Form and Function

Canadian Public Radio to the rescue again with a show on how humans use smell to pick their mates. The research started out with a group of men each wearing the same shirt overnight for two nights and then having women smell the shirts in a lab and report how appealing they found the smell of each shirt. (Hopefully the women were receiving some sort of stipend for their part in this.) The results indicated that women prefer the smell of men who are genetically dissimilar to themselves in the area of MHC genes. (Whether this "MHC" is the same as the "MHC" of "Major Histocompatibility Complex" they never said, but I'm guessing yes because the result of previous studies mating animals with dissimilar MHC genes resulted in offspring with stronger immune systems.) Women have also been found to find men who are MHC-dissimilar from themselves to be more sexually attractive. Interestingly, women who were on the Pill at the time of the trial tended to select the smell of MHC-similar men as being the most appealing. The researchers' theory as to why this may be is that while MHC-dissimilarity is most beneficial for health of offspring, consistent material support (e.g. food and shelter) during pregnancy and childrearing is also important; because the Pill induces a hormonal state similar to pregnancy, it may be that those women on the Pill were more likely to choose MHC-similar men, such as would occur with a closer genetic relative, as an evolutionary bet on receiving more "familial"-type assistance with childrearing.

Quirks and Quarks can be found here. The episode "Sniffing for Sex" is here.

I've come back to an entry I had thought about but never posted back when we were working on the digestive system. In my previous life as a grad student I was introduced to the idea of fractals, or shapes that appear similar at many different scales. These can be computed mathematically but I don't "do" math so I'll ignore that direction entirely. But what is interesting to me is the natural objects that display this same type of self-similarity. Coastlines are what got me interested because I was doing digital mapping and the generally, but not entirely, irregular shape of a coastline makes it pretty darn difficult to know what scale map you're looking at if there are no other identifying features. Snowflakes and clouds are other common examples of natural objects that display features of being fractal-like. But the best example I think, and one that I've not seen mentioned, is the multi-scale folding in the digestive system that creates all that surface area. If you had only the outline of a cross-section of plicae circularis, villi, and microvilli, I think they'd look pretty much the same. And because the human brain likes patterns, that makes me happy.

I've started reading through the CDC's pink book and it has a *lot* of interesting information on the history and epidemiology of the various diseases and their vaccines.

While waiting for some coil binding to be done at Kinkos I was browsing their display of laminated study guides covering everything from anatomy (the same one that came with our book) to golf short game techniques. I ended up buying a pretty great guide on vitamins and minerals, available online here. It covers daily doses (both in general and disease-specific), food sources, co-vitamins, deficiency symptoms, and toxicity symptoms. The back also has a table listing vitamins and drugs that interact adversely. Not bad for $5, I don't think.

Two good examples of kidney art in my opinion. I've been holding on to these most of the semester until we got to the right chapter.
This is a milagro ("miracle") that can be worn as a healing offering to the saints by someone who has kidney problems. It's another Etsy find.

Can you guess what this is? Well, the urinary system, obviously. But it's wallpaper! Isn't that fantastic? My husband Matt found it via his blogroll on BoingBoing but it was originally covered by the LA Weekly blog and is the work of California artist Shannon Wright.

Here's a close-up of the kidney itself.

I'm not very in tune with what's going on right now in the world of A&P, but I do know that in March of this year a whole bunch of Fort Collins residents were getting down to the business of making babies, because the birth situation for my doula partner and I for the end of December is starting to look really hairy.

You'll probably get other journal entries on this, but Time magazine announced a retail DNA test as its "Invention of the Year". The test, developed by a company called 23 and Me, is a personal DNA analysis that can give its purchasers information on the link between their genes and 90 traits and diseases. While affordable, personalized, genetic information may well be the wave of the future (this home saliva test costs $399), the 23 and Me test has its share of controversy, the most valid of which in my opinion is the quality of the information gained. Only 23 of the 90 traits or diseases tested for have enough science behind them to allow the company to develop "quantitative estimates and definitive explanations" of the results to their customers. Quite a few of these 23 conditions are medically significant (e.g. Parkinson's, Type II Diabetes) but the possibility of finding out whether I am likely to produce an excess of ear wax is not going to have me running for the checkbook. The remaining 68 genetic components tested for do not have enough scientific evidence behind them to confidently link the genetics to the potential resulting diseases or traits.

My assessment is that this type of test is the first step towards broadly used, highly personalized health care based on individual genetics but that we have a long way to go to bring the scientific basis for this kind of testing up to par.

I just cannot get on the bandwagon that says that we know what's going on with the relationship between diet, cholesterol, and heart disease to a level that allows us to dramatically reduce the rate of cardiac disease and resulting death in our population as a whole. The "Homeostatic Imbalance" entry on cholesterol levels on page 981 of the text seems like a good representation of how little we know. To rephrase its content:

1. We used the think that high total cholesterol levels and LDL to HDL ratios were the predictors of heart disease but now we think only LDL levels and other risk factors are better predictors.

2. Half of people with heart disease have "normal" (as defined by the AHA or whoever) cholesterol levels.

3. Many people with "bad" cholesterol levels do not have heart disease.

4. Still, statins are prescribed (supposedly only) to those people who a) are cardiac patients and b) have LDL levels over 130.

5. The number of people who meet those 2 criteria apparently number 10 million, because that's the number of people taking statins.

6. Everyone should change their diet, regardless of total cholesterol or HDL levels, despite the fact that only 15% of cholesterol in the body comes from diet, and that dietary restriction of cholesterol may result in deficiencies of other essential nutrients found in cholesterol-containing foods.

