W9 - Textbook Flashcards
What is it called when the immune system can become functionally depressed?
Immunodepression
What may immunodepression result in?
⬆️ susceptibility to infection
especially URTIs.
What can lead to immunodepression in athletes?
Stress i.e heavy training schedule + comp
What activates the innate immune system?
When an infectious agent tries to enter the body
The innate immune system is known as the 1st line of defence, what 3 general mechanisms in this have the common goal of restricting microorganism entry into the body?
- Physical/Structural barriers
- Chemical barriers
- Phagocytic cells
Give examples of physical/structural barriers in the 1st line defence of the innate immune system
Skin
Epithelial linings
Mucosal secretions
Give examples of chemical barriers in the 1st line defence of the innate immune system
pH of bodily fluids
Soluble factors
Give examples of phagocytic cells in the 1st line defence of the innate immune system
Neutrophils
Macrophages or monocytes
What activates the adaptive/acquired/specific immune system?
Infection due to failure of the innate immune system
Which lymphocytes play a big role in the adaptive/acquired/specific immune system?
T-lymphocyte
B-lymphocyte
What do T-lymphocyte and B-lymphocyte do?
Their receptors recognise the foreign mol (antigens) and cause specificity + memory that enable the immune system to create an augmented response when the body is REinfected by the SAME pathogen.
What is a pathogen?
Organism that causes disease
Where do WBCs (leukocytes) comes from?
Stem cells of bone marrow
What do leukocytes consist of?
Granulocytes (60-70%)
Monocytes (10-15%)
Lymphocytes (20-25%)
What protein do all T-lymphocytes express on the cell surface?
What does this mean they are designated as?
CD3
Designated as: CD3+
What protein do all B-lymphocytes express on the cell surface?
CD19
CD20
CD22
What do the T helper cells (subset of T-lymphocytes) express on their cell surface?
CD4
What protein do the cytotoxic T-cells express on their cell surface?
CD8
What do T-cells do?
Recognise short peptide sequences from antigens if on the surface of the cell + complexed w/ a major histocompatibility complex (MHC) mol.
What are cytokines?
Proteins acting as chemical messengers to stimulate growth, differentiation + functional development of the immune system cells through specific receptor sites on secretory cells or on adjacent cells.
Is cytokine action confined to the immune system?
NO, they also influence the CNS + neuroendocrine system
Innate immune system –> chemical barriers –> Soluble factors.
What comes under the soluble factors?
Lysozymes
Cytokines
Complement
Acute-phase proteins
What are the cellular components of the innate immune system?
Natural killer cells
Phagocytes
What are the natural killer cells in the cellular components of the innate immune system?
CD16+
CD56+
What comes under the phagocytes in the cellular components of the innate immune system?
Neutrophils
Eosinophils
Basophils
Monocytes
Macrophages
What are the cellular components of the adaptive immune system?
T-cells
B-cells
What are the SOLUBLE components of the adaptive immune system?
Immunoglobulins
What does ACUTE inflammation from the inflammatory response of the immune system cause?
⬆️ local bf in infected area
- Coupled w/ ⬆️ permeability of blood capillaries = facilitates entry of leukocytes + plasma proteins into the infected tissue.
What are the overall innate immune responses to an infectious agent?
Tissue macrophages
Neutrophils/Nk cells
What are the overall adaptive immune responses to an infectious agent?
T + B-lymphocytes
Antibodies
What does the macrophage do to the invading microorganism?
Ingests + isolates it in a vacuole in the cell by phagocytosis.
Macrophage secretes digestive enzymes (i.e lysozyme + elastase) + oxidising agents (i.e H peroxide).
Antigens on microorganism are digested + processed by macrophage + incorporated into its own cell surface.
Antigen is presented to other cellular immune components.
Helper T cells coordinate the response through cytokine release to activate other immune cells.
Mature b-cell stimulation results in proliferation + differentiation into immunoglobulin-secreting plasma cells.
Reaction of the immunoglobulin w/ a specific antigen forms an antibody-antigen complex.
What are antibodies essential to?
Antigen recognition + memory of earlier exposure to specific antigens
What do activated T-lymphocytes include?
Memory cells
Cytotoxic T-cells - attack infected host cells or foreign cells.
What are helper T-cells + suppressor T-cells important in?
Mobilising + regulating the entire immune response.
In what type of curve has the relationship between exercise + susceptibility to infection been modeled as?
J-curve (Nieman 1994)
Remember to look this up
What does the J-curve model suggest?
Although moderate PA may enhance immune function above sedentary levels, excessive amounts of prolonged, high-intensity exercise may induce detrimental effects on the immune function.
When is the extent of the depression in immune function following exercise most pronounced?
When exercise is:
- prolonged (1.5hr +)
- of moderate to high intensity
- Continuous rather than intermittent
- Performed w/out any CHO intake
Overview of why you get ill post exercise
⬇️ Blood glucose, muscle glycogen
⬆️ IL-6, stress hormones + free radicals
= Depression of immune cell function
