Micturition reflex and types of bladder

Rather than going into exaggerated details... I will only point the important facts.

1.    When urine starts collecting within the bladder. The detrusor muscle is stretched. This is detected via stretch receptors and is carried by the sensory nerve to the spinal cord.

2.    The reflex arc root value is S2 to S4, from these parasympathetic fibers arise, which causes contraction of the detrusor muscle.

3.   This arc is under the control of the higher centers ( frontal lobe and pons), which can either FACILITATE or INHIBIT this reflex arc.

The clinical aspects of this are-

Study group experience #2

Here's what we discussed so far:

Marfans syndrome
Clomiphene citrate
Fecal transplant and uses of urine
Addictions, Mental health and Breaking Bad 
Alcohol and ADH 

I must say, the group is much more fun than the limited "Study group discussions" I post on the blog.

The discussions on the topics are diverse, surprising and very interesting. We also did a lot of non study related random discussions on our respective countries, languages, DIY medical gifts and shadowing. Even though the group is active day and night because of the time zone difference, the messages don't feel like they're a drag in anyway. Almost everyone seems to love the idea and what we talk about. Group 1, you guys are absolutely amazing. The hard work involved in putting together the group was totally worth it! <3 p="">

Two or three members felt the discussions should be very limited to studies, science and entrance examination stuff. We made a separate mini group for that.  Personally, I think that we are humans and we tend to socialize and talk random wherever we go. It's hard to have a clear boundary for what should be discussed and what not. But anyway, the mini group option will be open for future group joiners!

Lastly, the Group 2 update: We have 20 people so far, the minute the number reaches close to 50, your group will be made. Sorry for the wait! :)

Study group discussion: Alcohol and ADH

Does alchol decreases ADH secretion?

Alcohol inhibits ADH, that's why we pee so much when we're drunk.

Does it inhibit ADH at the kidney level, or does it inhibit the thing in the pituitary gland that makes the gland release ADH?

It inhibits the production of ADH from the pituitary gland.

So it affects the hypothalamic neurons and interferes with it's secretion?

Yes.

Oh yes. Alcohol inhibits ADH. That's why it is said you don't buy alcohol, you only rent it because you pee the fluid that you took.

What would you take for dehydration by ethanol ?

Normal saline!

I have seen on television that they give some light yellow coloured fluid. They add something to saline, I think. 

Banana bag it's called!

Huh? Banana bag? Any special constituents?

It's given especially for alcoholics. Contains Thiamine, folic acid and stuff

A banana bag (or rally pack) is a bag of IV fluids containing vitamins and minerals. The bags typically contain thiamine, folic acid, and 3 grams of magnesium sulfate, and are usually used to replenish nutritional deficiencies or correct a chemical imbalance in the human body. The multi-vitamin solution has a yellow color, hence the term "banana bag".

Ooh. 

Study group discussion: Addictions, Mental health

Guys, what's mental health/addictions care like in your countries? Intertwined with primary care or no? It's a huge issue here (Canada) but there's a lot of stigma and lack of political push to get anything done, and these people often suffer from "physical" comorbidities because they don't trust the system. I'm interested in your thoughts.

In India, the majority of cases we see are schizophrenia and alcoholism when it comes to mental health.

The stigma here is because the infectious disease burden is too much and that's why mental health doesn't get that much political attention.

But overall, people who reach hospitals trust doctors and it is very much intertwined with primary care.

People get a pretty wide range of mental health things around here, although in child and youth it's mostly anxiety disorders or conduct disorder, sometimes depression.  In emergency psych there's a lot of schizophrenia spectrum and suicide.   There's actually a dedicated eating disorders program as well (for children youth and adults).  The problem with mental health services, though, is the lack of resources.   There's a 4 month waiting list for the eating disorders program, for example.  I think thats a problem in other countries, too, but I don't know.   Does anyone know stuff about resource allocation to mental health programs in other health care systems?

Currently in Canada.  I used to live in Hong Kong.
The mental health care system is even worse in Hong Kong.

I only start ward rounds next year so I'm not sure how accurate is my take on mental health... But depression is very common here (Singapore) because life tends to be very fast paced here!

In Honduras, we see addictions to alcohol, glue and Benzodiazepines.

Glue? Like glue sniffing?

Yeah, they smell glue here. It's very cheap and you can use it  many times. And paint thinner too.

