kidney and 3rd line of defense?? (1 Viewer)

[freyja*]

ok well i am really confused about how the kidney works...the nephron and reabsorbtion etc..
but i also cant quite get my litlle head around the 3rd line of defense, the t and b cells!!
there is just too much to remember!!!!!

 

[KingofthieF]

Wow!

hehe this is gonna be a hard question! Any way i'll try help ya a bit since i got 4 dayz before my next trial~~

how the kidney works

in the kidney works by three processes - filtration, reabsorption and secretion... filtration occurs in the bowman's capsule where under fluid coming from the glomerulus is put under high pressure, passes through the membranes and enter the bowman's capsule~~ this membrane does not allow white and red blood cells to pass through, hence the filtration~~

passive and selective reabsorption occurs along the tubule (proximal tubule, loop of Henle, distal tubule) where useful substances where remove from the filtrate (e.g. amino acid, water, NaCl) .. Heninmen textbook got a good diagram of what is absorbed back...

selective secretion occur in the distal tubule where the body, at the expense of energy, removes substances from the bloodstream (e.g. alcohol and poisons which is too big to pass through the membrane of Bowman's capsule)...

 

[KingofthieF]

carry on~

for the third line of defence~
it is necessary to know the different types of B and T cells, and how they interact with each other...

firstly when a antigen comes in, it is first digested by macrophage. The macrophage then displays specific recognition protein on their outer-coat, B cells detects this, clones itself and diffrentiate into either B memory cell or plasma cell (which produce antibody).

The T helper cell has an importance role in this by sending chemical signals to T cells and B cells that stimulate the cloning.
The t cells can differentiate into different types too - Natural Killer T cells (which kills the antigen directly, or secret chemical that destroys the cells harbouring antigen), suppressor T cell (stop the immune response once the antigen is gone), hypersensitive T cell, and memory t cell... it is the memory cells thar provides the immunity to that antigen...

what do i miss out?? ... i dun no.. and if i got something wrong pls tell me too... sometimes i get confused myself hahaha

hope it does a little help~

 

[freyja*]

thankyou!

what can i say, you are soooo nice!!!

i cant believe you are helping me...what a spin out...there are nice people in this world

i think having someone explain it to you makes more sense than reading it out of a textbook.
You are obviously a keen bio student

wish me luck in the exam...i could ask you a million more questions and just pick your brain but dont worry...i will control myself and do some of my own study

 

[freyja*]

actually one more little thing, well its not that little

but.....i dont understand xylem and phloem..??? Do i have some weird brain problem because it feels like i dont know anything even though i have been doing bio for ever!

oh yeah and my teacher told me that in the trial there is going to be question on one of the pracs that we did in maintaining a balance but i dont know which one it could be because she said it took us ages to do????

 

[KingofthieF]

Re: thankyou!

Originally posted by freyja*
i cant believe you are helping me...

hehe no worries... it's good revision for me as well

for xylem and phloem, they are transport vessels in plants...
xylem transports water and mineral ions (from the soils, e.g. Na+) in one direction - up only - as it is made of dead cells. The mechanism of the transport is a combination of root pressure, transpiratoin, and capillary effect (the pulling due to adhesion force between water and cell wall)...

for phloem it transport products of photosynthesis (e.g. glucose) in two directions up and down... the process of transportation is call translocation and a model to explain that is the source-path-sink system (and this work on the basis of osmosis)...

one more thing is the structure of these vascular vessels... eg for xylem is the spiral lignin and for phloem the companion cell, seive tube and seive plate...

i think this is all you need to know... good luck with ur trials

 

[freyja*]

you are my little minty lifesaver!!

you have all the qualties of a lifesaver....except of course i wouldnt eat you

anyway thanks so much for your help it has been so good!
Hopefully i will go ok in my exam, and i might have you to thank if i do...you have made me feel more confident. I think it is a just a mental thing...all about the positive thoughts!!

well i guess i should get back to the study, you never know i might even surprise myself, but then again bio never has been my forte

 

[smegger_em]

wow, how do you make it sound so much easier then my teacher?

 

[KingofthieF]

Originally posted by smegger_em
wow, how do you make it sound so much easier then my teacher?

hehe must be becoz my answer is too brief~~
your teacher's answer might give you more details

 

[Heavenzchild]

Hey KingofThieF, I noticed your location says Hobart, Tasmania are you doing the HSC this year???????? stupid question but, sorry..ehehe

 

[KingofthieF]

Originally posted by Heavenzchild
Hey KingofThieF, I noticed your location says Hobart, Tasmania are you doing the HSC this year???????? stupid question but, sorry..ehehe

hehe lol
I'm actually living in Sydney NSW and currently doing HSC

 

[El]

I kinda feel a bit wierd about coming into this convo (lol) but I have the same probs with bio- remembering xylem, phloem, secretion reabsorbtion, B & T cells etc. But my teacher is really cool, and cause our class is kinda small, he takes the time to make up little stories that helps us remember stuff. For eg. when you think of phloem think of the 'f' as in ph loem, then think of f ood and you eat your food off a plate. So then you remember that the phloem transportation uses plates etc. The B & T cells I made up my own little story, which is kinda embarrasing- but seeing as none of you know me... think of your body's defences as a castle, first line is the doors, second line is the non specific gaurds (inflammatory response, phagocytosis etc) and then you're third line is the knights. It sounds far-fetched but when you get a visual picture in your head of all this stuff, it's easier to remember. You're helper T cells are the guys that kid of hold down the enemy, and point them out to the killer T cells (cytotoxic) who are basically you're Robin Hood I'll kill anybody that threatens me kind of guys, then the supressor T cells are the ones who come in and break up the fight. It's a weird little analogy I guess, and don't ask me how I came up with it, I'm not into dungeons and dragons or any of that shit, but it just helps me remeber stuff. Make up some of your own- Ipromise it will help

 

[KingofthieF]

hehe pretty cool analogy~~
Definitely making analogies help to make things easier to understand