Reproduction 1 Flashcards
What structures make up the pelvic inlet?
The sacral promontory, ala of the sacrum, accurate line of the ilium, pecten pubis, pubic tubercle, pubic crest and pubic symphysis
What are the differences between the male and female pelvis?
Female pelvis is thin and light and the greater and lesser pelvis is shallow and wide - whereas male pelvis heavy and thick and narrow and deep
Pelvic inlet in females is oval-rounded, in males it is heart shaped
Subpubic angle is obtuse in females and acute in males
Pelvic outlet bigger in females
Females have a smaller acetabulum
What structures make up the pelvic outlet?
The inferior margin of the pubic symphysis, inferior rami of the pubic, sacrotuberous ligaments, tip of coccyx
Differentiate between the true and false pelvis.
True (lesser) pelvis is where the true pelvic organs are (bladder, ovaries, rectum etc.)
False (greater) pelvis consist of the ilia and provides support for the abdominal viscera, e.g. the intestines
What type of joint is the sacroiliac joint?
Synovial plane
What type of joint is the pubic symphysis?
Secondary cartilaginous
What is the anterior inferior wall of the pelvic cavity formed by?
Bodies and rami of the pubic bones and pubic symphysis
What muscle occupies the lateral wall of the pelvis?
Obturator internus
What muscle occupies the posterior wall of the pelvis?
Piriformis
What foramen does the obturator internus obscure?
Obturator foramen
What foramen does the obturator internus pass out from?
Lesser sciatic foramen
What foramen does the piriformis pass out from?
Greater sciatic foramen
What nerve plexus lies on the posterior wall of the pelvis (lying on top of piriformis)?
Sacral plexus
What are the two main branches of the sacral plexus?
Pudendal nerve (S2-4) and sciatic nerve (L4-S3)
Where do the femoral vessels line in the pelvis?
Anterior pelvic wall
What is the perineal body?
Fibromuscular mass in middle of perineum between anus and vagina
It is essential for the integrity of the pelvic floor
What muscles converge at the perineal body?
Bulbospongiosus, levator ani, external anal sphincter, superficial and deep transverse perineal muscles
What is the anococcygeal body?
Fibrous median raphe between the coccyx and anus
Composed of levator ani, external anal sphincter muscle fibres
What are the main parts of the pelvic diaphragm/floor?
Levator ani and cocygeus
Give two functions of the pelvic floor.
Support of abdominopelvic viscera (bladder, intestines, uterus…)
Urinary and faecal continence (sphincter action on rectum & urethra to resist increases in intraabdominal pressure during heavy lifting for e.g.)
What is the innervation of the pelvic floor?
Nerve to levator ani (branch of inferior rectal nerve) and coccygeal plexus
Injury to the pelvic floor can lead to what?
Urinary and faecal incontinence
Describe the course of the pudendal nerve.
Leaves the greater sciatic foramen and re-enters via the lesser sciatic foramen
Why might an episiotomy minimise long-term damage?
Doing 5 or 7o’clock episiotomy takes stress off of midline & perineal body which are most likely to rip during childbirth.
Midline/perineal body have very poor blood supply so healing would be poor and could lead to long term difficulties, e.g. with continence. Blood supply and therefore healing better with 5/7o’clock cut.
What structures may you feel during a digital PR examination?
M: prostate
F: cervix, tampon
Both: faeces, irregularities of the rectal wall/masses
Branches of the _________ arteries distribute blood to most of the pelvic organs, ,perineum, gluteal regions, expect testis, ovaries and upper part of the rectum.
Internal iliac arteries
Where do the superior and inferior vesicle arteries supply?
Bladder, seminal gland and prostate in males
Where do the uterine arteries supply?
Pelvic ureter, uterus, ligaments of uterus, uterine tube, upper vagina
Where do the gonadal arteries supply?
Testes/ovaries
Where does the superior rectal artery supply?
Upper rectum
Where do the middle and inferior rectal arteries supply?
Rectum and anal canal
Where does the vaginal artery supply?
Vagina and branches go to inferior part of bladder
Where does the internal pudendal artery supply?
Main artery to the perineum
Where does the obturator artery supply?
