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| − | | + | <big><center>[[Urinary System - Anatomy & Physiology|'''BACK TO URINARY - ANATOMY & PHYSIOLOGY''']]</center></big> |
| − | ==Introduction==
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| − | This muscular tube is the connection between the bladder and the external environment and plays a vital role in concious urinary continence.
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| − | ==The Layers of the Urethra==
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| − | 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.
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| − | ==Female==
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| − | * Empties at the external urethral orifice on the ventral wall of the vagina
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| − | * This is often at the vestibulo vaginal junction
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| − | * Only urine passes through it
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| − | * Length and diameter is species specific
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| − | ** Short and wide - mare
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| − | ** 2 fossa - bitch
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| − | ** Suburethral diverticulum - cow and sow
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| − | ==Male==
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| − | [[Image:maleluttri.jpg|right|thumb|250px|<small><center>A schematic overview of the path of the male urethra</center></small>]]
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| − | [[Image:sumbsbladurtri.jpg|right|thumb|250px|<small><center>A schematic overview of the blood supply to the bladder and urethra</center></small>]]
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| − | * Empties at tip of penis
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| − | * Divided into 3 parts
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| − | ** Pre-prostatic - bladder neck to seminal hillock
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| − | ** Prostatic portion - openings of deferant, vesicular and prostatic ducts
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| − | ** Penile portion - ischial arch to penile tip
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| − | ** Note the first 2 combined are called the pelvic portion
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| − | ==Muscles of the Urethra==
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| − | The '''urethralis''' muscle runs the entire length of the urethra and forms the external urethral sphincter.
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| − | 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.
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| − | =====Somatic Motor Supply - External Urethral Sphincter=====
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| − | * S1-S2
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| − | * Pudendal Nerve
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| − | * No synapse
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| − | * Innervates the urethral skeletal muscle - external urethral sphincter
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| − | * Function is to contract and retain urine
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| − | ==Blood Supply==
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| − | 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.
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| − | ==Revision==
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| − | {{Template:Learning
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| − | |flashcards = Use the [[Urethra - Anatomy & Physiology - Renal Flash Cards - Anatomy & Physiology|flash card revision resource]] for this section to test yourself.
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| − | |dragster = [[Canine Urinary Radiographical Anatomy Resources (I & II)|Canine Male Urethrogram Radiographic Anatomy (II)]]
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| − | }}
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| − | ==Webinars==
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| − | <rss max="10" highlight="none">https://www.thewebinarvet.com/urogenital-and-reproduction/webinars/feed</rss> | |
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| − | [[Category:Lower Urinary Tract - Anatomy & Physiology]][[Category:Bullet Points]]
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