Male sex organs and reproductive system

Diagram of the male reproductive system

The testicles are 2 organs that are covered by a sac of skin
called the scrotum. They produce hormones (mostly testosterone) and sperm.

The male reproductive system is controlled by the pituitary
gland in the brain. When puberty begins, the pituitary gland signals the
testicles by releasing the follicle-stimulating hormone (FSH) and the luteinizing
hormone (LH). The testicles then start to make testosterone and sperm.
Testosterone is responsible for male sexual development, including deepening of
the voice, enlargement of the penis and testicles, growth of facial and body
hair and muscle development.

The epididymis sits on the back of each testicle. It stores sperm cells so they can mature.

The vas deferens carries mature sperm to the urethra for
ejaculation.

The prostate is deep in the pelvis in front of the rectum and
below the bladder. It makes prostatic fluid. Prostatic fluid is rich in enzymes, proteins and
minerals that help protect and nourish sperm. During sex, the prostate pushes
prostatic fluid through the ducts and into the urethra. Prostatic fluid mixes
with sperm and other fluids in the urethra and is ejaculated as semen.

The seminal vesicles are glands found on each side of the
prostate. They make most of the fluid in semen. The seminal vesicles fuse with
the vas deferens to empty into the urethra.

The urethra carries urine (pee) from the bladder to the outside
of the body. It also carries sperm out of the body through the meatus (opening
of the urethra out of the body) during ejaculation.

Diagram of the penis

The penis has 3 parts. The shaft is the main part of the penis. The head of the penis is called the glans. The glans is covered by a loose fold of moveable skin called the foreskin (prepuce). Sometimes the foreskin is surgically removed in an operation called a circumcision. The base of the penis within the pelvis is called the root.

For the penis to penetrate a vagina or an anus during sex, it needs to be erect, or stiff. An erection begins when the brain sends a signal down the spinal cord through the nerves that run to the pelvis. Nerves signal the blood vessels inside of each corpus cavernosum of the penis to fill with blood. When the blood flow increases, the spongy tissue expands and causes the penis to stiffen and enlarge.

During an orgasm, the prostate, seminal vesicles and vas deferens contract to move semen near the top of the urethra and then out during ejaculation. Each ejaculation can release up to 500 million sperm. After ejaculation, the extra blood flows out of the penis and the penis becomes soft again.

For pregnancy, semen ejaculated into a vagina (in the female reproductive system) allows for sperm to swim up through the cervix and uterus into the fallopian tube to meet an egg (if one is there). It only takes one sperm to fertilize the egg. Once fertilized, the egg grows in the uterus becoming an embryo and then a fetus.

• Tim Rowe, MB BS, FRCSC, FRCOG

• John Robinson, PhD, R Psych

• Martini FH, Timmons MJ, Tallitsch RB. Human Anatomy. 7th ed. San Francisco: Pearson Benjamin Cummings; 2012.

• Cancer Research UK. Men’s Sexual Organs. 2018: https://www.cancerresearchuk.org/about-cancer/coping/physically/sex/mens-organs.

• American Cancer Society
  . Sex and the Adult Male with Cancer
  . 2021
  : https://www. cancer.org/treatment/treatments-and-side-effects/physical-side-effects/fertility-and-sexual-side-effects/sexuality-for-men-with-cancer/treatment-and-desire-and-response.html.

• American Society of Clinical Oncology. Sexual Health and Cancer Treatment: Men. 2019: https://www.cancer.net/navigating-cancer-care/dating-sex-and-reproduction/sexual-health-and-cancer-treatment-men.

• National Cancer Institute. Sexual Health Issues in Men with Cancer. 2018: https://www.cancer.gov/about-cancer/treatment/side-effects/sexuality-men.

• Cancer Research UK. About Sexuality and Sex Life. 2021: https://www.cancerresearchuk.org/about-cancer/coping/physically/sex/about-sexuality.

