The immune system

[Stick]

How much detail do we need to go into? By the looks of this board at the moment, there is a whole lot we need to understand. Unfortunately, my Biology teacher rushed through this chapter in three lessons and I haven't yet grasped the second and third lines of defence completely. Any help would be really appreciated.

[pi]

This board is going into a lot more detail than what is needed. Follow NoB and Biozone, that level of understanding is sufficient.

[Yacoubb]

How much detail do we need to go into? By the looks of this board at the moment, there is a whole lot we need to understand. Unfortunately, my Biology teacher rushed through this chapter in three lessons and I haven't yet grasped the second and third lines of defence completely. Any help would be really appreciated.

I think knowing different components of the non-specific and specific lines of defence would be sufficient. B and T-lymphocytes; know where they are produced and where they mature (i.e. B-cells are produced and mature in the bone marrow and T-cells are produced in the bone marrow but mature in the thymus). Know the importance of clonal selection/expansion (i.e. the proliferation of particular B-lymphocytes ensures there is a sufficient number of immunoglobulin to counteract the infection by a particular foreign antigen and sustain a humoral response to eradicate this 'foreign' antigen. Know about the lymphatic system; it consists of both B- and T-lymphocytes, lymph (fluid) that travels in one direction. The valves in the lymphatic vessels prevent the backflow of the lymph. The lymph carries various substances through the body to lymph nodes, where B and T-cells are in high concentrations. 2nd line of defence is really just knowing your phagocytes/macrophages, Natural Killer Cells, Interferon, Complement, Cytokines, Inflammation.

Also know about allergies, auto-immune diseases and Rhesus compatibility.

Immunity: can be acquired actively or passively.
* Active immunity can be acquired naturally or artificially [Memory Cells produced]
* Passive immunity can be acquired naturally or artificially [No memory cells produced]
Knowing how to identify each type is quite important. Typically, you'll be asked to identify which type of immunity has been acquired by a particular organism and to justify your selection. You'd then go on to mention for instance whether memory cells were produced or not, whether antibodies were directly administered as a drug or an attenuated pathogen was given and the immune response (Humoral) produced memory cells that retain memory of the foreign, non-self antigen and made the response to the antigen quicker if a second infection by the same antigen were to occur.

Hope this helped!

[ealam2]

Do we need to remember and know all five types of immunoglobulins and each of their functions for the exam?

[Yacoubb]

Do we need to remember and know all five types of immunoglobulins and each of their functions for the exam?

I think the only immunoglobulin class is class E (IgE) and its relation with allergies. Maybe know a little bit about each type but you don't have to remember characteristics of each immunoglobulin class. Typical questions involving immunoglobulin are like tables given and you have to recognise for instance that if agglutination is present (i.e. clumping of antigens by antibodies to assist in them being engulfed and destroyed), an organism has developed those antibodies through active immunity. However, the prospect of riding through this year in oblivion regarding what will be on the exam just compels me to learn the characteristics of IgG, IgA, IgM, IgD and IgE.

Ooh, might want to know that immunoglobulin class G is the only one that has the ability to cross the placenta and thus naturally (passively) immunise a foetus during pregnancy, because it is small enough to cross the placenta. 

[ealam2]

So basically it's best to know them all. Thanks!