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Urethra - Anatomy & Physiology (view source)
Revision as of 16:05, 6 January 2023
, 16:05, 6 January 2023no edit summary
<big><center>[[Urinary System - Anatomy & Physiology|'''BACK TO URINARY - ANATOMY & PHYSIOLOGY''']]</center></big>
==Introduction==
This muscular tube is the connection between the bladder and the external environment and plays a vital role in concious urinary continence.
==The Layers of the Urethra==
The layers of the walls of the urethra are largely similar to those of the [[Urinary Bladder - Anatomy & Physiology#Anatomy|urinary bladder]] apart from one significant difference; in both the male and the female the urethral submucosa has a network of veins which may contribute to continence by forming a kind of erectile tissue.
==Female==
* Empties at the external urethral orifice on the ventral wall of the vagina
* This is often at the vestibulo vaginal junction
* Only urine passes through it
* Length and diameter is species specific
** Short and wide - mare
** 2 fossa - bitch
** Suburethral diverticulum - cow and sow
==Male==
[[Image:maleluttri.jpg|right|thumb|250px|<small><center>A schematic overview of the path of the male urethra</center></small>]]
[[Image:sumbsbladurtri.jpg|right|thumb|250px|<small><center>A schematic overview of the blood supply to the bladder and urethra</center></small>]]
* Empties at tip of penis
* Divided into 3 parts
** Pre-prostatic - bladder neck to seminal hillock
** Prostatic portion - openings of deferant, vesicular and prostatic ducts
** Penile portion - ischial arch to penile tip
** Note the first 2 combined are called the pelvic portion
==Muscles of the Urethra==
The '''urethralis''' muscle runs the entire length of the urethra and forms the external urethral sphincter.
Unlike the [[Urinary Bladder - Anatomy & Physiology#Internal Urethral Sphincter|internal sphincter]] the external sphincter is composed of striated muscle fibres which are under the voluntary control of the somatic nervous system.
=====Somatic Motor Supply - External Urethral Sphincter=====
* S1-S2
* Pudendal Nerve
* No synapse
* Innervates the urethral skeletal muscle - external urethral sphincter
* Function is to contract and retain urine
==Blood Supply==
Blood Supply comes from the Urethral Artery which is a branch of the vaginal artery which in turn is a branch of the internal pudendal which is a branch of the internal iliac.
==Revision==
{{Template:Learning
|flashcards = Use the [[Urethra - Anatomy & Physiology - Renal Flash Cards - Anatomy & Physiology|flash card revision resource]] for this section to test yourself.
|dragster = [[Canine Urinary Radiographical Anatomy Resources (I & II)|Canine Male Urethrogram Radiographic Anatomy (II)]]
}}
==Webinars==
<rss max="10" highlight="none">https://www.thewebinarvet.com/urogenital-and-reproduction/webinars/feed</rss>
[[Category:Lower Urinary Tract - Anatomy & Physiology]][[Category:Bullet Points]]