I can fly?

I think the most commonly wished for "superpower" is the ability to fly.
That would in fact be too cool.
Whenever we picture people (or dragons, for that matter) with wings these are always IN ADDITION to our four limbs. Given the fact that wings in our branch of the evolutionary tree are the same genotypically as arms or forelegs, this is truly fantasy. Flight has evolved independently several times (insects, bats, and birds all got their wings under different circumstances), but it's a little late in the game for us to grow a third set of appendages.
That being said, wings are lovely! But they are still, for bad or good, IN PLACE OF arms.
On balance I'd rather have the latter.
Consider this the next time you dream of flying!

Anti-

-body!

Beautiful!

It came from...

...inner space!!

Here we see a macrophage (known as a monocyte when it is circulating in the bloodstream) "lasso-ing" pathogens.
Of all the fantastic attributes of the human organism, surely the immune system is the most elegantly onderful. Complex yet logical, layered and exquisitely specific, it has kept us ahead of the many parasites that view us as a tasty way to get their nutrients, a fine place to raise a family, and a legacy to pass on to their progeny.
Unfortunately it, like strange things everywhere, has been misunderstood, misrepresented, and lied about by pseudoscientifically literate people with willfully blunt and stupid axes to grind. This means you, anti-vaccine nuts! This means you, "allergy" gurus! This means you, antioxidant fanatics!
The only weapon against ignorance is knowledge--learn about your immune system today!

a-POP-tosis!

Otherwise known as programed cell death.
Natural selection occurs at the cellular level as well as that of the individual and species.
In apoptosis, the body produces many more times the number of cells it needs (in the brain, say) and then those that are selected live and the rest are instructed to die--
very quietly and neatly, without leaving inflammation or debris behind.
In a sense, then, we are continuously being carved from a block of living material;
the sculpture that is left is adapted to the environment (as well as beautiful to the eye!)
Fearfully and wonderfully made!

Making of bone....

...complex but beautifully logical and finely tuned!
First, cartilage does not "turn into" bone. Chondrocytes die through programmed cell death (apoptosis) and are then REPLACED by bone forming cells (osteocytes -> osteoblasts). These cells secrete a protein called osteoid, which is then hardened (utilizing other protiens, enzymes, and Vitamin D) with calcium and phosphate. Osteoclasts then model the final bone structure based on DNA instructions. Actually, though the skeleton provides critical infrastructure, the real critical function of bone is to provide a nanosecond-by-nanosecond supply of calcium, which is the major electrolyte involved in cell depolarization, neuronal signalling, and muscle contraction. It all works so beautifully! This is what millions of years of natural selection has accomplished...a symphony of bone!

Pretty, too!

Hyaline cartilage.

This is the wondrous
substance that covers the head of the femur and humerus and is stronger, smoother, and more resilient than any man-made substance.
"No body does it better...."

Two-edged sword....

...immune complexes.
As with all body systems, the key to homeostasis is RANGE. Too much can be as dangerous as too little....
Lymphocytes produce antibodies specific to the pathogen, which under normal circumstances engage with the rest of the reticuloendotheliel system to clear both without residua. In a variety of circumstances, though, these "immune complexes" circulate at a level that the body cannot manage. They then essentially "lodge" in places they don't belong (here, in the kidney) and cause ongoing inflammatory damage. Immune complex disease is a major problem with several autoimmune disorders (such as lupus) and a number of infections (notably hepatitis B and C).
We are, as a species, Goldilocks. Mostly our porridge and bed is just right; when they aren't, it's worse than bears!

University Day!

There is no app for this!
slogan on the front of a T-shirt from the American Museum of Natural History in NYC

More but less....

...stem cells.

They political controversy over stem cells (which are obtained from embryos, not fetuses, usually "left over" from reproductive technologies like IVF) has obscured the facts (surprise!). While theoretically powerful therapeutic tools, especially in the area of regenerating normally non-regenerative cells like neurons, the actual experience with stem cells has been disappointing, to say the least. Part of this has to do with the difficulty identifying the exact stage of the cell (unipotent, totipotent, cell line committed, etc.), but there have been numerous other technical problems. The potential is still there, but the vsion created 10 years ago now looks like the old Tomorrowland. Research should continue, but in the meantime it is still prevention rather than treatment that will make the greatest impact on health in this country and the world in general.

Iron!

