11. immunity Flashcards
lymph
fluid = water plus solutes form two sources, plasma and cells
Lymphatic vessels
carry lymph away from tissues, contain half valves that ensure one-way flow
Lymphatic capillaries
join to form lymphatic vessels, very permeable
Lymphatic tissue
diffuse lymphatic tissue
Lymphatic nodules
dense aggregations
Lymph nodes
distributed along vessels and filter lymph, contain macrophages and lymphocytes and if
Cancer cells often trapped in lymph nodes therefore take them out aswell
Lymphatic ducts:
drain tissues of body and move lymph into major veins
Tonsils
large groups of lymphatic tissues
Provide protection against bacteria
Palatine (tonsils), pharyngeal (adenoids), lingual
Spleen
monitors blood and detects and responded to foreign antigens, destroys defective red blood cells, regulates blood volume
Thymus
site of maturation of T cells, many T cells produced here
functions of the lymphatic system.
Fluid balance: excess interstitial fluid enters lymphatic capillaries and becomes lymph
Fat absorption: absorption of fat and other substances from digestive tract
Defence: fights infection
different types of innate immunity
- white blood cells
- inflammation
- fever
- chemical mediators
- physical barriers
what is innate immunity
Non-specific
- each time the body is exposed the response is the same, the body doesn’t remember if you have had it or not
- white blood cells
White blood cells: ingest foreign particles (phagocytosis)
produce chemicals to attract other immune cells to area
Produced in bone marrow and lymphatic tissue
Released into blood and transported around the body
types of white blood cells
Neutrophils: first cell to arrive, phagocytosis
Macrophages: more effective phagocyte
Basophils: produce histmine
Natural killer cells: can cause lysis of virus infected cells
physical barriers
prevent entry or remove microbes
- skin, mucous membranes, tears, saliva
- Inflammation:
local tissue response to damage
aims to rid the body of debris/ invader and prevent further pathogen entry
4 features
Redness: increased blood flow to region
Heat: increased blood flow to region
Swelling: capillaries become leaky, fluid leaves capillaries into surround tissue
Pain: increased fluid stimulates pain receptors
- Chemical mediators:
promote phagocytosis (help white blood cells get rid of bacteria) and inflammation
\ histamine: cause vasodilation, attract white blood cells
Cytokines: secreted by one cell and stimulates neighbouring cell to respond
Complement: stimulates lysis of invading pathogen cells
Interferons: anti-viral activity
fever
Fever: generalised response to tissue damage and infection
increase some antimicrobial substances
Decrease microbial growth
Increase body reactions that help tissue repair
what is adaptive immunity
Specificity - ability to recognise a particular substance
Memory - ability to remember previous encounters with specific substance and respond rapidly
Acquired during a lifetime due to exposure
types of adaptive immunity
Cell mediated immunity - T cells: specificity
Antibody mediated immunity - B cells: memory
Cell mediated immunity - T cells: specificity
Helper T cells and cytotoxic T cells
Cytotoxic T cell attaches to the target cell receptor detecting if there is any virus on the target cell
Helper T cells help to reproduce the cytotoxic T cells to enable more cells to recognise the virus
Cytotoxic T cells release cytokines to produce inflammation and initiate phagocytosis
The cytotoxic T cells kill any target cells that they come into contact with that have the virus
Antibody mediated immunity - B cells: memory
Phagocytosis of pathogen to express it on the cell surface
Helper T cell confirms if it is a virus or not
Interleukins are released to make the B cell divide
The B cell creates antibodies
affects of antibodies
inactivate the antigen by binding to it
Bind antigens together, 3 antibodies inhibit 4 antigens
Facilitate phagocytosis: antibody binds to antigen and then to a macrophage which engulfs them both
primary vs secondary immune response
Primary
fewer antibodies
Longer response time
Vaccinations act as a primary response
Secondary
shorter response time and stronger response
More antibodies recognising the pathogen
Booster acts as secondary response
antigen
foreign proteins in the body
active immunity
provided by own individual immune system
natural: antigens introduced through natural exposure
Artificial: antigens introduced through vaccines
passive immunity
transferred from another person or animal
natural : antibodies transferred from mother to child in breast milk
Artificial: antibodies produced from a person are injected into another person
chyle
lymph with a lot of fat
pathogen
foreign agent eg bacteria, pathogens introduce antigens into the body
Immunity
ability to resist damage from foreign substances
HIV
Destruction of helper T cells which impairs antibody mediated immunity
body is vulnerable and ordinary infections can be lethal
Enlarged lymph nodes
Bacteria in the tissues can enter the circulatory system through the permeable lymphatic capillaries of the lymphatic system. Bacteria will travel through the vessels and along the way become trapped in lymph nodes, particularly around the neck because of their closeness to the throat (pharynx) and nearby tonsils. Immune cells (lymphocytes and phagocytic cells) in lymph nodes will recognise the antigen and begin an immune response in order to remove the threat. These immune cells differentiate in the lymph nodes and multiply, which lead to the nodes become bigger.
Achy body
- This symptom can be a consequence of toxins (poisonous waste products) released into the body from the bacteria. This can cause an all over achy body/muscle.
- Aching can also be due to dehydration.
lymphocytes
white blood cells from bone marrow
macrophages
phagocytic cell important in inflammation and repair