Good grief.

Because my husband and I are apparently old and boring liberals, or something of the sort, we listen to a lot of public radio podcasts and a couple weeks ago we caught a really interesting segment from Canadian public radio on the history of the HIV virus. The researcher, Dr. Michael Worobey, had come across two tissue samples from the Congo, circa 1960, with different strains of HIV. Based on the the amount of difference between the two strains and the known rate of mutation in the HIV virus, he was able to estimate that the two strains had differentiated from a single strain beginning around the year 1900. 1900! About 70 to 80 years before any knowledge of the virus really hit the worldwide scene.

Dr. Worobey believes that that virus was present (but still lethal) in widely dispersed populations in Africa for many decades before being recognized as a unique condition because those who succumb to the HIV virus die of opportunistic infections, primarily tuberculosis in many non-industrialized countries, and therefore deaths from HIV were not unlike the many other TB-related deaths. He also believes that the virus would not have grown to epidemic proportions had Africa's population remained dispersed in small tribes, but that the growth of city populations in the 1900s allowed HIV to spread very quickly, becoming the worldwide epidemic it is today.

The .mp3 of the interview with Dr. Worobey can be downloaded here.

Well I just realized that my last two entries are about TV. How scholarly of me. So here's a meatier one on the use of aluminum in vaccines.

Aluminum salts (aluminum hydroxide and aluminum phosphate, collectively called alum) are used in many vaccines as adjuvants - components that increase the vaccine's effectiveness when combined with other vaccine ingredients but do not independently create a targeted immune response to any particular disease. The use of adjuvants creates a stronger and longer-lasting vaccine-induced immune response for a given amount of antigen, thereby requiring less antigen per dose and decreasing production costs.

The modes by which aluminum enhances the immune response occur at the level of macrophage and T-cell function and include (not necessarily an exhaustive list, just what I could find online without feeling like I was researching a dissertation):
1. Increased uptake of antigen by the antigen-presenting cell¹.
2. Increase in antigen-induced T-cell proliferation¹.
3. Increased ability of macrophages to induce a antigen-specific memory response².

Questions arise over safety of aluminum use in vaccinations as excess levels of aluminum in the tissues can result if the kidneys are unable to secrete any excess, potentially resulting in impaired bone formation and impaired neurologic function. The FDA limits intravenous aluminum to no more than 4 to 5 micrograms per kilogram of body weight per day³ based on a 1997 study⁴ of premature infants indicating that these low levels are safe. Full-term infants and older children with good kidney function, receiving the aluminum intramuscularly, are likely able to tolerate greater amounts, but no studies meeting these criteria seem to exist⁵. Safe levels in vaccines are therefore not established, but current levels are very high in relation to the 4 to 5 micrograms per kilogram of body weight recommendation for IV medications.

For the sake of an example, amounts for the vaccines on the AAP schedule for the 2 month visit are given here⁵ (by brand, aluminum amount in micrograms):


HIB
- PedVaxHIB 225
- all other 0

Pc
- Prevnar 125

DTaP
- Tripedia 170
- Daptacel 330
- Infanrix 625

Rotovirus
- all brands 0

Polio
- Ipol 0

So an average infant at 2 months old, weighing about 4.5 kilos, could receive no more than 22.5 micrograms of aluminum intravenously as per the FDA (based on the AAP study), but would receive between 295 and 975 micrograms at their well-baby visit assuming all AAP-recommended vaccines are given.

Resources

1. Mannhalter, J. W., H. O. Neychev, G. J. Zlabinger, R. Ahmad, and M. M. Eibl. 1985. Modulation of the human immune response by the non-toxic and non-pyrogenic adjuvant aluminium hydroxide: effect on antigen uptake and antigen presentation. Clin. Exp. Immunol. 61:143-151.

2. Romaniol, A.C., et al. Aluminum hydroxide adjuvant induces macrophage differentiation towards a specialized antigen-presenting cell type. Vaccine. 2004 Aug 13;22(23-24):3127-35.

3. http://www.fda.gov/ohrms/dockets/98fr/03-6227.html

4. Aluminum toxicity in infants and children, Committee on Nutrition, American Academy of Pediatrics, Pediatrics 1996; 97:413-416.

5. Sears, Robert W. The Vaccine Book. New York: Little, Brown and Company, 2007.

HBO has a new series out called True Blood about vampires able to make themselves public after a synthetic blood is developed by the Japanese that the vampires can consume in lieu of human blood. The plot revolves around Sookie, a human telepath, and her developing relationship with a vampire named Bill. When Sookie demands Bill tell her how he can be literally dead but seemingly alive, he tells her it's magic. When she scoffs he goes on to say:

"You think it's not magic that keeps you alive? Just 'cause you understand the mechanics of how something works doesn't make it any less of a miracle. Which is just another word for magic."

That's kind of how I've felt about taking A&P. No matter how much we know there will always be more that we have yet to lean. And the more we know the more we can wonder at the staggering complexity of what is.

There's a new show on TV called "The Drs." and the image above is from their set. I only watched a few minutes before being annoyed enough by several things to turn it off, but one of the most annoying is their set. There are some major problems with that attempt at an EKG reading along the front of the desk. That's one jacked-up P-wave and I bet it's hard to live without ventricular repolarization, eh?