The world could learn from the body's recycling abilities!
Once an organism has "filled the tank" with iron during childhood, it essentially needs no more during it's life unless it bleeds. Of course, in humans means women need refills, but men do not.
So, if a male shows up iron deficient it means he's bleeding, usually from the GI tract. Just one of the many clues we use to assess homeostasis!
On the other hand, genetic errors of protein synthesis can cause the body to "mishandle" iron, which, in excess, is toxic to our cells. A number of conditions can lead to iron overload (which is what is pictured in the liver microphoto above--iron staining blue), which can be fatal.
One of the reasons medicine and biology are so endlessly fascinating is this warp and woof of homeostasis--following the clues to diagnosis, resolution and hopefully better health!
Easy does it on the iron--an elegant sufficiency, as my Granny used to say, is all that's needed!

Not woven cloth....

...a fingertip!
Another miraculous aspect of the human body--the integument (skin).
Take good care of yours today.
And, yes, all fingerprints are unique!

Red, white, and beautiful!

Blood!

Building blocks

The average American knows even less about food than he or she does about the structure and functions of his/her body (this ignorance is part of a much broader scientific illiteracy).

The proteins we make as the basic function of metabolism must be constructed from amino acids--we do not absorb steak. The amino acids (generic structure pictured) must be obtained from the break down of more complex proteins--we cannot manufacture them ourselves. Only amino acids--not Big Macs or protein shakes or nuts--can be absorbed from the gut. They must then be stored as proteins that cells can in turn use to manufacture their more complex protein products, e.g. hormones, neurotransmitters, other signal and transport proteins. The nitrogen that is the unique ingredient in proteins (as opposed to carbohydrates and lipids) has to be "fixed" by bacteria and then converted into plants proteins--we cannot utilize the nitrogen that is in the air around us (80% of air is nitrogen). The fact is we are part of two biomass-wide cycles--the Nitrogen and Carbon Cycles. Our wastes (and remnants!) in turn contribute carbon and nitrogen to this biomass. The foodies would have you believe these substances are unique and magical--they are not. We are simply a stage in the cycles--but thankfully so! Without them we would have died out millennia ago.

The central dogma of cell biology....

...DNA makes RNA makes protein!

Resistance is NOT futile!

In fact, it is critical to effective cardiac performance.
Arteries (one pictured) have a significant layer of smooth muscle composing the tunica media, the middle layer. This muscle, under control of the autonomic nervous system, responds to a number of stimuli, with the "goal" being to maintain sufficient pressure in the arterial circulation such that all tissues maintain adequate blood flow (OXYGEN). If this muscle contracts, the pressure increases; if it relaxes, the pressure goes down. The net effect of this pressure is termed RESISTANCE, or AFTERLOAD, and is a key factor in setting stroke volume, which in turn determines cardiac output. The neuroendocrine system is exquisitely tuned to tissue oxygen status, and directs blood blow to where it is needed, nanosecond by nanosecond. For example, during "flight or fight" responses nervous activity and blood blow are directed away from the gut toward the muscles; this is why you may feel nauseated ("butterflies in the stomach") when you are stressed. On the other hand, after you eat blood flow is redirected to the gut and you often, then, will feel sleepy as blood is redirected away from the brain and muscles. The body wastes no energy--everything that it does is beautifully balanced to maintain your health!

Net it out!

One of the most fiendishly difficult concepts--because of the way it's taught rather than what it is--in biology is meiosis. This is how germ cells produce gametes. It involves replication, reduction, and, most importantly CROSSOVER, such that at each stage of the process genes are mixed (as opposed to mitosis, which produces IDENTICAL daughter cells). I was gratified to hear a student say yesterday, with that AH-HA look on her face, that she finally got it!
This is what teaching is all about!

Infinite...

...variety.
Genetics + epigenetics = every organism is unique.
Which gives every organism, species, family, class, genus, and life itself, the maximum opportunity to not only survive but thrive.
Appreciate our differences--they are what has allowed us to succeed. Sameness = death.

Mitosis

As we discussed in class, mitosis is actually replication of the nucleus. This is normally followed by division of the cell, which results in two identical daughter cells. The cell multiplies by dividing....
If, however, cell division DOES not follow, we have a cell with 96 chromosomes. As is the case with most of life's parameters, if a little bit is good a lot is not necessarily better, and may often be harmful. In this case we have aneuploidy (abnormal chromosome number),
which can lead to cell death or, even more maladaptive, cancer.
Be thankful for mitosis today!

A true work of art....

...the cell!