What is spermatogenesis?

Spermatogenesis is the process of sperm cell development within the male reproductive organs, the testes . Sperm cells are made in the walls of the seminiferous tubules, which constitute about 90% of the testicular mass. Sertoli cells support and nourish the immature sperm cells by giving them nutrients and blood products and help to transport them to the central channel of the tubule. Spermatogonia mature into spermatocytes, which in turn mature into spermatids and finally into spermatozoa as they move into the central lumen of the seminiferous tubule. The principal androgen, testosterone , and follicle-stimulating hormone (FSH) stimulate spermatogenesis.

Where in the body does spermatogenesis take place?

Spermatogenesis, the creation and development of sperm cells, occurs in the testes , the male reproductive organs. Within the testes are tightly coiled tubes known as seminiferous tubules, where sperm cells are produced within the walls. Supporting the immature sperm cells are Sertoli cells, which provide nutrients as the germ cells grow and move from the tubule's outer surface to its central channel. Spermatogonia, immature germ cells, originate from stem cells in the seminiferous tubules' outer wall and multiply through mitosis. Some become future sperm cells, while others remain as stem cells. Primary sperm cells move centrally, attach to Sertoli cells, and develop. After a resting phase, they divide into secondary sperm cells, which mature into spermatozoa. Once matured, sperm cells are transported through the seminiferous tubules and stored in the epididymis until ejaculation.

What main cell types are involved in spermatogenesis?

Spermatogenesis, occurring in the seminiferous tubules of the testes, involves several key cell types. Spermatogonia: These are undeveloped sperm-producing cells, or immature germ cells, derived from stem cells in the outer wall of the seminiferous tubules. Some spermatogonia differentiate into primary sperm cells. Spermatocytes: Primary spermatocytes mature from spermatogonia and eventually divide into secondary sperm cells. Spermatids: Spermatocytes mature into spermatids, which then mature into spermatozoa as they move into the central lumen. Sertoli cells: These cells support and nourish the immature sperm cells within the walls of the tubules by providing them with nutrients and blood products and transporting them during their growth. Leydig cells: Located beneath the tunica albuginea, in the septal walls, and between the tubules, these cells produce testosterone.

How does spermatogenesis change cells to form mature sperm?

Spermatogenesis is the process in which sperm cells are created and developed within the testes . Within the walls of the seminiferous tubules, immature germ cells, or spermatogonia, multiply through mitosis. Half become future sperm cells, while the other half remain as stem cells. Spermatogonia mature into spermatocytes, then into spermatids, and finally into spermatozoa as they move into the central lumen. Nuclear material in the sperm cell condenses into an oval-shaped head, partially covered by an acrosome, which helps the sperm enter the egg. A tailpiece, derived from the secondary sperm cell’s cytoplasm, attaches to the head, propelling the sperm.

What hormones control and regulate spermatogenesis?

The hormones that control and regulate spermatogenesis (the origin and development of sperm cells) are primarily testosterone and follicle-stimulating hormone (FSH). Testosterone, produced in the testes, and FSH, produced in the pituitary gland, stimulate spermatogenesis. The hypothalamus releases gonadotropin-releasing hormone (GnRH), which stimulates the anterior pituitary to produce luteinizing hormone (LH) and FSH. LH then stimulates the testes to produce testosterone. Sertoli cells produce inhibin, a polypeptide hormone, which, along with testosterone, inhibits FSH secretion. This interplay maintains a balance essential for sperm production.

How do factors like temperature or health affect spermatogenesis?

Spermatogenesis, the production of sperm, is influenced by various factors. Problems with sperm production, blockage of the sperm-delivery system, the presence of antibodies against sperm, testicular injury, anatomic abnormalities, and a varicose vein around the testicle can affect sperm quality or quantity. Testosterone and follicle-stimulating hormone (FSH) stimulate spermatogenesis. Sperm number, concentration, motility, and morphology are assessed via semen examination. Low sperm count is called oligospermia, and complete absence of spermatozoa is called azoospermia, which can be caused by obstruction, congenital disorders, or illnesses. Older men produce fewer and less motile sperm, and age is associated with decreased testosterone levels.

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Diagram illustrating spermatogenesis in male human anatomy, showing a cross-section of the testis with seminiferous tubules, detailed cells at various stages of sperm development, and a flowchart of cell divisions leading from primordial germ cell to mature sperm.

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What is spermatogenesis?
Spermatogenesis is the process of sperm cell development within the male reproductive organs, the testes. Sperm cells are made in the walls of the seminiferous tubules, which constitute about 90% of the testicular mass. Sertoli cells support and nourish the immature sperm cells by giving them nutrients and blood products and help to transport them to the central channel of the tubule.

Spermatogonia mature into spermatocytes, which in turn mature into spermatids and finally into spermatozoa as they move into the central lumen of the seminiferous tubule. The principal androgen, testosterone, and follicle-stimulating hormone (FSH) stimulate spermatogenesis.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Where in the body does spermatogenesis take place?
Spermatogenesis, the creation and development of sperm cells, occurs in the testes, the male reproductive organs. Within the testes are tightly coiled tubes known as seminiferous tubules, where sperm cells are produced within the walls. Supporting the immature sperm cells are Sertoli cells, which provide nutrients as the germ cells grow and move from the tubule's outer surface to its central channel.

