Heart Sounds Tutorial

Another free site with wonderful examples of various normal and abnormal heart sounds with matching physiological explanations. The animations are basic but clear. There is also a testing mode to make sure that you got it. Good revision for Year 3 to 5 students.

Testing, Testing, One, Two, Three...

You should by now be testing yourselves regularly to make sure that the material you are covering is moving from short-term to long-term memory. This website will help you do that by asking you to match structures to their name, and then label them yourself. Fifteen minutes each day should do the trick. Try it!

Aphorism

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."

- Albert Einstein (1879-1955)

A Court Case

No, don't worry, I have not been taken to jail. Take a look here though and you will find a tongue in cheek argument between the sympathetic and parasympathetic systems. Rather fun way to learn. Enjoy!

Learn the Blood Supply of the Brain

This website looks primitive but it's a great way to revise the blood supply of the brain and spinal cord. I particularly liked the quiz mode. Try it out and let me know what you think.

Eye Simulator

This website is a great way to revise the movements of the eyes and test yourself on cranial nerve lesions. Rather clunky, but it works, provided you have Shockwave installed.

Medical Mnemonics

Generally speaking, I'm not very keen on mnemonics, as I find them rather difficult to remember (unless I think them up myself). This is very much the case with most of the ones on this website kindly pointed out to me by Stefan (Year 2 Medicine). There are a few good ones though and here are my favourites for Neuro and Head and Neck:

ObliqLiques cause lateral rotation of eyeball.

Action of the obliques is opposite to their names. Action of the rectii is rightly fitting to their names.
Both superiors cause intorsion and both inferiors cause extorsion.

Geniculate bodies: paired to respective colliculi SLIM:
Superior colliculi: Lateral geniculate body.
Inferior colliculi: Medial geniculate body.

Geniculate bodies: medial vs. lateral system MALE:
Medial=Auditory. Lateral=Eye.
Medial geniculate body is for auditory system, lateral geniculate body is for visual system.

Spinal tracts: Gracilus vs. Cuneatus: origin from upper vs. lower limbs Gracilus is the name of a muscle in the legs, so Fasciculus Gracilus is for the lower limbs.

Precentral vs. postcentral gyrus: motor vs. sensory Just an extension of the rule that anterior = ventral = efferent = motor.
The precentral gyrus is on the anterior side of the brain, so is therefore motor.

Olivary nuclei: ear vs. eye roles Superior Olivary nucleus: SOund localization.
· Inferior olivary nucleus is therefore the one for sight [tactile, proprioception also].

Pterygoid muscles: function of lateral vs. medial "Look at how your jaw ends up when saying first syllable of 'Lateral' or 'Medial' ":
"La": your jaw is now open, so Lateral opens mouth.
"Me": your jaw is still closed, so medial closes the mandible.

Bifurcation vertebral landmarks · A bifurcation occurs on 4th level of each vertebral column:
C4: bifurcation of common carotid artery
T4: bifurcation of trachea
L4: bifurcation of aorta

Deep tendon reflexes: root supply "1,2,3,4,5,6,7,8":
S1-2: ankle
L3-4: knee
C5-6: biceps, supinator
C7-8: triceps

Interesting Article

Daniel McKean (Year 2 medicine) has forwarded to me this interesting link from the New Yorker. We have much to learn....

Whole Brain Atlas

Those of you struggling to conceptualise the brain in three dimensions and to distinguish between T1, T2 and CT scan images, would do well to peruse this web site. Great images and a good place to test your knowledge of normal brain structures as well as abnormal situations. Well worth a visit.

Great Student Blog

I came across this blog while looking for evidence that getting students to do dissections themselves improves exam performance. Suggest you scroll through some of the past entries: they are well worth the read.

Missing for a While...

Yes I know I have been too busy to keep this up, but here it goes again. For those of you who need a good revision of the cranial nerves, take a look here.

Interesting Medical Blogs

Once you start blogging, you begin to realise how much good stuff there is out there. Take a look at the BMJ blog. There is something for everyone.

Cinemeducation: Wit

The next movie to be screened is called Wit. It will be shown on Wednesday Nov 21 at the KSU Common Room at 2.30 followed by a discussion at 4pm. Times will be confirmed later. If you can't make it for the screening but wish to join the discussion, contact Daniel Azzopardi at MMSA. I will post some links to the movie later. It's a great movie. Don't miss it.

Biochemistry That Matters

but that apparently you have not covered yet....

A patient with familial hypercholesterolaemia undergoes a detailed serum lipid and lipoprotein analysis. Studies demonstrate elevated cholesterol in the form of increased LDL without elevation of other lipids. This patient's hyperlipidemia is best classified as which of the following types?

A. Type 1
B. Type 2a
C. Type 2b
D. Type 3
E. Type 5

The correct answer is B.

Hyperlipidemia has been subclassified based on the lipid and lipoprotein profiles. Type 2a, which this patient has, can be seen in a hereditary form, known as familial hypercholesterolemia, and
also in secondary, acquired forms related to nephritic syndrome and hyperthyroidism. The root problem appears to be a deficiency of LDL receptors, which leads to a specific elevation of cholesterol in the form of increased LDL. Heterozygotes for the hereditary form generally
develop cardiovascular disease from 30 to 50 years of age. Homozygotes may have cardiovascular disease in childhood.

Type 1 (choice A) is characterized by isolated elevation of chylomicrons.

Type 2b (choice C) is characterized by elevations of both cholesterol and triglycerides in the form of LDL and VLDL.

Type 3 (choice D) is characterized by elevations of triglycerides and cholesterol in the form of chylomicron remnants and IDL.

Type 5 (choice E) is characterized by elevations of triglycerides and cholesterol in the form of VLDL and chylomicrons.

