Anatomy - Retroperitoneum (bladder and pelvis) Flashcards
What is the function of the bladder?
Collection, temporary storage and expulsion of urine.
Give 3 ways in which the bladder is specialised for storage.
- Rugae give the bladder a great capacity to expand. 2. Detrusor muscle relaxes in storage, increasing bladder volume. 3. Urethral sphincters contract.
What is the interureteric bar?
A ridge of muscle between the two ureteric orficies.
What is the significance of the trigone?
It marks the two ureteric orifices and the urethral orifice. It is located in the fundus and it has a smooth wall in contrast to the rest of the bladder.
Which urethral sphincter is composed of skeletal muscle?
The external urethral sphincter.
Which urethral sphincter is under voluntary control?
The external urethral sphincter.
Which urethral sphincter is composed of smooth muscle?
The internal urethral sphincter.
Which urethral sphincter is under autonomic control?
The internal urethral sphincter.
What is the specialised smooth muscle of the bladder wall called?
The detrusor muscle.
What is the blood supply to the bladder?
The internal iliac arteries.
What nerve provides sympathetic innervation to the bladder?
The hypogastric nerve (T12-L2).
What is the affect of sympathetic innervation on the bladder?
Relaxation of the detrusor muscle and constriction of the internal urethral sphincters - this promotes urine retention.
What is the affect of parasympathetic innervation on the bladder?
Contraction of the detrusor muscle and relaxation of the internal urethral sphincters - this promotes micturition.
What is the role of the sensory nerves in the bladder wall?
They signal the need to urinate to the brain when the bladder becomes full.
Name 3 locations where the ureter narrows and renal stones may be present.
- Ureteropelvic junction. 2. As the ureter passes the pelvic brim. 2. Where the ureters enter the bladder.
Why is the ureter at danger of being damaged in a hysterectomy?
The uterine artery is ligated in a hysterectomy. The ureter passes immediately posteriorly to the uterine artery and so may be damaged.
What two lumbar plexus nerves have the same nerve roots?
Femoral and Obtruator - L2,3,4.
What 3 bones make up the hip bone?
- Ilium. 2. Pubis. 3. Ischium.
What is the socket called formed from the fusion of the ilium, pubis and ischium?
The acetabulum.
What bone articulates with the acetabulum?
The head of the femur.
Name 2 important ligaments that attach from the sacrum to the ischium.
- sacrospinous ligament. 2. sacrotuberous ligament.
Where does the sacrospinous ligament run between?
The sacrum to the ischial spine.
Where does the sacrotuberous ligament run between?
The sacrum to the ischial tuberosity.
Why are female pelvis’ different to males?
Female pelvis’ have special adaptations for childbirth.
What are the 3 main differences between male and female pelvis’?
- The female has a larger angled sub-pubic arch. 2. The pelvic outlet is rounder in females. 3. The ischial spine projects further into the male pelvic cavity.
What do the left gonadal veins (ovarian and testicular) drain into?
The left renal vein!
Give 3 functions of the pelvis.
- Transfers weight. 2. Provides attachment for muscles and ligaments. 3. Contains and protects pelvic viscera.
What are the two hiatuses of the pelvic floor?
- Urogenital hiatus. 2. Rectal hiatus.
What passes through the urogenital hiatus of the pelvic floor?
The urethra and the vagina.
What passes through the rectal hiatus of the pelvic floor?
The anal canal.
Give 3 functions of the pelvic floor muscles.
- They support abdomino-pelvic viscera. 2. They resist increases in intra pelvic pressures. 3. They maintain urinary and faecal continence.
What are the 2 main muscles of the pelvic floor?
- Levator ani muscles. 2. Coccygeus muscle.
What is the innervation to the levator ani muscles?
Branches of the pudendal nerve, S2, 3, 4 roots.
What is the function of levator ani?
Maintains faecal continence, during defecation this muscle relaxes.
Which muscles of levator ani are prone to injury in childbirth?
Pubococcygeus and puborectalis due to their medial position.
What is the innervation of coccygeus?
Ventral rami of S4 and 5.
What can happen if you damage the pelvic floor?
You may get prolapse of pelvic viscera.
What risk factors can increase the chance of prolapse?
- Increasing age. 2. Number of vaginal deliveries. 3. Family history. 4. Being overweight. 5. Chronic coughing e.g. a lung disorder.
How long is the female urethra?
4cm.
What is the prostatic part of the male urethra?
Where the urethra descends through the prostate (3cm).
What is the membranous part of the male urethra?
Where the urethra transverses the urogenital diaphragm (1cm).
What is the penile part of the male urethra?
Where the urethra travels through the bulb, corpus spongiosum and glans of the penis (15cm).
What dilation in the glans my impede a urethral catheter?
The navicular fossa.
How long is the male urethra?
15-20cm.
