Prab: /* Secretions */

2025-01-29T22:22:22Z

Secretions

← Older revision		Revision as of 22:22, 29 January 2025
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	===Secretions===		===Secretions===
	In human prostatic secretions, the protein content is less than 1%,~~{{citation needed\|date=October 2019}}~~ and the contents are slightly acidic. Contents include [[proteolytic enzyme]]s, [[prostatic acid phosphatase]], [[fibrinolysin]], and [[prostate-specific antigen]]. The secretions also contain [[zinc]].		In human prostatic secretions, the protein content is less than 1%, and the contents are slightly acidic. Contents include [[proteolytic enzyme]]s, [[prostatic acid phosphatase]], [[fibrinolysin]], and [[prostate-specific antigen]]. The secretions also contain [[zinc]].

	==Additional images==		==Additional images==
	<gallery>		<gallery>

Prab at 01:40, 30 August 2023

2023-08-30T01:40:59Z

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[[Anatomy]] > [[Gray's Anatomy| Gray's Anatomy of the Human Body]] > XI. Splanchnology > 3c. 6. The Prostate

[[Henry Gray]] (1821–1865). Anatomy of the Human Body. 1918.

== '''The Prostate''' ==
'''(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''' ===
The '''base''' (''basis prostatae'') 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''' ===
The '''apex''' (''apex prostatae'') is directed downward, and is in contact with the superior fascia of the [[urogenital diaphragm]].

[[File:Prostate.jpg|alt=The prostate gland|thumb|The prostate gland]]

FIG. 1160– Prostate with seminal vesicles and seminal ducts, viewed from in front and above. (Spalteholz.) (''Picture From the Classic Gray's Anatomy'')

=== '''Surfaces''' ===
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 prostatae'''

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 [[trabeculae]], 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]].
==Function==

===Male sexual response===
{{main|Prostate massage}}
During male seminal emission, sperm is transmitted from the [[vas deferens]] into the male urethra via the ejaculatory ducts, which lie within the prostate gland.<ref name=Ganongs2019 /> [[Ejaculation]] is the expulsion of semen from the urethra.<ref name=Ganongs2019 /> Semen is moved into the urethra following contractions of the smooth muscle of the vas deferens and seminal vesicles, following stimulation, primarily of the [[glans penis]]. Stimulation sends nerve signals via the [[internal pudendal nerve]]s to the upper lumbar spine; the nerve signals causing contraction act via the [[hypogastric nerve]]s.<ref name=Ganongs2019 /> After traveling into the urethra, the seminal fluid is ejaculated by contraction of the [[bulbocavernosus muscle]].<ref name=Ganongs2019>{{Cite book|title=Ganong's review of medical physiology|author1=Barrett, Kim E.|others=Barman, Susan M.,, Brooks, Heddwen L.,, Yuan, Jason X.-J.|isbn=9781260122404|edition=26th|location=New York|oclc=1076268769|year=2019|pp=411,415}}</ref>

It is possible for some men to achieve [[orgasm]] solely through stimulation of the prostate gland, such as prostate massage or [[Anal sex|anal intercourse]].<ref name="Rosenthal">{{cite book |first=Martha |last= Rosenthal| title = Human Sexuality: From Cells to Society | publisher =[[Cengage Learning]]|year = 2012|pages=133–135|accessdate = September 17, 2012| isbn = 978-0618755714|url =https://books.google.com/books?id=d58z5hgQ2gsC&pg=PT153}}</ref><ref name="Answer">{{cite book|title=The Orgasm Answer Guide|isbn = 978-0-8018-9396-4|publisher=JHU Press|year=2009|pages=108–109|accessdate=6 November 2011|url=https://books.google.com/books?id=Kkts3AX9QVAC&pg=PA108|author1=Komisaruk, Barry R. |author2=Whipple, Beverly |author3=Nasserzadeh, Sara |author4=Beyer-Flores, Carlos |lastauthoramp=yes }}</ref>

===Secretions===
In human prostatic secretions, the protein content is less than 1%,{{citation needed|date=October 2019}} and the contents are slightly acidic. Contents include [[proteolytic enzyme]]s, [[prostatic acid phosphatase]], [[fibrinolysin]], and [[prostate-specific antigen]]. The secretions also contain [[zinc]].
==Additional images==
<gallery>
File:Prostatehistology.jpg|Microscopic glands of the prostate
File:Gray543.png|The deeper branches of the internal pudendal artery.
File:Lymphatics of the prostate-Gray619.png|Lymphatics of the prostate.
</gallery>
==External links==
{{Male reproductive system}}
[[Category:Exocrine system]]
[[Category:Glands]]
[[Category:Mammal male reproductive system]]
[[Category:Sexual anatomy]]
[[Category:Prostate| ]]
{{grays}}

The Prostate - Revision history

Prab: /* Secretions */

Prab at 01:40, 30 August 2023