Pelvic muscles, ilium and femoral head
What arteries to pelvic organs come off of the internal iliac artery?
Superior and inferior vesical, uterine artery, middle and inferior rectal, internal pudendal and obturator arteries
What arteries to pelvic organs come off of the abdominal aorta?
Gonadal arteries
What arteries to pelvic organs come off of the uterine artery?
Vaginal artery
What artery to pelvic organs comes off of the inferior mesenteric artery?
Superior rectal artery
Venous drainage of pelvic structures involves which 5 veins?
Internal iliac veins, superior rectal veins, median sacral vein, gonadal veins, internal vertebral venous plexus
Which part of the rectum drains into the portal system?
Proximal rectum (drained by superior rectal vein which drains into inferior rectal vein)
What part of the rectum drains into the systemic circulation?
Middle and inferior rectum (middle and inferior rectal veins)
What is the significance of understanding the venous drainage of the rectum?
Site of portosystemic anastomosis which is susceptible to haemorrhoid formation
With which venous plexus does the prostatic venous plexus communicate with on its posterior side?
Internal vertebral venous plexus
What is the significance of the prostatic venous plexus draining into the internal vertebral venous plexus?
Root for metastasis of prostatic cancer (–> bone cancer)
What nerve supplies the skin of the root of the penis/labia?
Ilioinguinal nerve
Where does the ilioinguinal nerve originate?
L1
Where does the ilioinguinal nerve enter the inguinal canal?
At the superficial ring
Where does the genitofemoral nerve originate?
L1-2
What structures are supplied by the genital branch of the genitofemoral nerve?
Cremaster muscle and anterior scrotal skin
What is the cremaster muscle?
Flat muscle that covers the testis and spermatic cord
What is the importance of the genital branch of the genitofemoral nerve supplying the cremaster?
Supplies the motor portion of cremaster reflex
Cremaster reflex = contraction of cremaster when superomedial thigh touched
From which plexus does the pudendal nerve arise from?
Sacral plexus
What does the pudendal muscle innervate?
Skin and muscles of the perineum
From what segmental levels does the pudendal nerve arise?
S2-4
What bony landmarks are used when performing a pudendal nerve block during labour?
Ischial spines (pudendal nerve sits safely behind these)
What is the sympathetic nerve supply to the vas deferens, seminal vesicles and the epididymis?
L1, 2 via the hypogastric plexus
What is the sympathetic supply to the female genital tract?
Nerve fibres from the pelvic and ovarian plexuses
What is the parasympathetic supply to the female genital tract?
Fibres from splanchnic nerves (S2-4)
What is the parasympathetic supply to the female and male erectile tissues?
S2-4 via hypogastric plexus
What are erectile tissues?
Tissues that have large vascular spaces that can become engorged with blood
Corpus cavernosa, clitoris, bulbs of vestibule & (to lesser extent) corpus spongiosus (urethral patency)
Lymph from what structures drain into the external iliac lymph nodes?
Inguinal lymph nodes
Glans of penis, glans clitoris, membranous urethra, prostate, fundus of bladder, cervix, upper vagina,
ANTERIOR, SUPERIOR PELVIC ORGANS
Lymph from what structures drain into the internal iliac lymph nodes?
Gluteal region, deep perineum and inferior pelvic viscera
Lymph from what structures drain into the sacral lymph nodes?
Rectum and posterior wall mainly
POSTERIOR, INFERIOR PELVIC ORGANS
Lymph from what structures drain into the common iliac lymph nodes?
Drainage from the main three groups: external, internal and sacral lymph nodes
Reproductive organs can be split into which 3 groups?
- External genitalia
- Gonads
- Tube system
- Accessory (copulatory) glands
What are the male internal reproductive organs?
Testis, ductus deferens, seminal gland, prostate, epididymis, bulbourethral glands
Why are the testes located outside the abdominopelvic cavity?
Cooler temperature - spermatogenesis occurs optimally below body temperature
What are the layers of the inguinal canal and what abdominal muscle/fascia do these layers relate to?
