LP #99 Defence Mechanisms Flashcards
- diffuse & fxnal collection of organs & lymphoid tissue
* very sensitive to changes in the environment, including effects of stress & emotions
The immune system
*Loose reticular CT w/macrophages & lymphocytes
Lymphoid tissue
*Discrete & encapsulated
Lymphoid organs
Lymphoid organs? (6 types)
- Thymus
- Lymph nodes
- Tonsils
- Spleen
- Peyer’s patches
- MALT
*Site of T-lymphocyte maturation?
Thymus
*Engage in lymphocytic & phagocytic activity?
Lymph nodes
*Trap & destroy harmful bacteria?
Tonsils
- cleanses blood: removes old RBCs, platelets, bacteria, toxins & cellular debris
- storage (Fe & thrombocytes)
- immune surveillance & response
Spleen
- Aggregates of lymphoid nodules
- In the GI tract
- Destroy harmful bacteria
Peyyer’s patches
- Mucosa associated lymphoid tissue
- In respiratory & digestive tracts
- Destroys invading bacteria & viruses
MALT
Lymph nodes:
- Structurally= _________
- Functionally=_________
- Lymphatic system
* Immune system
Lymph nodes:
- macrophages allow for ________ ________
- Lymphocytes allow for ________ ________
- Innate response
* Adaptive response
- encapsulated
- compartmentalized by CT
- Inner core: reticular tissue w/macrophages & lymphocytes
- # of afferent vessels > # of efferent vessels
- located at drainage jxns
Lymph nodes
Immunity: adaptive defences
*3 important features
- Ability to distinguish self from non-self
- Specificity (Ag-specific)
- Memory
- body substances do not normally elicit an immune response
* this stems from the immune system’s ability o recognize proteins found on external surfaces of the body’s cells
Ability to distinguish self from non-self
*Immune cells respond to the presence of given antigens by producing specific antibodies against these antigens
Specificity (Ag- Specific)
*Sensitized lymphocytes retain memory of an Ag for many years father initial exposure to the Ag
Memory
Where are lymphocytes produced?
Red bone marrow
- Ability to initiate an immune response & carry it to completion
- Process of lymphocyte maturation; lymphocytes are immunocompetent cells
Immunocompetency
- Genes determine type & specificity of receptor
- 20-30% of total circulating WBCs
- circulate in blood
- have specific receptors to a specific Ag
Lymphocytes
2 lymphocytes populations?
- B-cells
* T-cells
- 10-20% of lymphocytes
- Humoral immunity
- Mature in bone marrow
B-cells
- 60-70% of lymphocytes
- Responsible for cell-mediated (cellular immunity)
- Mature in thymus gland
T-cells
Both B-lymphocytes & T-lymphocytes:
- Distinct fxns
- Different surface markers
- Mediate specific immune responses
Blood types?
A, B, AB, O
Type A blood can give blood to
A, O
Type B can give blood to
B, O
Type AB can give blood to
(Universal recipient)
AB, A, B, O
Type O blood can give blood to
Only O (Universal donor)
Rhesus (Rh)?
Type of protein found on red blood cells (blood group antigen)
Ppl with Rh factor protein present on their RBCs are considered to be?
Rh-positive
Ppl with no Rh factor protein present on their RBCs are considered to be?
Rh-negative
