Samenvatting
Samenvatting pathology
- Vak
- (WBFA02405)
- Instelling
- Rijksuniversiteit Groningen (RuG)
Samenvatting pathology
[Meer zien]Voorbeeld 4 van de 99 pagina's
Voorbeeld 4 van de 99 pagina's
In winkelwagengesponsord bericht van onze partner
Voorbeeld van de inhoud
PATHOLOGYIMMUNOLOGY
The immune system protects the body from damage. The immune system carries out
its functions by distinguishing ‘self ‘ - the body’s normal cells - from ‘nonself’. Nonself
includes viruses, bacteria, parasites, allergens, and other disease-causing
pathogens. Substances that trigger the body’s immune response are called
immunogens. Immunogens that react with products of the immune response are
known as antigens.
Diphtheria is a serious infection caused by strains of the bacteria called
Corynebacterium diphtheriae that make toxin. It can lead to difficulty breathing, heart
rhythm problems, and even death. Vaccines are recommended for infants, children,
teens, and adults to prevent diphtheria. It is fatal in 5/10% of the cases (mostly in
children under 5 and adults above 40).
The diphtheria toxin with subunits A, B, T
bind to a membrane receptor that induces
endocytosis. The diphtheria toxin is now
taken up into the cell. Acidification
(verzuring) of the endosome causes the
active A unit to be released. Unit A
inhibits protein synthesis and thus cause
cell death.
Endosomes are a collection of
intracellular sorting organelles in
eukaryotic cells.
Cholera is an infectious disease caused by the bacterium Vibrio cholerae. This
bacterium produces toxins that cause an efflux of water and ions into intestinal
lumen, leading to diarrhea and vomiting. This will lead to dehydration. The disease is
transmitted primarily by contaminated water or food. Dehydration leads to a bluish
grey skin (blue death). It can be treated with a short-term vaccine and proper
sanitation.
Measles is a highly contagious illness. This means it's very easily spread to others.
Measles is caused by a virus found in the nose and throat of an infected child or
adult. The mortality is 0.2-10%. Diarrhoea and vomiting are also complications in this
disease, leading to dehydration. Pneumonia (longontsteking) can also be
determined. There is a vaccine for measles.
Pertussis is a respiratory infectious disease caused by a bacterium, Bordetella
pertussis, which is transmitted mainly by the droplets produced during coughing.
Pertussis is highly contagious. The mortality is 0.5% and there is a vaccine available.
1
,Scarlet fever is an infectious disease caused by Streptococcus pyogenes. The signs
and symptoms include a sore throat, fever, headache, swollen lymph nodes, and a
characteristic rash. The face is flushed and the rash is red. There is no vaccine.
Instead, it is treated with antibiotics. It can induce autoimmune responses.
Smallpox was an infectious disease caused by variola virus. Symptoms are vomiting,
fever, sores and typical pox that leave people scarred for the rest of their life. The
smallpox vaccine is the first vaccine to be developed against a contagious disease.
This was called variolation (variola vaccination).
People who are against vaccination: there is
already a reduced amount of people dying of
measles before the vaccinations were
produced, so vaccinations are not needed. But
on the other hand, the amount of people that
got measles didn’t reduce. This happened when
the vaccinations were introduced, so
vaccinations are definitely useful.
There is evidence shown that there is no link between vaccinations and autism.
People thought there was a link, but the group of children was not selected well.
Immune system:
- Defense against external threats (microorganisms ‘infections’, particles,
unrecognized human particles ‘transplant or blood’)
- Defense against internal threats (tumors)
- Control of tissue regeneration and scarring
Innate immunity: immunity you are born with.
- Fast (sec-hours)
- Not specific
- Limited recognition and limited memory
- Limited recognition of self
- Not flexible (limited recognition)
Adaptive immunity: immunity you have to develop
after birth.
- Humoral immunity (producing of antibodies by b-cells)
- Cell-mediated immunity (T-helper cells and T-effector cells)
- Slow (days-weeks)
- Specific
- Recognize millions of antigens and memory
- Distinguishes self/nonself
- Fast expansion/flexible (recognize fast and much)
Epithelial cells form a physical barrier that prevents pathogens, toxins, and other
unwanted materials from entering the body.
