q&a

the cardiovascular system is a complex beast.  there is an incredible amount of anatomy and even more physiology to learn before the system can be understood, even at a basic level.  so i have decided to focus a question on the small stuff.   which type of capillary is found in the lungs?

we learned about three kinds of capillaries:
1) continuous capillaries - found abundantly in the skin and muscles, uninterrupted lining, tight junctions
2) fenestrated capillaries - same as continuous but with oval pores, permeable to fluids
3) sinusoidal capillaries - leaky, allow large particles to pass

none of these sound like the kind of capillary that would be found in the lungs, exchanging carbon dioxide and oxygen.  i did some research on the respiratory system and learned the following.  pulmonary arteries branch into pulmonary capillary networks surrounding the alveoli which are air cells of the lungs where respiratory gases are exchanged.  so i haven't determined which type of capillary is found in the pulmonary capillary network, but i did learn that the gas is not exchanged directly from the capillary, rather it is exchanged from the alveoli, which is connected to lungs via the respiratory bronchiole.

woman, homegirl, lady, lass, chica

mary roach, author of bonk, has a very wry and creative way of teaching me about my own body.  there are loads of tidbits in bonk that i find compelling and extremely hard not to share with all of my female friends.  this is one of the most fascinating things i have learned:

when women get turned on they get "wet."  this lubrication is plasma secreting from the capillaries in the nether region.  who knew, right?!  in our culture, this wetness is a nice, even requisite part of sex.  if a woman does not or cannot produce enough for the ease of penile sliding, she needn't fret, our capitalist friends have produced all kinds of synthetic lubes.

if, however, this woman lives in parts of africa, haiti or indonesia her wet vagina is a turnoff.  wow!  i didn't see that coming.  in those places, men prefer dry sex and the women accommodate.  they use all types of drying agents including newspaper, cotton, rock salt, detergent, bark and dried animal excreta.  most of us probably have a similar reaction to that new information.  ouch, coach.  but roach goes on to explain that women in "developed" countries are regularly taking part in an even more damaging practice - using super absorbent tampons.  unfortunately, they have been shown to cause the outer layer of the vaginal cells to dry out so severely that it peels away.  ouch.  again.

an alternative for women who can't help but shed their uterine walls once per month, is to use a diva cup.  it is a friendly option for our sensitive bodies, it is convenient and reliable, there is no risk of toxic shock syndrome, and it is an environmentally friendly choice.

organic

organ donation is a highly volatile subject for many.  and rightfully so.  our body is the most sacred possession we have, the only possession we have.  so it is no surprise that there is much discussion about the best organ donation policies.


on january 21, this article was posted in the online huffington post:

Colorado Organ Donor Legislation Pulled

DENVER — A Colorado bill that defaults all driver's license applicants as organ donors is unlikely to become law this year.

Democratic Sen. Lucia Guzman told Denver's KUSA-TV that she is dropping her proposal that the state change to a "presumed consent" system.

That system automatically classifies all applicants for driver's licenses and state ID cards as organ and tissue donors unless they opt out. Such donations are used in several European countries but have raised ethical concerns in the U.S.

The Colorado proposal was introduced last week and sparked fears and opposition from many.

Supporters say they will drop the proposal for now.

Colorado Senate bill: http://goo.gl/MlKSw

should colorado adopt an opt-out policy for organ donation?

yes -
1) there is a shortage of organs available for transplant every year, and although most of the public says that they would donate their organs to help someone else, less are actually registered to donate
2) currently, the family gets the final decision and may override the wishes of the potential donor.
3) the family of a potential donor is in a fragile state after the death of a loved one and they don't need the extra stress of deciding whether to donate organs.
4) this new law retains the role of the potential donor to decide whether or not to donate organs, and requires him/her to be acquainted with the law - like most other laws.
5) this maximizes the number of donated organs.

no -
1) this doesn't mean that more organs will be available.  some could see this as a threat to their rights and may result in less donors than we see currently.  there are some cultural and religious rituals that do not support organ donation.
2) the presumption of consent (potentially despite family wishes) could be traumatic for the family of the donor.  this could result in poor publicity or distrust of the medical profession.
3) there could be medical issues with removal or organs for donation that the family could reveal in a screening before donation.
4) a person may not opt-out because of a misunderstanding and their organs may be removed despite an objection to the procedure.
5) this helps the family stay involved with the donation and support the program.

