Human reproduction

The glands of the outer zone are lined by tall columnar cells that secrete prostatic fluid under the influence of androgens from the testis. A deep fascia, or sheet of connective tissuesurrounding the structures in the body of the penis is prolonged to form the suspensory ligament, which anchors the penis to the pelvic bones at the midpoint of the pubic arch.

The ductus deferensor vas deferens, is the continuation of the duct of the epididymis. The egg simultaneously moves through the Fallopian tube away from the ovary. The prostate is of a firm consistency, surrounded by a capsule of fibrous tissue and smooth muscle.

Various abnormalities can occur during development of sex organs in embryos, leading to hermaphroditismpseudohermaphroditismand other chromosomally induced conditions.

Human reproduction

Two lobes at the side form the main mass and are continuous behind the urethra. The glans is traversed by the urethra, which ends in a vertical, slitlike, external opening. The male reproductive system The male gonads are the testes; Human reproduction are the source of spermatozoa and also of male sex hormones called androgens.

The mucous membrane lining the interior is in longitudinal folds and is mostly covered with nonciliated columnar cells, although some cells have nonmotile cilia. External genitalia The penis The penisthe male organ of copulation, is partly inside and partly outside the body.

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The prostate is shaped roughly like an inverted pyramid; its base is directed upward and is immediately continuous with the neck of the urinary Human reproduction. The sperm being one of approximately million sperm in a typical male ejaculation travels through the vagina and cervix into the uterus or Fallopian tubes.

The bulbourethral glandsoften called Cowper glands, are pea-shaped glands that are located beneath the prostate gland at the beginning of the internal portion of the penis. The breasts develop, and there is a Human reproduction of body fat in accordance with the usual contours of the mature female.

In females at puberty, the external genitalia enlarge and the uterus commences its periodic activity with menstruation. The hormone may also be necessary to cause maturation of sperm and to heighten the sex drive of the male.

The zygote then becomes implanted in the lining of the uterus, where it begins the processes of embryogenesis and morphogenesis.

They are composed of a network of small tubes, or tubules, and saclike structures; between the tubules are fibres of muscle and elastic tissue that give the glands muscular support. The first stage begins with psychogenic impulses in higher neural centres, which travel through multineuronal pathways and cause excitation of sacral parasympathetic outflow innervating vascular tissues of theā€¦ Development of the reproductive organs The sex of a child is determined at the time of fertilization of the ovum by the spermatozoon.

Process[ edit ] "Coition of a Hemisected Man and Woman" c. The prostatic utricle is a short diverticulum or pouch lined by mucous membrane; it may correspond to the vagina or uterus in the female.

A group of short glands that are closest to the urethra and discharge mucus into its channel are subject to simple enlargement. They are mostly fixed in location within the ovary until their transit to the uterus, and contain nutrients for the later zygote and embryo.

In the middle of the urethral crest is a small elevation, the colliculus seminalis, on which the opening of the prostatic utricle is found. Erection is brought about by distension of the cavernous spaces with blood, which is prevented from draining away by compression of the veins in the area.

It is imperfectly divided into three lobes. Human male reproductive system The male reproductive system contains two main divisions: Each spermatozoon is a slender elongated structure with a head, a neck, a middle piece, and a tail.

The base of the glans has a projecting margin, the corona, and the groove where the corona overhangs the corpora cavernosa is referred to as the neck of the penis. The longitudinal muscle fibres are well developed, and peristaltic contractions contractions in waves move the sperm toward the ampulla.

On each side is a depression, the prostatic sinus, into which open the prostatic ducts. Growth of axillary armpit and pubic hair is more abundant, and the hair becomes thicker. Pregnancy can be avoided with the use of contraceptives such as condoms and Intrauterine devices.

Together they extend from the testis to the urethra, where it lies within the prostate. These cells are located in the connective interstitial tissue that holds the tubules together within each lobule.

When the fetus is developed enough to survive outside of the uterusthe cervix dilates and contractions of the uterus propel it through the birth canal, which is the vagina. The fluid excreted by these glands is clear and thick and acts as a lubricant; it is also thought to function as a flushing agent that washes out the urethra before the semen is ejaculated; it may also help to make the semen less watery and to provide a suitable living environment for the sperm.

The testes The two testesor testicles, which usually complete their descent into the scrotum from their point of origin on the back wall of the abdomen in the seventh month after conceptionare suspended in the scrotum by the spermatic cords.

There are some scattered hairs and sebaceous glands on its surface. The ova, which are the female sex cells, are much larger than the spermatozoon and are normally formed within the ovaries of the female fetus before its birth.Reproduction is a basic drive in all animals, including humans.

About the Journal

Think you Human reproduction what human reproduction is all about? Discover the biology of sex. Human Reproduction questions for your custom printable tests and worksheets. In a hurry? Browse our pre-made printable worksheets library with a variety of activities and quizzes for all K levels.

About the Journal. Human Reproduction features full-length, peer-reviewed papers reporting original research, concise clinical case reports, as well as opinions and debates on topical issues.

Papers published cover the clinical science and medical aspects of reproductive physiology, pathology and endocrinology; including andrology, gonad.

Human Reproduction is a peer-reviewed scientific journal covering all aspects of human reproduction, including reproductive physiology and pathology, endocrinology. The human reproductive system is different in males and females.

When a sperm and egg join, the egg is fertilised and a baby starts to develop. The flagship journal of the European Society of Human Reproduction and Embryology. Publishes full-length, peer-reviewed papers reporting clinical science and me.

Human reproduction
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