• Cancer Research UK. How Cancer Can Affect Your Sexuality and Sex Life. 2018: https://www.cancerresearchuk.org/about-cancer/coping/physically/sex/effects#.

26.1A: Overview of the Male and Female Reproductive Systems

1. Last updated

2. Save as PDF

The human reproductive system functions to produce human offspring, with the male providing sperm and the female providing the ovum.

Learning Objectives

• Summarize the reproductive systems of men and women

Key Points

• The male reproductive system consists of external organs. The testes in the scrotum produce the male gamete, sperm, which is ejaculated in seminal fluid by the penis.
• The female reproductive system primarily consists of internal organs. The female gamete, ovum, is produced in the ovaries and is released monthly to travel to the uterus via the Fallopian tubes.
• Fertilization can occur if the penis is inserted through the vulva into the vagina and sperm is ejaculated towards the cervix. If an ovum is currently in the uterus, it can then be fertilized by sperm that manage to enter the cervix.
• Once fertilized, an ovum becomes a zygote and if all goes well, develops into a fetus in the uterus.
• Natural birth occurs when the fetus is pushed from the vagina after nine months in the uterus.

Key Terms

• fallopian tubes: The Fallopian tubes, also known as oviducts, uterine tubes, and salpinges (singular salpinx) are two very fine tubes lined with ciliated epithelia leading from the ovaries of female mammals into the uterus, via the utero-tubal junction.
• penis: The male sexual organ for copulation and urination; the tubular portion of the male genitalia (excluding the scrotum).
• vagina: A fibromuscular tubular tract which is the female sex organ and has two main functions: sexual intercourse and childbirth.

EXAMPLES

While the ultimate purpose of the human reproductive system is to produce offspring, the proximate purpose is to produce pleasure and induce bonding. This can be seen in our closest relatives, the bonobo chimpanzees, who have sex for a wide variety of reasons including pleasure, bonding, and alleviating tension in addition to producing offspring.

The reproductive system or genital system is a set of organs within an organism that work together to produce offspring. Many non-living substances, such as fluids, hormones, and pheromones, are important accessories to the reproductive system. Unlike most organ systems, the sexes of differentiated species often have significant differences. These differences allow for a combination of genetic material between two individuals and thus the possibility of greater genetic fitness of the offspring.

The Reproductive Process

Human reproduction takes place as internal fertilization by sexual intercourse. During this process, the erect penis of the male is inserted into the female’s vagina until the male ejaculates semen, which contains sperm, into the vagina. The sperm travels through the vagina and cervix into the uterus for potential fertilization of an ovum. Upon successful fertilization and implantation, gestation of the fetus occurs within the female’s uterus for approximately nine months (pregnancy). Gestation ends with labor resulting in birth. In labor, the uterine muscles contract, the cervix dilates, and the baby passes out through the vagina. Human babies and children are nearly helpless and require high levels of parental care for many years. One important type of parental care is the use of the mammary glands in the female breasts to nurse the baby.

The Male Reproductive System

The human male reproductive system is a series of organs located outside of the body and around the pelvic region. The primary direct function of the male reproductive system is to provide the male gamete or spermatozoa for fertilization of the ovum. The major reproductive organs of the male can be grouped into three categories. The first category is sperm production and storage. Production takes place in the testes, housed in the temperature-regulating scrotum. Immature sperm then travel to the epididymis for development and storage. The second category, the ejaculatory fluid-producing glands, includes the seminal vesicles, prostate, and vas deferens. The final category, used for copulation and deposition of the spermatozoa (sperm) within the female, includes the penis, urethra, vas deferens, and Cowper’s gland.

The Human Male Reproductive System: Cross-sectional diagram of the male reproductive organs.