Had read about it in forensics class but never thought it is actually prevalent!

Dendrite sniffing is common here (India)

I believe it. We get a lot of hand sanitizer stolen around here. (Canada)

Apparent cases coming to see psychiatrist eye is a small proportion.

Dendrite?

Dendrite is one kind of a glue.

I'm a bit surprised too. Maybe it's naiveness or lack of exposure to such news... But the last time I heard that people used thinners or glue or nail polish to sniff was in my psych class.

I suppose almost all volatile substance can be used this way.

I have to admit, glue and paint thinner smells good.

I see lots of it in emerg... Mostly, the homeless. Its very sad.

So how do they present clinically?

Sort of like asphyxia? That's what I had read..They keep sniffing and in a daze forget to breathe.

Had a case a few weeks ago where this guy inhaled those cans of air dusters used to clean computers.

Hypoventilation, respiratory acidosis.

He just kinda passed out on the side of the road, but became conscious rather quickly once we talked to him.

Decreased LOC usually, sometimes combative, crazy heart rates. Mostly they just look inebriated. 

Super paranoid. Depends on what they abused.

They present with very serious brain damage. Usually they dont come to the hospital, they die from TB and AIDS in the streets without medical attention.

What we get in our emergency is mostly organophosphorous poisoning.

OP poisoning is very prevalent out here. It's the only thing farmers have access to!

Atropine then pralidoxime.

Yes.

If we're unsure of the pesticide, we don't prescribe pralidoxime.

Here (Honduras), farmers are always getting snake bites

Barba amarilla they call them.

Oh. We get snake bites too.

Study group discussion: Fecal transplant and uses of urine

Speaking of that, in the show Greys Anatomy, they use poop to cultivate natural flora in a person who overused antibiotics.

I saw a video of that on minute earth on youtube. Esp in conditions of inflammatory bowel disease!

It's called a fecal transplant or something.

It's in trials in many hospitals.
As per JAMA, NEJM.

I read that they're treating enterocolitis from resistant strains of C.difficile by inserting a nasoduodenal tube and administering donor feces

Do you think patients would be as ready to accept a fecal transplant as they would, per say, a blood donation?

Donno about patients but I wouldn't accept a fecal transplant!

I think it differs from different races, cultures to your personal beliefs.

But i guess we all value our life the most. Given as a last resort, I suppose the patient would accept.

It's all about circumstances.

Does anyone have a link to a publication on the fecal transplant?

@above GIYF.
GOOGLE IS YOUR FRIEND.

Giyf haha love that!

Searching on Google is tough. I'd love to be spoon fed with links!

Googling fecal transplants just gives a range of DIY kits...

Put in right keywords, use search tools and the first link is what all you need.

Hahaha gross. DIY fecal transplants sound um... messy.

Do you guys know urine can be used as an eye wash?
But it shouldn't be infected.
It's one of the uses of urine if your stranded with no water.
First use is, of course, drinking it to prevent dehydration.

Idk if you've heard about this in other countries but we in the USA say use urine on jellyfish stings

Oh yes, that too. I watched a Rhett and Link video on YouTube a long time back on the uses of urine.

Study group discussion: Clomiphene citrate

Please can you explain me the mechanism of Clomiphene citrate?
Clomiphene citrate is a Selective Estrogen Receptor Modulator!

Clomiphene citrate's primary action is to block the oestrogen receptors on the pituitary.

Hence, because of the lack of negative feedback..more of FSH is produced.. Hence more follicles.

This primarily used in ovulation induction in woman.. Main example polycystic ovarian syndrome.

Also, in males it is used if the cause of impotency is less gonaodotrophins.

Important viva question is.. Dose in females is 50mg OD but in males its 25 mg.

Ooh. Why is the dose lesser in males?

Oh that.. I never searched for it. But best guess would be in males the breakdown would be slower. Hence less drug.

Also, remember after the follicles are well stimulated injection hcg is given (cause it mimics LH) and brings out ovulation.

Extra: Side effect of clomiphene citrate is ovarian hyperstimulation syndrome in females

But never ever give hcg to a woman with PCOD.. It's contraindicated cause already LH is high. Else you will cause ovarian hyperstimulation syndrome.

Oh it's HCG, I thought it's clomiphene which was the culprit.

From what I read clomiphene does cause OHS by its own... But the gonadotrophins given externally are the major culprits.

