Prostate Development: Difference between revisions

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:{{Template:Genital Links}} | [[Puberty Development|Puberty]]
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== Some Recent Findings ==
== Some Recent Findings ==
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* '''The role of Wnt5a in prostate gland development'''<ref name="PMID19389372"><pubmed>19389372</pubmed></ref> "The Wnt genes encode a large family of secreted glycoproteins that play important roles in controlling tissue patterning, cell fate and proliferation during development. Currently, little is known regarding the role(s) of Wnt genes during prostate gland development. The present study examines the role of the noncanonical Wnt5a during prostate gland development in rat and murine models. In the rat prostate, Wnt5a mRNA is expressed by distal mesenchyme during the budding stage and localizes to periductal mesenchymal cells with an increasing proximal-to-distal gradient during branching morphogenesis. Wnt5a protein is secreted and localizes to periductal stroma, extracellular matrix and epithelial cells in the distal ducts. While Wnt5a expression is high during active morphogenesis in all prostate lobes, ventral prostate (VP) expression declines rapidly following morphogenesis while dorsal (DP) and lateral lobe (LP) expression remains high into adulthood. Steroids modulate prostatic Wnt5a expression during early development with testosterone suppressing Wnt5a and neonatal estrogen increasing expression."
* '''The role of Wnt5a in prostate gland development'''<ref name="PMID19389372"><pubmed>19389372</pubmed></ref> "The Wnt genes encode a large family of secreted glycoproteins that play important roles in controlling tissue patterning, cell fate and proliferation during development. Currently, little is known regarding the role(s) of Wnt genes during prostate gland development. The present study examines the role of the noncanonical Wnt5a during prostate gland development in rat and murine models. In the rat prostate, Wnt5a mRNA is expressed by distal mesenchyme during the budding stage and localizes to periductal mesenchymal cells with an increasing proximal-to-distal gradient during branching morphogenesis. Wnt5a protein is secreted and localizes to periductal stroma, extracellular matrix and epithelial cells in the distal ducts. While Wnt5a expression is high during active morphogenesis in all prostate lobes, ventral prostate (VP) expression declines rapidly following morphogenesis while dorsal (DP) and lateral lobe (LP) expression remains high into adulthood. Steroids modulate prostatic Wnt5a expression during early development with testosterone suppressing Wnt5a and neonatal estrogen increasing expression."
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Revision as of 21:58, 29 May 2013

Introduction

Historic drawing of the fetal male urogenital system

In humans, the male accessory glands are the seminal vesicles, prostate gland, and the bulbourethral glands. The male gonad, the testis, differentiates embryonically initially under the influence of the Y chromosome. Later under the influence the gonad-derived fetal testosterone acting through androgen receptors, a region of the urogenital sinus (UGS) mesenchyme differentiates to form the primordial prostate buds. The buds then signal back to the overlying epithelium, inducing duct formation, this was one of the early studied (1970's) example of an mesenchymal-epithelial interaction in development. Interestingly, the female equivalent gland originally called Skene's gland, then paraurethral gland has now also been renamed the female prostate.

The reproductive function of the prostate becomes active at puberty where prostate secretions contribute the majority by volume of the ejaculate containing spermatozoa.

The prostate gland is generally in the news due to its late postnatal adult growth changes, enlarged due to benign nodular hyperplasia, and the male health effects of prostate cancer. Prostate cancer is the second most common malignant tumor in western males and anatomically involves the prostate peripheral zone.

There are also currently separate pages describing Genital - Male Development | Spermatozoa Development | Testis Development | Prostate Development.


