Case 14 Flashcards
What is the clinical relevance of the rectovesical pouch?
It is the most inferior portion of the pelvic cavity where fluid from trauma is most likely to collect in males.
Describe the rectovesical pouch in males
It is a reflection of the pelvic peritoneum which dips behind the urinary bladder and rectum, and lines the back of the seminal vesicle and prostate.
Describe the clinical relevance of the pouch of Douglas (rectouterine pouch)
In females it is where fluid is most likely to collect e.g. from trauma
Describe the pelvic peritoneum in females
It starts from the superior border of pubic symphysis and continues over the urinary bladder, dips down into the vesicouterine recess and is reflected back up onto the funds and portion of the body of the uterus. It continues down the surface of the uterus to the posterior fornix. the pelvic basin of the rectouterine pouch, back onto the rectum and to the abdominal wall.
Identify the 7 branches of the anterior division of the internal iliac artery
- Umbilical → Superior vesicle (bladder, urethra)
- Obturator → Towards obturator foramen
- Inferior vesicle (Male) / Vaginal (Female)
- Uterine → Uterus, cervix, vagina, uterine tubes
- Middle Rectal → Rectum
- Inferior Gluteal → Gluteal Region
- Internal Pudendal → Perineum (deep to levator ani)
What arch attaches to and divides the obturator internus in 2?
The tendinous arch
What is located in the urogenital hiatus in females?
Urethra and vagina
What muscles make up the pelvic diapragm and pelvic floor?
Pelvic Diaphragm
Levator ani (iliococcygeus, pubococcygeous, puborectalis)
Ischiococcygeous
Pelvic wall
Piriformis
Obturator internus
What is the puborectalis?
The puborectalis forms a sling around the rectal junction to create the anorectal junction, unless undergoing defecation.
Describe the false greater pelvis
The false greater pelvis occurs from the iliac crest to the pelvic inlet and contains abdominal viscera, not pelvic.
Describe the true lesser pelvis and pelvic inlet
The true lesser pelvis occurs from the pelvic inlet to the pelvic outlet and contains the true pelvic viscera.
The pelvic inlet is where the pelvic cavity begins.
Describe the male pelvic viscera
Sperm travels into the pelvis from the testes through the ductus deferens along the bladder, underneath and into the prostate gland where it unites with the urethra. The male reproductive and urinary tracts merge, however in females they are completely separate.
The seminal vesicles sit behind the bladder and provide fluid for the sperm to travel within.
Main content – Distal Urinary, reproductive and digestive tracts
Describe the female pelvic viscera
The fundus is in front of the uterine tube. The fallopian (uterine) tubes and the ovaries are not directly connected. Fimbriae (cilia) help to guide the eggs into the fallopian tube where fertilisation occurs, avoiding oocyte entry into the abdominal cavity.
Describe the position of the uterus
The vaginal canal slopes posteriorly towards the rectum whilst the cervix and uterus curve anteriorly to sit over the bladder. The junction between the vagina and cervix is known as the angle of anteversion.
The junction between the cervix and uterus is known as the angle of anteflexion.
The opposite to anteflexed is retroflexed and the opposite to anteverted is retroverted. There is increased risk of prolapse with retroversion or retroflexion. Prolapse is where one or more of the organs in the pelvis slip down from their normal position ad bulge into the vagina.
Describe the ligaments in females
Suspensory ligament - ovarian vessels to pelvic walls
ovarian ligament - ovary to uterus
Round ligament - passes through the inguinal canal and attaches to the external genitalia
Describe the anal and urogenital triangle
The anal triangle and urogenital triangle are divided by an imaginary line between the ischial tuberosities.
The anal triangle contains the anal canal and external anal sphincter. It also contains a fat filled space with pudendal neurovasculature known as the ischio-anal fossae. It lies lateral to the anal canal.
The sacrotuberous ligament attaches the sacrum and the ischial tuberosities.
Contents of the male deep pouch
Urethra urethra sphincter bulbourethral glands deep transverse perineal muscle perineal neurovasculature
Contents of the female deep pouch
Urethra urethral sphincter vagina deep transverse perineal muscle perineal neurovasculature
Muscles in the male and female superficial pouch
Bulbospongiosis muscle covers the (corpus spongiosum)
Ischiocavernosus muscle covers the corpus cavernous
Superficial transverse perineum
Contents of the male superficial pouch
Penis - corpus spongiosusm contains the urethra
corpora cavernosa paired structures- crura attach to the ischiopbic rami
Scrotum containing the testes and spermatic cord (ductus deferens)
Contents of the female superficial pouch
Clitoris -
corpus spongiosum attached to the perineal membrane
Corpora cavernosa paired structures - crura attach to the ischiopubic rami
main pubis, labia major and minor
Describe the neurovasculature of the perineum
Pudendal nerve (S2-S4) - gives rise to the inferior rectal nerve and perineal nerve and its branches
Describe the blood supply of the perineum
Internal pudendal artery which is a branch of the anterior division of the internal iliac artery
Pelvic fistula and it’s causes
An abnormal connection via a tunnel-like hole between two epithelium-lined organs or vessels
Causes:
Obstructed/prolonged labour, severe inflammation due to infection, pelvic surgery, trauma
Prostate gland location and the 3 prostate glands
Superiorly - bladder
Inferiolaterally - levator ani
posteriorly - ampulla
anteriorly - pubic symphysis
- Inner periurethral glands (opens directly into urethra)
- Outer periurethral glands (ducts connect into urethra)
- Main prostatic/external glands
Pale columnar epithelium and as you move towards the urethra they become more cuboidal and transitional like the urethra
Gland Secretions - acid phosphatase, citric acid and amylase
Arterial supply and innervation of the prostate gland
Arterial supply:
Inferior vesicle artery
middle rectal artery
internal pudendal
Innervation:
Sympathetic fibres originating T12-L3
Parasympathetic fibres originating S2-S3
Functions of Sertoli cells
Located in the seminiferous tubules
Respond to FSH to cause spermatogenesis
1. Attachment and reattachment of sperm to cells - guide towards lumen
2. Provide nutrients
3. Tight junctions between cells - provide safe, immunological environment
4. Fluid secretions - flush immotile sperm
5. Phagocytosis of dead sperm and residual cytoplasm
Steroidogenesis
Testosterone precursors are covered to testosterone or DHT via 5a reductase. They either bind to peripheral targets (active - 2%) or SHBG/albumin to act as a reservoir (inactive - 98%).