Inner –> outer
Tunica albiunginae
Tunica vaginalis (peritoneum) - has visceral and parietal layer
Internal spermatic fascia (transversalis fascia)
Cremaster muscle and fascia (internal oblique muscle)
External spermatic fascia (external oblique muscle)
What are the main contents of the inguinal canal?
Ilioinguinal nerve
Genital branch of the genitofemoral nerve
Lymphatics and blood vessels
Vas deferens
What are the main contents of the spermatic cord?
Vas deferens, testicular artery, genital branch of the genitofmoral nerve
How are the testes suspended in the scrotum?
By the spermatic cord
What is the tunica albunginae?
Tough, outer fibrous layer of the testis, it encloses the testes and penetrates into the parenchyma of each testicle with diaphragms, dividing it into lobules
What are the two layers of the tunica vaginalis?
Parietal - covers internal spermatic fascia
Visceral - covers testis
What material is present between the two layers of the tunica vaginalis?
A small amount of serous fluid
What is a hydrocele?
Excess of fluid within the tunica vaginalis
Causes incl. trauma, idiopathic, tumour etc.
What is a haematocele?
Blood within the tunica vaginalis
At what vertebral level do the testicular arteries come off of the aorta?
L2
The testicular arteries travel retroperitoneally and cross two important structures near the pelvic brim before they go through the inguinal canal. What are these?
Ureters and inferior parts of external iliac arteries
What term is used for the 8-12 anastomosing veins associated with the testis?
Pampiniform plexus (formed by testicular veins emerging from the testes and epididymis)
What is the function of the veins in the pampiniform plexus?
Drainage of epididymis and testis
Also acts as a heat exchange mechanism to cool down blood to keep testes at a temperature more suitable for spermatogenesis
Into which veins do the testicular veins drain?
Right - IVC
Left - left renal vein
What is a variocele?
Pathological dilatation & increased tortuosity of the pampiniform plexus due to a blockage proximally of the spermatic veins
Which two lymph node groups receive lymph from the testis?
Right and left lumbar nodes and para-aortic lymph nodes
What is the vas deferens?
Muscular tube that arises from the tail of epididymis, transverses the inguinal canal, crossing over the external iliac vessels and terminates as it joins the seminal gland duct to form the ejaculatory duct
Where are the bulbourethral glands?
In the urogenital diaphragm
Where are the seminal glands?
Either side of posterior surface of bladder
What secretions are produced by the seminal vesicles?
A thick alkaline fluid that mixes with sperm as they pass the ejaculatory duct and urethra (main constituent of sperm)
Where is the prostate gland?
Fused to the neck of the bladder
Surrounds prostatic urethra
What secretions are produced by the prostate?
Prostatic fluid (slightly alkaline, milky fluid)
What is the structure of the prostate gland?
2/3rd gland, 1/3rd muscle surrounded by a dense fibrous capsule
What is PBH?
Benign Prostatic Hypertrophy
Enlargement of prostate leads to compression of urethra –> bladder outlet obstruction
What part of the urethra do the bulbourethral glands empty into?
Penile/spongey urethra (nb - ducts pass obliquely)
What secretions are produced by the bulbourethral glands?
Mucus like secretions
What lymph nodes drain lymph from the prostate?
Internal iliac & sacral
What lymph nodes drain lymph from the seminal vesicle?
Internal & external iliac
What lymph nodes drain lymph from the scrotum?
Superficial inguinal
What lymph nodes drain lymph from the penis?
Skin - superficial inguinal
Glans/distal spongey urethra - deep inguinal and external iliac
Cavernous bodies & proximal spongey urethra - internal iliac
What do the testes look like histologically?
Convoluted seminiferous tubules
4-8 layers of cells
Spermatozoa in the lumen
Leydig cells in the interstitial spaces between tubules
What does prostate look like histologically?
Serous alveoli with infolding epithelium Trabeculae of muscular stroma
Amorphous eosinophilic masses, called corpora amylacea in the alveoli of older men
What do seminal vesicles look like histologically?
No sperm in lumen
Highly recessed and irregular lumen forming crypts and giving honeycombed appearance
Well developed muscular externa
What does vas deferens look like histologically?
Lumen stellate shape
A thick walled muscular tube
Epithelial lining and its supporting lamina propria are thrown into longitudinal folds
