Infertility and The Male Reproductive System

By Michael Russell



From several reports and studies available, about a third of infertility problems are due to problems with the male reproductive tract, another third due to problems in the female reproductive system, while others are either due to a combined factor or are unexplained.



Unlike the female sex, that has a very complicated reproductive system, the male system is less complicated and most causes of male infertility can be traced to sperm disorders. Several million sperm cells is are released in the male ejaculation (semen) during sexual intercourse. However, out of these millions

deposited into the vagina, only a few hundreds will finally make the journey to the female egg and have a chance of fertilizing it. The number of sperm that make this all-important journey determines to a large extent, a man's chances of getting his partner pregnant. This is because, the more sperm cells that get to the egg, the better the chances of a successful fertilization.



There are several biological reactions that occur at the point of contact between the sperm cell and the egg. The more sperm cells that come close to the egg, the more likelihood that one of them will posses what it takes to cross the 'protective walls' around the egg. There are several factors that determine the success of the male sperm in this respect, these include;  the number of sperm cells released known as 'sperm count', the motility of the sperms, the sperm quality and the shape and size of the sperm cells.



Problemswith any of these factors may cause difficulties with

fertility.  Sperm count, i.e. the number of sperm cells released

in the semen, is a very important factor in male fertility.  A

larger amount of sperm cells is almost always a guarantee that

enough cells would make the journey to the egg and achieve the

needed fertilization. However, what seems to be even more crucial is the vitality and motility of these sperm cells.  A few virile cells reaching the egg would produce a better result than a bunch of abnormal sperm cells. Some men with a low sperm count, but high sperm quality happen to be fertile. The sense here is that, an optimal sperm count with high quality sperm cells is the key to male fertility. 



Problems with any part of the male reproductive tract generally tells on the sperm quality and sperm count. There are several health and environmental issues that affect male fertility.



Age - As with the whole body, a man's reproductive capacity reduces with age and this also affects the sperm quality. It is estimated that as from age 35, the male sperm quality may start

diminishing and this may also affect the sperm count and motility.



Lifestyle Choices - Environment and the lifestyle choices you

make can also have an impact on your fertility. Prolonged exposure to extreme heat from hot baths, steam rooms or wearing tight underwear may affect your fertility. Exposure to toxic

substances like pesticides, radioactivity or electromagnetic

emissions, especially at work may cause sperm abnormalities. It

is always advised that you consult your healthcare provider if

you are concerned about these and other occupational hazards.



The use of drugs such as those for heart diseases and high blood pressure tend to exert adverse effects on male fertility and some cancer treatments, especially when chemotherapy is involved may also contribute to infertility.



Diseases like diabetes, central nervous system problems and most sexually transmitted diseases have been shown to be bad for fertility. Untreated STDs are known to destroy parts of the male reproductive tracts through which sperm is transported.



Alcohol abuse and cigarette smoking have a negative impact on

sperm production and a number of lubricants used during sexual

intercourse, such as vagina creams, have also been shown to have negative effects on male sperm quality.



Outside these environmental and 'self imposed' factors, there are other structural and anatomical factors that may also cause sperm

disorders and fertility problems.



Erectile dysfunction is the inability to get or maintain an erection. It is the commonest anatomical cause of male infertility. Undescended testes, retrograde ejaculation and scrotal varicoele are other structural problems of the male reproductive tract that may affect fertility.



If you have any concern about your reproductive health or you seem to suffer from any of the conditions above, you should talk to your healthcare provider NOW. You stand a better chance if you seek help early enough.

What Makes a Normal Distribution Normal?

Good question...

What makes 98.60 degrees normal?

What makes people normal?



Generally, references to a statistical distribution or just a "distribution" mean a "frequency distribution." That is, what is the number of times or the frequency with which each value in the distribution occurs.



As it turns out, a large percent of all frequency distributions meet the same set of criteria. Such distributions are called "normal." A more popular term is "bell curve."



NOTE: "Bell" is not a technical term. However, because the term stuck, for convenience it is used in this series.



These normal types of distributions have many uses in market research and other statistical applications. A lot of statistical theory that applies to market research assumes normal distributions.



Examples of normal distributions in humans include: height; weight; test scores especially for standardized tests such as I.Q.; and various abilities, traits, tastes, and preferences. All assume a large number of people being "measured." One notable exception is income earned, which will be discussed in the next article with distributions that are not normal.



Normal distributions also are common in both nature and business. For example, light bulb packages have information on the number of hours the bulb should last, the watts (energy used), and the lumens (light output).



Each of those numbers is an arithmetic mean of the frequency distribution generated by testing large numbers of light bulbs. Each of those distributions is bell-shaped or normal.



So what are the criteria for a distribution to be normal?



1) The distribution is unimodal (only one most frequently occurring value).

2) The arithmetic mean, the mode, and the median are all the same value. That value is the value representing the highest point on the distribution;

3) The distribution is bi-laterally symmetrical.

BY WHAT?!

Bi-laterally symmetrical means the left half is a mirror image of the right half (unless you're left-handed, then the right half is a mirror image of the left half).

4) One standard deviation--hereafter noted as 1�OE --measured each way from the arithmetic mean (what's referred to as plus or minus one standard deviation or � 1�OE) represents slightly over 68 percent of all the values in the distribution. � 1.96 �OEs represents the middle 95 percent of the values. You can go to readily available tables to see how many standard deviations from the mean are associated with what percent of all the values in the distribution. This percent is often referred to as the "area under the curve." For instance, � 1�OE covers slightly over 68 percent of the area under the curve. The curve is the graphic representation of the frequency distribution.

and

5) There are some other criteria, but the above ones are the main ones (at least for now).



Normal distributions come in various sizes and shapes but all meet the criteria noted above. Some normal distributions look like they are relatively short and spread out; other normal distributions look relatively tall and thin. The largest percent of all normal distributions are in between those more extreme shapes and are the true bell curves.



In market research, you might want to ask consumers how they would rate the service they received. A properly designed survey would gives choices such as "excellent" "good" "fair" "poor" "very poor." A future article will deal with the problems of such surveys. The point here is that the choices have to be symmetrical in terms of balancing the choices around the middle of the distribution. The results should produce a normal distribution. If the results are not "normally distributed" you should be suspicious of the results. Contrary to what many are led to think, not everything is good or excellent.