Dec. 02, 2010

Is there a reverse seasonal affect disorder that causes summer blues?

by Molly Nickerson

The change of seasons is sensed by organisms in a variety of ways, but one of the most influential for humans is the increase or decrease in day length. Although various factors likely contribute to variations of SAD, changes in daylight and a disruption of the melatonin/serotonin balance is key. Some of us, based on our genetic disposition, are very sensitive to the changes in daylight that occur with the change in seasons.

Ask Dr. Molly, depression, seasonal affective disorder
Oct. 03, 2010

What are freckles and why does the sun make them more prominent?

by Molly Nickerson

Overall skin coloration is determined by the degree to which cells in the skin called melanocytes produce the pigment melanin. Melanin is also responsible for hair and eye coloring. The subtype pheomelanin is responsible for red hair, while the subtype eumelanin is responsible for grey, black, yellow, and brown hair. People with certain ancestries have the genetic coding to create a lot of melanin in their skin and therefore have dark skin. Albinism occurs in individuals who produce no melanin. Freckles are small bunches of melanin that are visible on ...

Ask Dr. Molly, freckles, melanin, sunlight
Aug. 13, 2010

What is responsible for our taste preferences and why do they change with age?

by Molly Nickerson

Our tongue senses only five different tastes- sweet, sour, bitter, salty, and a fifth called umami. The umami responds to salts of glutamic acid, which would be associated with meat broth or aged cheese. Taste receptors function through either a transmembrane ion channel (sour and salty) or a G-protein-coupled receptor (sweet and bitter) and are bundled in groups of 50-150 to form taste buds. Each taste bud probably has a few representatives from each of the five taste classes, but receptors for each of these tastes are focused in different ...

Ask Dr. Molly, aging, sensation, spicy, taste
May. 12, 2010

What is lactic acid and why does it cause a burning feeling?

by Molly Nickerson

We all know that feeling- from running too far, too fast. Or from pedaling a bike up a hill really hard. (If you don’t, you might want to get out more….) That nauseating feeling in your muscles that makes you stop and lingers for a short while is due to the build-up of lactic acid, which is simply a byproduct of the muscular metabolic process.Muscle contraction begins with a signal from your brain, which propagates through your nervous system and causes the release of the neurotransmitter acetylcholine at the neuromuscular ...

Ask Dr. Molly, Exercise, lactate threshold, lactic acid, pyruvic acid
Apr. 26, 2010

How does the sun give me vitamin D?

by Molly Nickerson

Vitamin D is a critical nutrient for our bodies. It is responsible for the maintenance of normal blood levels of calcium and phosphorus. By aiding in the absorption of calcium, vitamin D plays a vital role in the maintenance of bone strength. The diseases that caused by a lack of vitamin D are rickets in children (skeletal deformities) and osteomalacia in adults (weak bones and muscles). Recently, vitamin D has been found to protect against diseases such as osteoporosis, hypertension, cancer, and some autoimmune conditions.

Ask Dr. Molly, sun, vitamin D
Mar. 18, 2010

Why doesn’t my immune system mount a response to my tattoo?

by Molly Nickerson

Well, it tries… and succeeds in its own way. However, success on the part of the immune system may actually contribute to the permanence of a tattoo.Skin is an incredible organ. It represents approximately 7% of one’s body mass and is responsible for very important tasks such as regulating body temperature, restricting water loss, and protecting all of our other organs from bacteria and chemicals. In order to maximize its ability to ward off invading pathogens and particles, the skin is immunologically robust. In the skin, the immune system primarily ...

Ask Dr. Molly, Science, immune response, tattoo
Sep. 24, 2009

Why does asparagus make my pee smell funny?

by Molly Nickerson

Asparagus-induced aromatic pee is an event that has always amazed me because it happens so quickly. When you eat asparagus, it goes into the stomach to be broken down by acids in the stomach, just like any other food. The nourishing elements of the meal are absorbed into the blood stream and the food molecules travel through the bloodstream to the liver and kidneys for purification. This is all normal and good. Waste that is collected in the kidneys is excreted in urine. Asparagus, unlike other vegetables, contains asparagusic acid. ...

