The nervous system is the body's controller, and works by using electrical signals. It has three functions: 1) sensory receptors monitor both internal and external body changes, referred to as sensory input ; 2) it then processes this sensory input to make decisions about how to respond - called "integration;" and 3) forces a response by activating effector organs (glands or muscles) called motor output.
The nervous system is commonly described as having two parts: the Central Nervous System, or CNS, which is comprised of the brain and spinal cord; and the Peripheral Nervous System, or PNS which is composed of the nerves emanating from the CNS.
The PNS is further subdivided into the afferent and efferent sections.
The afferent, or sensory, division is a series of nerve fibers that carry signals from sensory receptors to the CNS. The efferent (motor) division carries signals from the CNS to the muscles and glands causing contraction or secretion. The nervous system, being highly complex, is further subdivided. The sensory division is further divided by different body areas: a somatic (sensory) subdivision for skin, skeletal musculature, and bones; and a visceral (sensory) area for the guts - digestive tube, lungs, heart, bladder, liver, etc. Now for the motor division: it contains a somatic motor component for innervation of most skeletal muscles; and a visceral motor component for innervation of smooth and cardiac muscles (viscera and glands).
The somatic sensory subdivision containing sensors for what is happening on the skin - touch, pain, pressure, vibration, temperature; and proprioceptive sensors, which measure muscle, tendon, and joint stretch. They essentially monitor body position and movement - like roll, pitch, and yaw on a satellite. Proprioception is body sense. There are also a group of "local" somatic senses - like in the eye, and ear (hearing and balance).
The visceral senses are stretch, pain, and temperature. Nausea and hunger are also visceral senses, as is taste.
The general somatic motor subdivision sends messages to contract skeletal muscles. Since we have control of this system, it is also called the voluntary nervous system (VNS).
The general visceral motor division of the PNS is responsible for contraction of smooth and cardiac muscle, as previously stated, and is also called the autonomic nervous system, or ANS. Since its functions, like flow through the digestive tube and the pumping of the heart, are uncontrollable (Unless you are a ??? What are those guys called - a fakir?) it is also known as the involuntary nervous system, or INS.
The story of the nervous system is a long complicated one, and will be continued in future Newsletters. For a graphic depiction of the nervous system and its various divisions/subdivisions see Figure 4-1.
Urine farming? Yes, it may become a reality. There are currently ongoing attempts to genetically engineer cows to produce milk containing specific proteins that are pharmaceutically viable. For instance, milk containing a blood-clotting agent is currently being developed.
Now there is some thought that animals can be engineered to produce pharmaceutically useful urine. So far, mice have been developed that produce HGH (Human Growth Hormone) in their bladders. While the mice only produce a small quantity, they prove that the theory can work. Now it is on to cows - bigger animals, more urine.
[This isn't too far-fetched, I once had a brain tumor removed by a combination of surgery, chemotherapy, and radiation treatment; and I was part of an experiment that used a "chemo" drug made from cow urine, or so I was told. I even had to sign a form before being allowed to participate in the program. I'm sure it was a liability release - you know, in case I started to moo, or something.] Back to the subject at hand. There is currently an estrogen made from horse urine that is on the market - it is used for estrogen replacement therapy (ERT).
An advantage to using bioengineered urine is that it can come from both males and females, unlike milk. And it is produced from birth to death.
The possibility of urine farming first came up when a gene active only in the bladder was discovered. Its function is to encode proteins (uroplakins), which form part of the bladder lining. Rather than try to further discuss the technical aspects of this procedure, let's suffice it to say that urine farming seems to have possibilities, but has a long way to go before it becomes reality. In addition to cost (A sheep or goat can be engineered to produce a desired product, but at a cost of about $60,000. But a whole herd can be produced from that one using normal breeding methods.) and volume issues, there are myriad technical problems to resolve. Not the least of which is collection. Maybe permanent catheters will be the answer.
The preceding information comes from the January 1998 issue of Science News magazine.
Are tanning booths safe? Not likely. Their safety has previously been questioned in the Newsletter, and here is further support for their lack of safety: from the February 1998 issue of the University of California at Berkeley Wellness Letter. It was reported that a government panel has recommended that ultraviolet light from any source, like tanning booths, be added to the list of cancer-causing substances. [This is just more of the over-whelming evidence that the only safe tan comes from a bottle.]