Only our species has a distinctive mushroom-capped glans, which is connected to the shaft of the penis by a thin tissue of frenulum (the delicate tab of skin just beneath the urethra). One of the most significant features of the human penis is the coronal ridge underneath the gland around the circumference of the shaft. Magnetic imaging studies of heterosexual couples having sex reveal that during coitus, the typical penis expands to fill the vaginal tract, and with full penetration can even reach the woman’s cervix and lift her uterus. This combined with the fact that human ejaculate is expelled with great force and considerable distance (up to two feet if not contained), suggests that men are designed to release sperm into the uppermost portion of the vagina. This may be an evolutionary adaptation to expel the semen left by other males while at the same time increasing the possibility of fertilization with the current male’s semen.

The Female Reproductive System

The human female reproductive system is a series of organs primarily located inside the body and around the pelvic region. It contains three main parts: the vagina, which leads from the vulva, the vaginal opening, to the uterus; the uterus, which holds the developing fetus; and the ovaries, which produce the female’s ova. The breasts are also a reproductive organ during parenting, but are usually not classified as part of the female reproductive system. The vagina meets the outside at the vulva, which also includes the labia, clitoris, and urethra. During intercourse, this area is lubricated by mucus secreted by the Bartholin’s glands. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the Fallopian tubes. At certain intervals, approximately every 28 days, the ovaries release an ovum that passes through the Fallopian tube into the uterus.
If the ova is fertilized by sperm, it attaches to the endometrium and the fetus develops. In months when fertilization does not occur, the lining of the uterus, called the endometrium, and unfertilized ova are shed each cycle through a process known as menstruation.

The Human Female Reproductive System: The female reproductive system is largely internal.

LICENSES AND ATTRIBUTIONS

CC LICENSED CONTENT, SHARED PREVIOUSLY

• Curation and Revision. Authored by: Boundless.com. Provided by: Boundless.com. License: CC BY-SA: Attribution-ShareAlike

CC LICENSED CONTENT, SPECIFIC ATTRIBUTION

• Reproductive system. Provided by: Wikipedia. Located at: en.Wikipedia.org/wiki/Reproductive_system. License: CC BY-SA: Attribution-ShareAlike
• penis. Provided by: Wiktionary. Located at: en.wiktionary.org/wiki/penis. License: CC BY-SA: Attribution-ShareAlike
• vagina. Provided by: Wikipedia. Located at: en.Wikipedia.org/wiki/vagina. License: CC BY-SA: Attribution-ShareAlike
• fallopian tubes. Provided by: Wikipedia. Located at: en.Wikipedia.org/wiki/fallopian%20tubes. License: CC BY-SA: Attribution-ShareAlike
• Female Reproductive System. Provided by: Wikimedia. Located at: upload.wikimedia.org/wikipedi…em_lateral.png. License: Public Domain: No Known Copyright
• Male Reproductive System. Provided by: Wikimedia. Located at: upload.wikimedia.org/wikipedi…le_anatomy.png. License: Public Domain: No Known Copyright

1. Back to top

• Was this article helpful?

1. Article type

   Section or Page

   License

   CC BY-SA

   Show TOC

   no

2. Tags

   This page has no tags.

Anatomy and function of the male reproductive system

In men and women, the genital organs are located both inside the pelvic cavity and outside it. Most of the male reproductive system is located outside. Such a device in wildlife is a demonstration of its strength and superiority. Perhaps this is why many, if not most, men are embarrassed to see a doctor if they have problems in their intimate life.

This article is not to be used for diagnosis, treatment, and is not a substitute for seeing a doctor.

The reproductive system of a man is extremely important, as well as other systems of the body that ensure normal life. Therefore, an untimely appeal to a specialist or, even worse, ignoring the warning signs, creates much bigger problems than they were originally.

The male reproductive system has three main tasks:

1. Formation of spermatozoa in the testes (seniferous tubules). In the process of one ejaculation, 30-500 million spermatozoa come out.
2. Evacuation of seminal fluid from the male genital organs and its delivery to the female.
3. Synthesis of the main androgen (a group of steroid sex hormones in men) – testosterone.

