense and long-term training on the immune system.
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
13.1.4. Discuss the relationship between exercise and susceptibility to infection.
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.
13.1.5. Describe strategies for minimizing risk from infection among athletes.
- 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.
Explain the J curve in relation to exercise and susceptibility to infection
- 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
