Topic 13: Exercise and Immunity (Not Finished) (HL) Flashcards
Pathogen
Any organism or substance capable of causing disease
Self
Refers to 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
- 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
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 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.
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 is a term for all WHITE blood cells that fight off diseases
- 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, and symptoms like pain, heat, redness, swelling, and possible loss of function.
B.2. Clotting
- 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
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