2
,Tissue-resident immune cells are immune cells existing in non-immune organs like
skin, liver, lung and gastrointestinal tract. They include epithelial cells, macrophages,
dendritic cells and mast cells. They can release cytokines and chemokines in
response to stimulation.
White blood cells are immune cells that circulate in the blood and lymphatic system.
There are 5 main types:
- Neutrophils – main action against bacterial and
fungal infections.
- Monocytes – main action against bacterial
infections.
- Eosinophils – main action against parasitic
infections.
- Basophils – responsible for responses to allergens.
- Lymphocytes – main action against viral infections.
Neutrophils, eosinophils, and basophils are granulocytes since they have cytoplasmic
granules which can digest microorganisms. Lymphocytes and monocytes
are agranulocytes since they lack granules in their cytoplasm.
B-lymphocyte: produce antibodies. These antibodies bind to pathogens or
to foreign substances, such as toxins, to neutralize them.
T-helper lymphocyte: CD4+. They may activate cytotoxic T-cells or they
may activate B-cells by releasing cytokines.
T-cytotoxic lymphocyte: CD8+. Killing of intracellular pathogens,
and the elimination of mutated and cancerous cells.
Leukocytes (= white blood cells) are part of the body's immune
system. They help the body fight infection and other
diseases. Types of leukocytes are granulocytes
(neutrophils, eosinophils, and basophils), monocytes,
and lymphocytes (T cells and B cells).
All leukocytes develop from stem cells in bone marrow
or yolk sac/fetal liver. The stem cell develops into a
progenitor cell that can differentiate into many types of
cells.
Committed progenitor cells: myeloid stem cells. Myeloid
stem cells are derived from hematopoietic stem cells.
They undergo differentiation to produce precursors of
erythrocytes, platelets, dendritic cells, mast cells,
monocytes, and granulocytes.
During development, one set of immature lymphocyte
precursor cells, the T lymphocytes, migrates from the
3
, bone marrow to the thymus gland, where they
mature. Another group known as B lymphocytes (B
cells) remains in the bone marrow. Natural killer cells
form a third category of lymphocytes. They are
thought to develop in bone marrow as well as in
other tissues.
Macrophages are developed from yolk sac/fetal liver.
Monocytes are a type of white blood cell. They are
the largest type of leukocyte in blood and can
differentiate into macrophages and monocyte
derived dendritic cells.
Cytokines serve as messengers for the immune system. They are produced in
response to a threat and represent the communication network for the immune
system. Chemokines induce targeted migration of leukocytes (white blood cells) to
sites of inflammation in the body, and thus play a crucial role in the immune system.
Membrane receptors are used for the interaction with other cells
and recognition of microbes/threats (through antigens).
Epitope: part of an antigen that is recognized by the immune
system
An antigen is a component that induces an immune response in
the body. It is often foreign or toxic to the body (bacteria/virus)
and binds to a specific antibody.
The mass of all immune cells in the body equals the mass of the
brain. Platelets are a component of blood whose function is to
react to bleeding from blood vessel injury by clumping, thereby
initiating a blood clot.
Lymphoid tissue:
- Primary lymphoid tissues – immune cells form and mature here:
thymus gland and bone marrow
- Secondary lymphoid tissues – active mature immune cells:
spleen, lymph nodes, GALT, tonsils)
GALT: gut-associated lymph tissue. Protect the body from invasion in
the gut.
Tonsils (amandelen): set of lymphoid organs facing into the
aerodigestive tract (luchtwegen).
The spleen plays very important roles in regard to red blood cells and
the immune system. It removes old red blood cells and holds a reserve of blood. The
spleen houses antibody-producing lymphocytes and monocytes, which remove
antibody-coated bacteria and antibody-coated blood cells by way of blood and lymph
node circulation. These monocytes, upon moving to injured tissue, turn into dendritic
cells and macrophages while promoting tissue healing.
4
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper BerberBoesenkool. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €7,49. Je zit daarna nergens aan vast.
Is Stuvia te vertrouwen?
4,6 sterren op Google & Trustpilot (+1000 reviews)
Afgelopen 30 dagen zijn er 75282 samenvattingen verkocht
Opgericht in 2010, al 15 jaar dé plek om samenvattingen te kopen