The urethra is the tube that carries urine from the bladder to the outside of the body. It has some differences between males and females. The male urethra is longer (18-20 cm) and curved, serving the dual functions of urination and ejaculation. It has two parts - the posterior urethra near the bladder and anterior urethra in the penis. The female urethra is shorter (4 cm) and straight, serving only urination. It opens between the clitoris and vaginal opening. Both have internal and external sphincters to control urination.

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
i) 4cm in length
ii) Lies in the pelvis
iii) 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
i) Lies in perineum &
penis
ii) 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
i) 1-1.5 cm in length
ii) Extends vertically from bladder neck to prostate
iii) 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

19. 3. Membranous part
i) shortest part ,, 1.5 cm long
ii) 2nd 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 .
1) 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.

33. 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

34. course
sagittal section

35. external
urethral orifice
vaginal orifice
anus
clitoris
external
opening

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

37. 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—

38. 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

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

44. parts of penis

52. PARTS OF URETHRA
• Two parts—
1] Posterior urethra (proximal urethra)- near to bladder
i) short , 4cm in length
ii) Lies in the pelvis
iii) 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)
i) Long , 16 cm long
ii) Lies in perineum & penis
iii) It has 2 parts--
a) bulbar urethra– within bulb of penis
b)penile/pendulus urethra/spongy urethra –
within body of penis

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

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

56. urethral crest
coronal section