Lymphatics And Immunity Flashcards
Lymphatic capillaries: (not present in bones, teeth, bone marrow and CNS)
• Extremely permeable tissue.
• Weave between tissue cells and blood capillaries in loose connective tissue and collect excess protein containing fluid = lymph.
• When interstitial fluid pressure exceeds that in lymphatic capillary fluid moves in through “mini-valves”.
From capillaries lymph flows - collecting vessels - trunks -ducts
What does the lymphatic system consist of?
Lymphatic vessels which transport fluid that has left the vascular system back to the blood and lymph organs that house phagocytes
which two large ducts in the thoracic region is lymph delivered to?
- Right lymphatic duct
2. Thoracic duct
What is lymph
Lymph is a transparent, colourless, watery liquid which is derived from tissue fluid and contained within lymphatic vessels.
Lymph Nodes (Lymph tissue and organs)
- Large clusters near skin surface in inguinal, axillary and cervical regions.
- Macrophages in lymph nodes destroy pathogens and cellular debris.
- Lymphocytes search for antigens.
- Lymphadenopathy = inflamed, painful nodes due to bacterial infection.
Spleen ( Lymph tissue and organs)
- Site of lymphatic proliferation, immune surveillance and response.
- Stores breakdown products of RBC
- Site of RBC production in fetus until birth.
- Stores platelets and old or defective RBC
Thymus (Lymph tissue and organs)
- Involved in storage and activation of T lymphocytes in immune response.
- Atrophies after puberty
What is Palantine and where is it located? (Tonsils (Lymph tissue and organs))
2, large paired tonsils at posterior end of oral cavity
Where is Lingual Located? (Tonsils (Lymph tissue and organs))
base of tongue
Where is Pharyngeal (adenoids if enlarged) Located? (Tonsils (Lymph tissue and organs))
in posterior wall of nasopharynx
Where is Tubal Located? (Tonsils (Lymph tissue and organs))
around opening of auditory tubes
Peyer’s Patches: (Lymph tissue and organs)
Isolated clusters of lymph follicles in distal small intestine
What are 2 divisions of the immune system?
innate and adaptive: that work both independently and in conjunction to provide resistance to disease.
Innate (Non-specific) Immunity :
This system provides immediate response to all _______ substances
This system provides immediate response to all foreign substances
First line of defense = skin, mucous membranes and secretions.(Innate Immunity)
- Provide physical barrier
- Acidity of secretions
- HCl and enzymes kill pathogens
- Saliva cleans mouth and lacrimal fluid in the eyes contain bacteriocidal lysozymes..
- Mucous traps organisms
Second line of defense (Innate Immunity)
innate cellular and chemical defences
What do Phagocytes do?
(Second line of defense (Innate Immunity))
engulf and destroy pathogens that breach membrane
NK cells causes ?
Second line of defense (Innate Immunity)
cause apoptosis of virus infected and cancer cells
What does Inflammation do?
Second line of defense (Innate Immunity)
prevents spread of injurious agents, disposes of pathogens and dead tissue, promotes tissue repair. Chemical mediators attract phagocytes and other immune cells to the area.
What are Interferons ?
Antimicrobial Proteins (Innate Immunity)
secreted by virus infected cells to protect surrounding cells from infection by “interfering” with viral replication. Not virus specific .
Alpha ( from white blood cells)
Beta ( from fibroblasts)
Gamma ( from lymphocytes)
What happens when Complement is activated?
Antimicrobial Proteins (Innate Immunity)
when activated unleashes mediators that amplify the inflammatory process.
What is a Fever?
Antimicrobial Proteins (Innate Immunity)
– systemic response to invading organisms. Pyrogens secreted by leukocytes and macrophages when exposed to foreign substances.
Adaptive (Specific) Defences
This system differs from the Innate Defences how? ( 4 points)
This system differs from the Innate Defences:
- It needs to be “primed” by prior exposure to an antigen before it can mount a response.
- Response is directed against specific substances.
- Response is systemic.
- Has memory
Adaptive Immunity has 2 separate systems
Humoral Immune Response
Cell-Mediatedd Immune responce
What is Humoral Immune Response?
- Lymphocyte activated is B cell
- Made, stored and mature in red bone marrow. Once mature, B cells circulate and “seed” in lymph nodes, spleen and other lymphoid organs where they encounter antigen.
What is Cell – Mediated Immune Response (CMI):?
- Lymphocyte activated = Tcell.
- Made in red bone marrow. Mature in thymus. Constantly circulate through the body however, increased in numbers in the lymph nodes.
- Respond to and recognize antigen fragments displayed on cells surfaces
active immunity
occurs when the person is exposed to a live pathogen, develops the disease, and becomes immune as a result of the primary immune response.
passive immunity
is a short-term immunization by the injection of antibodies, such as gamma globulin, that are not produced by the recipient’s cells.
Allergy
Under certain circumstances abnormal responses or allergic reactions occur when a foreign substance or antigen, enters the body.
AIDS
This is a condition contracted as result of the human immunodeficiency virus (HIV) which progressively destroys the immunity of the individual.