There still seems to be some controversy about whether or not to take multivitamin/mineral supplements. Many nutritionists/dietitians continue to claim that a healthy diet obviates the need for multivitamin/mineral supplements, and that is sound advice, IF you eat a healthy diet; but many of us don't. It is pretty clear that, at the very least, those over the age of 65, should probably take a "multi." In reality, the diets of many older adults are deficient in vitamins C, D, B6, B12, and folacin; and the minerals zinc, magnesium, and calcium. Many older adults don't eat enough fruits or vegetables - a major source for vitamins and minerals.
As early as age 50 the immune system starts a decline. Production of antibodies and T-cells (major factors in the body's anti-bioterrorist forces) starts to drop. Some studies have suggested that nutrients like vitamin B-6, beta carotene, zinc, and other vitamin/mineral supplements may help improve the efficacy of the immune system.
Vitamin D, which aids absorption of calcium, is another potentially healthful supplement. Consequently, the editors of the U. C. Berkeley Wellness Letter recommend a daily multivitamin/mineral particularly for older adults. They also recommend, for everyone, higher doses (above the RDA) of the antioxidants vitamin E and C (above the RDA) - 200-800 IUs of E and 250-500 mg of C. And possibly calcium supplements as well - 1300-1500 mg for women over age 50 and men over age 65. These recommendations are in addition to, not instead of, a healthy diet. Foods, especially fruit, vegetables, and whole grain, are loaded with nutritionally beneficial ingredients.
A currently popular ergogenic aid, creatine, is being used to improve athletic performance during quick, high-intensity activities (e.g., weight lifting/training, short sprints, or jumping,). They have no effect on aerobic performance.
Creatine is an amino acid, but not part of protein. In the body it is found in muscles in the compound creatine phosphate; an energy source for short-term, explosive activities. One to two grams of creatine per day is/are ordinarily derived from food. It is also made in the liver, pancreas, and kidneys. Some studies have supported creatine supplement use for improved short-duration, explosive activities. But some studies have failed to show such results; maybe because the supplement wasn't taken in large enough doses, or for a long enough duration. After a "loading" period, muscle creatine was quantitatively increased by up to 40%. But, should you use it? Maybe not, for the following reasons:
The previous information was primarily extracted from the January 1998 issue of the University of California at Berkeley Wellness Letter.
A toe raise is an exercise that is not very often done, but which can be beneficial, especially for those with shin splints. It strongly works the anterior tibialis muscle that runs along the shin bone (tibia), and is a prime mover during ankle dorsi flexion (moving toes toward the shin). One way to do this exercise is to put your heels on a board (anything that will keep your heels a couple of inches off the floor). Now move your toes toward your shins, and squeeze the muscle before reversing the motion by pointing your toes plantar flexion), then repeat until you complete your set. Resistance can be added by having a partner loop a towel across the top of the base of the toes, or by using bands/tubing, or ankle weights - use your imagination. This area is generally ignored, but as previously mentioned, may help prevent or mitigate shin splints by helping to maintain balance between opposing muscles in the leg (gastrocnemius/soleus in the calf with the tibialis anterior along the shin). Without resistance it at least provides a good stretch.
Finally! "Afterburn" described - its effectiveness, that is. You say you've never heard of it? It is the revved up metabolism that you experience after aerobic exercise. Depending on time and intensity of your activity, your metabolism is temporarily speeded up for some length of time - from a few minutes to a few hours.
Perhaps surprisingly to some, 60-75% of our daily calories burned occurs while we aren't doing much of anything (like working at a desk, playing couch potato (where one's eyes and remote control finger get most of the exercise), or even sleeping). When you do aerobic exercise, you burn some calories during the activity, and a few more afterward (after-burn). It is theorized that during the body's cool-down, metabolism takes time to return to normal, just like body temperature and heart rate. Until you return to "normal," you will burn approximately 15% more calories. So, if you burn up 100 calories during walking, cycling, or whatever; you will burn an extra 15 calories between the time you stop the exercise and the time you return to normal. Not a big deal.
So, whether you know it or not, what you want to do is to start a weight training program to permanently elevate your metabolism. More lean body mass (muscle) yields an increase in resting metabolic rate. There have been studies that reported a 4-8% metabolism increase among those who weight trained as opposed to a non-weight training group. That increase is permanent. Clearly the longer you participate in weight training the better off you will be (metabolically speaking, and otherwise). For the rest of your life would be good.
As we age (after about the mid-20's), we lose about 1% of our muscle mass each year, until - well, forever. Even if your weight remains constant from high school to old age, your muscle mass is reduced and your fat mass increases. The decreasing muscle mass results in a commensurate decrease of your metabolic rate. So, you have two choices: decrease your caloric intake, or get fat (or increase the intensity of your exercise). OR, start a weight training program (actually a resistance or weight-bearing program, of which weight training is best); and don't stop, this is forever. You will at least be able to more-or-less hold your own against the inexorable body composition assault.
