Region 7 - Pelvis Flashcards
Where does the bladder sit in relation to the pubic bones?
Posterosuperior
What does the bladder rest on?
Anteriorly: - Pubic bones and pubic symphysis Posteriorly: - Prostate (males) - Anterior vagina (females)
What features of the bladder inner surface allow stretching?
Transitional epithelium
Rugae
Where does the bladder lie in infants and children?
Abdomen (empty and full)
At what age does the bladder begin to lie in the greater pelvis?
6 years
Where does the bladder lie from puberty onwards?
Lesser pelvis when empty
Rises to suprapubic region as it fills
What connects the pubic symphysis to the apex of the bladder?
Urachus:
- Remnant of allantois; a canal draining foetal bladder via umbilical cord
What is the trigone of the bladder?
The inferoposterior, triangular base of the bladder
An internal area of smooth mucous membrane
What muscle encircles the orifices of the trigone?
Detrusor muscle
What is the alternative name for the internal urethral sphincter? What muscle is it a continuation of?
Sphincter vesicae (not complete) Detrusor muscle
What ligaments how the neck of the bladder in place?
Puboprostatic (males)
Pubovesical (females)
What is the blood supply to the bladder in males?
Superior vesical arteries (x2)
Inferior vesical artery
What is the blood supply to the bladder in females?
Superior vesical arteries (x2)
Vaginal artery
Where do the arteries that supply the bladder arise from?
Superior vesical arteries:
- Patent umbilical artery (anterior division of internal iliac artery)
Inferior vesical/vaginal artery:
- Anterior division of internal iliac artery
What arteries can give small branches to the bladder?
Obturator artery
Inferior gluteal artery
What is the venous drainage of the bladder?
Vesical plexus -> Internal iliac vein
What provides SNS innervation to the bladder?
Inferior thoracic and upper lumbar cord:
- Via hypogastric plexus and nerves to the vesical plexus
What provides PNS innervation to the bladder?
Pelvic splanchnic nerves -> Inferior hypogastric plexus
What does PNS innervation to the bladder do?
Contracts detrusor muscle
Inhibits internal urethral sphincter
Where does lymph from the ureter drain?
Lumbar
Common iliac
External iliac
Internal iliac
Where does lymph from the bladder drain?
Internal iliac
(Some to external iliac superiorly)
(Some from neck to sacral nodes)
Where does lymph from the urethra drain?
Internal iliac Males: - Spongy urethra -> Deep inguinal Females: - Some to sacral nodes
What is the relation of the rectum to the peritoneum?
Upper 1/3 covered by visceral peritoneum
Middle 1/3 has peritoneum on anterior surface
Lower 1/3 is infraperitoneal
What is the course of the rectum?
From S3 (rectosigmoid junction) To tip of coccyx
What forms the 3 lateral flexures in the rectum?
3 internal transverse rectal folds:
- 2 on left
- 1 on right
What supports the rectal ampulla?
Levator ani
Anococcygeal ligament
What is the arterial supply to the rectum?
Superior rectal artery (inf. mesenteric)
Middle rectal artery (int. iliac)
Inferior rectal artery (int. pudendal)
What conveys SNS supply to the rectum?
Lumbar splanchnic nerves
Hypogastric/pelvic plexuses
(Via peri-arterial plexuses)
What conveys PNS supply to the rectum?
Pelvic splanchnic nerves (S2-S4):
- Inf. hypogastric plexus -> Rectal plexuses
What is the lymphatic drainage of the rectum?
Pararectal nodes:
- Inferior mesenteric
- Internal iliac
What is the broad ligament?
Double layer of peritoneum extending from sides of uterus to lateral walls and floor of pelvis
What part of the broad ligament is prolonged laterally over and contains the ovarian vessels?
Suspensory ligament of the ovary
What ligament lies posterosuperiorly between the layers of the broad ligament?
Ligament of the ovary
What ligament lies anteroinferiorly between the layers of the broad ligament?
Round ligament of the uterus
What part of the broad ligament do the uterine tubes lie in anterosuperiorly?
Mesosalpinx
What part of the broad ligament do the ovaries lie in posteriorly?
Mesovarium
What part of the broad ligament lies inferiorly and is the main part?
Mesometrium
What are the ligaments, attached to the cervix, that support the uterus?
Uterosacral (sacrocervical) Transverse cervical (cardinal): - Cervix to obturator fascia (lateral pelvic wall) Pubocervical (pubovesical): - Cervix to pubic symphysis
What is anteversion of the uterus?
Long axis of uterus bent forward on long axis of vagina
What is the angle of anteversion of the uterus?
90 degrees
What is anteflexion of the uterus?
Long axis of uterus bent forward at internal os with long axis of vagina/cervix
What is the angle of anteflexion of the uterus?
170 degrees
What is the arterial supply to the ovaries?
Paired para-aortic branches at L2
Where does the right ovarian vein drain?