Physiology Question Explanation

Only one of you attempted this question, which actually is extremely important. Hence it's worth re-stating together with the explanation for all you clinical students out there.

A 26-year-old man is admitted through the emergency department to the hospital for a heroin overdose. His heart rate is 45 beats/min, and his blood pressure is 75/40 mm Hg. Which of the following best depicts the results from an arterial blood sample ?

pH PaCO2 (mm Hg) HCO3- (mEq/L)
A. 7.22 66 26
B. 7.34 29 15
C. 7.40 40 24
D. 7.47 20 14
E. 7.49 48 35

The correct answer is A.

This man has a respiratory acidosis. Overdose with drugs that suppress ventilation (e.g., heroin, morphine, barbiturates, methaqualone, and "sleeping pills") often causes hypercapnia. In patients with an intact renal response, the respiratory acidosis causes a compensatory rise in plasma HCO3-, which lessens the fall in pH. However, the renal response requires several days to develop fully. The plasma HCO3- of 26 mEq/L (normal: 22-28 mEq/L) for this man is typical of acute respiratory acidosis with little or no renal compensation.

Choice B reflects metabolic acidosis.

Choice C is normal.

Choice D reflects respiratory alkalosis.

Choice E reflects metabolic alkalosis.

Mastication Question

Question: Contraction of which muscles contributes most to the backward movement of the lower jaw during the process of mastication?

Answer: Mastication is a complex process involving alternating elevation, depression, forward movement, and backward movement of the lower jaw. The backward movement step is accomplished by the posterior fibers of the temporalis muscle.

The digastric helps to depress the lower jaw during chewing.

The lateral pterygoid helps to move the lower jaw forward during chewing.

The medial pterygoid helps to elevate the lower jaw during chewing.

The mylohyoid helps to depress the lower jaw during chewing.

Letter to God

Dear God,

As You undoubtedly know, there is a little argument down here about intelligent design and evolution. If You really did create us in a day, and if You ever find humans worth another try, there are a few anatomical modifications that we hope You might consider the next time around.

As it happens, Lord, some of the organs You included in the mix have not turned out so well. Tonsils and appendixes don't seem to be especially useful apart from keeping surgeons occupied, or as clues to infection with "mad cow disease." And sinuses. Even if they do lighten the head, all they ever do is get infected. Couldn't we just have stronger neck muscles?

Our perversity in wanting to walk upright, when it is clear that this was not Your intention, has led to some real problems with our spines and leg joints. Would it be possible for You either to fix the pelvis at a right angle to prevent us from this error, or strengthen our weight bearing joints? We also hope You will anticipate our penchant for portable email devices by designing tiny little fingertips to operate the keys.

And the aesthetically splendid symmetry—could You extend it even further? It would certainly cut down our problem with trauma and strokes to have each side of our brain perform exactly the same functions. The rest of the head is outstanding, as are the limbs, but when we get into the thorax and abdomen, we have a few requests. You probably did not intend us to discard our diet of berries and nuts for fatty meats and pastries, but that's what happened, with disastrous consequences to our cardiovascular systems. Two hearts and a lipid-resistant lining to blood vessels would be just the thing (or give us an enzyme that transforms our preferred cuisine to harmless molecules).

We found out about alcohol, Lord, so it would be nice to have a liver (and maybe a pancreas) in reserve. Or You might remove the enzymatic chain that metabolises alcohol and make us too sick to consume it. Ditto for all the other drugs we seem so prone to abuse.

Thanks to Your gracious allotment of intelligence, we are on the verge of creating plenipotentiary cell banks, but there is a serious unresolved problem of individual compatibility. Somewhere—perhaps in redesigned sinuses, if for some reason You prefer that we keep them—there might be a little storehouse of such cells that could be tapped into when the need arises.

Despite the beautiful symmetry and economy of design with which we are blessed, it has occurred to us that the placement of our genital and excretory organs in such close proximity was either done to remind us of Original Sin, or because there did not seem to be a satisfactory anatomical alternative. Could You think about this? No obvious repositioning arrangement comes to mind, but some kind of retractable underarm mechanism might be practical.

In fact, this whole survival of the species thing deserves some rethinking. The delicate balance between the pleasures of sex and the pain of reproduction has been an issue for our womenfolk, who have borne the brunt of the pain. Maybe if they were given only two or three eggs together with a comfortable course of pregnancy and childbirth, the need for an endless succession of menstrual periods and the hot flushes of menopause could be eliminated without endangering our continued existence here on earth.

We hope, Lord, that You do not take offence at these suggestions, which are offered in all humility from creatures who surely do not fully understand the reasons that went into Your marvel of design, from its coating of skin to its molecular engineering, and we are truly grateful for Your efforts on our behalf.

PS: We know You have a sense of humour, Lord, but could you please do something about adolescence?

---

Paul Brown, BMJ, June 2006

Medical Maltese

Attention ALL international students. Today is your last chance to register for the crash course in Medical Maltese starting Wednesday. Classes will be held at the Medical School (SLH for 2 weeks, then transferring to MDH) from 2 to 3.30pm.

Be there or be square....

Muscles of Mastication

Some of you appeared confused by the muscles of mastication last week. Try this one:

Contraction of which of the following muscles contributes most to the backward movement of the lower jaw during the process of mastication?

A. Digastric
B. Lateral pterygoid
C. Medial pterygoid
D. Mylohyoid
E. Temporalis

Correct answer and explanation next week.

Achieving Your Childhood Dreams

"Achieving Your Childhood Dreams", the inspirational and moving "Last Lecture" given by Professor Randy Pausch (www.randypausch.com) at Carnegie Mellon University (Sept 2007).

Have patience with the intro….it’s worth it.