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Sperm cell formation begins 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; the cells get pushed closer to the lumen as maturation continues. 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 Leydig/interstitial cells , which produce testosterone once the male reaches puberty.

When the sperm have developed flagella they leave the seminiferous tubules and enter the epididymis ( [link] ; [link] ). This structure lies along the top and back side 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. Although a vasectomy is in many cases reversible via surgery, it is still considered to be a permanent procedure.

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.

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.

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

Gametogenesis: spermatogenesis

Gametogenesis, the production of sperm and eggs, involves the process of meiosis. During meiosis, two nuclear divisions separate the paired chromosomes in the nucleus and then separate the chromatids that were made during an earlier stage of the cell’s life cycle. Meiosis and its associated cell divisions produces haploid (n) cells with half of each pair of chromosomes normally found in diploid (2n)cells. The production of sperm is called spermatogenesis    .

Spermatogenesis

Spermatogenesis occurs in the wall of the seminiferous tubules, with the most primitive cells at the periphery of the tube and the most mature sperm at the lumen of the tube ( [link] ). Immediately under the capsule of the tubule are diploid, undifferentiated cells. These stem cells, each called a spermatogonium (pl. spermatogonia), go through mitosis to produce one cell that remains as a stem cell and a second cell called a primary spermatocyte that will undergo meiosis to produce sperm.

The diploid primary spermatocyte goes through meiosis I to produce two haploid cells called secondary spermatocytes. Each secondary spermatocyte divides after meiosis II to produce two cells called spermatids. The spermatids eventually reach the lumen of the tubule and grow a flagellum, becoming sperm cells. Four sperm result from each primary spermatocyte that goes through meiosis.

Questions & Answers

What is the meaning of the word cell?
hafsa Reply
unit
Samiullah
what happened when the hand accidentally touches a hot abject
Tumbu Reply
quickly removes its hand
hafsa
what is cell
Ernest Reply
cell can be defined as the smallest unit of life
alhassan
what is a hormone
Michael Reply
hormones are the body's chemical messengers and are part of the endocrine system,.
Nisa
why are the pictures showing
Anasili Reply
I don't get your question well
Prophet
The Cowper's gland, prostate gland and the seminar vesicle are involved in the secretion of seminal fluid which consist of enzyme,protein in form of amino acid and a very important hormone called what?
ANGEL Reply
testosterone
Prophet
what is reflex action
vanya
what is the specialize functions of the organs
Donieta Reply
what organs?
Maureen
what is the faction of photo receptors in the eye
Mutangana Reply
transduction of light to nervous impulses occurr it is located in the retina
Maureen
wat are e constituents of blood
marybertiny Reply
Can a cell be destroyed by the bacteria
Makhanya Reply
anamia. because of loss of blood
fon Reply
Name the element which is liquid
Sandeep Reply
hg
RC
CO2
Maureen
Bromine
Aaron
what is the dept of respiration plz?
Maureen
Maureen where are you from
Omokaro
mercury
VANESSA
bromine
VANESSA
which of the muscle can work with out getting tired?
nikkita
heart
Anam
Hg
Samiullah
what is the unit of muscles?
Samiullah
acid are organic or inorganic
Samiullah
why is the baby formed in the uterus n not else where?
Ekali Reply
you may help me ,to know why
mar
lo i am inn
mar
the womb is to protect the baby because inside the womb the lay in a fluid called the amniotic fluid which keeps the baby warm and it also have the placenta which the baby feeds from
Maureen
atom, molecules, organelle, cell, tissue, organ, organ system
Cheila Reply
sub atom atom molecular molecules and cells.
Advertus
cells structural level.
Advertus
what is microorganisms I am a laboratory student.
Advertus
a small organism
Rahbliss
small organism that can only be seen under a microscope
Maureen
i am just interested to be part of ,to learn
mar
explain why is it that old peoples as from the age of 60 usually have eye problems?
Kenn Reply
most old people suffere eye problems.because of short sight where individuals with this kind of problems see only near objects clearly but not distance objects, this is cause by elongated eyeball so light from distance is focus infront the retina so the image on the retina is blurred .
Munyah

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Source:  OpenStax, Human biology. OpenStax CNX. Dec 01, 2015 Download for free at http://legacy.cnx.org/content/col11903/1.3
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