IVC
Where does the left ovarian vein drain?
Left renal vein
Where do nerves supplying the ovaries arise?
Aortic plexus
What structures of the female reproductive system drain lymph to the aortic nodes at L2?
Ovaries
Fundus
Uterine tubes
Where does lymph from the isthmus of the uterine tubes drain to?
Superficial inguinal niodes
Where does lymph from the body of the uterus drain?
External iliac nodes (via broad ligament)
Where does lymph from the cervix drain?
Internal iliac nodes
Some to sacral
Where does lymph from the external cervical os drain?
Internal iliac nodes -> Superficial inguinal nodes
What is formed when the vas deferens and the duct from the seminal vesicle join?
Ejaculatory duct
Within what structure does the urethra meet the ejaculatory duct?
Prostate
What are the dimensions of the seminal vesicles?
5cm long
10-15cm long is uncoiled
What do the seminal vesicles secrete?
Liquid component of semen
Fructose
What part of the prostate is related to the neck of the bladder?
Base of prostate
What proportions of the prostate are glandular and fibromuscular?
2/3 glandular
1/3 fibromuscular
What surrounds the prostate?
Fibrous capsule
What is the structure of the anterior surface of the prostate?
Muscular
What is the posterior surface of the bladder related to?
Rectal ampulla
What is the inferolateral surface of the prostate related to?
Levator ani
What does the prostate produce?
Proteolytic enzymes
Acid phosphatase
What structures support the prostate?
Puboprostatic ligament (to pubic symphysis) Levatore prostatae
What is the venous drainage of the prostate?
Deep dorsal vein of penis -> Prostatic venous plexus -> Internal iliac vein
What is the arterial supply to the seminal vesicles?
Branches from:
- Inferior vesical arteries
- Middle rectal arteries
What is the arterial supply to the prostate?
Prostatic branches from:
- Internal iliac arteries
- Inferior vesical arteries
- Internal pudendal arteries
- Middle rectal arteries
What lobe of the prostate often enlarges most? What can this cause?
Middle lobe
Obstruction of internal urethral orifice
How does prostatic enlargement affect urination?
Impedes urination by distorting prostatic urethra
What are the symptoms of prostate enlargement?
Nocturia
Dysuria
Urgency
In what populations is prostatic enlargement most common?
Males older than 50 years
What is the lymphatic drainage of the seminal vesicles?
Upper parts -> External iliac
Lower parts -> Internal iliac
What is the lymphatic drainage of the prostate?
Internal iliac
What is the lymphatic drainage of the male urethra?
Prostatic part -> Internal iliac
Spongy part -> External iliac and deep inguinal (distally)
Membranous/Intermediate part -> External iliac
What is the lymphatic drainage of the testes?
Aortic nodes at root of testicular artery at L2
What is the lymphatic drainage of the skin of the penis and the scrotum?
Superficial inguinal
What structures form the urogenital triangle?
Lines from pubic symphysis to each ischial tuberosity and a line between the ischial tuberosities
What structures form the anal triangle?
Lines from coccyx to each ischial tuberosity and a line between the ischial tuberosities
What are the boundaries of the perineum?
Anteriorly - Pubic symphysis
Anterolaterally - Ischiopubic rami
Laterally - Ischial tuberosities
Posterolaterally - Sacrotuberous ligaments
Posteriorly - Inferiormost sacrum and coccyx
What structures form the anterior boundaries of the ischioanal (rectal) fossa?
Colles’ fascia
Inferior urogenital diaphragm
What structures form the lateral boundaries of the ischioanal (rectal) fossa?
Ischial tuberosity
Obturator internus
What structures form the medial boundaries of the ischioanal (rectal) fossa?
Levator ani
External anal sphincter
What structures form the posterior boundaries of the ischioanal (rectal) fossa?
Gluteus maximus
Sacrotuberous ligament
What structure forms the superior boundary of the ischioanal (rectal) fossa?
Levator ani
What structure forms the inferior boundary of the ischioanal (rectal) fossa?
Skin
What are the contents of the ischioanal fossae?
Branches of pudendal vessels and nerves:
- Inferior rectal nerve
- Inferior rectal artery and vein
Adipose tissue
What is the course of the anal canal?
From superior aspect of pelvic diaphragm
To anus
What parts of the anal canal does the internal anal sphincter surround?
Superior 2/3
What type of muscle is the internal anal sphincter and what nerves innervate it?
Smooth:
- SNS (maintains contraction)
- PNS (allows defaecation)
Where do the anal columns lie?
In the mucous membrane of the internal superior half of the anal canal
What is contained in the anal columns?
Terminal vessels of:
- Superior rectal artery
- Superior rectal vein
What lies at the superior ends of the anal columns?
Anorectal junction
What joins the anal columns at their inferior ends? What are these lying just inferior to?
Anal valves
Lying just inferior to the anal sinuses (secrete mucus to aid defaecation)