the reader's muscle

from ben marcus' feature article in the october 2005 issue of harper's:

In the left temporal lobe of the brain, below the central sulcus of Ronaldo, but above and tucked behind both Broca's area and Heschl's gyri, sits Wernicke's area, a tufted bundle of flesh responsible for language comprehension... Think of Wernicke's area as the reader's muscle, without which all written language is an impossible tangle of codes, a scribbled bit of abstract art that can't be deciphered. Here is where what we read is turned into meaning, intangible strings of language animated into legitimate shapes. If we do not read, or do so only rarely, the reader's muscle is slack and out of practice, and the stranger, harder texts, the lyrically unique ones that work outside the realm of familiarity, just scatter into random words. The words may be familiar, but they fail to work together as architectural elements of a larger world.

queen amygdala

on tuesday night's season premiere of House M.D., a young girl showed extraordinary courage in facing her impossibly dire situation. naturally, dr. house dismissed her bravery as unremarkable, going so far as to posit that the girl was not showing genuine, organic courage but rather that her courage was merely a "fake" emotion conjured by her damaged brain.

it was my first time watching a full episode of house. at first i was skeptical, but by the end i was hooked. and what made it all the more riveting was my freshly garnered understanding of brain anatomy. the amygdala is the so-called "fear center" of the brain. a clot in that region of the girl's brain, so the logic went, could have canceled her fear response, thereby explaining her intrepidness. but omar epps spotted the clot in her hippocampus, and so house was wrong, which he in the end grudgingly admitted.

however, according to the notes for a class i had today, projections from the hippocampus to the amygdala provide sensory information about the context of fearful stimuli, a sort of background picture as the brain tries to size up a scary situation. a lesion in this pathway should somehow erase certain components of fear, although which i do not know yet.

you can't spell sclerotic without erotic

ever wondered what the sclerosis in multiple sclerosis and amyotrophic lateral sclerosis--aka lou gehrig's disease--stands for? well, i always have, and i've also always wondered why it's not multiple scleroses. after all, it's not called the march of dimis, right? har

anyway, here is my newfound understanding of sclerosis. the term is not derived from any neuroanatomy per se but rather from the word sclera, also known as the white of your eye. if you've ever poked at your eye with your finger as i do every morning to put in my contacts, you know that your eyeball is firm and springy, as if it were covered in taut rubber. in sclerotic diseases, the body responds with a process called reactive astrocytosis. this is, in essence, scar formation in the nervous system, analogous to the shiny, tough scars that form on your skin after a cut heals. like superficial scars, these nervous glial scars were found on autopsy to be much firmer than average nervous tissue, and thus the name sclerosis was born. in multiple sclerosis, for example, the immune system goes haywire and starts attacking the body's own nerve cells, resulting in sclerotic lesions that eventually clog up the nervous system. the image i always think of is wolverine plunging the syringe full of liquid adamantium into lady deathstrike, thereby filling her circulatory system with metal. beautiful, i know.

negligent

i haven't been posting because i don't have internet access at home.

exam is on monday, pray for me please.

yumch

the four muscles actively involved in chewing are (drumroll please):

the masseter, the lateral pterygoids, the medial pterygoids, and the temporalis. the buccinator (ever wonder what the bucc. on music scores stood for?) helps keep food centered in the mouth; if they push too hard, cheeks are bitten.

one of the boys

today was a good day, despite having fallen further behind in neuro. i went to ccf rather anxious about work--i had to meet with my lab project advisor and my writing partner (both cards fellows), and i thought i would be facing a double busting of the chops. but, as it turned out, overworked genius doctors in training still have the capacity for sympathy. vivek even asked me to teach his kid mandarin, so i'm going over to his place sunday to babble meaninglessly in chinese with his son for 3 hours, to the tune of $30 too. then brian, instead of reaming me for my 32109482093rd crappy draft of the review we're working on, calmly suggested that we pass my latest effort to the boss for another go round. on top of all this, my very first pcr was a success; i would post a picture of the radiograph here but that would be too loserly even for me.

still, the point of this blog is to study, and that's not happening right now. i've thought about making this more public too, since ideally there would be some element of accountability by virtue of people reading. but the reason i didn't just start blogging about school stuff on xanga was because i didn't want to clog people's subscriptions with my irrelevant bullshit (read: blatant swipe at certain xangas), although it could be argued that i was doing that before i made the switch. in any case, neuro stuff is pending. personal guarantee.

*sigh*

i've never been this busy before, never ever. the bird flu i contracted from dr. wang last week didn't help the cause either. now i'm mired in two reviews, a world of pain otherwise known as neuro, and already dragging my feet with lab work. like today, i'm copping out of lab so i can finish a second draft of a paper, but of course i can't email it out until tomorrow because my house still doesn't have internet.

all this on top of the fact that i still wish i owned a jetski, so that i could have driven down to louisiana over the long weekend and shuttled people out of their personal public health hell. everything--my insignificant but significant problems, everyone else's significant but insignificant problems--is making me so mad, but i don't even have time to fume.

it's good to be a guy

so, today i had one of those moments where something completely obvious but heretofore unnoticed suddenly becomes apparent to you. like, for example, the morning i realized that the word "deodorant" was, in effect, "de-odorant," i.e. something that removes odor. previous to that epiphanous moment, someone could have divided the word as deodo-rant and i would not have noticed anything out of the ordinary.

anyway, this morning i was frantically trying to catch up on neuroanatomy when i came across the term "epidural." epidurals are perhaps most famous as those fearsome shots administered to expectant mothers delivering their babies in order to numb their pain. well, it turns out that the dura mater is a membrane that covers the central nervous system--not just the brain, as i had previously though. the epidural space is that thin sliver of space immediately outside of the dura, containing mostly fatty tissue, lymphatics, and tangles of veins (in the spinal region). an injection of local anesthetic into this epidural space produces a so-called "saddle" nerve block, aka a paravertebral nerve block. and this is why women receive epidurals, although my mom was a soldier and decided to go without one for both me and my sister. which is why i'm a soldier too.