Ask Dr. Molly, asparagus, olfactory
Mar. 17, 2009

How Do IUDs Work?

by Molly Nickerson

An intrauterine device (IUD) is a type of contraception that is used all over the world. In the United States, there are two different versions.

Ask Dr. Molly, contraception, IUD, IUS
Jan. 26, 2009

Is There a Limit to How Long my Hair will Grow?

by Molly Nickerson

Hair can be considered in two separate sections, the root and the shaft. The hair root is located inside of the follicle and exists below the portion of the skin while the shaft is the portion of hair that extends out from the skin. The root of the hair receives nutrients from the blood through the dermal papilla. The nutrients that are supplied to the root of the hair through the dermal papilla, combined with oil from the sebaceous gland, can contribute to hair’s strength. This strength of the hair ...

Ask Dr. Molly, follicle, hair
Jan. 04, 2009

Why can't my dog eat chocolate?

by Molly Nickerson

Your dog can actually eat a little bit of chocolate, but if they eat about an ounce of milk chocolate per kilogram of body weight or as little as a couple of mouthfuls of cocoa mulch, there will be trouble.

Ask Dr. Molly, chocolate, dogs, theobromine
Nov. 30, 2008

If cigarettes make you feel calmer and caffeine makes you more energetic, then why do people enjoy smoking cigarettes an

by Molly Nickerson

The active ingredient in cigarettes in nicotine, and its extremely addictive nature is reflected by the fact that it is used by approximately 35% of the US population.1 Nicotine works by binding to one type of acetylcholine receptor in the body.

Ask Dr. Molly, caffeine, cigarettes
Oct. 29, 2008

What is the difference between Type I and Type II Diabetes?

by Molly Nickerson

Diabetes is a Greek term that means siphon. The first Greek physicians noticed that individuals with this disorder “passed water like a siphon.”

Sep. 30, 2008

Why do all of my clocks have an 8-minute snooze setting?

by Molly Nickerson

My first thought on this question was that perhaps the manufacturers of alarm clocks couldn't decide between the not-quite-long-enough 5-minute snooze and the potential for falling completely back asleep afforded by the ten minute snooze.So, they compromised after many lively debates on the topic and now we all have an 8-minute snooze session. As a scientist, I wanted to determine the neurological basis for keeping a person on the fine line that separates sleep from wakefulness. It turns out, however, that the true basis for the 8 (to 9) minute ...

Ask Dr. Molly, REM, sleep, snooze
Sep. 12, 2008

Why Do My Shoes Stink?

by Molly Nickerson

I have been observing the prevalence of stinky feet and shoes and realized a couple of things. First of all, stinky shoes are more common in humid environments. Secondly, they are usually shoes that have been sweated in, like running shoes. Dress shoes with which a person wears wool socks or no socks tend to be less stinky.The reason is that bacteria thrive in moist environments like those created with sweat and cotton socks. With the right environment, the bacteria feast on the dead skin cells from your feet and ...

Ask Dr. Molly, bacteria, shoes
Aug. 17, 2008

Why Does my Heart Start Beating Really Fast After I hear a Loud, Surprising Noise?

by Molly Nickerson

An increase in heart rate is one component of the "fight or flight" response. When we are startled, frightened, or angry, our bodies automatically ready themselves to stand up and fight or to run away.

Ask Dr. Molly, heartbeat
Aug. 11, 2008

What is the Best Brain Food?

by Molly Nickerson

There are two ways to answer this question- one could consider the fuel consumed on a daily basis by our brain or one could take a longterm perspective of overall brain health.From day to day, our brains primarily utilize glucose as fuel. Glucose is a simple sugar that is the most convenient form of fuel for cells. Although the brain is only two percent of the body’s total weight, it consumes an average of 70 percent of the body’s glucose, which comes as no surprise because we have up to ...

Ask Dr. Molly, brain, Food
Aug. 02, 2008

It's too Confusing to be Healthy

by Molly Nickerson

Dear Dr. Molly,How am I supposed to know what is good for me and what is bad for me? Whenever I read the paper or a magazine, there are results from a new study that contradict that last study. What gives?Pullman, Washington

Ask Dr. Molly, clinical research, coffee, Health, study results

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