My personal USMLE Problem( yes I think i am queen :p)- Physio Thread

[HarveyR]

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Major basic protein is a toxic component of the lysosomal granules and is an important mediator in the death of parasites and protozoa.

Hey lovelies! What does it mean by "Toxic component of lysosome"? Does it mean free Major basic protein outside lysosome is toxic to our own body cells? Or toxic to the parasite/protozoa?

 

[Thrombophlebitis]

Toxic to your body cells and protozoa.

 

[theforeigndoc]

hmm is it toxic? or does it induce harm becuz major basic protein causes an immune response?

 

[HarveyR]

hmm is it toxic? or does it induce harm becuz major basic protein causes an immune response?

Your answer makes sense, maybe by tonality @Thrombophlebitis mean it was harmful but in the traditional toxic way. XD

 

[HarveyR]

Okay buddies! Thank you for your replies, however I have another question.
I read from somewhere that someone with Thromboasthenia shows agglutination in Ristocetin cofactor Assay. How is it so when thee is a deficiency of GPIIb/IIIa and interwinding between platelets via Fibrinogen ( Factor 1)?

Is it bcs there is bonding with GPIb via vWB factor and the thingy similar to sub endothelial collagen on the assay?

 

[HarveyR]

Can anyone please explain me what does this mean 🙁

• Thrombin directly activates platelets via proteolytic cleavage of the protease-activated receptor.

 

[HarveyR]

Anyone??

 

[worldbeater]

Thrombin acts directly on the transition from fibrinogen to fibrin to form a clot.

Platelets recognize a break in the basement membrane, where type 4 collagen is exposed. Platelets anchor to gp1b and expose their gp2b/3a to other platelets, which causes release of TXA2, promoting vasoconstriction and platelet aggregation.

That's what I know. Not sure where your going with your question.

 

[HarveyR]

hey guys! I hope you have been fine. Just another Question. So what are exactly the Absolute refractory period for Action potentials? Is it Both depolarization and repolarization period? Or just depolarization?
🙁 Me be stuck here like there is no tomorrow.

 

[DandyLion]

http://www.physiologyweb.com/lectur...onal_action_potential_refractory_periods.html

 

[HarveyR]

Hey people
Hope you are doing well. Can please anyone give me good notes on Autonomic Controll of the Heart? I am really lost on that area 🙁

 

[walakin25]

Hey people
Hope you are doing well. Can please anyone give me good notes on Autonomic Controll of the Heart? I am really lost on that area 🙁

lets call upon mr knowitall @worldbeater 😉

 

[worldbeater]

lets call upon mr knowitall @worldbeater 😉

Thanks for the complement! It will give me some good fuel for motivation for this week. I definitely don't know everything and still have work to do, but I am making progress in the right direction everyday.

give me good notes on Autonomic Controll of the Heart? I am really lost on that area

That's a really general topic and I am actually not that strong in it, it would be better if you could post some practice questions where you are missing the concept, we can figure it out together.

 

[HarveyR]

Oh I got it finally
In order to learn this topic properly yo obviously need a diagram that summarizes Autonic nervous system. And then you need to know different types of receptors. Make sure to repeat them without looking. And now simply know what type of receptors are present. All over the heart you have Beta1 receptors. And you know that beta 1 s are adrenergic receptors. Secondly you only SA and AV nodes have M2 ( muscaric receptors accepting nothing but acetyl choline.

I need to know more details on what else Beta-1 receptors cant accept other than Norepinephrine 😀

@walakin25 and @worldbeater

 

[worldbeater]

I need to know more details on what else Beta-1 receptors cant accept other than Norepinephrine

I don't know what they can't accept, but B1 receptors in general do the following:
-are on the heart as you said, so increase heart rate
-increase constriction/velocity
-decrease glucagon (so causes an increase in insulin, these two oppose each other)
-increase renin
-are present on the j-g apparatus
-responsible for SBP (along with alpha 1)
-Gs is associated with it (I don't know what that means, I match it to B1 if a question comes up on it)
--present on the lungs(?) (I know usually you use a b2 agonist for a case like asthma, but I think I had a question with b1/lungs - clarification from anybody would be appreciated)

In general, if there is a "1" after the receptor, it's responsible for constriction, if there is a "2" it's responsible for relaxation

Norepinephrine acts on alpha 2, thats why B1 wouldn't accept it.

All this is in the Notes (and I am assuming First Aid), so as the poster said just make a chart on paper and add stuff to each receptor as you do more questions, you will get more familiar with the receptors the more you work with it. This chart is really important, you can knock out 10-15 questions easily by just knowing it, it was the most important thing we were taught outside of the regular lecture.

 

[HarveyR]

The pulmonary circulation has low resistance and high compliancerelative to the systemic circulation.

Can any please help to explain this line?

 

[HarveyR]

Hey guys! hope you are doing well. Is it possible for anyone to explain me what is meant by Fixed H+ in the kidney and where it is produced? Your help would really be appreciated.