Fill up this form to notify us about any comment that you find to be objectionable or improper. Please also do provide us the reason for your objection.

In: home > Preconception / How Babies are Made - The Basics / The Reproductive System of a Man

The Reproductive System of a Man

preconception How Babies are Made - The Basics

The Reproductive System of a woman
The Menstrual Cycle
The Hormones
The Reproductive System of a Man
The Role of Testosterone
The Sperm's Odyssey in the Female Reproductive Tract
The Process of Fertilisation

The Reproductive System of a Man

The male reproductive system begins in the scrotum, the sack behind the penis. This contains two testicles, which make men's sex cells, called sperm; and the male sex hormone, called testosterone. The testicles feel solid, but a little spongy, like hard boiled eggs without the shell. They hang from a cord called the spermatic cord. It's normal for one testicle to hang lower than the other; and for one testicle to feel slightly larger than the other.

The testicles make sperm best at a temperature a few degrees cooler than normal body temperature. This is why nature designed a scrotum - so that the testes can hang outside the body to keep them cool. 

The testicles start making sperm when a young man reaches puberty. This is in response to the male sex hormone, testosterone, which starts being produced at this time. The testes keep making sperm for the rest of the man's life.

The sperms are produced inside several hundred coiled microscopic tubules called seminiferous tubules in the testes. These tubules converge and collect into a delta (like the mouth of a river) near the upper part of the testis called the rete testis which then empties through a series of very small ducts out of the testis towards the epididymis. The epididymis is an amazing structure - it is a very long tiny tubule, which runs back and forth in convolutions and loops to form a tiny compact structure with a head, body and tail that sits like a cap on the top of and behind the testis. The tail of the epididymis then leads to the vas deferens - a thin cord like muscular tube, which is part of the spermatic cord and which ends at the ejaculatory duct in the prostate. Here is joined by the seminal vesicle ducts and they all open into the prostatic part of the urethra - which in turn leads to the urethra in the penis.

Mature sperm take about 75 days to develop in a process called spermatogenesis. Sperm production takes place as though it were on an assembly line - with the more mature sperms being passed along toward the center of the tubule from where they swim towards the efferent ducts of the testis towards the epididymis. This can be a very "temperamental" assembly line - things often go wrong, causing low sperm counts.

When the sperm leave the testis, they are not yet able to swim on their own. They acquire the capacity to do so in their passage through the epididymis - which is like a swimming school for the sperm. They spend between 2 to 15 days here during which they attain maturity and fertilising potential. Sperm are propelled along this tunnel by frequent contractions of its thin muscular wall. Most of the mature sperm are then stored at the end of the epididymis - where they wait to be rushed through the vas deferens and ejaculated at the time of orgasm.

During ejaculation, the epididymis and vas deferens muscles contract to propel the sperm into the ejaculatory duct. Here the sperm is joined with the secretions of the seminal vesicles and prostate gland (which contribute the bulk of the seminal fluid) to form the semen. The powerful muscles surrounding the base of the urethra then cause the semen to squirt out of the penis at the time of orgasm. Semen and urine never mix in a healthy male ( even though the final passage for both is common) because the bladder sphincter muscle contracts during sexual stimulation, thus closing down the exit from the bladder to the urethra during ejaculation - preventing urine from leaking forward out of the bladder during sex and also preventing semen from accidentally going backward into the bladder.

What about the penis and fertility? Most men equate their fertility potential with their virility - and therefore the size of their penis. However, the size of the penis has little to do either with fertility potential or with sexual ability. (In any case, if you worry that your penis is too small, you're not alone - most men think their penises are too small !)

During ejaculation, about one teaspoon of semen spurts out of the penis. Semen is a milky white color, the consistency of egg white. Sperm account for only about 2 to 3% of semen. Most of it consists of seminal fluid - the secretion of the seminal versicles and the prostate gland, which provide a vehicle for the sperm into the vagina. 

A normal ejaculation contains 200 to 500 million sperm. How can so many sperm fit into only a teaspoon of semen? Simple - sperm are very tiny. If one average ejaculation filled an Olympic size swimming pool, each sperm cell would still be smaller than a goldfish. Sperms are the smallest living cells in the human body - and the egg the largest. Basically, sperms are designed so that they can deliver their contents - the male genetic material - to the egg. This is why they are designed like projectiles - the male DNA is in the chromosomes in the sperm head nucleus, and the tail propels the sperm up towards the egg. 

Sperm are also very fragile. Men make so many because very few survive the swim through the female reproductive system to fertilize an egg. Perhaps the reason for this is an evolutionary hangover. Female fish deposit eggs on the sea-bed. This is why male fish need to produce millions of sperm which are sprayed into the sea water where millions will be wasted in order to ensure that some reach the eggs.

What happens to the sperms if you don't have sex for many days? Unfortunately, you cannot "store up" sperms. If ejaculation does not occur for many days, the sperms in the reproductive ducts simply die. This is why a sperm count done after many days of abstinence shows a high number of dead or immotile sperms. But just like you cannot store your sperm, you cannot run out of sperm either - masturbation and sex cannot use sperm up. The body keeps making sperm as long as a man has even one normal testicle.