life or death

the barbara walters special, a matter of life and death, focuses on the dichotomy of our hearts, it's strength and fragility.  she shares statistics: our hearts beat 100,000 times, pumping 2,000 gallons of blood, filled with oxygen, through our bodies.  in an average lifetime, this amazing muscle will beat more than 2.5 billion times.  and then she highlights the scary truth that heart disease is america's number one killer.  specifically, she shared her own story and interviewed former president bill clinton, david letterman, robin williams, regis philbin and charlie rose, who have all had major heart surgery to save their lives.


i learned more about how heart surgery works and the impressive operating room technology.  a surgeon stops your heart and uses a machine to oxygenate and pump blood throughout your body while he operates on the cardiac muscle.  it was fascinating to hear personal stories about different signs, symptoms, and recoveries.  but i was disappointed that the focus was on the technology available to "right our wrongs" and only the last few minutes of the special focused on prevention.  in our society, most people are not willing to do the work to stay healthy by eating right and exercising and this special perpetuated (and darn near encouraged) that habit.  it encourages me to be thankful for the work that local health practitioners are doing to help educate the public about maintaining heart health.

get pumped

wow!  look at my arms!  they are super vascular!  molly, why do my arms get vascular from time to time?

coincidentally, i am studying the cardiovascular system right now, and i have some theories...

you get vascular because:
- your body fat is lower than 10%
- you are very hydrated
- you are using steroids
- your veins are close to the surface
- you work out regularly and you need to transport more blood to respiring cells for gas exchange, increased blood flow causes your veins and arteries to stretch
- you are too warm and your body is increasing heat loss from the surface of the skin by via vasodilation
- your body is used to caffeine which is a vasoconstrictor, but you haven't had caffeine today
- you consumed a lot of salt which causes high blood pressure and makes veins pop
- you drank alcohol which is a vasodilator
- you are using speed  ;)

if none of these are true, i have more musing to do...

mama mia!

my mother is one of the lucky ones who gets to listen to my educational monologues after i learn something new about the human body.  i don't know if she would tell you the same -- the "lucky" part.

she and i talked at length about current options for women who are dealing with the pains and discomforts of menopause.  unfortunately, it is inevitable that women will go through menopause, rife with physical and emotional changes.  as if the hot flashes, night sweats, irregular periods and weight gain weren't enough, women also experience a decline in hormone levels which can cause moodiness, depression and loss of libido.

many women cope with these changes by using hormone replacement therapy, taking a supplement of estrogen paired with progestin (synthetic progesterone).  hormone therapy was thought to have long-term benefits of preventing heart disease and osteoporosis and it was used routinely until 2002 when a large clinical trial unearthed it's health risks.  these risks include heart disease, stroke, breast cancer, blood clots and abnormal mammograms.  depending on a woman's health history, hormone therapy is still the most highly-recommended treatment for coping with menopause symptoms, but there are more options for women who are at high-risk or women who don't want to supplement with synthetic hormones.  some women change their lifestyle while others choose a natural herbal supplement like estroven.

the discussion about hormone therapy is a complicated one, and one that won't be over soon.

pop!

recently our friend jeremi stopped over and couldn't find his way out of our cozy apartment.  alas, we all sat down with a beer and got to talking about a&p.  he studied neurophysiology, so he appeared less bored than many of my other friends who "get" to learn all about the human body when they hang out with me these days.


anyway, he made a comment that triggered my google search button, and in turn, my blogger keyboard.  he wishes he could wear contact lenses but he claims his eyeballs build pressure and change shape when he exercises and the contacts pop off his eyeball.  what?!?!  i've never heard such a thing.  and despite some significant research, i couldn't find anything reliable to prove or disprove jeremi's theory.  but i did find an interesting (although also unreliable) q&a about sunbathing with contact lenses.

Q: If you sunbathe while wearing contact lenses, is there a potential problem with heat dispersal? — S., England

A: Not really, but your corneas can swell and make your lenses fit tighter, causing some temporary redness and irritation. I recommend that my patients put some form of lubricating drops in their eyes before tanning. And remember to wear protective glasses to block the really harmful UV radiation from getting to your eyes — it has been linked to cataracts, macular degeneration, etc. — Dr. Dubow

if corneas can swell from uv radiation it is not far-fetched to think they might also swell from high-intensity exercise.  but in this case, it sounds like the swollen corneas cause the contact lens to fit tighter, not to pop out of the eye.  i will be sure to ask my eye doctor about this next time i go in for my annual pupil dilation.