Designer estrogen? What's that? It is an alternative to natural estrogen for ERT (estrogen replacement therapy). It is designed to relieve some of the effects of menopause, while avoiding the pitfalls: loss of bone density (osteoporosis), and increased risk of heart attack and breast cancer. The first of its kind, raloxifene, is due to hit the market in mid-1998. You might want to talk to your doctor about it.
(Q) I have heard that raloxifene, the first designer estrogen, is due out soon, but that it has, for me, a major shortcoming; it is not particularly effective against major hot flashes. Is that true?
R.A., San Jose, CA
(A) Yes it seems that raloxifene is better at countering some of the side-effects of natural hormone (estrogen/progesterone) replacement like osteooporosis, breast cancer, and heart disease rather than intense hot flashes. However, one possible strategy that has been suggested is to use normal hormone replacement early in menopause, and then switch to a synthetic later when the side effects are more likely to show up. This is something for you and your doctor to work out once raloxifene (or other designer estrogens) are actually available.
(Q) Is "grazing" considered a good eating pattern? I haven't heard it mentioned lately?
B.P., Portland, OR
(A) Yes, it is considered a healthy eating style to adopt. "Grazing," as most of you know is an eating pattern whereby one eats all day long - like a horse or cow - frequent small meals (snacks); and not junk. Nancy Clark, a well-known nutritionist at Sports-Medicine Brookline, an athletic injury clinic near Boston; says essentially that many people skip breakfast, maybe grab a machine snack in the afternoon, then gorge on an often late, big dinner. Some people actually think they can lose weight this way, but they won't. They end up lowering their metabolism, and getting fatter. In addition, your energy level takes a roller coaster ride, and your brain can get starved, thereby lowering mental acuity - the mid-afternoon slump, as it were.
According to David Jenkins, a professor of nutritional sciences at the University of Toronto, little meals all day long keep your energy level up consistently. It is important to eat early and often. An added bonus is that this eating pattern seems to keep one's cholesterol level low.
(Q) This isn't actually a question, but an idea important enough that I would like to pass it along to as many people as possible.
Somewhere I recently came across the idea of making and carrying a Medical History Card containing, at least:
(A) My non-answer to your non-question is: Great Idea! Other suggested information includes:
Carry this information with you at all times, along with any other critical information that you can think of.
I once spent three days in a hospital, unconscious, and as a John Doe for quite a few hours. I had been in some kind of bicycle accident, and wasn't carrying any kind of ID or medical information.
(Q) I am trying to eliminate as much fat from my diet as possible, but I read an article that contradicted all of the no/lowfat advice that is so popular. Who should I believe?
A.D., Walla Walla, WA
(A) Both, more-or-less. You will most likely benefit from lowering your fat intake, especially saturated and trans fats, but at the same time, fat is an important nutrient. In addition to being a major energy source, it is required to prevent development of deficiencies in vitamins A, D, F, and K; which lead to dry skin, psoriasis, hair loss, and, potentially, slow healing. Maybe even a decrease in strength and endurance. Maybe more? So don't get overzealous about avoiding fat. Remember that it is normally recommended that 20 -30% of our total daily calories be from fat.
(Q) Is there any way to demystify medical terms? Most physicians use nothing but "med-speak," and I don't understand a word of it.
N.M.F., Las Vegas, NV
(A) Yes. Those mystifying medical terms that doctors throw around are relatively easy to understand once you understand the code (a list of prefixes, root words, and suffixes). For instance: what in the heck is "spondylolysis?" It isn't so intimidating when you break it up: spondyl(o) = vertebrae, lyis = dissolve. Hence, dissolution of a vertebrae. On the other hand, "spondyloitis" is: spondyl(o) = vertebrae, itis = inflammation.
Hence - inflammation of vertebrae. Some other examples are: cardi(o) = heart, encephal(o) = head, cerebr(o) = brain, plasty = repair, scope = instrumentation, scopy = examination, gyn = woman, andr(o) = man, angio = vessel, arthr(o) = joint. So, pancreatitis is an inflamed pancreas. Arthritis is an inflamed joint. Appendicitis is - yes, an inflamed appendix. A more complete list will appear in next month's Newsletter.
(Q) What is an angioplasty?
MAF
(A) YES, you all got it - repair of a vessel.
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