Urethra

ANATOMY

1. URETHRA

2. URETHRA A tubular structure emerging from the neck of bladder and opens to the exterior It is outlet of bladder & eliminates urine to outside Present in both male & female but there are some differences b/w the two

3. difference Male urethra 1 Long 2 Length= 18- 20 cm 3 Function— i ) urination ii) ejaculation of semen 4 Course– curved (double) Female urethra 1 Short,, 2 Length= 4 cm 3 Function—only urination 4 Course– nearly straight 5 Foley cathetarisation is easy

4. Foley catheter in urethra male female

5. Male urethra It is 18-20 cm in length Extends from internal urethral orifice (in bladder to external urethral orifice ( meatus ) [ at the tip of glans penis]

6. Course------ is not straight -------is curved( double) emerges from the neck of urinary bladder enters into prostate passes through the urogenital diaphragm enters into bulb of penis then body of penis --- finally opens at the tip of glans penis simplified fig.

7. Course----- curved {double}

8. How to insert foleys catheter & why you have to lift up the penis to insert foley catheter

9. PARTS OF URETHRA Two parts— 1 ] Posterior urethra (proximal urethra) 2] Anterior urethra (distal urethra)

10. PARTS OF URETHRA…… 1] Posterior urethra (proximal urethra)- near to bladder 4cm in length Lies in the pelvis It has 3 parts----- a) pre-prostatic part —b/w bladder & prostate b) prostatic part —within prostate c) membranous part – through perineal membrane

11. PARTS OF URETHRA…… 2] Anterior urethra (distal urethra)--- i ) 16 cm long Lies in perineum & penis It has 2 parts-- a) bulbar urethra – within bulb of penis b) penile/ pendulus urethra/spongy urethra – --within body of penis

12. prostatic urethra bulbar urethra penile urethra preprostatic urethra membranous urethra posterior urethra anterior urethra

13. features of each part

14. 1. pre-prostatic part 1-1.5 cm in length Extends vertically from bladder neck to prostate Surrounded by proximal/internal urethral sphincter --- made up of smooth muscle bundle iv) Function of internal urethral sphincter — a) maintains the urinary continence b) prevents retrograde flow of seminal ejaculate into bladder v) Applied – this part can be damage by a) bladder neck surgery, b) TURP (transurethral resection of prostate) vi) So retrograde ejaculation of semen occur in such patient ,, may lead to infertility

15. pre- prostatic part

16. 2. prostatic part i ) 3-4 cm in length ii) It passes through the substance of prostate iii) Posterior wall of this part– presents a) urethral crest – midline ridge/mucosal fold b) prostatic sinus – depression on both side of crest ---- prostatic ducts –open in sinus c) verumontanum / colliculus seminalis – ---an elevation at urethral crest ,, ---- prostatic utricle open here ----- ejaculatory duct – open here * prostatic utricle – small blind sac ,,develop from paramesonephric duct or urogenital sinus,, homologus to vagina of female ,, also k/a vagina musculine * Ejaculatory duct = vas deferens + duct of seminal vesicle

17. urethral crest coronal section

18. sagittal section view coronal section view 1 3 2

19. 3. Membranous part i ) shortest part ,, 1.5 cm long 2 nd most narrowest part (most narrowest part is external urethral orifice) iii) Passes through perineal membrane iv) surrounded by distal / external urethral sphincter ----- has voluntary control ----- maintains urinary continence ---made up of urethral smooth muscle ,, urethral striated muscle ,,pubourethral part of levator ani muscle

20. 4.Anterior urethra It extends from membranous urethra to external urethral orifice . bulbar urethra– ---lies in the bulbospongiosus (of penis) --- widest part of urethra --- Bulbourethral glands open in it 2)Penile urethra- ---lies in corpus spongiosum --- its terminal part is dilated in glans penis – k/a navicular fossa --- numerous urethral glands open in it bulbar urethra navicular fossa

