Pelvic Viscera Flashcards
Describe the retropubic space.
- Space b/w bladder/urethra & pubis
- aka Pre-vesicle space
Explain how a needle inserted through the lower abdominal wall over the pubic symphysis can enter a distended bladder without entering the peritoneal cavity.
- Needle inserted just above pubic symphysis
Describe the structures which support the urinary bladder
- Neck of bladder is most fixed part
- Pair of tough fibro-muscular bands connect posterioinferior aspect of each pubic bone to the neck of bladder and pelvic part of urethra
- in women, called Pubovesical ligaments
- in men, called Puboprostatic ligaments
- Medial pubovesical ligament (medial puboprostatic ligament in male)
- Lateral pubovesical ligament (lateral puboprostatic ligament in male)
Describe internal anatomy of the urinary bladder
- Ureters enter bladder obliquely at Trigone to prevent reflux of urine
- Internal urethral sphincter associated with neck of bladder
- Sphincter is a circular cuff of smooth muscle and is innervated by the autonomic nervous system
- Fundus consists of smoothmuscle
- External genitalia attached underneath pelvic floor
Compare the innervation of the internal and external urethral sphincters.
- Internal: sympathetic
- External: pudendal
Describe the muscles and nerves (visceral afferent, somatic efferent, sympathetic, parasympathetic) involved in normal micturition and urinary continence
- Bladder filling: sympathetics
- Bladder emptying: parasympathetics
- Pelvic splanchnic nerves (parasympathetic) contraction of bladder
- Inferior hypogastric plexus (sympathetic) contraction of internal urethral sphincter
- Visceral afferents senation of fullness
- Pudendal nerve (somatic efferent) contraction of external urethral sphincter
Compare and contrast the male versus the female urethra.
Males:
- 3 parts of urethra
- Preprostatic part of urethra
- Prostatic part of urethra
- Membranous/Spongy part
- Lift penis for cath to pass this area
Females:
- Female urethra is short, approx 4 cm in length
- External urethral orifice opens into vestibule b/w labia minora anterior to the opening of vagina
- lower UTI
Arterial supply to rectum and anal canal
- S. Rectal artery is the direct continuation of the I. Mesenteric artery is a branch of anterior division of internal iliac artery
- Middle Rectal a. is a branch of anterior division of Internal Iliac a.
- I. Rectal a. is a branch of I. Pudendal a.
Compare the internal and external submucosal venous plexus of the anal canal
- Internal rectal venous plexus in submucous space: enlarged artery does not cause pain therefore no anesthesia required during surger
- External Rectal Venous plexus in perianal splace: enlarged artery causes pain
Compare the location and innervation of the internal and external anal sphincters.
- External Anal Sphincter innervated by Pudendal nerve
- Internal Anal Sphincter innervated by Autonomic Nervous system
Compare voluntary micturition/urinary continence in adults with reflex voiding in children prior to “potty training”.
- Infant: no cortical control of Ext. sphinchters
- Once cortical control of Ext. Sphincters is learned, voiding can be controlled (potty training) therefore achieving urinary and fecal continence
Compare the location and symptoms of the internal versus external haemorrhoids
- External: at anal margin
- Internal: start above pectinate line
Describe the lymphatic drainage of rectum and anal canal
- Lymphatic drainage of rectum to I. Mesenteric Lymph nodes
- Lymphatic drainage of anal canal above the pectinate line is to the Internal Iliac nodes
- Int. Iliac -> Common -> Iliac -> Lumbar
- Below the pectinate line is to the Superficial Inguinal lymph node
- S. Inguinal -> Deep Inguinal -> Ext. Iliac -> Common Iliac -> Lumbar