One fact HCG is obtained from urine of pregnant woman. Even FSH and LH..urine of menopausal woman. I guess better recombinant counterparts are available though.

The conversation lead to urine and fecal transplants, will be published in the next post!

Study group discussion: Marfans syndrome

Today I learned that if someone has Marfans disease and they complain of a "tearing" feeling in their chest, they are probably having an aortic dissection and need surgery quick. Our patient made it to the hospital alive, but apparently it's commonly fatal.

Aortic dissection presents with pain radiating to the back. The radiation of pain hint is given in many multiple choice questions.

Marfan syndrome patient tend to have weak or bad joint... But how could they hyperextend their finger?

Because they have a defect in fibrillin synthesis. Synthesis of any structure with fibrillin is affected.

Good to know! I'll keep that in mind.

Fibrillin will form elastic connective tissue right?

Ohhh cool! Didn't know the association!

Fibrillin is a component of lots of types of connective tissue, I guess.

Yep

Mini mnemonic on Marfan: Marfan - Fibrillin - Marfibrillin (Merging words to remember!)

Marfan is associated wth ectopic lentis, right?

Yes, Marfans is associated with ectopia lentis. Another condition associated with ectopia lentis is homocystinuria.

What's ectopia lentis?

Displacement of the eye's lens.

Paracellular leak in the thick ascending limb

This fact had boggled me since first year physiology, finally got it figured out

Paracellular leak- sodium, potassium and chloride are absorbed into the cell by Na-2Cl-K transporter. But potassium is more permeable, hence it diffuses back into the luminal fluid. This creates positivity in the luminal fluid, which repels positive ions. Hence Mg, Ca, Na are pushed by the paracellular pathway to be absorbed.  

-M-

Study group discussion: Epigenetics

Epigenetic science is a whole new perspective. To bioethics and to humanity.

Yeah there will be some secondary factors that control this epigenetic modulation.

Decitabine and aza cytidine also work by epigenetic modulation.

I didn't get the cytidine epigenetic modulation bit. Can you please elaborate?

Epigenetics is a process where one gene is active at one time and other gene is inactive same time and vice versa.

This is due to some secondary factors.

Drugs like Decitabine and aza cytidine used in MDS has minor mechanism in epigenetics.

That's all I know ;)

Amazing.

Also epigenetics means
he interaction between the nature and nurture. Genetics and environment.

It means that if you're having a gene for diabetes doesn't make you diabetic, until there's a reaction with your environment.

Study group discussion: Deep vein thrombosis

One common fact I read a few days back was after a long journey by plane, our shoes feel tighter. It's cause of venous pooling due to lack of use of calf muscles. Hence, we have slight oedema.

This is important in case of people prone to deep vein thrombosis. So they are at a high risk of life threatening pulmonary embolism.

I use the loo so many times in planes to prevent that :P

Me too.. Shuffled from seat to seat without bothering to put those shoes on.

One documentation of case was for a man who flew for 14 hrs and got pulmonary embolus!

Study group discussion: Fetal hemoglobin

What is the difference between fetal Hb (HbF) and adult Hb (HbA)? In term of the structures?

HbA has two beta chains and HbF has two gamma chains.

The gamma fraction allows fetal Hb to have higher affinity of it for oxygen which allows it to extract oxygen from maternal blood.

And inducing Hb F production is also used in the treatment of sickle cell anemia.

Hydroxyurea is the drug used for the same.

Hb F production starts from 8th week of intra uterine life.

Fetal Hb has more affinity towards oxygen than adult Hb, meaning the oxygen dissociation curve is shifted left compared to normal adult Hb.

Left doesn't leave the oxygen! (http://medicowesome.blogspot.ae/2013/05/oxygen-hemoglobin-dissociation-curve.html)

The primary structural differences between HbF and HbA are located in or near the 2,3-BPG binding site between the γ1-γ2 interface of HbF and the β1-β2 interface of HbA. The net effect of these structural differences is that 2,3-BPG binds less tightly to deoxyHbF by comparison to deoxyHbA. Thus, 2,3-BPG does not stabilize the deoxyHbF as effectively as it stabilizes deoxyHbA, thus accounting for the leftward shift of the O2 saturation curve of HbF compared to HbA when tested with the same concentration of 2,3-BPG.