21. SPHINCTERS OF URETHRA TWO— 1 internal urethral sphincter — ---is involuntary ----surrounds internal urethral orifice & preprostatic urethra 2 external urethral sphincter– --- is voluntary ---surrounds membranous urethra

22. Transverse section of different part of urethra i ) pre- prostatic part– stellate shape-- ii) prostatic part– crescentic shape/ semilunar - iii) membranous part--- stellate shape iv) bulbar & penile part– transverse slit shape v) external urethral orifice– sagittal slit shape **Significance of different shape is ---- ---- Mentain the continuous stream of urine flow ( projectile stream)

23. Arterial supply 1) urethral artery – br. of internal pudendal artery 2) dorsal artery of penis- br. of internal pudendal artery Venous drainage--- 1) Anterior urethra— drained by dorsal vein of penis----internal pudendal vein--- prostatic venous plexus 2)Posterior urethra— drained by prostatic and vesicle -venous plexus----- internal iliac veins

24. Lymphatic drainage i )prostatic urethra---- internal iliac LN ii)membranous urethra---- internal iliac LN iii) anterior urethra--& glans ---deep inguinal LN Nerve supply — by autonomic nerve mainly i -sympathetic fibres from superior hypogastric plexus [L1-L2segment] ii-parasympathetic fibres- S2 to S4 sp. Segments iii-somatic fibres from pudendal nerves Source of development— vesicourethral canal of primitive urogenital sinus

25. applied 1 -urethritis – infection & inflammation of urethra -- N.gonorrhoea 2 rupture of urethra – ------due to injury by a fall astride/straddle 3 hypospadias —urethra opens at under surface(ventral)of penis 4 epispadias – urethra opens on the dorsum of penis * fall astride = fall on surface keeping legs apart so that injury goes to perineum

26. 3 . hypospadias —urethra opens at under surface(ventral)of penis

27. 4 . epispadias – urethra opens on the dorsum of penis

28. Q. From AIPGME Exam.

29. FEMALE URETHRA It is 4cm long & 6mm in width Homologus to prostatic urethra It begins from internal urethral orifice and passes downwards & forwards Opens in the vestibule b/w clitoris & vaginal orifice Ext. urethral opening lies 2.5 cm behind the glans clitoris *clitoris = homologus organ to penis

30. course sagittal section

31. external urethral orifice vaginal orifice anus clitoris external opening

32. Sphincter of female urethra It has also internal & external urethral sphincter

33. Glands around the female urethra These glands open in female urethra— 1 urethral glands – mucous glands 2 para -urethral glands == corresponds to prostate 3 greater vestibular glands —

34. Arterial supply i ) superiorvesical artery ii) vaginal artery Venous drainage— --- Through vesical venous plexus into internal pudendal vein Lymphatic drainage— ---Internal and external iliac lymph node Nerve supply— ---By sympathetic,, parasympathetic & somatic narve fibres Applied – urethritis ,, rupture of urethra d/t injury

35. Epithelium of urethra Epithelium of urethra Transitional epithelium a t the proximal end ( near the bladder ) Stratified and pseudostratified columnar – mid urethra (in males) Stratified squamous epithelium a t the distal end ( near the urethral opening )

36. parts of penis

37. PARTS OF URETHRA Two parts— 1 ] Posterior urethra (proximal urethra)- near to bladder short , 4cm in length Lies in the pelvis It has 3 parts a) pre-prostatic part —b/w bladder & prostate b) prostatic part —within prostate c)membranous part – through perineal membrane 2] Anterior urethra (distal urethra) Long , 16 cm long Lies in perineum & penis It has 2 parts-- a) bulbar urethra – within bulb of penis b)penile/ pendulus urethra/spongy urethra – within body of penis

38. Organs of the Urinary System kidneys ureters urinary bladder urethra

39. function Kidney– formation of urine Ureter – carrying of urine from kidney to bladder Urinary bladder– storage of urine Urethra– voiding /elimination of urine

40. urethral crest coronal section