Genital Links: genital | Lecture - Medicine | Lecture - Science | Lecture Movie | Medicine - Practical | primordial germ cell | meiosis | endocrine gonad‎ | Genital Movies | genital abnormalities | Assisted Reproductive Technology | puberty | Category:Genital
Female | X | X inactivation | ovary | corpus luteum | oocyte | uterus | vagina | reproductive cycles | menstrual cycle | Category:Female
Male | Y | SRY | testis | spermatozoa | ductus deferens | penis | prostate | Category:Male
Historic Embryology - Genital 
General: 1901 Urinogenital Tract | 1902 The Uro-Genital System | 1904 Ovary and Testis | 1912 Urinogenital Organ Development | 1914 External Genitalia | 1921 Urogenital Development | 1921 External Genital | 1942 Sex Cords | 1953 Germ Cells | Historic Embryology Papers | Historic Disclaimer
Female: 1904 Ovary and Testis | 1904 Hymen | 1912 Urinogenital Organ Development | 1914 External Genitalia | 1914 Female | 1921 External Genital | 1927 Female Foetus 15 cm | 1927 Vagina | 1932 Postnatal Ovary
Male: 1887-88 Testis | 1904 Ovary and Testis | 1904 Leydig Cells | 1906 Testis vascular | 1909 Prostate | 1912 Prostate | 1914 External Genitalia | 1915 Cowper’s and Bartholin’s Glands | 1920 Wolffian tubules | 1935 Prepuce | 1935 Wolffian Duct | 1942 Sex Cords | 1943 Testes Descent | Historic Embryology Papers | Historic Disclaimer

| Puberty

Some Recent Findings

Male urogenital development (stage 22)
  • The role of Wnt5a in prostate gland development[1] "The Wnt genes encode a large family of secreted glycoproteins that play important roles in controlling tissue patterning, cell fate and proliferation during development. Currently, little is known regarding the role(s) of Wnt genes during prostate gland development. The present study examines the role of the noncanonical Wnt5a during prostate gland development in rat and murine models. In the rat prostate, Wnt5a mRNA is expressed by distal mesenchyme during the budding stage and localizes to periductal mesenchymal cells with an increasing proximal-to-distal gradient during branching morphogenesis. Wnt5a protein is secreted and localizes to periductal stroma, extracellular matrix and epithelial cells in the distal ducts. While Wnt5a expression is high during active morphogenesis in all prostate lobes, ventral prostate (VP) expression declines rapidly following morphogenesis while dorsal (DP) and lateral lobe (LP) expression remains high into adulthood. Steroids modulate prostatic Wnt5a expression during early development with testosterone suppressing Wnt5a and neonatal estrogen increasing expression."

Textbooks

Historic drawing of the human prostate
  • Human Embryology (2nd ed.) Larson Chapter 10 p261-306
  • The Developing Human: Clinically Oriented Embryology (6th ed.) Moore and Persaud Chapter 13 p303-346
  • Before We Are Born (5th ed.) Moore and Persaud Chapter 14 p289-326
  • Essentials of Human Embryology, Larson Chapter 10 p173-205
  • Human Embryology, Fitzgerald and Fitzgerald Chapter 21-22 p134-152
  • Developmental Biology (6th ed.) Gilbert Chapter 14 Intermediate Mesoderm

Prostate Development Overview

  1. fetal testosterone stimulates urogenital sinus mesenchyme through androgen receptors
  2. urogenital sinus mesenchyme acts on the overlying epithelium to stimulate cell proliferation
  3. urogenital sinus epithelium then forms prostate ductal progenitor, the prostatic buds
  4. prostatic buds then grow into the urogenital sinus mesenchyme

Prostate Bud Growth

  1. specification phase - instructive developmental cues define where buds will form in the UGS
  2. initiation phase - prostatic buds begin to form
  3. elongation phase - proliferation, cell adhesion, and cell migration coordinate outgrowth of prostatic buds into UGM.

Based on the recent review.[2]


Genital Development Overview

Three main stages during development, mesonephric/paramesonephric duct changes are one of the first male/female differences that occur in development, while external genitaila remain indeterminate in appearance for quite a while.

