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− | {{toplink
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− | |backcolour = C1F0F6
| + | ==Introduction== |
− | |linkpage =Urinary System - Anatomy & Physiology
| + | |
− | |linktext =URINARY SYSTEM
| + | This muscular tube is the connection between the bladder and the external environment and plays a vital role in concious urinary continence. |
− | |maplink = Urinary System (Content Map) - Anatomy & Physiology
| + | |
− | |pagetype =Anatomy
| + | ==The Layers of the Urethra== |
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| + | |
− | <br>
| + | 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. |
− | This is the connection between the bladder and the external environment. | |
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| ==Female== | | ==Female== |
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| * This is often at the vestibulo vaginal junction | | * This is often at the vestibulo vaginal junction |
| * Only urine passes through it | | * Only urine passes through it |
− | * The urethral submucosa has a network of veins which may contribute to continence by forming a kind of erectile tissue.
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| * Length and diameter is species specific | | * Length and diameter is species specific |
| ** Short and wide - mare | | ** Short and wide - mare |
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| ==Male== | | ==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 | | * Empties at tip of penis |
| * Divided into 3 parts | | * Divided into 3 parts |
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| ** Penile portion - ischial arch to penile tip | | ** Penile portion - ischial arch to penile tip |
| ** Note the first 2 combined are called the pelvic portion | | ** 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. |
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| + | =====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 |
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| ==Blood Supply== | | ==Blood Supply== |
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− | Blood Supply comes from the Urethral Artery | + | 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== |
| + | |
| + | {{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)]] |
| + | }} |
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| + | |
| + | ==Webinars== |
| + | <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]] |