<< Chapter < Page Chapter >> Page >
Micrograph shows human sperm, which have an oval head about 3 microns across and a very long flagellum.
As seen in this scanning electron micrograph, human sperm has a flagellum, neck, and head. (credit: scale-bar data from Matt Russell)

Sperm form in the walls of seminiferous tubules that are coiled inside the testes ( [link] ; [link] ). The walls of the seminiferous tubules are made up of the developing sperm cells, with the least developed sperm at the periphery of the tubule and the fully developed sperm next to the lumen. The sperm cells are associated with Sertoli cells that nourish and promote the development of the sperm. Other cells present between the walls of the tubules are the interstitial cells of Leydig , which produce testosterone once the male reaches adolescence.

When the sperm have developed flagella they leave the seminiferous tubules and enter the epididymis ( [link] ; [link] ). This structure lies along the top and posterior of the testes and is the site of sperm maturation. The sperm leave the epididymis and enter the vas deferens, which carries the sperm behind the bladder, and forms the ejaculatory duct with the duct from the seminal vesicles. During a vasectomy, a section of the vas deferens is removed, preventing sperm (but not the secretions of the accessory glands) from being passed out of the body during ejaculation and preventing fertilization.

The bulk of the semen comes from the accessory glands associated with the male reproductive system. These are the seminal vesicles , the prostate gland    , and the bulbourethral gland    ( [link] ; [link] ). The secretions from the accessory glands provide important compounds for the sperm including nutrients, electrolytes, and pH buffering. There are also coagulation factors that affect sperm delivery and motility.

Art connection

Illustration shows a cross section of the penis and testes. The penis widens at the end, into the glans, which is surrounded by the foreskin. The urethra is an opening that runs through the middle of the penis to the bladder. The tissue surrounding the urethra is the Corpus spongiosum, and above the Corpus spongiosum is the Corpus cavernosum. The testes, located immediately behind the penis, are covered by the scrotum. Seminiferous tubules are located in the testes. The epididymis partly surrounds the sac containing the seminiferous tubules. The Vas deferens is a tube connecting the seminiferous tubules to the ejaculatory duct, which begins in the prostate gland. The prostate gland is located behind and below the bladder. The seminal vesicle, located above the prostate, also connects to the seminal vesicle. The bulbourethral gland connects to the ejaculatory duct where the ejaculatory duct enters the penis.
The reproductive structures of the human male are shown.

Which of the following statements about the male reproductive system is false?

  1. The vas deferens carries sperm from the testes to the seminal vesicles.
  2. The ejaculatory duct joins the urethra.
  3. Both the prostate and the bulbourethral glands produce components of the semen.
  4. The prostate gland is located in the testes.
Male Reproductive Anatomy
Organ Location Function
Scrotum External Supports testes and regulates their temperature
Penis External Delivers urine, copulating organ
Testes Internal Produce sperm and male hormones
Seminal Vesicles Internal Contribute to semen production
Prostate Gland Internal Contributes to semen production
Bulbourethtral Glands Internal Neutralize urine in urethra

Female reproductive anatomy

A number of female reproductive structures are exterior to the body. These include the breasts and the vulva, which consists of the mons pubis, clitoris    , labia majora    , labia minora    , and the vestibular glands ( [link] ; [link] ).

Side and front views of female reproductive organs are shown. The vagina is wide at the bottom, and narrows into the cervix. Above the cervix is the uterus, which is shaped like a triangle pointing down. Fallopian tubes extend from the top sides of the uterus. The Fallopian tubes curve back in toward the uterus, and end in fingerlike appendages called fimbrae. The ovaries are located between the fimbrae and the uterus. The urethra is located in front of the vagina, and the rectum is located behind. The clitoris is a structure located in front of the urethra. The labia minora and labia majora are folds of tissue on either side of the vagina.
The reproductive structures of the human female are shown. (credit a: modification of work by Gray's Anatomy; credit b: modification of work by CDC)

The breasts consist of mammary glands and fat. Each gland consists of 15 to 25 lobes that have ducts that empty at the nipple and that supply the nursing child with nutrient- and antibody-rich milk to aid development and protect the child.

Questions & Answers

10 difference between male and female reproductive system
Ina Reply
if a phase is omitted ,what will happen to the cell
Ewemoje Reply
discribe advantages and disadvantages of asexual and sexual reproduction
basi Reply
Compared to separate sexes and assuming self-fertilizing is not possible, what might be one advantage and one disadvantage to hermaphroditism?
Gift Reply
is nature of their environment among
basi
why are the laws of thermodynamics considered laws of nature and not scientific theories
Yolonda Reply
archea were given their own separate domain because they are?
Yolonda
which of the following is a basic component of all of the others?
Yolonda
which of the following organization levels is the least inclusive
Yolonda
which cell feature is absent in bacterial cells
Yolonda
which metric movies the base unit of measurement by one thousandth (0.001)?
Yolonda
What is biology?
Blessing Reply
List the branches of biology
Blessing
List the branches of biology
Blessing
List the branches of biology
Blessing
List the branches of biology
Blessing
must all prokaryotic cells posses a cell wall?
chris Reply
what is biology?
Cathy Reply
biology is basically the study of life
Robert
that's true
Tonia
it's the study of living things
Tonia
biology is defined as the study of living and nonliving things
Ina
Biology is not only the study of life but it is the study of death too.
Koushik
What is a celiac disease
Falase Reply
distinguish between properties and characteristics
Elee Reply
what are organelles
Elee
organelles are substances that makes up a cell
chris
organelles are special features of a cell that perform a specific task
Enock
what is biology
Prevail Reply
biology is science that studies life
Elee
it's the study of living and non living things
now that we have an estimate for the diameter of the cell.what estimate can we make about the volume of the cell?
faxhood Reply
why too much insulin result in low blood sugar
Leri Reply
For example, too much exercise can cost you to lose to much weight. Too much insulin will pull to much sugar out of your systemic system into your cells.
Eric
difference between DNA and RNA
Eyitayo Reply
DNA is deoxyribonuclaic acid. Deoxy refers to a lack of oxygen. The Ribose moity is missing an OH group. I think it is missing from the second C of the ring. RNA is ribonucleic acid. DNA has our genetic code in on it. RNA is translated from DNA and carries the blue print for protein synthesis.
Eric
The OH group on RNA prevents it from being reactive. But it is very unstable though. Would you want such a power tool floating around in your body, no. And you have three types of RNA: mRNA, tRNA and rRNA. Please let me know it this helped?😄
Eric
o
Browse
Eric answered this question perfectly
what determines the aeration level in the soil
Shola Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Concepts of biology. OpenStax CNX. Feb 29, 2016 Download for free at http://cnx.org/content/col11487/1.9
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Concepts of biology' conversation and receive update notifications?

Ask