Expert answers
Ask Expert

Videos related to this article (126)
Hilarious Baby
Getting Ready for a Baby
Family Planning
Baby Care
Diet Concerns in Pregnancy
Stress Concerns in Pregnancy
Weight Loss Concerns
Need for Folic acid during Pregnancy
All about PCOS
Advice for Women with PCOS
Getting Pregnant with PCOS
Natural Pregnancy with PCOS
Best Position to Get Pregnant
Getting Pregnant
The Act of Fertilization
Understanding Ovulation
Female Reproductive System
Tips for Painless Childbirth
Pregnant with Triplets
Full Term of Pregnancy
Missing Birth Control Pills
IUD for Birth Control
Methods of Birth control
Tips for Getting Pregnant After Being on Birth Control
Developmental Stages in Pregnancy
Different Stages of Pregnancy
Events Leading to Birth of the Baby
The Pill for Birth Control
Loss of Pregnancy - Miscarriage
Shock of Miscarriage
Losing a Baby
Feelings of Miscarriage
Abortion - Medical termination
Abortion Procedure
Feelings after Abortion
Demonstration of Abortion
Pregnancy and Health
Yoga to Improve Fitness During Pregnancy
Nutrition during Pregnancy
Harmful Habits on Pregnancy
Being Overweight during Pregnancy
Weight Gain Concerns during Pregnancy
Successful Pregnancy story
Ultrasound Scanning in Pregnancy
Fitness during Pregnancy
Advice Related to Pregnancy
First Time Pregnant
Pregnancy Fears
Tips for Getting Pregnant
Process of Implantation
Process of Fertilization
Best time to get Pregnant
Working of the Body during Pregnancy
Care during Pregnancy
Healthy Lifestyle for Healthy Pregnancy
Partner Support during Pregnancy
Get Pregnant with Diabetes
Gestational Diabetes
Managing Diabetes in Pregnancy
Diabetic Mother
Risks Associated with Pregnancy in 40s
Weight Gain during Pregnancy
Testing for Pregnancy
Diet in Pregnancy
Fertility and Food
Food Enhancing Fertility
A Guide to Fertility Food
Information about Varicocele
Effects of Medications on Male fertility
Male Infertility
Before Pregnancy Care
Week by Week Changes in Pregnant Women
Effect of Smoking in Pregnancy
Chicken Pox and pregnancy
Birth of Triplets
Giving Birth to Multiples Naturally
Growth and Development of Fetus in Womb
Twins in Ultrasound
Screening for Cystic Fibrosis
Detecting Cystic Fibrosis
Detecting Cystic Fibrosis with Sweat Test
Inheritance Pattern of Cystic Fibrosis
Right Time for Getting Pregnant
When Can Pregnancy Occur?
Signs and Symptoms of Pregnancy
Process of Ovulation and Conception
Woman Carrying Twin Pregnancy
Dangers of Smoking and Drinking During Pregnancy
Comfortable Sleeping Position during Pregnancy
Diet during Pregnancy
How to Calculate Fertile Days
The Best Time for Conception
The Process of Fertilisation
The Process of Ovulation and Fertilisation
Tips for Getting Pregnant Quickly
Getting Pregnant Faster
How to Predict Ovulation and Fertility
Coping with Irregular Periods
Understanding PCOS and Irregular Periods
Spotting and Irregular Periods
Problem of Irregular Periods
Ready for Fatherhood
First Experience of Babysitting
Enjoy Fatherhood
Way to Fatherhood
Are You Ready for Parenthood?
Emotionally Ready for Pregnancy
Teenage Pregnancy
Getting Ready for Pregnancy
Ideal Diet for Pregnant Women
Foods to Avoid in Pregnancy
Organic Foods for Getting Pregnant
Healthy Foods in Pregnancy
How to Get Pregnant After 40
Tips for Getting Pregnant After 40
Health Issues and Pregnancy
How to Get Pregnant Easily
Benefits of Exercising During Pregnancy
Pregnancy Exercises
Tips For Losing Weight Before Getting Pregnant
Weight Loss Before Pregnancy
Increasing Chances of Conception With Diabetes
Increasing Chances of Conception With Diet
Tips For Increasing Chances Of Conception
Factors Affecting Chances of Conception

You may also be interested in:

The role testosterone in males is multi-fold. Testosterone is the main male sex hormone. It is responsible for sperm pr..
Save Edit
Sort by Newest

yelga.4 years ago
I have a small penis.Will this affect my fertility? I know penis size does not matter but this is worrying me.
Vicky.4 years ago
Can anybody explain me what happens during intercourse? I have a low sperm count so if I abstain from sex, will my sperm count increase? Will this help me in making my partner pregnant easily?
Mandy.4 years ago
Knowledge of male reproductive system is essential for understanding the process of reproduction. It helps in understanding the concept of fertility.
Preconception Topics..

Best Position to Get Pregnant Video
Spotting and Irregular Periods Video...

All tips on Diet
You ever wanted in one place.
No need to go anywhere else. No spam.

*No spam only genuine emails
The Hormones
The Role of Testosterone