  1. Differentiation of gonad (Sex determination)
  2. Differentiation of internal genital organs
  3. Differentiation of external genital organs

The 2nd and 3rd stages dependent on endocrine gonad. Reproductive development has a long maturation timecourse, begining in the embryo and finishing in puberty. (More? Puberty Development)


Mouse Prostate Development

The mouse has been used extensively as a model of prostate embryonic development. A similar androgenic regulation occurs of in ventral epithelial bud affecting number and pattern forming in the mouse urogenital sinus.[3]

  • begins in fetal mice ductal progenitors (or buds) emerge from urogenital sinus epithelium
  • prostatic buds develop in response to androgens, which activate androgen receptors in UGS mesenchyme
  • two rows of 3-4 prostatic buds at birth


Links: Mouse Development

Prostate Histology

Prostate histology 01.jpg Prostate histology 02.jpg Prostate histology 03.jpg
Human prostate histology Corpora Amylacea Submucosal gland
(adult, H&E low power overview) (adult, H&E detail) (adult, H&E high power detail)

Anatomy

The prostate is the largest accessory sex gland in men (about 2 × 3 × 4 cm). It contains 30 - 50 tubuloalveolar glands, which empty into 15 - 25 independent excretory ducts. These ducts open into the urethra. The glands are embedded into a fibromuscular stroma, which mainly consists of smooth muscle separated by strands of connective tissue rich in collagenous and elastic fibres. The muscle forms a dense mass around the urethra and beneath the fairly thin capsule of the prostrate.

Macroscopically the prostrate can be divided into lobes, but they are inconspicuous in histological sections. In good histological sections it is possible to distinguish three concentric zones, which surround the prostatic part of the urethra.

  • peripheral zone contains large (main glands) whose ducts run posteriorly to open into the urethra
  • internal zone consists of the so-called submucosal glands
  • innermost zone contains mucosal glands

Secretory Glands

The secretory alveoli of the prostate are very irregularly shaped because of papillary projections of the mucosa into the lumen of the gland. The epithelium is cuboidal or columnar. Basal cells are again present, and the epithelium may look pseudostratified where they are found. The secretory cells are slightly acidophilic and secretory granules may be visible in the cytoplasm. Small extensions of the apical cytoplasm into the lumen of the alveoli may represent cells which release their secretory products (secretion is apocrine/merocine). The secretion of the prostate contains citric acid, the enzyme fibrinolysin (liquefies the semen), acid phosphatase, a number of other enzymes and lipids. The secretion of the prostate is the first fraction of the ejaculate.

The secretory ducts of the prostate are lined by a simple columnar epithelium, which changes to a transitional epithelium near the openings of the ducts into the urethra.

Corpora Amylacea

A characteristic feature of the prostate is the appearance of corpora amylacea in the secretory alveoli. They are rounded eosinophilic bodies. Their average diameter is about 0.25 mm (up to 2 mm). They appear already in the seventh month of foetal development. Their number increases with age - in particular past 50. They may undergo calcification. Corpora amylacea may appear in semen.

Additional Histology Images

Above text and images modified from: Blue Histology - Prostate

Movies

Genital development animations

Urogenital sinus 001 icon.jpg Urogenital septum 001 icon.jpg
Urogenital Sinus Urogenital Septum
Male external 001 icon.jpg Testis 001 icon.jpg
Male External Testis Descent


Historic Images of Genital Changes

Urogenital Indifferent Urogenital Male Urogenital Female
Urogenital indifferent Urogenital male Urogenital female

Prostate at Puberty

Historic Gray's Anatomy - The Prostate

FIG. 1160– Prostate with seminal vesicles and seminal ducts, viewed from in front and above. (Spalteholz.)

