GI Anatomy 5 Flashcards
What is the retropubic space?
Extraperitoneal space between the pubic symphisis and the bladder
What is the rectovesical pouch?
Extraperitoneal space between the rectum and the bladder in the male
What is the uterovesical pouch?
Extraperitoneal space between the uterus and the bladder in the female
What is the rectouterine pouch (pouch of Douglas)?
Extraperitoneal space between the rectum and the uterus
What is significant clinically about the rectouterine or rectovesical pouch?
Most inferior part of the abdominal cavity where pus collects due to gravity
To the level of what may a severely distended bladder extend?
The level of the umbilicus
What is suprapubic catheterisation and when may it be needed?
Catheterising the bladder through the anterior abdominal wall
May be necessary when the prostate is markedly large and a urethral catheter can’t be passed
What are the 4 surfaces of the bladder?
1) Fundus (superiorly)
2) Base (posteriorly)
3) 2 inferolateral surfaces
Where do the base and the inferolateral surfaces of the bladder meet and what exits the bladder at this point?
Meet at the neck of the bladder which leads to the urethra
What is the median umbilical ligament and how may it be identified?
From the apex of the bladder to the umbilicus, slender fibrous chord which is the obliterated remnant of a foetal structure the urachus. It produces a midline ridge of peritoneum on the anterior abdo wall inferior to the umbilicus
What forms the posterior relation of the bladder in females?
Uterus
Where do the ureters enter the pelvic inlet?
Anterior to the bifurcation of the common iliac, lateral to the base of the bladder
What is the trigone bounded by and what is significant about this part of the bladder wall?
Bounded by the 2 ureteric openings superolaterally and the urethral opening inferiorly
Rugae are absent here
Is the internal urethral sphincter under voluntary or involuntary control and what is it formed by?
Involuntary, formed by the circular arrangement of the detrusor muscle around the neck of the bladder
What is the detrusor muscle?
Network of smooth muscle fibres contained in the bladder wall
In males, which structure separates the bladder neck from the pelvic floor?
The prostate
What is the normal capacity of the bladder?
400-600ml
What is the blood supply to the bladder?
1) Superior aspect - superior vesical artery (from the root of the umbilical artery from the anterior trunk of the internal iliac)
2) Rest of the bladder - inferior vesical artery in men or vaginal artery in women (from the anterior trunk of the internal iliac)
What is the nerve supply to the bladder?
Vesical plexus, originates from the pelvic plexuses (inferior hypogastric plexuses) PS S2-S4, S L1-L3
What effect does PS have on the bladder?
Stimulate bladder contraction
What is the prostatic urethra and what empties into it?
Part of the urethra in the males which runs through the prostate, ejaculatory ducts open up into it
What is the urethral crest in males?
Longitudinal midline fold of mucosa in the prostatic urethra
How do secretions from the prostate reach the urethra?
Through the ejaculatory ducts which open into the prostatic urethra
Where does the prostatic venous plexus lie?
Plexus of veins that lies between the fibrous capsule and thick sheath derived from the pelvic fascia surrounding the prostate
How is clinical examination of the prostate carries out?
Rectal examination
What is the posterior midline sulcus of the prostate and when may it be obliterated?
Palpable midline sulcus in the prostate but may be obliterated in patients with prostatic enlargement
In which group is prostatic enlargement common?
Elderly
What is the most common symptom of benign prostatic enlargement?
Frequent need to urinate - puts pressure on bladder and urethra
Difficulty fully emptying the bladder - urinary outflow obstruction
How might the prostate be approached surgically without entering the peritoneal cavity?
Via the perineum, cut in the perineum
What what route does prostatic cancer sometimes spread to the verterbral column?
Via lymphatics, lymph nodes along internal iliacs and external iliac arteries - common iliac nodes - lateral aortic lumbar nodes - origin of thoracic duct at T12
Where does the vas deferans originate and where does it enter the abdomen?
Originates from the tail of the epididymis in the scrotum, enters through the superficial ring and then the deep inguinal ring
What is the final dilated part of the vas deferans called?
the ampulla
What does the ampulla of the vas deferans join with to form the ejaculatory duct?
Outlet of the seminal vesicles
What do the seminal vesicles produce?
Seminal fluid
70% of fluid in total containing fructose
What does the testes produce?
Spermatozoa
What part of semen does the prostate gland produce?