Structure and functions of the external male genitalia

The group of male external reproductive organs includes:

• Penis (penis) – an organ involved in sexual contact, spewing seminal fluid. The place of attachment of the phallus to the pubis is the root. The body of the penis and the head are covered by the foreskin (skin fold), which normally should easily and painlessly move away, exposing the head. In the foreskin there are multiple glands that produce smegma (sebaceous lubricant). Internally, the penis consists of two cavernous (cavernous) and one spongy (spongiform) bodies. It is to the cavernous bodies that a man owes the appearance of an erection, in which the bodies are filled with blood and “swell”, increasing the size of the penis. In the spongy body is the urethra (urethra), which blocks the path for the passage of urine during intercourse and ejaculation.
• Testicles (testicles) – olive-shaped paired organs of different sizes produce testosterone and spermatozoa. They are located in the sac (scrotum), which acts as a “climate control”. For healthy spermatogenesis (sperm production), the testicles must be maintained at a constant temperature below general body temperature. This provides the scrotum and the external location of the testicles. Otherwise, spermatogenesis will be impaired, which will negatively affect fertility (the ability to conceive).
• The epididymis is an oblong narrow paired organ, part of the vas deferens. In the epididymis, spermatozoa accumulate and mature for further advancement into the vas deferens. Spermatozoa accumulate in a thickening formed in the tail. In the scrotum, the appendage is adjacent to the testicle, forming a pocket. Normally, it is easily palpable through the scrotum.

Male internal genitalia

The main internal male organ is the exocrine androgen-dependent prostate gland, nut-shaped, located in the center of the pelvis near the bladder. The function of the gland is to control urination, erection, ejaculation, ensure the viability of spermatozoa and transport them.

Isolate the secretory and barrier function of the prostate. The gland produces its own secret, which enters the sperm during ejaculation. The secret contains enzymes, acids, immunoglobulins and other trace elements. The secret also contains immunity factors that allow the prostate to perform a barrier function, which consists in preventing the penetration of pathogenic microflora from the urethra into the urinary tract and preventing the spread of microorganisms from the urethra to the vas deferens. The presence of zinc ions in secret protects the male genital tract from infection. The work of the gland is controlled by pituitary and steroid hormones, estrogens.

Male internal genital organs also include:

• Deferent ducts — their task is to transport ejaculate to the urethra, which can also be attributed to the reproductive system. The ducts originate from the appendages of the testicles.
• Seminal vesicles – produce a fluid that is part of the semen. The secret of the bubbles, containing a large amount of fructose, is “responsible” for the vital energy of spermatozoa.
• Bulbourethral glands – tiny pea-sized Cooper glands located near the prostate, secrete into the urethra. The secret of the glands lubricates the walls of the urethra, neutralizes the acidity of urine.

Hormones that regulate the function of the male reproductive system

The function of the reproductive system in men is regulated by three main hormones:

• Luteinizing (LH).
• Follicle stimulating (FSH).
• Testosterone.

LH and FSH are pituitary hormones. Testosterone is synthesized under the influence of LH, spermatozoa are formed under the influence of LH. Testosterone is responsible for the timely appearance of secondary sexual characteristics, seminal fluid production, muscle building, physical strength and endurance, libido, voice pitch.

Function of hormones in the male reproductive system

Read more about hormones in men in this material – note. altravita-ivf.ru

Sperm formation

Spermatogenesis (production of seminal fluid) is carried out under the influence and control of hormonal substances. It starts from the moment of puberty (11-15 years), therefore, until this age, spermatozoa are not produced in the boy’s body. When testosterone reaches the age-appropriate level in a teenager, this leads to the activation of stem cells in the testicles (spermogonia). Spermogonium is converted into spermatocytes containing a double chromosome set. Spermatocytes divide, forming, in turn, secondary spermatocytes, which contain one chromosome set each.

