Why when we doo-doo (move out bowls) why does it smell so badly? I understand that it's wast but what about it makes it smell so bad?

Certain classes of organic (carbon-containing) substances contain other elements that are particularly offensive to the HUMAN sense of smell. The elements roughly in the order ofdecreasing nastiness are: Sulfur, Nitrogen, and Phosphorous and combinations thereof. Probably the most familiar is hydrogen sulfide (the odor of rotten eggs) even though it does not contain any carbon. Others that you might be familiar with are butyl mercaptan C4H9--SH (skunk), and methyl mercaptan CH3--SH the chemical added to "natural" gas so that it is easily identified in case of a leaky gas main or a gas stove left on accidently. The various sulfur containing chemicals occur as part of the normal digestive processes in all mammals. The diet and the animal's particular digestive system determine the types and amounts of the very large number of possible odiferous substances.

If you can get past the smell there are several interesting questions that do not have entirely satisfactory answers. What is it in the evolution of humans that make certain substances so putrid smelling? Is there some evolutionary advantage to this sensitivity? I do not think anyone really knows (or should I say "nose") the answer.

Some substances (hydrogen sulfide is the classical example, but not the only one) are foul smelling at low concentration, but are less offensive, or even odorless at high concentration. In the case of hydrogen sulfide this is quite dangerous, because what you do not smell can definitely harm you. In addition, what humans find offensive other creatures find very attractive. In the case of feces flies are attracted quite strongly to that class of compounds. Other compounds (insect repellants are the classic example) are fairly odorless to humans, but very repellant to insects. Some animals (tracking dogs for example) can smell various "human" or other animal odors in incredibly small concentrations. In addition, there are cultural, or learned, differences in what some people find offensive, but others do not. These are but a few of the interesting aspects of odor, which is probably the least well understood of all the human senses.

What causes hiccups?

Hiccups are sudden, involuntary contractions of the diaphragm muscle. As the muscle contracts repeatedly, the opening between your vocal cords snaps shut to check the inflow of air and makes the hiccup sound. Irritation of the nerves that extend from the neck to the chest can cause hiccups.

Although associated with a variety of ailments (some can be serious such as pneumonia or when harmful substances build up in the blood for example from kidney failure), hiccups are not serious and have no clear reason for occurring.

Hiccups Causes

Many conditions are associated with hiccups, but none has been shown to be the cause of hiccups.

• If you eat too fast, you can swallow air along with your food and end up with a case of the hiccups.

• Any other practices that might irritate the diaphragm such as eating too much (especially fatty foods) or drinking too much (drunk people hiccup) can make you prone to having hiccups.

• In these instances, your stomach, which sits underneath and adjacent to the diaphragm, is distended or stretched. Because they occur in relation to eating and drinking, hiccups are sometimes thought to be a reflex to protect you from choking.

Why do ladies menstruate? Why can't males menstruate?

Women menstrate because they have to prepare an egg in order to get fertilized. Men can not menstruate because they do not produce eggs. Menstruation begins around 15 and ends around a stage in the female life cycle called menopause. Menopause occurse anywhere between 45 to 55. This is the stage in which a woman stops ovulating and menstruating and can no longer get pregnant.

What is menstruation?

Menstruation is a woman's monthly bleeding, also called a period. When you menstruate, your body is shedding the lining of the uterus (womb). Menstrual blood flows from the uterus through the small opening in the cervix, and passes out of the body through the vagina. Most menstrual periods last from three to five days.

What is the menstrual cycle?

Menstruation is part of the menstrual cycle, which prepares your body for pregnancy each month. A cycle is counted from the first day of one period to the first day of the next period. The average menstrual cycle is 28 days long. Cycles can range anywhere from 21 to 35 days in adults and from 21 to 45 days in young teens.

Body chemicals called hormones rise and fall during the month to make the menstrual cycle happen.

What happens during the menstrual cycle?

In the first half of the cycle, levels of estrogen (the “female hormone”) start to rise and make the lining of the uterus (womb) grow and thicken. At the same time, an egg (ovum) in one of the ovaries starts to mature. At about day 14 of a typical 28-day cycle, the egg leaves the ovary. This is called ovulation.

After the egg has left the ovary it travels through the fallopian tube to the uterus. Hormone levels rise and help prepare the uterine lining for pregnancy. A woman is most likely to get pregnant during the three days before ovulation or on the day of ovulation. Keep in mind, women with cycles that are shorter or longer than average may ovulate earlier or later than day 14.

If the egg is fertilized by a man’s sperm cell and attaches to the uterine wall, the woman becomes pregnant. If the egg is not fertilized, it will break apart. If pregnancy does not occur, hormone levels drop, and the thickened lining of the uterus is shed during the menstrual period.

In the picture below, the egg has left the ovary and is on its way through the fallopian tube to the uterus.

What is a typical menstrual period like?

During your period, the thickened uterine lining and extra blood are shed through the vaginal canal. Your period may not be the same every month and it may not be the same as other women's periods. Periods can be light, moderate, or heavy, and the length of the period also varies. While most periods last from three to five days, anywhere from two to seven days is normal. For the first few years after menstruation begins, longer cycles are common. A woman's cycle tends to shorten and become more regular with age. Most of the time, periods will be in the range of 21 to 45 days apart.