20% of the fluid containing acid phosphatase and proteolytic enzymes
What part of semen does the bulbourethral gland produce?
5% of it, mucoproteins
What is a vasectomy? Where along the course of the vas deferans is this carried out?
Surgical division of the ductus deferans, at the beginning, a portion of the scrotum is removed
What are the 3 parts of the uterus?
1) Fundus
2) Body
3) Cervix
The fundus of the uterus lies superiorly to what?
The entrance of the uterine tubes into the uterus
In which axis is the uterus flattened?
The uterus is flattened antero-posteriorly
Through what structures does the cervix open into the vagina and the body of the uterus?
1) Into the vagina = external os
2) Into the uterus = internal os
What are the 3 layers of the uterine wall and what is each made up of?
1) Epimetrium - outer serosal layer derived from peritoneum
2) Myometrium - smooth muscle
3) Endometrium - inner glandular layer which undergoes cyclic, hormone - driven thickening and breakdown
What are the normal and possible abnormal positions of the uterus?
1) Normal - uterus flexes over the bladder anteriorly
2) Retroverted - the uterus points superiorly abnormally
3) Retroflexed - the uterus flexs back on itself towards the rectum abnormally
What are fibroids and in which group are they common?
Benign tumours of muscular and fibrous tissue typically develop in the uterine wall - common in elderly women
What 4 ligaments provide mechanical support for the uterus and what can happen if these become weakened?
1) Cardinal ligament
2) Round ligament of the uterus
3) Pubocervical ligament
4) Uterine axis
Uterine prolapse
In which part of the uterine tube does fertilisation normally take place?
In the ampulla
The round ligament and the ovarian ligament are remnants of which embryological structure?
The gubernaculum which attaches the gonad to the labioscrotal swellings in the embryo
What is the course of the round ligament of the uterus?
Passes over the pelvic inlet to reach the deep inguinal ring, then courses through the inguinal canal to end in connective tissue related to the labium majus in the perineum
What is the relationship between the uterine artery and the ureter and why is this surgically important?
The ureter passes beneath the uterine artery (‘water under the bridge’) in the base of the broad ligament adjacent to the cervix.
This is surgically important as in a histerectomy the uterus and the uterine arteries are removed - the ureter is in danger of being accidentally damaged
By what is the ovary attached to the broad ligament?
Its attached to the posterior leaf of the broad ligament via a double layer of peritoneum called the mesovarium
By what is the ovary attached to the uterus?
The ligament of the ovary
In what do the ovarian artery and vein travel to the ovary?
Ovarian suspensory ligament `
Where do the ovarian arteries originate and what do they supply?
Originate from the abdominal aorta, supply the ovaries
Also anastamose with the uterine artery and enlarge significantly during pregnancy to augment uterine blood supply
Why might the anastamoses between the uterine and ovarian arteries be a problem in women who undergo uterine artery embolism to treat fibroids?
Could lead to increased pressure in/dilation of the ovarian arteries to provide a collateral blood supply to the uterus
Which nerve lies adjacent to the ovary on the lateral wall of the pelvis?
Obtruator nerve
Why might the relationship between the obtruator nerve and the ovary be useful in diagnosing ovarian cancer?
Ovarian tumour suppresses the obtruator nerve
Obtruator nerve provides sensation to upper leg and motor to leg
Symptoms of impingement = aching in the groin, inner thigh and knee, weakness of the leg, numbness of thigh, abnormal walking pattern
What is the fornix?
Gutter in the vagina around the cervix, have an anterior posterior and 2 lateral fornices
Posterior fornix is closely related to which part of the peritoneal cavity and why might this be useful?
Rectouterine pouch
Lowest part of peritoneal cavity where pus collects, can be palpated in vaginal examination, drained through the posterior fornix without entering the peritoneal cavity
What is the lymphatic drainage of the vagina and uterus?
Leave pelvic cavity superiorly and drain, via vessels that accompany the ovarian arteries, directly into lateral aortic or lumbar nodes, and in some cases the pre aortic nodes on the anterior surface of the aorta - continue to the origin of the thoracic duct at T12
Where does the rectum run from and too?
S3 to ano rectal junction
What is the difference in peritoneal attachment between the sigmoid colon and rectum?
Sigmoid colon = intraperitoneal = sigmoid mesocolon
Rectum = retroperitoneal
