Man : Without You (The Body)
§ The human body
o is a great, sweaty,
o fluid-filled machine,
o moving and mixing chemicals with precision and
coordination,
o making everything from memories to mucus.
§ some of the complex, beautiful or
just plain gross mysteries of how you function.
i.
Your Skin Has Four Colors
o All skin, without coloring, would appear creamy
white.
o Near-surface blood vessels add a blush of red.
o A yellow pigment also tints the canvas.
o Lastly, sepia-toned melanin, created in response to ultraviolet rays, appears black in large amounts.
o These four hues mix in different proportions to
create the skin colors of all the peoples of Earth.
ii.
The World Laughs With You
o Just as watching someone yawn can induce the behavior in yourself, recent evidence suggests that laughter is a social cue for mimicry (copy, imitate).
o Hearing a laugh actually stimulates the brain
region associated with facial movements.
o Mimicry (copy, imitate) plays an important role in social
interaction. Cues like sneezing, laughing, crying, yawning may be ways of creating strong social bonds within a group.
iii. Big Brains Cause Cramped Mouth
o Evolution isn't perfect.
o If it were, we might have wings instead of wisdom teeth.
o Sometimes useless features stick around in a species simply because
they're not doing much harm.
o But wisdom teeth werent always a cash crop for
oral surgeons.
o Long ago, they served as a useful third set of
meat-mashing molars. But as our brain grew our jawbone structure changed, leaving us with
expensively overcrowded mouths.
iv.
Cell Hairs Move Mucus
o Most cells in our bodies sport hair-like organelles
called cilia that help out with a variety of functions, from digestion to hearing.
o In the nose, cilia help to drain mucus from the nasal cavity down to the throat.
o Cold weather slows down the draining process,
causing a mucus backup that can leave you with snotty sleeves. Swollen nasal
membranes or condensation can also cause a stuffed schnozzle.
v.
Puberty Reshapes Brain Structure, Makes for Missed
Curfews
o We know that hormone-fueled changes in the body are
necessary to encourage growth and ready the body for reproduction.
o But why is adolesence so emotionally unpleasant? Hormones like testorone actually influence the development of neurons in
the brain, and the changes made to brain structure have many behavioral
consequences.
o Expect emotional awkwardness, apathy and poor decision-making skills as regions in the frontal cortex
mature.
vi.
Thousands of Eggs Unused by Ovaries
o When a woman reaches her late 40s or early 50s, the
monthly menstrual cycle that controls her hormone levels and readies
ova for insemination ceases.
o Her ovaries have been producing less and less
estrogen, inciting physical and emotional changes across her body. Her
underdeveloped egg follicles begin to fail to release ova as regularly as
before.
o The average adolescent girl has 34,000
underdeveloped egg follicles, although only 350 or so mature during her life
(at the rate of about one per month). The unused egg follicles then
deteriorate.
o With no potential pregnancy on the horizon, the
brain can stop managing the release of ova.
vii.
Much of a Meal is Food For Thought
o Though it makes up only 2 percent of our total body
weight, the brain demands 20 percent of the body's oxygen and calories.
o To keep our noggin well-stocked with resources,
three major cerebral arteries are constantly pumping in oxygen.
o A blockage or break in one of them starves brain
cells of the energy they require to function, impairing the functions
controlled by that region. This is a stroke.
viii.
Bones Break (Down) to Balance Minerals
o In addition to supporting the bag of organs and muscles that is our body, bones help regulate our calcium levels.
o Bones contain both phosphorus and calcium, the
latter of which is needed by muscles and nerves.
o If the element is in short supply, certain hormones
will cause bones to break down, bones add calcium levels in the body until the
appropriate extracellular concentration is reached.
ix.
Body Position Affects Your Memory
o Can't remember your anniversary, hubby?
o Try getting down on one knee.
o Memories are highly embodied in our senses. A scent or sound may evoke a distant episode from one's childhood.
o The connections can be obvious (a bicycle bell
makes you remember your old paper route) or inscrutable.
o A recent study helps decipher some of this
embodiment. An article in the January 2007 issue of Cognition reports
that episodes from your past are remembered faster and better while in a body
position similar to the pose struck during the event.
x.
Your Stomach Secretes Corrosive Acid
o There's one dangerous liquid no airport security
can confiscate from you: It's in your gut.
o Your stomach cells secrete hydrochloric acid, a
corrosive compound used to treat metals in the industrial world.
o It can pickle steel, but mucous lining the stomach
wall keeps this poisonous liquid safely in the digestive system, breaking down.
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