no edit summary
Line 1: Line 1: −
{{toplink
+
 
|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==
}}
+
 
<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.   
      
==Female==
 
==Female==
Line 14: Line 13:  
* 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.
   
* Length and diameter is species specific
 
* Length and diameter is species specific
 
** Short and wide - mare
 
** Short and wide - mare
Line 21: Line 19:     
==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
Line 28: Line 27:  
** 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.
 +
 +
=====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==
   −
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.
 +
 
 +
==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]]