Saheh's 3/4 question thread

[Russ]

okeydokey awesome,

so any idea how this would stop pain?

Pain is a nerve signal. To send nerve signals you need to depolarise the membrane to produce an action potential. If your membrane is hyperpolarised then its gone the other way, and its even harder than usual to generate an AP. Thus, less pain

[saheh]

that makes sense thanks




What do cell-mediated and humoral mediated mainly target??
so is humoral mainly extracellular pathogens?
and cell mediated for infected cells? (apcs would come under this part?)

[saheh]

also, is it only self cells with MHC markers? and the just APC cells have MHC II? Is it suffice to say that it is the antigen of foreign tissue that is identified as non-self?

[duhherro]

also, is it only self cells with MHC markers? and the just APC cells have MHC II? Is it suffice to say that it is the antigen of foreign tissue that is identified as non-self?

All cells except RBC's have MHC 1 marker, immune cells have MHC 2. Yeah the antigen presented by the APC's are identified as nonself

[saheh]

Ahhk
So if there's a question, how does the body recognise foreign/non-self cells? you'd say, the antigen is detected that does not match the body's self cells   ?
and then is engulfed and antigen placed on MHCII marker?



Also:
what are plant defences, specifically the chemical ones?
I know things like waxy-cuticle and thick bark,
but there's nothing in the textbook.

[duhherro]

Ahhk
So if there's a question, how does the body recognise foreign/non-self cells? you'd say, the antigen is detected that does not match the body's self cells   ?
and then is engulfed and antigen placed on MHCII marker?



Also:
what are plant defences, specifically the chemical ones?
I know things like waxy-cuticle and thick bark,
but there's nothing in the textbook.

Well macrophages just engulf the foreign pathogen, and then they display an antigen that is foreign onto the MHC 2 marker. T-cells will recognise the antigen on the APC as foreign and will go do the appropriate response


Plant defences
- Produce enzymes that digest pathogenic fungi walls
-Seal off infected areas (or dropping of the leaf if the infected area is there)
-Production of toxic chemicals in response to an insect bite leading to providing a barrier to the entry of foreign pathogen or just deterring the insect from biting more.

[Russ]

You can use MHC as a self marker as well, it's a major part of what causes transplant rejection. T cells can recognize non self MHC and target it, which results in normal immune activation targeted against the cell with the non self MHC

[saheh]

ahh you two are awesome!


thanks!!

[Gazillionaire]

Can someone explain the similarities and differences between AIDS and HIV?

[saheh]

HIV is the virus that causes AIDS, which attacks Th cells and leads to a weakened immune system

thats alll i know, may want to clarify :p

[InsaneMcFries]

HIV is a retrovirus (RNA instead of DNA) and therefore also contains reverse transcriptase to convert its DNA to RNA.
It also mutates which is why they can't produce an effective vaccine.

[Russ]

HIV is a retrovirus (RNA instead of DNA) and therefore also contains reverse transcriptase to convert its DNA to RNA.
It also mutates which is why they can't produce an effective vaccine.

Other way round, be careful not to mix the two up by mistake

[saheh]

In anaerobic respiration, do animal cells produce Co2?
I know they produce lactic acid

In plants it's ethanol and co2
Plus 2 ATP per glucose

Considering humans Breathe out co2? :p

[Daenerys Targaryen]

no they dont, only lactic acid and the ATP

[saheh]

Ok thankyou!!