Animal Lesson 7 Flashcards
(60 cards)
Pathogen
Any foreign thing that’s not supposed to be there (virus, bacteria, etc).
Innate immunity
In all animals. Recognition of traits shared by broad ranges of pathogens, using a small set of receptors to recognize it. Rapid response as it happens as soon as you get infected. Includes Barrier and internal defences.
Adaptive immunity
Vertebrates only. Recognition of traits specific to
particular pathogens, using a vast array of receptors. Lock and key finds the actual pathogen and targets it one on one. Slower response. Third line of defence. Have humeral and cell-mediated response.
Vertebrates
Animals with a backbone (fishes and humans).
Barrier defenses
The first line defence (primary defence).
* Skin
* Mucous membranes (will trap things from getting in)
* Secretions
Internal defences
The second line of defence. If they break into the body. They will target everything in hopes of getting everything.
* Phagocytic cells
* Natural killer cells
* Antimicrobial proteins
* Inflammatory respons
Humoral response
Antibodies defend against infection in body fluids (blood, interstitial, lymph).
Cell-mediated response
Cytotoxic cells defend against infection in body cell (cells that have already been infected). They try to kill these infected cells.
Barrier defenses prevent what?
most pathogens from entering the body. We wash our hands to get rid of bacteria.
Skin/Shells/Cuticle (in worms)
Thickened outer surface inhibits entry by pathogens. It’s physical barrier.
Mucous membranes
Mucus (thicken fluid) secreted by internalized external surfaces (ie. nose, mouth, body parts that face the outside but are internal) traps microbes and other particles.
Secretions – saliva, tears
Washing action prevents microbial colonization (when they divide and divide). Hostile chemical environment: Lysozyme, acidic pH (that prevent the growth of pathogens).
Phagocytic Cells
Recognize molecules characteristic of a set of pathogens (not from own body) and will engulf it. That recognized molecule is absent from vertebrates
and is an essential component of certain groups of
pathogens. The molecule that its recognizing has to be one of the things that the virus needs to survive but can’t be found in our own bodies or else we will start eating our own cells.
Why is it important for the component to be essential
to the pathogen?
So they don’t adapt and evolve into something else that’s unrecognizable the next time.
How do phagocytes destroy pathogens?
Phagocytosis.
Where are phagocytes located?
̶ Blood
̶ Skin
̶ Mucous membranes
̶ Lymph
How does phagocytosis works?
The phagocytic cell notices a pathogen and engulfs it into a vacuole then fuses with a lysosome containing digestive enzymes. These digest the pathogen into bits and pieces and spits it out.
Parts of lymphatic system
Thymus. Peyer’s patches (in small intestine). Appendix
(cecum). Adenoid. Tonsils. Lymphatic vessels. Spleen
Lymph nodes (that swell when sick).
Lymphatic vessels is interconnected with what?
With blood capillaries.
Why do lipids go through the lymphatic system?
Because fats are too large.
Lymph nodes
Have lymphatic vessels lead into lymph node. Macrophages live permanently live in there. Masses of defensive cells are stored there and ready to be disposed when you have an inflection. They get to infected area through blood vessel capillary system. They also can put fluid that leak from circulatory system back to that system and also monitor it to make sure there is no pathogens in it (makes sure blood is clean before returned back).
Natural Killer Cells
Recognize surface proteins of virus-infected or
cancerous cells. They target them and release chemicals that cause apoptosis (cell death) in infected or cancerous cells.
Antimicrobial proteins
Attack pathogens or impede their reproduction. ie. interferons and complement proteins.
Interferons
A protein are secreted by virus-infected cells. Help surrounding cells from further inflected by the viruses. Trigger surrounding cells to produce chemicals that inhibit viral reproduction.