Male pelvis Flashcards
What is the sacral promonotory and ala of the sacrum?
What is the arcuate line (OF THE ILIUM)?
(Not same as the arcuate line of the rectus sheath)
What is the pecten pubis also called?
Where is it located?
AKA Pectineal line
Ridge on the superior ramus of the pubic bone
Describe the location of the pubic crest.
What attaches here?
Medial to the pubic tubercle
Gives attachment to:
rectus abdominis
external oblique muscle
pyramidalis muscle.
What are the boundaries of the pelvic outlet
Anterior -> pubic symphysis
Anterolaterally -> pubic rami
Posteriolaterally -> sacrotubeorus ligaments
Posteriorly -> coccyx
Which parts of the pelvis are termed the true and false pelvis?
True below inlet
False above inlet
How do the greater and lesser pelvis (pelvis major and minor) differ in male and female?
Greater pelvis:
- Female: Shallow
- Male: Deep
Lesser Pelvis:
- Female: Wide and Shallow
- Male: Narrow and Deep
What is the shape of the pelvic inlet and outlet like in men and women?
Pelvic inlet:
- Female: Oval and rounded
- Male: heart shaped
Pelvic outlet:
- Female: Comparatively large
- Male: comparatively small
How does the subpubic angle differ between males and females?
Female: Obtuse
Male: Acute
How do the obturator foramens differ between men and women?
Females -> oval
Male -> round
How does the acetabulum differ in men and women?
Females -> small
Men -> large
What type of joints are the sacroiliac and pubic symphysis joints?
Sacroiliac joint -> synovial plane
Pubic symphysis -> secondary cartilaginous
What are the walls of the pelvic cavity?
- Antero-inferior wall
- (formed by the bodies and rami of the pubic bones and the pubic symphysis)
- Two lateral walls
- Posterior wall
Which muscle occupies the lateral pelvic wall?
Obturator internus
Which muscle is present on the posterior wall of the pelvis?
Piriformis
Which nerve network lies on the muscle forming the posterior wall of the pelvis?
Sciatic
What forms the pelvis floor?
Levator ani + ischiococcygeus
Levator ani = puborectalis, pubococcygeus, iliococcygeus
What is a raphe?
A groove in an organ or tissue
Marks the line where two halves fused in the embryo
What are the perineal and anococcygeal bodies?
Pernieal body -> firbomuscular mass that lies in the middle of the pernieal membarne that maintains the integrity of the pelvic floor
Anococygeal mass -> musculotendinous mass that lies between the coccyx and the anal canal
What is the function of the pelvic diaphragm/ floor
- Support of abdominopelvic viscera
- Resistance to increases in intra-abdominal pressure
- Urinary and fecal continence
What is the innervation of the pelvic diaphragm/ floor?
PUDENDAL NERVE
Damage to the pelvic floor during childbirth is common and potentially damaging.
Why?
Weakening of levator ani and pelvic fascia
This alters position of the neck of the bladder and urethra
Can cause urinary stress incontinence
What is an episiotomy and why does it minimise damage during childbirth?
Enlarges vaginal opening by cutting into muscular area between vagina and anus (perineum)
Usually medio-laterally
Reduces…
Excessive tearing of pelvic floor
Spread of tears
Name 3 parts of the alimentary system that are present in the pelvis
Rectum
Anal canal
Transverse colon
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except what?
Gonads (testes and ovaries)
Upper part of rectum
The venous drainage of the pelvis structures consists of which 5 different veins?
Internal iliac veins
Superior rectal veins
Median sacral vein
Gonadal veins
Internal vertebral venous plexus
Which part(s) of the rectum drain into the portal and systemic circulation?
Superior = portal
Middle and inferior = systemic
The veins along the sides and base of the prostate join to form the prostatic venous plexus.
With which venous plexus does the prostatic venous plexus communicate on its posterior side?
This drains into the internal vertebral venous plexus.
Cancer commonly spreads through this route from prostate to vertebral bodies
Which nerve supplies skin at the root of the penis in the male and the labia in the female?