(Prostata; Prostate Gland)


The prostate (Fig. 1160) is a firm, partly glandular and partly muscular body, which is placed immediately below the internal urethral orifice and around the commencement of the urethra. It is situated in the pelvic cavity, below the lower part of the symphysis pubis, above the superior fascia of the urogenital diaphragm, and in front of the rectum, through which it may be distinctly felt, especially when enlarged. It is about the size of a chestnut and somewhat conical in shape, and presents for examination a base, an apex, an anterior, a posterior and two lateral surfaces.

The base (basis prostatæ) is directed upward, and is applied to the inferior surface of the bladder, The greater part of this surface is directly continuous with the bladder wall; the urethra penetrates it nearer its anterior than its posterior border.

The apex (apex prostatæ) is directed downward, and is in contact with the superior fascia of the urogenital diaphragm.

Surface

The posterior surface (facies posterior) is flattened from side to side and slightly convex from above downward; it is separated from the rectum by its sheath and some loose connective tissue, and is distant about 4 cm. from the anus. Near its upper border there is a depression through which the two ejaculatory ducts enter the prostate. This depression serves to divide the posterior surface into a lower larger and an upper smaller part. The upper smaller part constitutes the middle lobe of the prostate and intervenes between the ejaculatory ducts and the urethra; it varies greatly in size, and in some cases is destitute of glandular tissue. The lower larger portion sometimes presents a shallow median furrow, which imperfectly separates it into a right and a left lateral lobe: these form the main mass of the gland and are directly continuous with each other behind the urethra. In front of the urethra they are connected by a band which is named the isthmus: this consists of the same tissues as the capsule and is devoid of glandular substance.

The anterior surface (facies anterior) measures about 2.5 cm. from above downward but is narrow and convex from side to side. It is placed about 2 cm. behind the pubic symphysis, from which it is separated by a plexus of veins and a quantity of loose fat. It is connected to the pubic bone on either side by the puboprostatic ligaments. The urethra emerges from this surface a little above and in front of the apex of the gland.

The lateral surfaces are prominent, and are covered by the anterior portions of the Levatores ani, which are, however, separated from the gland by a plexus of veins.

The prostate measures about 4 cm. transversely at the base, 2 cm. in its antero-posterior diameter, and 3 cm. in its vertical diameter. Its weight is about 8 gm. It is held in its position by the puboprostatic ligaments; by the superior fascia of the urogenital diaphragm, which invests the prostate and the commencement of the membranous portion of the urethra; and by the anterior portions of the Levatores ani, which pass backward from the pubis and embrace the sides of the prostate. These portions of the Levatores ani, from the support they afford to the prostate, are named the Levatores prostatæ.

The prostate is perforated by the urethra and the ejaculatory ducts. The urethra usually lies along the junction of its anterior with its middle third. The ejaculatory ducts pass obliquely downward and forward through the posterior part of the prostate, and open into the prostatic portion of the urethra.


Structure

The prostate is immediately enveloped by a thin but firm fibrous capsule, distinct from that derived from the fascia endopelvina, and separated from it by a plexus of veins. This capsule is firmly adherent to the prostate and is structurally continuous with the stroma of the gland, being composed of the same tissues, viz.: non-striped muscle and fibrous tissue. The substance of the prostate is of a pale reddish-gray color, of great density, and not easily torn. It consists of glandular substance and muscular tissue.

The muscular tissue according to Kölliker, constitutes the proper stroma of the prostate; the connective tissue being very scanty, and simply forming between the muscular fibers, thin trabeculæ, in which the vessels and nerves of the gland ramify. The muscular tissue is arranged as follows: immediately beneath the fibrous capsule is a dense layer, which forms an investing sheath for the gland; secondly, around the urethra, as it lies in the prostate, is another dense layer of circular fibers, continuous above with the internal layer of the muscular coat of the bladder, and blending below with the fibers surrounding the membranous portion of the urethra. Between these two layers strong bands of muscular tissue, which decussate freely, form meshes in which the glandular structure of the organ is imbedded. In that part of the gland which is situated in front of the urethra the muscular tissue is especially dense, and there is here little or no gland tissue; while in that part which is behind the urethra the muscular tissue presents a wide-meshed structure, which is densest at the base of the gland—that is, near the bladder—becoming looser and more sponge-like toward the apex of the organ.