I spent the weekend at the Yoga Journal conference in Estes Park steeped in anatomy, not the least of which was an acute awareness of being sore in just about every muscle group from my elbows to my knees. Child's pose? I'll meet you there in about 5 minutes because it will take me that long to get down to the floor. But I did attend one lecture towards the end (a lecture! sitting on a chair! i've never been so happy to see a chair in my whole life) that touched on the relationship between both anatomy and the chakras and the biochemistry (physiology) and the practice of yoga.

First, the chakras. I'm not necessarily a woo-woo chakras kind of girl, but the speaker did make an interesting point about the location of the chakras in relation to the major endocrine organs and their functions. As I search around online, this seems to be "common chakra knowledge" but it was all new to me. The piece about the gland functions connecting to the chakra functions isn't really firmed up in my mind yet so I'm going to skip writing about it, but here's the anatomy piece.

1st chakra - base of the tailbone - no endocrine activity
2nd chakra - pelvic region - gonads
3rd chakra - just inferior to the ribcage - pancreas and adrenals
4th chakra - level of the sternum - thymus gland
5th chakra - at the throat - thyroid gland
6th chakra - between the eyebrows - hypothalamus, pituitary and pineal glands
7th chakra - crown of the head - no endocrine activity

Okay, so that seems interesting. The speaker also mentioned a study showing that yoga increases GABA levels by a significant amount, accounting for one's feeling of well-being after yoga class. I could only get to the abstract and the study itself has some design issues as far as I'm concerned (total of 19 participants, not controlled for other types of exercise), but the results looked promising:
"There was a 27% increase in GABA levels in the yoga practitioner group after the yoga session (0.20 mmol/kg) but no change in the comparison subject group after the reading session ( −0.001 mmol/kg) (t = −2.99, df = 7.87, p = 0.018)."

There was quite a bit of attention paid to CPR in 2005 when the American Heart Association announced that CPR using chest compressions only had been shown to be as beneficial as chest compressions plus rescue breaths. My first CPR recertification since the announcement was earlier this year, and although the press had widely reported that the breaths were being eliminated from CPR training, that turned out to be untrue. (Side note: I took the class at PVH with mostly PVH staff, and there was one NICU nurse in the class who had never once taken CPR or neonatal resuscitation in her 20 year career. How does that happen?)

We learned both the chest compressions and rescue breaths, although at a higher compression:breath ratio than in years past. The instructor explained that they'd found that some potential rescuers did not want to perform mouth to mouth breathing on a stranger and were therefore doing nothing. For those victims who's collapse or accident is witnessed (i.e. it is known immediately rather than discovered after an unknown amount of time) and who can receive professional emergency care within only a few minutes, compression-only resuscitation is as effective as compressions plus breaths. Anyone who has been down an unknown amount of time or will experience a time delay before paramedics arrive must receive breaths to oxygenate the blood. Most resources suggest 4 minutes is the time frame in which the brain can survive on oxygen already in the blood, but the world record for breath holding is 8 minutes plus, so I suppose 4-8 minutes from collapse to EMS care is an approximate range of time in which compression-only CPR can be effective.

I'm obsessed with Etsy at the moment, and I came across a heart scarf that I think is actually quite lovely, though not very anatomically correct.

So, this can be filed in the "creative posts" category, because I don't know anywhere else one could categorize a recipe for placenta smoothie. Yeah, eating one's own placenta. Gross? Yes. But maybe not crazy. The placenta manufactures and presumably stores many hormones, the same ones that go haywire shortly after birth, and who's to say upping those maternal hormone levels through ingestion of the placenta can't have any benefit? Maybe a little oxytocin to encourage uterine involution? How about a little estrogen and progesterone to counteract the emotional effects of the giant postpartum hormonal crash? Physiologically, I can buy it. Gastronomically, it's hard to swallow. Oh yeah, it's my blog and I'll pun if I want to.

There are some studies out there that address the postpartum benefits of placentophagy but mostly I've found lots and lots of anecdotal stories from women who've once suffered postpartum depression (PPD) and rave about how eating their placenta prevented a recurrence after future births. As one blogger described her PPD: "It's like PMS a thousand times over. I don't know how else to tell you how bad it was except to say "It got so bad that I'm eating my placenta in order to get rid of it." Yeah. That bad."

There are many possible placenta preparations, including cooked and dried, but I'm including a recipe for raw placenta smoothie.

1/2 c. raw placenta, cubed, membranes removed
1 c. frozen berries
1/2 frozen banana
1 c. berry juice

Whir until smooth in a blender.

Warning, long post ahead. I have a lot to say on this subject.

Unfortunately my "real world" hormone experience and my conventional medical experience of same have been less that what we might call awesome. Just thinking about it makes me want to drag out the trusty soapbox for a good old-fashioned rant, but I'll try to stick to the physiology as best I understand it (not well) and minimize the ranty side-notes.

Once upon a time and for quite a few years I took hormonal birth control in the form of a monophasic combined estrogen and progesterone pill and had few complaints. Side effects were limited to the occasional hot flash: real deal I-will-either-die-or-cook-my-internal-organs-by-being-this-hot hot flashes. Not too bad compared to what was to follow. At some point I decided to change pills to try and combat my chronic skin issues and was prescribed a triphasic with a much different formulation. Big, big, huge mistake.

Old Rx
progesterone - high
estrogen - low
androgen - moderate

New Rx
progesterone - low
estrogen - moderate
androgen - low

Some of the resulting side-effects are easy to explain. For example, the low androgen level that was supposed to improve my acne totally bottomed out the old sex drive (irony - my skin never did improve). Other side-effects are commonly attributed to BCP's with this particular hormone profile¹ but I can't seem to find any physiological explanation of exactly how these effects come about. In this category we have moodiness and migrane-type headaches (both supposedly due to higher estrogen). I even had some side-effects that were directly opposite what one would expect with this formula¹ - major depression and extreme nausea despite lower progesterone, and weight loss despite higher estrogen.