Testosterone or testosterone pre cursors are converted to oestrogen via aromatase
HPT Axis
The hypothalamus secretes GnRH which acts on the anterior pituitary gland. This the secretes FSH to act on Sertoli cells and LH to act on leydig cells. Sertoli cells cause spermatogenesis and produce inhibin which inhibits FSH via negative feedback.
Leydig cells release testosterone to act on the seminiferous tubules and peripheral targets.
Describe spermatogenesis
Spermatocytogenesis
Meiotic divisions - 4 haploid spermatids
Spermiogenesis
1. Golgi coalesce to form the acrosome
2. Mitochondria align and form the mid piece of the tail
3. Sertoli cells remove residual cytoplasm to form immature immotile spermatozoa.
Maturation at the epididymis
Closure of acrosomal binding sites to prevent hyperactivity
Sperm becomes motile
Storage at ductus deferens (approx 2-3 months)
Describe the composition of semen
60% seminal vesicle - thick alkaline fluid
20% prostate - thin milky fluid (citrate, zinc, PSA)
10% Bulbourethral gland - mucus
Semen enters the ampulla and then travels through to the ejaculatory duct, through the penile urethra and then deposited into the vagina.
Clinical Reasoning of breast lump
Fibroadenoma (Breast Mouse)
Highly mobile, smooth, painless, benign lump
Common in early 20s
Fibrocystic Changes
Multiple, tender, painful, benign lumps
Due to hormonal changes in week before menstruation
Breast Cyst
Fluid filled, painful lump
Common in pre-menopausal women (30s-50s)
Breast Abscess
Fluid filled painful lump - clinically indistinguishable from cysts due to infective symptoms - hot, swollen
Fat necrosis
Painless lump, erythema/bruising due to trauma
Lipoma
Several benign lumps - well circumscribed, soft, smooth, lobulated non tender. Found in breasts, abdomen, neck commonly
Breast Cancer
Lump with skin changes - tethering, nipple discharge, eczematous changes.
Peau d’orange - indicates secondary metastatic spread
Benign (smooth, regular borders, mobile)
DCIS - ductal lump, nipple discharge
LCIS - Abnormal cells in lobule - asymptomatic
Malignant (hard, irregular, fixed, skin/nipple changes)
Inflammatory carcinoma - red, hot, swollen breasts
Paget’s disease - follicular, red, eczematous rash at nipple/areola with palpable nipple lump
Spread - direct to muscles, axillary spread, haematogenous
Breast Cancer modifiable and non-modifiable risk factors
Modifiable Increasing age large gap between menarche and menopause Female FH Radiation
Non modifiable Not breast feeding nulliparous/first child over 30 COCP/HRT obesity sedentary lifestyle
Breast Cancer Triple Assessment
Specialist examination
Mammogram>40, ultrasound<40
Fine needle aspiration
Chemotherapy
2,3,4 weekly cycles combination drugs which target multiple signalling pathways to reduce resistance and attack heterogenous tumours
Adjuvant - after surgery to reduce relapse risk
Neo-adjuvant - before surgery to increase operability
Metastatic - palliative treatment only
Side effects:
Alopecia/rashes
GI disturbances - mucosal linings - diarrhoea/constipation/nausea
BM - reduced erythrocytes, platelet, leukocytes = reduced clotting = anaemia
Non-targeted anti cancer drugs
Alkylating agents - cyclophosphamide
cross link alkyl groups of guanine which stops DNA replication
Platinum agents - cisplatin
DNA inter and intra strand cross links stops DNA replication
Antimetabolites - methotrexate
inhibit DHFR enzyme - stops nucleotide synthesis
Anthracyclines - doxorubin
Inhibit topoisomerase II enzyme - stops DNA reannealing
inhibits DNA helicase
produces a reactive O2 radical species
Antimicrotubule agents
Vinca alkaloids - vincristine - stops mitotic spindle formation
Texans - docetaxel - inhibits mitotic spindle contraction
Targeted Cancer Drugs
Hormone antagonists - Tamoxifen (SERM)
Competitive inhibitor of ERs, forms a tamoxifen:ER dimer, binds to DNA - unstable complex
Protein Kinase Inhibitors - imatinib
Inhibit kinase domains which form the proliferative fusion protein that allows unregulated tumour division
Cancer Immunotherapy
- Monoclonal antibodies
- Cancer Vaccines - HPV
- Immune checkpoint inhibitors - PD-1 antagonists - deactivate PD-1 receptors on T cells which tumours bind to to evade immune system