The glandular substance is composed of numerous follicular pouches the lining of which frequently shows papillary elevations. The follicles open into elongated canals, which join to form from twelve to twenty small excretory ducts. They are connected together by areolar tissue, supported by prolongations from the fibrous capsule and muscular stroma, and enclosed in a delicate capillary plexus. The epithelium which lines the canals and the terminal vesicles is of the columnar variety. The prostatic ducts open into the floor of the prostatic portion of the urethra, and are lined by two layers of epithelium, the inner layer consisting of columnar and the outer of small cubical cells. Small colloid masses, known as amyloid bodies are often found in the gland tubes.

Vessels and Nerves

The arteries supplying the prostate are derived from the internal pudendal, inferior vesical, and middle hemorrhoidal. Its veins form a plexus around the sides and base of the gland; they receive in front the dorsal vein of the penis, and end in the hypogastric veins. The nerves are derived from the pelvic plexus.



Gray's Images: Development | Lymphatic | Neural | Vision | Hearing | Somatosensory | Integumentary | Respiratory | Gastrointestinal | Urogenital | Endocrine | Surface Anatomy | iBook | Historic Disclaimer
Historic Disclaimer - information about historic embryology pages 
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Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)
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Reference

Gray H. Anatomy of the human body. (1918) Philadelphia: Lea & Febiger.


Cite this page: Hill, M.A. (2024, March 28) Embryology Prostate Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Prostate_Development

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G


Abnormalities

Benign Nodular Hyperplasia

A postnatal adult ageing effect with an onset about 45 years of age, the prostate becomes enlarged due to benign nodular hyperplasia. By 60 years of age and older about 3/4 of the males are affected of which half will be symptomatic. This condition affects the mucosal glands.

Prostate Cancer

Prostate cancer is the second most common malignant tumor in western males and anatomically involves the prostate peripheral zone.

The dog has been used as a model of this condition as this species also spontaneously develop prostatic neoplasia. The cell line CT1258 has been derived from a spontaneous canine prostate carcinoma and can induce tumour formation in mice.


(More? "Movember")

References

  1. <pubmed>19389372</pubmed>
  2. <pubmed>18977204</pubmed>
  3. <pubmed>19941349</pubmed>


Pubmed Bookshelf

Reviews

<pubmed>20930191</pubmed> <pubmed>18801537</pubmed> <pubmed>18752494</pubmed> <pubmed>18557761</pubmed> <pubmed>18462432</pubmed> <pubmed>12645922</pubmed> <pubmed>10506934</pubmed> <pubmed>2577188</pubmed>

Articles

<pubmed>19523480</pubmed> <pubmed>18804104</pubmed> <pubmed>18393306</pubmed> <pubmed>18339840</pubmed> <pubmed>18028901</pubmed> <pubmed>17478449</pubmed> <pubmed>681909</pubmed>

Search PubMed

Search Pubmed "Prostate Embryology" Oct 2010 - All (775) Review (113) Free Full Text (171)

Search Pubmed: Prostate Embryology | Prostate Development | Corpora Amylacea |

Additional Images

Terms

  • 5-α-reductase - enzyme that converts testosterone to dihydrotestosterone.
  • androgen receptor - (AR)
  • benign prostatic hyperplasia
  • mesenchyme - embryonic connective tissue
  • paraurethral gland - (Skene's gland) - female prostate gland is the correct nomenclature
  • prostate gland - Greek, prostates = "one who stands before", "protector", a female prostate gland exists
  • prostate cancer
  • UGE - urogenital epithelium
  • UGS - urogenital sinus

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, March 28) Embryology Prostate Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Prostate_Development

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G