Also on the list of side-effects I experienced during this time (a whole year this went on):
extreme anxiety
insomnia
memory problems
difficulty focusing on a task
unusual glucose sensitivity, swinging from hyper- to hypo- states
poor immune function/frequent respiratory infections
feeling jittery, "amped up"

I finally went off BCPs altogether and many of these issues improved; some resolved within months, some over the course of several years, some remain at lower levels even today (I've been off for five and half years). After stopping the Pill, however, one new symptom emerged: tremendous, bone-crushing fatigue. I initially suspected thyroid issues and saw more than one doctor for thyroid testing but the results always came back normal and no alternative theories were ever suggested. I finally, finally, after a few years came across what I believe to be an explanation for everything: the adrenals. I came across some information indicating that changing sex hormone levels can impact adrenaline and cortisol levels². And why not? The adrenals produce them all. In 2007 I diagnosed myself as having had adrenaline/cortisol overproduction during the Year of Hell (explaining many of those symptoms), followed by hypoadrenia/adrenal fatigue after I stopped the Pill, explaining the overwhelming fatigue. Since I'd gotten nowhere looking for a solution with conventional doctors, I found a licensed naturopath (not covered by insurance) who would send in my saliva for hormone testing (also not covered), and validated my own theory. Lab results from July 2007:

Cortisol
7am 18 normal (range 13-24)
11am <1 depressed (range 5-10)
4pm <1 depressed (range 3-8)
11pm <1 depressed (range 1-4)

I wont' go into the treatment protocol I've been following (lots of effective but "not approved by 'real' doctors" stuff there) and I'll try not to be too bitter about all the time it took to get it sorted out and how profoundly unhelpful so many medical professionasl were throughout the process, but I think there are some good take-home lessons to be found here:

1. Hormones are inter-related. You can't go banging away at one (or more) without affecting something else. Hormone interactions are often poorly understood and related functional conditions may be denied altogether (just ask Wikipedia).
2. If you don't get an answer from the expected sources, that does not mean no answer exists. Expect to have to do all the work yourself to find it.

Sources
1. Family Practice Notebook Online, oral contraceptive pages: http://www.fpnotebook.com/Gyn/Pharm/OrlCntrcptvSdEfctMngmnt.htm
2. Schwarzbein, M.D., Diana. The Schwarzbein Priciple II: The Transition. 2002.

You Know You're in A&P When...

...You are soooo happy that you have the summer off before taking the second semester of A&P.

I don't know about anyone else in class, but my brain is full. I am glad to have the next 3 months to let the information settle. Some will probably settle right on out altogether and need to be relearned next semester, but I'm okay with that. I'm definitely feeling like a wussy student at the moment. Gone are the days where I took 15 credits and worked part time and slept hardly ever and still made it work. Four credits and lots of sleep are more my speed these days.

This class was a good experience for me, I learned lots of things that will be useful as I work in the birth field. And I am looking forward to next semester: endocrine system, reproductive system, genetics - yea, yea, yea! All things that interest me both personally and professionally. See you then!

Reading about 3-dimensional and panoramic vision in Chapter 15 reminded me of some information from my Vertebrate Biology class and I think it's kind of interesting. It is the predators of the food chain (including dogs and cats both domestic and wild as well as humans) that have eyes set forward on the head and as a result have depth perception. This allows precise movements when hunting and capturing their prey. The prey species (including mice, rabbits, and horses) have wide-set eyes that give them a large visual field to be on the lookout for something that might be hunting them. They do not require detailed depth perception for their survival, only the ability to detect a threat and perform a simple reflex - run like hell.

Since we've been talking and reading about reflexes I thought I'd write a little about the hyper-reflex in pre-eclamptic women known as clonus but have been able to find much less online information than I'd like. I thought the internet knew everything! Maybe I'm just not putting in the right combination of search words, but I'll include what information I have been able to find.

Clonus is the repetition of involuntary muscle contraction and relaxation that occurs in response to a rapid stretching of the muscle. It is most commonly tested in the ankle by a quick manual dorsiflexion of the foot. If the foot repeatedly plantarflexes/dorsiflexes in response to the test, the individual is said to have a positive sign for clonus. If this sign is present in the non-pregnant person it indicates a CNS problem which may include MS, ALS, Huntington's disease, or spinal cord injury among others. In the pregnant woman it generally occurs along with other signs of pre-eclampsia such as high blood pressure and proteinuria. Unfortunately this is where the extent of the useful information I've been able to find generally ends. I was hoping to find an explanation of the exact mechanism that causes this sign in relation to pre-eclampsia but mostly find only vague references to "hyperreflexia", "reflex irritability", and "CNS involvement". The best deduction I've been able to make is that clonus is a result of the hypertension that occurs with this disorder which can cause vasospasm, edema, and ischemia in the brain. Surely this would qualify as "CNS involvement". Much of the pathophysiology of pre-eclampsia and eclamptic seizures is unknown and several theories exist as to the underlying cause.

I'm totally embarrassed that only today did I have what Oprah would call an "aha moment" about the Na⁺/K⁺ pump as it relates to a cell's resting membrane potential. I've been going along with the nagging question, "If the pump is moving two postively charged ions, how does this result in a negatively charged cell?". Well today I have the answer (thank you Figure 11.8). More K⁺ than Na⁺ passes through leakage channels, down the gradient created by the pump, thus creating a net negative charge!