Spermatogonia, immature germ cells, originate from stem cells in the seminiferous tubules' outer wall and multiply through mitosis. Some become future sperm cells, while others remain as stem cells. Primary sperm cells move centrally, attach to Sertoli cells, and develop. After a resting phase, they divide into secondary sperm cells, which mature into spermatozoa. Once matured, sperm cells are transported through the seminiferous tubules and stored in the epididymis until ejaculation.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What main cell types are involved in spermatogenesis?
Spermatogenesis, occurring in the seminiferous tubules of the testes, involves several key cell types.
- Spermatogonia: These are undeveloped sperm-producing cells, or immature germ cells, derived from stem cells in the outer wall of the seminiferous tubules. Some spermatogonia differentiate into primary sperm cells.
- Spermatocytes: Primary spermatocytes mature from spermatogonia and eventually divide into secondary sperm cells.
- Spermatids: Spermatocytes mature into spermatids, which then mature into spermatozoa as they move into the central lumen.
- Sertoli cells: These cells support and nourish the immature sperm cells within the walls of the tubules by providing them with nutrients and blood products and transporting them during their growth.
- Leydig cells: Located beneath the tunica albuginea, in the septal walls, and between the tubules, these cells produce testosterone.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How does spermatogenesis change cells to form mature sperm?
Spermatogenesis is the process in which sperm cells are created and developed within the testes. Within the walls of the seminiferous tubules, immature germ cells, or spermatogonia, multiply through mitosis. Half become future sperm cells, while the other half remain as stem cells.

Spermatogonia mature into spermatocytes, then into spermatids, and finally into spermatozoa as they move into the central lumen. Nuclear material in the sperm cell condenses into an oval-shaped head, partially covered by an acrosome, which helps the sperm enter the egg. A tailpiece, derived from the secondary sperm cell’s cytoplasm, attaches to the head, propelling the sperm.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What hormones control and regulate spermatogenesis?
The hormones that control and regulate spermatogenesis (the origin and development of sperm cells) are primarily testosterone and follicle-stimulating hormone (FSH).

Testosterone, produced in the testes, and FSH, produced in the pituitary gland, stimulate spermatogenesis. The hypothalamus releases gonadotropin-releasing hormone (GnRH), which stimulates the anterior pituitary to produce luteinizing hormone (LH) and FSH. LH then stimulates the testes to produce testosterone. Sertoli cells produce inhibin, a polypeptide hormone, which, along with testosterone, inhibits FSH secretion. This interplay maintains a balance essential for sperm production.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How do factors like temperature or health affect spermatogenesis?
Spermatogenesis, the production of sperm, is influenced by various factors. Problems with sperm production, blockage of the sperm-delivery system, the presence of antibodies against sperm, testicular injury, anatomic abnormalities, and a varicose vein around the testicle can affect sperm quality or quantity.

Testosterone and follicle-stimulating hormone (FSH) stimulate spermatogenesis. Sperm number, concentration, motility, and morphology are assessed via semen examination. Low sperm count is called oligospermia, and complete absence of spermatozoa is called azoospermia, which can be caused by obstruction, congenital disorders, or illnesses. Older men produce fewer and less motile sperm, and age is associated with decreased testosterone levels.
2 Britannica Sources
1. infertility: Abnormalities of sperm production
2. testis: Regulation of testicular function
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

spermatogenesis, the origin and development of the sperm cells within the male reproductive organs, the testes. The testes are composed of numerous thin tightly coiled tubules known as the seminiferous tubules; the sperm cells are produced within the walls of the tubules. Within the walls of the tubules, also, are many randomly scattered cells, called Sertoli cells, that function to support and nourish the immature sperm cells by giving them nutrients and blood products. As the young germ cells grow, the Sertoli cells help to transport them from the outer surface of the seminiferous tubule to the central channel of the tubule.

Sperm cells are continually being produced by the testes, but not all areas of the seminiferous tubules produce sperm cells at the same time. One immature germ cell takes as long as 74 days to reach final maturation, and during this growth process there are intermittent resting phases.

The immature cells (called spermatogonia) are all derived from cells called stem cells in the outer wall of the seminiferous tubules. The stem cells are composed almost entirely of nuclear material. (The nucleus of the cell is the portion containing the chromosomes.) The stem cells begin their process by multiplying in the process of cell duplication known as mitosis. Half of the new cells from this initial crop go on to become the future sperm cells, and the other half remain as stem cells so that there is a constant source of additional germ cells. Spermatogonia destined to develop into mature sperm cells are known as primary sperm cells. These move from the outer portion of the seminiferous tubule to a more central location and attach themselves around the Sertoli cells. The primary sperm cells then develop somewhat by increasing the amount of cytoplasm (substances outside of the nucleus) and structures called organelles within the cytoplasm. After a resting phase the primary cells divide into a form called a secondary sperm cell. During this cell division there is a splitting of the nuclear material. In the nucleus of the primary sperm cells there are 46 chromosomes; in each of the secondary sperm cells there are only 23 chromosomes, as there are in the egg. When the egg and sperm combine and their chromosomes unite, the characteristics of both individuals blend and the new organism starts to grow.

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The secondary sperm cell still must mature before it can fertilize an egg; maturation entails certain changes in the shape and form of the sperm cell. The nuclear material becomes more condensed and oval in shape; this area develops as the head of the sperm. The head is covered partially by a cap, called the acrosome, which is important in helping the sperm to gain entry into the egg. Attached to the opposite end of the head is the tailpiece. The tail is derived from the secondary sperm cell’s cytoplasm. In the mature sperm, it consists of a long, slender bundle of filaments that propel the sperm by their undulating movement. Once the sperm has matured, it is transported through the long seminiferous tubules and stored in the epididymis of the testes until it is ready to leave the male body.

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Kara Rogers.

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