From: Tory Brady (toryb@exploratorium.edu)
Date: Tue May 08 2001 - 16:28:36 PDT
Message-Id: <l03110701b71ddd20eaa6@[192.174.3.223]> Date: Tue, 8 May 2001 16:28:36 -0700 From: Tory Brady <toryb@exploratorium.edu> Subject: Re: pinhole human biology questions
Hi Mike. I will answer what I can...
1. Don't know-- maybe the music teacher can help you.
2. You breathe out the same amount of "air" that you inhale, but it is
different in composition. According to the text, "Biology" by Campbell,
"Starting with glucose or other organic fuel and using oxygen, respiration
yields water, carbon dioxide, and energy in the form of ATP and heat." The
carbon dioxide is transported to the pulmonary capillaries in the form of
carbonic acid (dissociated into bicarbonate and H+) In the lungs it
reconverts to CO2 and is expired. In normal quiet breathing, the
contraction of the diaphragm and external intercostal muscles increases the
thoracic and lung volum, decreasing intrapulmonary pressure to about -3mm
Hg.
Relaxation of the diaphragm and external intercostals, plus elastic recoil
of lungs, decreases lung volume and increases intrapulmonary pressure to
about +3mm Hg. Since the pressure gradients are the same, it seems the
amount of gas entering or leaving would be about the same.
3. The active chemical in most asthma inhalers is a form of epinephrine,
which causes bronchodilation, or the opening of the bronchioles that have
"swollen shut" in an allergic response.
4. Bruising is caused by the breaking of tiny capillaries and the
subsequent bleeding under the skin in the area of the bruise. So, since
there are blood vessels supplying the bones, you could say you got a "bone
bruise" if the blow was hard enough to break some of the capillaries
supplying the outer surfaces of the bone.
5. The propensity to get asthma is a very charged issue right now.
Research has shown that children who live in areas near freeways, large
incinerators, and just generally toxic areas tend to have a higher
incidence of asthma. (I used to teach in a school that was next door to a
refinery and every teacher had an inhaler or two in their desks for the
kids in their class with asthma.) It is no surprise that the areas
described are often low-income areas. Low income moms are more likely to
need Ceasarean sections for a number of reasons. Also, mothers who have
Caesarian sections are statistically less likely to bresat-feed or to
succeed at breast-feeding than vaginal birth moms. Breast feeding
transfers to the infant large numbers of antibodies that are not yet being
manufactured by the baby's immature immune system. This could also be a
factor in the asthma incidence. This would be a great topic for your kids
to research!
6 Hiccups can be cause dby a number of things-- too much CO2, a rub
stimulus from something touching the diaphragm, etc. Like other muscle
spasms, sometimes they can be alleviated by changing the position of the
muscle, by contracting or expanding it, or by taking in more O2.
7. I don't think so-- seems like it sometimes, and maybe intrathoracic
pressure would squeeze heart, but I think rather than skipping a beat the
beat would be indetectable. Have to check that one out...
Good questions! Lots of possibilities for further thinking.
-- Tory Brady, TI
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