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Lymphatic system function
- maintain balance of fluids in body
- works with white blood cells to fight off infection
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Lymph
- interstitial fluid (plasma)
- colourless or pale yellow
- composition is much like plasma
- much more fluid-like than blood
- as blood circulates, some plasma leaks and becomes part of interstitial fluid
- lymph forms in close-ended tubes in capillary beds
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Lymphatic valve
prevent backflow
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Lymph nodes
- store lymphatic cells while they develop
- contain macrophages that trap and destroy bacteria
- an infection may cause
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First line of defence: physical
- non-specific, will destroy EVERYTHING
- skin, mucous membranes, hair, cilia
- oil on skin has bactericides, kills bacteria
- sweat has low pH, kills bacteria
- lysozyme secreted in bodily fluids also kills bacteria
- tears wash away bacteria
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Second line of defence: macrophage
- non-specific, will destroy EVERYTHING
- only come into play if bad stuff gets into blood
- specialized white blood cells eat the invader by phagocytosis
- produces pus
- neutrophils attack infected cells destroying the cell and the microbes
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Inflammatory response
redness, heat, and pain
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Phagocytosis
wrapping cell membrane around bad cells, eats it pacman style
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Third line of defence: immunity
- bad stuff activates specific cells
- intrusion of bad stuff creates antibodies
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Antigen
protein nametag/identifier
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T-cells
- produced in bone marrow, stored in thymus
- 3 types: helper, killer, suppressor
- killer aka cytotoxic T-cells, go and kill anything with a specific nametag
- helper T-cells recognise a specific nametag and signal to the B-cells to make antibodies for it
- suppressor T-cells suppress other cells
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B-cells
- made and stored in bone marrow
- memory
- makes antibodies
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Third line of defence: immunity
intrusion of bad guys stimulates antibody production
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Foreign body can use its antigen to bind to a cell, killing the cell
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Lymphokine
- chemical sent by helper T cell
- reaches B cells, causes them to divide rapidly and produce the antibody to the invader
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Helper T cell
- activates killer T cells
- activates lymphokine
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Autoimmune disorder meaning
T cells/antibodies attack body's own cells
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Rh factor
makes a blood type positive or negative
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Blood types
- A, B, AB, O
- different blood types have different antigens
- A: A antigen, Anti-B antibody
- B: B antigen, Anti-A antibody
- AB: A, and B antigen, no antibodies, universal accepter
- O: Anti-A, Anti-B antibodies, no antigens, universal donor
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Agglutination
- clumping of red blood cells
- happens when wrong blood type is donated
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Rhesus factor marker
- means positive blood type
- Rh- can donate to Rh+, but Rh+ cannot donate to Rh-
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Lack of Rhesus factor marker
means negative blood negative
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O positive versus O negative
- O positive can only donate to O positive, A positive, B positive, AB positive
- O negative is the true universal donor
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erythroblastosis fetalis
mum's, dad's blood types conflict, blood starts to agglutinate
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2 types of allergies
- Acute: occur within seconds, disappear within 30 minutes, body releases histamines, making blood vessels more permeable, skin swollen and red, antibodies release fluids to flush out the bad stuff
- Delayed: set off by T-cells, slower and last longer
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HIV versus AIDS
- HIV is the virus
- AIDS is the symptom
- HIV virus destroys helper T cells
- body fluid to body fluid
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