Fetal hb has more affinity because of poor binding of 2,3-DPG by the gamma polypeptide chain so it can take larger volume of oxygen than adult hb at low oxygen pressure

A higher affinity for oxygen allows higher concentrations of oxygen into fetal circulation, however this also inhibits oxygen dissociation into fetal tissue where the oxygen is needed. To overcome this, other mechanisms are in place to ensure oxygen delivery to fetal tissue: Increased Crit – higher number of red blood cells per blood volume. This is a common reaction to reduced oxygen availability. Exacerbated Bohr effect – acidic pH has a greater effect on oxygen unloading in fetal tissues allowing better oxygen delivery. Acidic pH shifts the fetal oxygen-haemoglobin dissociation curve to the right, so that oxygen unloading can occur at higher oxygen partial pressures.

Adult haemoglobin starts to be produced in utero, at around the 13th week of gestation.

I think it's 30the week the switch over from fetal Hb to adult Hb.

Its by 6th month of life.. That's when majority of a child's RBC shifts to adult haemoglobin. It's important in case of thalasaemia.. Because that's when most symptoms start showing.

What I meant to say was - Initiation of production of HbA starts from 13th week gestation.

At first, there is gradual increase in concentration of HbA until it reaches 20-30% of total Hb.

And the switch is not completed until 6 months of age.

What my hemaologist taught was HbA production will be started from 30th week of gestation and by 6th month of life only HbA is produced.

And the main function of HbF is delivering oxygen in hypoxic condition like immediately after birth.

But don't we need HbF to take oxygen from the maternal blood in the first place?

Because the partial pressures in the placenta aren't enough to allow the transfer from what I've studied.
Everything takes part in delivering oxygen depending upon tissue tension of O2. Before 7th week, there are embryonic Hb like portland, gower, etc.

Embryonic erythropiesis takes place from yolk sac.

From 7th week to 30th week liver.

After 30th week, long bones start erythropoesis.

Gene for both HbA and HbF are present since birth but Its all epigenetics that make these genes to produce one kind in one period and other type in other period.

Oh I didn't know the Hb concept in such depth.

My sir told these details. Epigenetics is given in Robbins 5th chapter.

That's all!
Be sure to let us know if there are any errors or corrections.
-IkaN

Study group experience #1

It was SO very exciting to meet new people from all over the world. I got to speak to my followers directly which I don't get to do very often with the one sided blogging.

We had people from different countries and I was internal fan girl screaming throughout the process. (Still am!)

As promised to not leave you out, this is what we discussed in the group:

Fetal hemoglobin
Epigenetics
Deep vein thrombosis

We were talking about how everyone is from different age groups and grades, some younger than others. One of the group members said, "No one is small in the face of a big dream." I found it to be very motivational. Elegantly put!

We had one negative experience, a member was sending dating messages to a girl and she left the group :(
To future group joiners, make sure you report if such a thing happens to you so that we can ban the user.

The first group is full. The plan is to not add more than 50 people in one group. (It'll prevent too many anonymous users and it won't be too annoying!) The 50 spots which are empty can be used up by friends of trusted group members on request.

The new comers will be added in the second group and everyone will get a spot. Maybe in the future we'll segregate people on time zones but for now you'll be randomly allocated.

Thank you for the wonderful experience, awesome medicos!

Looking forward to more <3

-IkaN

Medicowesome study group on Whatsapp

Some of my friends discuss questions and concepts on Whatsapp. So for a long time, I've been wanting to do this. Make a huge all time accessible study group where we can learn!

This is the first trial attempt, of course. It may not work. It might work brilliantly.

If it doesn't work out, we dissolve the group and pretend it never happened T_T

If it does, we'll be learning something new on a daily basis *_*

So who's in?

All you've got to do is message me your number. You can email me at medicowesome@gmail.com with "Whatsapp study group" in the subject.

IMPORTANT: Make sure you include your proper country code when you email me your number. (Otherwise your number won't be displayed in my Whatsapp list and I might miss you out!) 

DO NOT ignorantly leave your contact details publicly in the comments for everyone to see! *whispers* Keep it secret, keep it safe.

I'll message you in a week max.

I have a lot in mind but it varies with the response. Let's try this out first and see how it goes!

PS: I'll also try posting what we discuss on the group out here as well for those who don't have access / are uncomfortable with Whatsapp.

*hoping for the best*

-IkaN