Moments like this make me wonder to what extent my educational history could be summed up as, "Memorize stuff. Comprehension is optional." Maybe I should have a shirt made.

One of my TV channels is Discovery Health which brings a lot of interesting shows my way. Recently I watched one on Twin to Twin Transfusion Syndrome which was interesting because I know probably less than I should about multiple pregnancies. So I'll start here with the most interesting (to me) part of identical twin embryonic development, specifically the way in which the number of days post conception at which splitting occurs affects various aspects of the twins' development. The listed "days post-fertilization" are approximate.

* If the zygote splits 1-3 days post-fertilization, the twins will have separate placentas and amnions. All identical twins except this type are at risk of developing TTTS.

* If the split occurs 4-8 days post-fertilization the twins will share a placenta but will have separate amnions.

* If the split occurs 9-13 days post-fertilization the twins will share the placenta, chorion, and amnion, meaning that they live in the same amniotic sac during gestation.

* If the split occurs on day 14 post-fertilization or beyond, conjoined twins will result.

Twin to Twin Transfusion Syndrome occurs in about 20% of twin pregnancies where both babies share the same placenta. It is caused when blood flow from the placenta is shared unequally between the babies or blood vessels directly connect the babies' umbilical cords. Sometimes both conditions exist. One twin, the "recipient" will receive an excess of blood, straining the heart and resulting in an excess of amniotic fluid (secreted as urine). The "donor" twin has a very low blood volume resulting in slowed growth and a lack of amniotic fluid.

Treatments are few and are frequently unable to provide a positive outcome for both twins or even for one of them. The most conventional treatment is the draining, generally repeated, of the excess fluid that collects around the recipient twin. An alternative treatment, and the focus of the show I was watching, consists of intrauterine laser treatment to coagulate blood vessels that connect the donor and recipient twins in an effort to restore equal blood flow to both babies.

Oxytocin

How could I not write about oxytocin? As the "love hormone" and with many implications in birth and breastfeeding, oxytocin is near and dear to me. Oxytocin is both a hormone and a peptide-type neurotransmitter and is produced in the hypothalamus then moved to the pituitary where it is packaged into vesicles. Oxytocin is released when oxytocin cells in the hypothalamus send an action potential along their axons to the pituitary, signaling the pituitary to release the contents of the oxytocin vesicles into the blood plasma by means of exocytosis. Oxytocin, along with vasopressin, are the only hormones to be released at such a distance from the locations where their effect occurs. I suppose it's obvious that this allows synthetic forms of oxytocin such as Pitocin to create uterine contractions when administered by IV or intramuscular injection in the leg, but I'd never really thought of it specifically so I'm finding it interesting. Oxytocin is received by specific oxytocin receptors that are necessary for oxytocin to enter the tissues of the body and produce its intended effect. I found information on pharmaceuticals that act as oxytocin receptor antagonists used for preventing pre-term labor, but no information on whether any type of anagonist is naturally produced in the body. I've suspected that there is simply because I've seen Pitocin given to women in late pregnancy with no effect. No contractions, nothing. Given that oxytocin, in combination with other hormones, is largely responsible for mother-infant bonding immediately after birth, it is probably obvious that there are concerns both about the use of synthetic forms of oxytocin used in birth as well as postpartum care routines that distract the mother from her baby or separate the baby from the mother. Quoting renowned French obstetrician Michel Odent regarding generation of the oxytocin peak that occurs immediately after birth*:

"It is easier if the place is very warm (so that the level of hormones of the adrenaline family is as low as possible). It is also easier if the mother has nothing else to do but look at the baby’s eyes and feel contact with the baby’s skin, without any distraction." and "In the particular case of the hour following birth, in physiological conditions, the high peak of oxytocin is associated with a high level of prolactin, which is also known as the "motherhood hormone." This is the most typical situation for inducing love of babies."

Dr. Odent has an entire book dedicated to the subject of the hormones of birth, breastfeeding, and mothering, titled The Scientification of Love, and hopefully some day I'll get around to reading it.

Histamine

Histamine is an amine-type neurotransmitter that plays roles in immune function, smooth muscle contraction, gastric acid secretion, and vascular permeability. Most histamine is produced and stored in mast cells, particularly in areas where injury is common such as the nose, mouth, feet, and blood vessels. A small portion of the body's total amount of histamine is stored and is active in the brain. When histamine is released it can bind with one of four histamine receptor types. The H₁ receptor is the classic type we think of when we think of histamine, resulting in allergic reactions such as difficulty breathing and hives. This type of receptor is found in smooth muscle, endothelial tissue, and in the brain. The H₂ receptor is found on parietal cells and causes gastric acid to be secreted. The H₃ receptor inhibits release of the neurotransmitters histamine, acetylcholine, norepinepherine, and serotonin. The H₄ receptor is found in the small and large intestines as well as in the thymus, spleen, bone marrow, and basophils. Its function is unknown. After being released, histamine is broken down by the enzyme acetaldehyde dehydrogenase. (I thought this next part was interesting because it goes against common assumptions.) It is not an excess of histamine that is responsible for heightened reactions to common allergens, but a deficiency of acetaldehyde dehydrogenase.