Ilioinguinal nerve
What nerve root does the ilioinguinal nerve originate from?
L1
The ilioinguinal nerve enters the inguinal ring where?
Superficial inguinal ring
What is the nerve root of the genitofemoral nerve?
L1-L2
(genitofemoral nerve lies on the illiopsoas
The genitofemoral nerve enters the inguinal canal where?
Deep inguinal ring
What structures in the male are supplied by the genital branch of the genito-femoral nerve?
Anterior scrotum and cremaster muscle
What is the clinical significance of the loss of the genital branch of the genitofemoral nerve?
Cremaster reflex lost -> no temperature control of testes
What plexus does the pudendal nerve arise from?
Sacral plexus
What two muscles in the reproductive organs does the pudendal nerve supply?
Bulbospongiosus and ischiocavernosus muscles
From which segmental level(s) does the pudendal nerve arise?
S2-S4
How does the pudendal nerve travel from pelvis to perineum?
(why is it important to know this?)
Via the gluteal region
This arrangement is essential to understand in bilateral pudendal nerve block for pain relief during childbirth
What bony landmark do you look for when performing a pudendal nerve block during labour?
Ischial spine
Sympathetic fibres from L1-L2 travel via what plexus to supply the vas deferens, seminal vesicles, prostate and epididymis in the male?
Hypogastric plexus
What nerves supply sympahethic and parasympathetic innervation to the female genital tract?
Sympathetic -> pelvic and ovarian plexus
Parasympathetic -> pelvic splanchnic nerves (S2, S3 and S4)
What innervates erectile tissue in both male and female?
Parasympathetic fibres from S2, S3 and S4 via the hypogastric plexus
What forms erectile tissues?
Tissues with numerous vascular spaces that may become engorged with blood
Name the 4 primary node groups in the pelvis
Common iliac lymph nodes
External iliac lymph nodes
Internal iliac lymph nodes
Sacral lymph nodes
The external iliac lymph nodes drain what?
Inguinal lymph nodes
Adductor region of thigh
Superior part of the anterior and middle pelvic organs
The internal lymph nodes drain what?
Gluteal region
Deep perineum
Inferior pelvic viscera
What do the sacral lymph nodes drain?
Rectum
Posterior wall of pelvis
(posteroinferior pelvic viscera)
What do the common iliac lymph nodes drain?
external & internal iliac LNs
Sacral LNs
What 3 categories can the reproductive organs be grouped into?
- Gonads:
- Testes or ovaries
- Where gametes or sex cells are produced
- Site for the production of important sex hormones
- External genitalia
- Internal genitalia
- Tube system for conveying gametes
- Accessory glands which support the gametes and lubricate the copulatory organs
What is included in the male internal reproductive organs?
Testis
Vas deferens
Seminal glands
Prostate
Epididymis
Bulbourethral glands
In the male the gonads are located outside the abdominopelvic cavity, but remain intimately connected to the structures located there.
What purpose does this serve?
Temperature regulation
What are the main contents of the spermatic cord?
Vas deferens
Pampiniform plexus
Cremaster muscle
Testicular artery
Genitofemoral nerves
Lymphatics
The ovoid testes are suspended in the scrotum by what?
Spermatic cords
What is the tough outer fibrous layer of the testis?
Tunica albuginea
The tunica vaginalis is a peritoneal sac covering the testis.
What are the two layers of the tunica vaginalis?
Parietal and visceral
What material is present between the two layers of tunica vaginalis?
Fluid lubricating layers
Increase in blood between the two layers of tunica vaginalis is called what?
Haematocoele
What vertebral level fo the testicular arteries arise from the abdominal aorta?
L2
Name two important structures the testicular arteries pass near the pelvic brim before they travel through the inguinal canal
Ureters
Inferior parts of the external iliac arteries
What is the term used for the 8-12 anastomosing veins associated with the testis?
Pampiniform Venous Plexus
What is the function of the pampiniform venous plexus?
Venous return and temperature regulation of testes
Into which vein does the right and left testicular vein drain?