The spermatocytes are then transformed into spermatid cells, which undergo spermiogenesis (the final stage of spermatogenesis). Spermatid cells turn into spermatozoa, which mature in the epididymis. After maturation, the sperm are ready to fertilize the egg.

The speed of movement of spermatozoa is 20 cm / h with a length of only 0.05 mm.

Menopause in men: myth or reality?

Menopause or menopause is the cessation of the activity of the female sex glands (ovaries), as a result of which menstruation completely stops. The reason for this is the cessation or a significant decrease in the production of estrogen by the ovaries. Men never stop producing testosterone, and any man can theoretically become a father in old age. Exceptions are severe diseases or congenital anomalies that affect spermatogenesis and erectile function. With age (from 35-45 years old), testosterone production begins to decline, and fertility also decreases accordingly. Having passed the analysis for testosterone, men have the opportunity to assess the state of their health.

Reducing the production of male sex hormones occurs under the influence of various factors: endocrine diseases, obesity, chronic diseases, STDs, stress, constant overheating of the testicles in saunas, baths, frequent hypothermia, depression, trauma, accidents (electric shock, accidents) and so Further. The impact of adverse factors leads not only to a decrease in testosterone production, but also to erectile and ejaculatory dysfunction.

The structure of a flower and the meaning of its main parts

Contents

1. Main parts of the flower
2. Receptacle
3. Sepals
4. Petals
5. Stamens
6. Pistil

9001 7

Flowers are the distinguishing feature of flowering or angiosperms, which make up the majority of the plant kingdom. These are the reproductive organs of the plant, from which fruits with seeds are formed. Flowers are of two types – bisexual and unisexual. Bisexual flowers are hermaphrodites, meaning they have both male (stamens) and female (pistil) reproductive parts.

On the other hand, unisexual flowers have either male (stamens) or female (pistil) reproductive parts. Plants that bear both staminate (male) and pistillate (female) flowers on the same individual are called monoecious, while those that bear only staminate (male) or only pistillate (female) flowers are called dioecious.

Flowers have evolved to have a bright and colorful appearance (for the most part) which is necessary to attract pollinators such as birds, butterflies, bees and wasps.

Scheme of the structure of a loose flower. Image: Wikimedia Common

Although the flowers vary in shape and size, their anatomy is usually the same:

• The stem part includes the pedicel and receptacle;
• The leaf part consists of sepals and petals;
• The generative part is formed by stamens, pistil or pistils.

A flower that has all parts is called complete, and a flower that lacks one or more parts is called incomplete.

Flower parts are also subdivided into fertile or reproductive (stamens, pistil or pistils) and sterile (perianth).

Let’s look at the main parts of the flower in more detail:

Receptacle

The receptacle is an extended structure at the end of the pedicel to which all other parts of the flower (sepals, petals, stamens, pistils) are attached. The receptacle has a stem (shoot) origin, in contrast to the rest of the parts that have a leaf origin.

Sepals

Flower buds are often covered with green leafy structures called sepals that protect them during the bud stage. All the sepals of a flower form an outer whorl called the calyx. Although the sepals are usually green, they can vary in color depending on the type of plant.

Plant flowers such as anemones do not have sepals, while in some flowers they are modified into bracts, small leaf-like structures located around the flower. The bracts of some plants can be larger and brighter than the petals. Petalless flowers usually have modified sepals that are larger and brightly colored to attract pollinators.

Petals

Petals are the most visible part of the flower structure due to their bright color (in most cases) and sometimes scent. Their main function is to attract pollinators as well as protect the internal reproductive parts of the flower.

Some flowers have missing or reduced petals. The whorl of petals is called a corolla. The calyx and corolla together form the perianth.

Stamens

The stamen is the male part of the flower, and together all the stamens form the inner third whorl of the floral structure, the androecium. Each stamen is made up of a long, tubular filament with a sac at the top, called an anther. Pollen grains contain male reproductive cells or male gametes and are produced in anthers (each anther contains many pollen grains).

One pollen grain contains vegetative and generative cells.