GABA

Gamma-aminobutyric acid (GABA) is an amino acid that acts as the primary inhibitory neurotransmitter in the adult human brain. In some other species or in the immature human brain GABA has a primarily excitatory effect. GABA receptors are found in the membranes of both pre- and post-synaptic neurons. To produce an inhibitory effect, when GABA binds to its receptor sites, either Cl^- flows into the cell or K⁺ flows out, causing hyperpolarization of the cell membrane, and making it more unlikely that an action potential will be fired by that neuron. GABA has more than one type of receptor and many drugs produce their effects by interacting with these receptors. Benzodiazepines (e.g. Xanax, Valium, Rohypnol), for example, bind the alpha and gamma sites of the GABA_A receptor, resulting in sedation, muscle relaxation, decreased anxiety or other effects depending on the specific drug. (I looked into this particular group further because I take small doses of Xanax to fly and thought maybe it would be a good idea to know what was going on in there.) Alcohol, barbituates, some anesthetics, and even the herb valerian also act as GABA agonists.

You Know You're in A&P When...

...You misread a business sign advertising "Crystal Gardens" as "Costal Gardens".
...You purchase Atlas of the Human Body by Vigue and Martin off the bargain racks at Barnes & Noble for its lovely anatomical drawings.

I've recently started reading the classic book Childbirth Without Fear, first published in 1942, and written by Dr. Grantly Dick-Read. This book first formalized the theory that pain in childbirth results primarily from the presence of fear in the birthing woman and first named the Fear-Tension-Pain Syndrome that is still commonly taught in prenatal childbirth classes today. I'm only a portion of the way through the book and only have his say-so on certain anatomical information presented as we haven't gotten as far as the uterus in class, but with the heavy emphasis on the importance of the state of the nervous system during birth, I thought the ideas presented in the book are relevant at this point. I will try to summarize the most important points as he presents them:

1. No other normal physiological process of the body is expected to be or is experienced to be painful. Only when bodily processess exceed physiological norms is pain experienced.

2. The parasympathetic nervous system controls the longitudinal muscle fibers that contract to cause the cervix to dilate and the baby to move down the birth canal. The sympathetic nervous system controls the circumferential muscle fibers that cause constriction of the uterus and restriction of the birth process. Also controlled by the sympathetic nervous system is the muscle tissue that surrounds the blood vessels serving the uterus.

3. In the absence of fear, the fight or flight response of the sympathetic nervous system is inactive, allowing birth to progress smoothly and according to the physiological norms of this body function.

4. In the presence of fear, the sympathetic nervous system cause the circumferential muscle fibers of the uterus as well as muscle fibers that surround the uterine blood vessels to contract, causing excessive muscle tension between the longitudinal and circumferential fibers as well as restricted uterine blood flow. These effects result in pain.

I'm rather impressed by the many ways Dr. Dick-Reads observations of modern obstetrics apply as clearly today as they did in 1942 and am greatly enjoying reading the detailed, original explanation that forms a primary foundation of the childbirth program I teach. A good read!

Alright, so I finally started studying for the next exam. Probably shouldn't admit I wasted the whole week of spring break when I clearly should have been writing blog posts and spreading out the exam preparations, but there it is.

One question: The examples in the book of flexion and extension as they relate to the shoulder joint make no sense to me. If flexion lessens the angle at a joint and brings two bones closer together, how does this apply to moving the whole arm anteriorly at the shoulder? Which two bones are being brought closer together that are not also brought closer (but in the opposite direction) by moving the arm posteriorly at the shoulder? Perhaps I am exceptionally dumb but this just does not make sense to me.

One observation: Question number 21 of the True/False quiz for Chapter 8 reads -
"The temporomandibular joint is very complex. What is the purpose of this question? Complexity is subjective. The knee is the most complex joint in the body, for example. Besides, the answer says 'relatively' rather than 'very'."
The answer, apparently, is "True".
The explanation, aka the only part of this question that makes any sense, reads - "The TMJ is a synovial joint and is relatively complex just like all synovial joints."
What the heck? I'm guessing someone's edits made it into the actual question which should just read, ""The temporomandibular joint is relatively complex." Good for a laugh, I guess.

One suggestion: I move that the entire lab practical be made of questions regarding our favorites, similar to "What is your favorite bone and why?" from the last practical. For example, "What is your favorite synovial joint and why?" or "What is your favorite abbreviation for calcium?" (I'm a fan of Ca²⁺ myself). Imagine the ease of setup and grading! Everyone wins!

I've been receiving chiropractic care for years for neck pain and headaches and have recently added deep tissue massage to the regimen to help my adjustments last longer. Like fundal massage I feel like deep tissue massage is almost a misnomer. In "massage", the recipient is peacefully zoned out on Enya, relaxed as a noodle. Deep tissue massage, however, focuses very pointedly on sliding the fascia over its underlying tissue and on stretching the deeper muscles and muscular attachment sites. Deep tissue massage hurts like crazy. It requires deep breathing and concentration. It leaves me sore for days. It inspires me to ask my massage therapist if all massage therapists are sadists, to which replies, "That question comes up fairly often." I take that as an admission of the truth in my question.

So I've been totally avoiding this assigned entry on why we're heading in the professional direction that brought us to A&P because at this juncture I'm not committed to necessarily going to nursing school. If I were to go to nursing school it would be primarily to have a resulting job that paid me more than $5K a year. (I keep telling my husband that someday we'll retire off the "doula monies". Then we laugh like crazy.) But choosing a field for its financial security has gotten me in trouble in the past, resulting in my EBT (everything but thesis) degree, which of course is really no degree at all. I have friends that are nurses and they both say the same thing - they like the actual work of nursing and hate the hospital politics and staffing problems. And I figure that I would like the actual work of nursing and hate the rest as well. So I'm not committed at this point.