Right = IVC
Left = Left renal vein
Which two lymph node groups recieve lymph from the testis?
Right and left lumbar
Para-aortic lymph nodes
Describe the route of the vas deferens
arises from the tail of the epididymis
traverses the inguinal canal
enters the pelvis by crossing over the external iliac vessels.
Terminates by joining the duct of the seminal gland to form the ejaculatory duct
WHat secretions are produced by the seminal vesicles?
65-75% of seminal fluid
Thick alkaline fluid
(Rest produced by prostate)
What is the clinical significance of drainage from the prostatic venous plexus?
Gives passage to parasympathetic fibres
which give rise to the cavernous nerves that convey the fibres that cause penile erection
What are the Bulbourethral (Cowper’s) Glands?
These are small, paired structures located in the urogenital diaphragm which empty into the penile/ spongy urethra.
They produce mucus like secretions which enter the urethra during sexual arousal, contributing less than 1% of semen
What is the lymphatic drainage of the prostate?
Internal iliac and sacral nodes
What is the lymphatic drainage of the seminal vesicle?
External iliac
What is the lymphatic drainage of the scrotum?
Superficial inguinal
What is the lymphatic drainage of the penis?
Superficial and deep inguinal
What are the histological features of the testes (seminiferous tubules)?
Convoluted tubules sectioned in various planes.
4-8 layers of cells.
Spermatozoa in the lumen.
Leydig cells in the interstitial spaces between tubules
What are the histological features of the prostate?
Serous aveloi with infolding epithelium.
Trabeculae of muscular stroma
Amorphous eosinophilic masses, called corpora amylacea, in the elveoli in older men
What are the histological features of the seminal vesicle?
No sperms in the lumen
Highly recessed and irregular lumen forming crypts and cavities giving a honey combed appearances
Well developed muscular externa
What are the histological features of the ductus deferens?
Lumen Stellate in shape
A thick walled muscular tube
Epithelial lining and its supporting lamina propria are thrown into longitudinal folds
What imaging is this and what is it showing
USS
Shows the testes (right) and epididymis
What is this imaging and what is it showing
USS of testes
Yes there is a mass in it but who gives a fuck
What imaging is this and what are the arrows pointing to
MRI
Green -> Bladder
Orange -> seminal vescile
Blue -> anal canal
What image is this and what is the arrow pointing to
MRI
Prostate
What is the function of the crmaster and dartos muscles?
Thermoregulation of the testes
What is this and label 1, 2 & 3
Speramtic cord
1- Internal spermatic fascia
2- cremaster muscle
3- External spermatic fascia
What is number 8
Tunica albuginea
Why is the left testicular cancer more dangerous than the right?
As the left testicual (gonadal) vein drains into the left renal vein, so the cancer can spread to the kidenys more easily
What are the fluids secreted by the prostate, seminal vesciles and bulbourethral galnds
Prostate -> liquid rich in citric acid and proteolytic enzymes (lquifies coagulated semen)
Seminal vesicle -> thicc alkaline fluid that contains fructose, prostaglandins, fibrinogen and Vit. C
Bulbourethral glands -> Mucous like secretions during sexual arousal (pre-cum)
What prostatic fluid contains
Fructose
Vit. C
Fibrinogen
Prostaglandins
What are the sympathetic (L1-L2) and parasymapthetic (S2-S4) responses for sexual activivity in a man
(erection, emission, ejaculation, emission)
Erection -> parasympathetic
Emission -> sympahetic
Ejaculation -> paraympathetic & sympathetic
Remission -> sympathetic
For ejaculation:
Parasympathetic -> contraction of external uertheral sphincter
Symaphetic - contraction of internal urethral sphincter
What does the inguinal canal contain
Ilio-ingunial nerves
Inguninal LN
Spermatic cord
Spermatic cord contains
Genito-femoral nerve
Testicular artery
Vas deferens
Panpiniform plexus
Cremaster muscle
How do the gonadal arteries travel
Retroperitoneally
