Exam (elaborations)
Cell Recognition and the Immune System
- Course
- Institution
- Book
Cell Recognition and the Immune System
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
Chapter 32: Innate Immunity EXAM 2
Seller
Follow
maxmaxwellmm254
Content preview
Cell Recognition and the Immune SystemGet a hint
The human body's two types of defences to protect itself from pathogens - ANSWER: -
Non-specific
> General and immediate defences
- Specific
> Less rapid but longer-lasting
Non-specific - ANSWER: - Skin forming a barrier to prevents pathogens from entering
- Phagocytosis - to kill any pathogens
Specific - ANSWER: Involves lymphocytes (a type of white blood cell) and takes two
forms:
1) Cell-mediated responses involving T-lymphocytes
2) Humoral responses involving B-lymphocytes
How are all lymphocytes able to distinguish between the body's own cells and
molecules (self) and those that are foreign (non-self)? - ANSWER: 1. All types of cells,
self or non-self, have specific molecules on its surface that identify it
2. There is a variety of types of these molecules, but it is the proteins (glycoproteins)
that are the most important:
- Proteins have a huge variety and a highly specific tertiary structure
- It is this variety that distinguishes once cell from another
What do protein molecules on lymphocyte surfaces allow the immune system to
identify? - ANSWER: o Pathogens (e.g. HIV)
o Non-self material (e.g. cells form other organisms of the same species)
o Toxins (e.g. those produced by certain pathogens, like the bacterium that causes
cholera)
o Abnormal body cells (e.g. Cancer cells)
What is the first stage to removing the threat foreign cells pose? - ANSWER: Identifying
them
How can the immune response be an issue for organ transplantation and what is done
to overcome this issue? - ANSWER: - The immune system will recognise tissue or
organ transplants as non-self and therefore tries to destroy the transplant
- To minimise tissue rejection, donor tissues for transplants are normally matched as
closely as possible to those of the recipient
- Best matches are often from relatives
, - In addition, immunosuppressant drugs are often administered to reduce the level of
the immune response
We lymphocytes produced in response to an infection? - ANSWER: No - they already
exist
Why is there a high probability that when a pathogen enters the body a lymphocyte will
'recognise' the pathogen? - ANSWER: Given there are ten million different types of
lymphocyte, one of these lymphocytes will have a protein on its surface that is
complementary to one of the proteins of the pathogen
What explains the lag time between the body's exposure to a pathogen and the body's
defences bringing it under control? - ANSWER: Clonal selection
Clonal selection - ANSWER: 1. As there are so many different types of lymphocytes,
there are very few of each type
2. When an infection occurs, the one type already present that has the complementary
proteins to that of the pathogen is stimulated to divide to build up its numbers to a level
where it can be effectively destroyed
How do lymphocytes recognised own body cells? - ANSWER: 1. In the foetus, the
lymphocytes are constantly colliding with other cells
2. Infections in the foetus are rare as it is protected from the outside world by the mother
and the placenta
3. So therefore, lymphocytes collide almost exclusively with the body's own material
(self)
4. Some of the body's lymphocytes will have receptors that exactly fit those of the
body's own cells
5. These lymphocytes either die or are suppressed
6. The only remaining lymphocytes are those that might fit foreign material (non-self),
and therefore only respond to foreign material
In adults where are lymphocytes produced? - ANSWER: In the bone marrow
What happens to any lymphocytes that show an immune response to self-antigens? -
ANSWER: They undergo apoptosis (programmed cell death) before they differentiate
into mature lymphocytes
> No clones of these anti-self lymphocytes will appear in the blood, leaving only those
that might respond to non-self antigens
If a pathogen is to infect the body what must it first do? - ANSWER: Gain entry
What is the body's first line of defence against pathogens? - ANSWER: Creating a
physical or chemical barrier
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller maxmaxwellmm254. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $17.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
79650 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now