But even if I continue on as a doula the information will be helpful for me, particularly in reading research papers dealing with various aspects of prenatal health and birth care. If I end up pursuing homebirth midwifery it would be even more helpful in that I think it's important to fully understand the care I would be providing, and anatomy and physiology would be huge keys to that understanding. Of course this path would have its own rewards and challenges. Being able to be a part of actual cooperative health care with a midwifery client would be great. Being responsible for providing primary care is a Big Deal, and I'm not sure I'm ready for that.

So I suppose I could say that it's not that I have no idea of "why", but have many complex "whys" to consider, and don't have a clear answer or a clear path at this point.

I have a passing interest in graphic and web design and just could not look at that plain blogger template anymore. One pre-made template featuring Johnny Depp in Pirates of the Caribbean had its obvious charms, but I settled on (hopefully more scholarly) flowers.

Going through the bones of the skull (zygomatic bone, parietal bone, sphenoid bone...) I'm starting to feel like Harlan Pepper in Best in Show, recounting his childhood talent of naming "every nut that there was" - " Peanut. Hazelnut. Cashew nut. Macadamia nut".

Why should what is mostly one solid mass have so many freaking bones, anyway? Oh right, to protect our mushy brains. I'll take that excuse under consideration.

Every time we learn new information, the opportunity arises to see our usual world in a new way. I've had a few experiences cast in a fresh light since taking this class and have a short list of items that will tell you "You Know You're in A&P When...". I only have 3 items in the list so far, but hopefully I can add on as the semester progresses.

You Know You're in A&P When...

...Your new favorite words are lambdoid and phalanges.
...You correct your doctor when she holds her hands over the wrong side of her body when gesturing toward the liver.
...You specifically curse your eccrine glands as your sweaty foot slides across your yoga mat yet again.

I had to laugh when we were assigned an entry on "anatomy in art" because I found this when searching for anatomical images weeks ago:

My search brought up this art exhibit summary on boingboing.net:

"This Korean art exhibition explores the fictional anatomy of cartoon characters, with elaborate faked-up skeletons for Looney Toons characters, anatomical drawings of Mickey and friends, and many other artifacts from the study of toon anatomy."

Despite a history with both vertebrate biology and, you know, childhood, it took me a minute to be sure that that the imagined skeleton seen here is indeed that of Bugs Bunny. Here's a link to more of the show.

As a doula I've seen a lot of benefit from the use of Transcutaneous Electrical Nerve Stimulation (TENS) for decreasing the intensity of labor pain. A TENS unit is a small battery-powered system that sends a mild electrical current along lead wires to sticky electrode pads that are placed on the body on either side of the mid-sagittal plane in the area that is experiencing pain. The electrical stimulation runs between the electrodes creating a buzzing feeling in the skin and, if turned up to higher levels, some involuntary muscle contraction. I've long understood that the stimulation works based on the "Gate Control Theory of Pain" by competing with pain reception in the brain, but decided to go digging for the details on how and why this theory explains the benefit of TENS use.

I found these lovely diagrams on Wikipedia and managed to decipher the explanation sufficiently (would have probably been easier to do after neuro A & P but oh well) to satisfy my curiosity, and I am including the explanation as follows.


Part One: No Competing Stimulus
In this diagram, stimulus (represented by the lightening bolt) is carried along a C fiber (which is specialized for pain reception) and arrives at the projection neuron which then passes the message along unimpeded toward the brain, resulting in the experience of the sensation of pain.

Part Two: With Competing Stimulus
Pain stimulus is carried along the C fiber to the projection neuron. At the same time, non-painful stimulus (in this example the buzzing sensation generated by the TENS) is carried by a A β fiber to both the projection neuron and an inhibitory interneuron. Firing of the inhibitory interneuron inhibits firing of the projection neuron, and no stimulus signal is sent to the brain, essentially closing the "gate" by which pain signals were being sent and thereby reducing the overall experience of pain. Presumably not all inhibitory interneurons are being fired by the competing stimulus and some sensation of pain is still experienced.

I'm not really able to duplicate my Venn diagram from class, but here is a list of the similarities and differences we came up with for ET and CT.

Similarities
Both include protection as one of their functions
Each has at least some origin in the mesoderm
Each has a nonliving component (basal lamina for ET, ground substance and fibers for CT)

Epithelial Tissue
Innervated
Avascular
Originates in all 3 embryonic layers
Functions: secretion, absorption, filtration, excretion, sensory reception
Cells are tightly packed and closely bound
Polar due to apical and basal surfaces
Highly regenerative

Connective Tissue
Only some types innervated
Varying degrees of vascularity
Originates entirely in the mesoderm (mesenchyme)
Functions: binding, support, insulation
Some cells are sparsely distributed and unbound
Non-polar
Highly, moderately, or poorly regenerative

I believe I understand all the concepts presented in class content so far with the main challenge being the sheer quantity of information to remember. I swear I have a mental block or some sort of profound aptitude problem relating to chemistry but the review went off pretty smoothly, so fingers crossed for that portion of the exam. I've started review of the anatomical names and body cavities from Chapter 1 and at the moment am working my way through the study guide for Chapter 4 while tissues are still fresh in my mind.

A belated posting of my muddiest point from last week's class on Tuesday. I actually shared confusion on the same question that was raised in class on filtration as a form on passive diffusion. I'm pretty sure I got it cleared up with the drawing that went on the board. A fluid can be moved through a membrane at the location where the vessel that holds it moves from a smaller to a larger diameter because of the increased pressure applied to the fluid in the narrower portion of the tube. If that's not correct then I'm still muddied...

