Urethral crest

Information about Urethral crest

The male urethra laid open on its anterior (upper) surface. (Urethral crest labeled at upper right.)
Latincrista urethralis urethrae masculinae, crista urethralis urethrae femininae
subject #256 1234
Dorlands/Elsevier c_62/13538713
The urethal crest is an anatomical feature present in the urinary system of both males and females.

In males, the urethral crest is known as the ''crista urethralis masculinae, or the crista phallica, and is a longitudinal fold on the posterior wall of the urethra extending from the uvula of the bladder through the prostatic urethra..[1] It is from 15 to 17 mm. in length, and about 3 mm. in height, and contains muscular and erectile tissue. When distended, it may serve to prevent the passage of the semen backward into the bladder.[2]

In females, it is known as the crista urethralis femininae, and is a conspicuous longitudinal fold of mucosa on the posterior wall of the urethra.[3]

Additional images


Vesiculæ seminales and ampullæ of ductus deferentes, seen from the front.


External links

References

1. ^ [1]
2. ^ [2]
3. ^ [3]


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Male reproductive system
Scrotumlayers (skin, Dartos, External spermatic fascia, Cremaster, Internal spermatic fascia) • Perineal raphe • Spermatic cord
Testeslayers (Tunica vaginalis, Tunica albuginea) • Appendix • Mediastinum • Lobules • Septa • Leydig cell • Sertoli cell • Blood-testis barrier
SpermatogenesisSpermatogonium • Spermatocytogenesis • Spermatocyte • Spermatidogenesis • Spermatid • Spermiogenesis • Spermatozoon
seminal tractSeminiferous tubules (Tubuli seminiferi recti, Rete testis, Efferent ducts) • Epididymis  (Appendix) • Vas deferens • Ejaculatory duct  Seminal colliculus
urinary tractInternal urethral orifice • Urethra (Prostatic, Intermediate, Spongy) • Urethral crest • Urethral gland • External urethral orifice
PenisCorpus cavernosum • Corpus spongiosum • Navicular fossa of male urethra • Glans penis • Fundiform ligament • Suspensory ligament • Foreskin • Frenulum
accessory glandsSeminal vesicles  (Excretory duct of seminal gland) • Prostate  (Prostatic utricle, Prostatic sinus) • Bulbourethral glands
Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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The urinary system is the organ system that produces, stores, and eliminates urine. In humans it includes two kidneys, two ureters, the bladder, and the urethra. The analogous organ in invertebrates is the nephridium.
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In anatomy, the urethra is a tube which connects the urinary bladder to the outside of the body. The urethra has an excretory function in both genders to pass urine to the outside, and also a reproductive function in the male, as a passage for sperm.
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uvula of urinary bladder, caused by the middle lobe of the prostate.

Pathology

It is often enlarged in benign prostatic hypertrophy.

See also

  • palatine uvula
  • urinary bladder

External links

  • uvula+of+bladder

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The prostatic urethra, the widest and most dilatable part of the urethra canal, is about 3 cm. long.

It runs almost vertically through the prostate from its base to its apex, lying nearer its anterior than its posterior surface; the form of the canal is spindle-shaped,
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Semen is an organic fluid (also known as seminal fluid) that usually contains spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals for fertilization of female ova. The process of discharge is called ejaculation.
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In anatomy, the urinary bladder is a hollow, muscular, and distensible (or elastic) organ that sits on the pelvic floor in mammals. It is the organ that collects urine excreted by the kidneys prior to disposal by urination.
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The mucous membranes (or mucosae; singular: mucosa) are linings of mostly endodermal origin, covered in epithelium, and are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs.
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The State University of New York Health Science Center at Brooklyn, better known as SUNY Downstate Medical Center, is an academic medical center and is the only one of its kind in the Borough of Brooklyn in New York City.
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Georgetown University is a private, Jesuit, research university, located in Washington, D.C.'s Georgetown neighborhood. Father John Carroll founded the school in 1789, though its roots extend back to 1634.
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human male reproductive system is a series of organs located outside of the body and around the pelvic region of a male that contribute towards the reproductive process.

The male contributes to reproduction by producing spermatozoa.
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The reproductive system is the ensembles and interactions of organs and/or substances within an organism that strictly pertain to reproduction. As an example, this would include in the case of female mammals, the hormone estrogen, ova, and the uterus and the vagina, and the breasts.
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In some male mammals, the scrotum is a protuberance of skin and muscle containing the testicles. It is an extension of the abdomen, and is located between the penis and anus.
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The dartos is a layer of smooth muscular fiber outside the external spermatic fascia but below the skin.

Gender differences

  • In males it is termed tunica dartos and lies beneath the skin of the scrotum.

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The external spermatic fascia (intercrural or intercolumnar fascia) is a thin membrane, prolonged downward around the surface of the cord and testis. It is separated from the dartos tunic by loose areolar tissue.
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The cremaster muscle is a muscle that covers the testis.

Contraction

Its function is to raise and lower the scrotum in order to regulate the temperature of the testis and promote spermatogenesis.
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The internal spermatic fascia (infundibuliform fascia) is a thin layer, which loosely invests the cord; it is a continuation downward of the transversalis fascia.

Additional images



The scrotum.

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The perineal raphe extends from the anus, through the mid-line of the scrotum (scrotal raphe) and upwards through the posterior mid-line aspect of the penis (penile raphe).

It is observed as a noticeable line.
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spermatic cord is the name given to the cord-like structure in males formed by the vas deferens and surrounding tissue that run from the abdomen down to each testicle.

Contents of spermatic cord


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The testicle (from Latin testis, meaning "witness",[1] plural testes) or ballock is the male generative gland in animals. This article will concentrate on mammalian testicles unless otherwise noted.
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The tunica vaginalis is the serous covering of the testis.

It is a pouch of serous membrane, derived from the saccus vaginalis of the peritoneum, which in the fetus preceded the descent of the testis from the abdomen into the scrotum.
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For other structures with the same name, see Tunica albuginea.

The Tunica Albuginea is the fibrous covering of the testis.

It is a dense blue-white membrane, composed of bundles of white fibrous tissue which interlace in every direction.
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The appendix testis (or Hydatid of Morgagni) is a vestigial remnant of the Müllerian duct, present on the upper pole of the testis and attached to the tunica vaginalis. It is present about 90% of the time.
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The mediastinum testis is a network of fibrous connective tissue that extends from the upper to near the lower extremity of the testis, and is wider above than below.
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The glandular structure of the testis consists of numerous lobules.

Their number, in a single testis, is estimated by Berres at 250, and by Krause at 400.

They differ in size according to their position, those in the middle of the gland being larger and longer.
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septa which extend between the mediastinum testis and the tunica albuginea, and consists of from one to three, or more, minute convoluted tubes, the tubuli seminiferi.

Additional images




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Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle. They can secrete testosterone and are often closely related to nerves. Leydig cells have round vesicular nuclei and a granular eosinophilic cytoplasm.
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A Sertoli cell (a kind of sustentacular cell) is a 'nurse' cell of the testes which is part of a seminiferous tubule.

It is activated by follicle-stimulating hormone, and has FSH-receptor on its membranes.
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The blood-testis barrier (abbreviated as BTB) is a physical barrier between the blood vessels and the seminiferous tubules of the animal testes.

The barrier is formed by tight connections between the Sertoli cells, which are sustentacular cells (supporting cells) of the
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