For many years women were told that they should not breastfeed while taking medications. But today, with consideration for the risks of not breastfeeding as well as information provided by the study of transfer of medications from mother to baby, most women are able to safely combine medications and breastfeeding.

There are multiple factors that determine infant exposure to medications through breastmilk. Some of the factors that occur at the site of the milk production cells are described below:

1. Mother's stage of lactation. In the early days of breastfeeding, the specialized epithelial cells that produce milk (i.e. lactocytes) are small and unjoined, allowing free intercellular transfer of medications from the mother's plasma to the milk. However, because total amounts of available milk are small during this time, total transfer to the baby is lessened. Between 3 and 5 days postpartum, as milk production increases, the lactocytes increase in size and form tight junctions, and all further transfer must occur transcellularly, primarily through passive diffusion.

2. Maternal plasma concentration of the drug. As maternal plasma concentration increases, the drug moves through the lactocyte and into the milk along its concentration gradient, with maximum transfer occurring when levels peak in the maternal plasma. As the mother's body metabolizes the medication and plasma concentration levels fall below milk concentration levels, many drugs will pass back into the mother's blood.

3. Molecular weight of the drug. Transcellular diffusion requires that the drug compound pass through the cell membrane of the lactocyte, a process that is more difficult for larger molecules or molecules that are not protein bound and therefore less lipid soluble. At molecular weights greater than 500 daltons, diffusion through the cell becomes more difficult, and drugs with molecular weights greater than 1000 daltons do not pass in clinically significant amounts. One very common medication, insulin, falls into this category.

Resources

Thomas Hale, Chapter 5: Drug Therapy and Breastfeeding in Breastfeeding and Human Lactation, edited by Jan Riordan.

Here are my results from the VARK questionnaire:

Visual: 4
Aural: 2
Read/Write: 8
Kinesthetic: 2

The only surprise for me was that I did not know that there was a learning style scheme that included a read/write component. I'd only previously heard of the visual/auditory/kinesthetic system. Of those 3, I would certainly have pegged myself as a visual learner, which is supported by the VARK results, but with the read/write component included, I had no doubt that that would be my strongest learning style. I've always been a big reader and continue to do most of my professional continuing education through reading and writing. I've never been one to re-write class notes, but flashcards and repeatedly re-reading notes have always been staple study techniques for me when large measures of memorization are involved. I think most academic study is geared to a read/write learning style which is to my advantage.

(I included the famous quote that ends with "form ever follows function" in the header of this blog. I've frequently heard "form follows function" in reference to evolution and if forced to guess, might have attributed the quote to Darwin. Turns out the phrase was made famous by renowned late 19th/early 20th Century architect Louis Sullivan. Who knew?)

I'm working on the endless task of decluttering our household, and today I was making some hard decisions about which books to keep ("All of them!" my mind screams) and which to donate to the library. One that made the cut to keep was The Beak of the Finch by Jonathan Weiner. It follows the work of Peter and Rosemary Grant on the subject of natural selection within Darwin's finches (specifically the ground finches, genus Geospiza) in the Galapagos. Their findings on speciation and genetic variability over short time frames have more to do with the study of evolution than anatomy or physiology, but the relationship between beak size/shape and food sources are a perfect example of the relationship between form and function.


1. Geospiza magnirostris - Large ground finch - large "crushing-type" beak, feeds on large seeds
2. Geospiza fortis - Medium ground finch - smaller "crushing-type" beak, feeds on smaller seeds
3. Geospiza (now Camarhynchus) parvula - Small tree finch, small and narrow beak, feeds on insects
4. Certhidea olivacea - Warbler finch - long and narrow beak, feeds on insects

The thick and powerful beaks of the ground finches are perfect for crushing the hard exterior of seeds in order to access the edible fruits within. And the longer and narrower beak of the tree and warbler finches are suited to picking insects from crevices where they may hide.

* There is a great drawing of adaptive radiation amongst the finches here.
* There is a nice summary of the Grants' work here.

First things first, my introduction. I graduated in 1997 with a B.S. in Animal Ecology from Iowa State University. I worked for the U.S. Forest Service doing GIS (Geographic Information Systems) work and a tiny bit of field work and wildland firefighting from 1997-2001, first in Minnesota, then here in Colorado. I moved to Fort Collins in 1999 to start a Master's at CSU in remote sensing and GIS, but after finishing all my coursework and with my thesis staring me in the face, I had something of a career crisis and began considering moving into a different line of work. My thesis languished for several years until I finally committed to not finishing my degree, and in the mean time I trained and began working as a doula (professional labor and birth support person). I continue to work as a doula today and now also teach a childbirth preparation series called Hypnobabies and breastfeeding classes as well. I have been with my husband Matt for 6 years and do not have children.

As for why I'm taking A&P, that's an excellent question that frankly I'm still asking myself. As much as I love working in the childbirth field, every so often I give some hard thought to the irregular work and low-paying nature of the job. Recently I looked into what it would take for me to become a nurse through the UNC second degree program, and A&P is the first step in that process. So for the moment I am starting to work my way through the prerequisites and will make a final decision about pursuing nursing, or perhaps midwifery, on down the line.

My greatest strength and greatest weakness as a student are probably the same: I have already spent a lot of time as a student. I am willing and able to do my work, study, I generally get good grades, etc. No mysteries there. But it is definitely weird to be going back to undergraduate classes after spending 3 years in graduate school and having left my early 20's far behind. And general chemistry and biology were are looooong time ago, so I'm glad we're doing a review.