Flashcards in Repro - male repro and pelvis osteology Deck (85):
What is the scrotum?
A cutaneous fibro-muscular sac for the testes and associated structures. It is situated posteriorinferior to the penis and inferior the pubic symphysis.
What divides the scrotum into two compartments - one for each testis?
Septum of the scrotum
Describe the regions the tests descends through and at what times in embryological development?
Starts - Mesonephric ridge (upper lumbar regions, at lower pole of kidneys)
3 months - reach the iliac fossa
7 months - travel through the injuinal canal
8 months - reach the external ring
9 months - enter the scrotum
What is the gubernaculum attached to in a male embryo?
Tethers testis to labioscrotal folds (genital swelling-> scrotum)
How is the processus vaginalis formed?
A musculo-fascial layer evaginates into the scrotum as it develops, together with the peritoneum to form the processus vaginalis.
What is the name of the vestigal remenant of the gubernaculum in males?
What is the arterial blood supply to the testis?
Testicular arteries - arise just inferior to the renal arteries from the abdominal aorta.
Describe the course of the testicular arteries from their origin at the abdominal aorta to the testis:
Arise just inferior to the renal arteries and pass retroperitoneally and cross over the ureters and the inferior part of the external iliac arteries to reach the deep inguinal rings. The arteries then pass through the inguinal canal, emerging through the superficial inguinal rings and enter the spermatic cords.
Describe the two routes that venous flow from the testis can take:
1. Testes-> pampiniform venous plexus -> right testicular vein-> IVC
2. Testes-> pampiniform venous plexus -> left testicular vein -> left renal vein
How does vasculature help to thermoregulate the testis?
The paminiform plexus wraps itself around the testicual arteries and acts as a heat exchanger with the testicular arteries -> arterial blood cooling down before it reaches the testis and venous blood warming up before it enters the testicular veins.
Where is the epididymis located?
Superior and posterolateral surface of the testis.
What are the main functions of the epididymis?
Sperm transport, maturation and storage.
Describe the movement of sperm through the sections of the epididymis and what happens to them there:
During their passage from head->body-> tail of the epididymis they undergo structural maturation and become motile - capabilities that are essential for their successful fertilisation. They are then stored in the tail segment until ejaculation.
What nerve plexi supply the scotum?
Lumbar and sacral plexi
What nerve plexi supply the testis and epididymis?
Testicular plexus - network derived from renal and aortic plexi.
Where does lymph from the testis drain?
Into the paraaortic nodes.
Where does lymph from the scrotum drain?
Into the superficial inguinal nodes.
What is the main function of the vas deferens?
Transport sperm rapidly to the prostatic urethra.
What happens to the vas deferens during ejaculation?
Rich autonomic innervation of the smooth muscle fibres of the vas deferens permits rapid contractions, which propel the tube's contents towards the ejaculatory ducts.
What happens to the ejaculatory duct and the duct of the seminal vesicles during ejaculation?
They dilate to facilitate the passage of the sperm and the seminal gland secretions, into the prostatic urethra.
Describe the passage of the vas deferens from the tail of the epididymis to the prostatic urethra:
It ascends in the spermatic cord, transverses the inguinal canal, tracks around the pelvic side wall, passes between the bladder and the ureter, behind the bladder before forming a dilated ampulla and opening into the ejaculatory duct which then enters the prostate to joint the prostatic urethra.
Describe the passage of the spermatic cord:
It runs from the deep inguinal ring (lateral to the inferior epigastric vessels) to the posterior border of the testis via the inguinal canal and superficial inguinal ring.
What are the neurovascular and duct system structures that the spermatic cord contains:
1. Testicular arteries
2. Pampiniform plexus
3. Cremasteric arteries
4. Artery to Vas
5. Genital branch of the genitofemoral nerve
Duct system structures:
1. Vas deferens
What are the coverings of the spermatic cord from superficial to deep? What are their origins in the anterolateral abdominal wall?
1. External spermatic fascia - aponeurosis of external oblique
2. Cremasteric muscle and fascia - internal oblique and transversalis
3. Internal spermatic fascia - transversalis fascia
4. Processus vaginalis
What is the difference between the processus vaginalis and tunica vaginalis?
The processus vaginalis is an embryological outpouching of the parietal peritoneum. The tunica vaginallis is a remnant of the embryological processus vaginalis which creates a serous covering for the testis.
Where are the seminal vesicles located?
These two glands are located posterior to the prostate, between the bladder and the rectum.
What does the gland body of the seminal vesicles consist of?
A highly convoluted tube which joints the ampulla of the vas deferens to from the ejaculatory duct.
What is the location of the prostate gland?
It surrounds the urethra at its origin from the bladder.
Name the structure that the base of the prostate has an anatomical relationship with:
Neck of the bladder
Name the structure that the apex of the prostate has an anatomical relationship with:
urethral sphincter and deep perineal muscles
Name the structure that the musclular anterior surface of the prostate has an anatomical relationship with:
Name the structure that the posterior surface of the prostate has an anatomical relationship with:
Ampulla of rectum
Name the structure that the inferior-lateral surface of the prostate has an anatomical relationship with:
Describe the structure of the prostate:
It is surrounded by a fibro-muscular capsule from which branching septae divide it into numerous small, but separate, compound alveolar glands from which excretory ducts originate and open independently into the prostatic urethra. The septae are characterised by discrete bundles of smooth muscle fibres interweaving with the connective tissues.
What do prostatic secretions contain?
Prostaglandins, proteolytic enzymes and citric acid.
Where are the bulbourethral glands located?
Posterior and lateral to the membranous portion of the urethra at the base of the penis, between the two layers of the fascia of the urogenital diaphragm, in the deep perineal pouch. They are enclosed by transverse fibers of the sphincter urethrae muscle.
Describe the structure of the bulbourethral glands:
Contain tubular and alveolar-type glands.
What is the function of the bulbourethral glands?
They secrete a clear water secretion, rich in mucins, just prior to ejaculation, that may lubricate the distal urethra, and neutralize acidic urine which remains in urethra.
What are the three main sections of the penis:
Root, body and glans.
What is the arterial blood supply to the penis?
Branches of the internal pudenal arteries.
(Abdominal aorta-> common iliac -> internal iliac -> anterior division of internal iliac -> internal pudenal artery)
Describe the venous drainage of the penis:
blood from cavernous spaces drains into -> venous plexus of the penis -> deep dorsal veins of the penis -> prostatic venous plexus -> internal iliac vein -> IVC
What is the function of the bulbospongiosus muscle?
Helps to expel the last drops of urine and maintain erections (prevents urethra from being compressed during an erection and pulsatile emission of semen during ejaculation).
What is the function of the pair of ischiocavernosus muscle?
Compresses veins, therefore helps maintain erections.
Describe the different sections of the male urethra:
1. Pre-prostatic: very short, neck of the bladder
3. Membranous: passes through perineum and pelvic floor
4. Spongy (or penile)
Which part of the urethra is at greatest risk of trauma?
The membranous portion as it is the least distensible - greatest at risk of trauma in catheterisation.
What is a hydrocoele?
Serous fluid accumulating in the tunica vaginalis
What is a haematocoele?
Blood collecting in the tunica vaginalis
What is a varicocoele?
Varicosities of the pampiniform plexus
What is a spermatocoele?
Retention cyst within the epididymis, aka an epididymal cyst.
What is epididymitis?
Inflammation of the epididymitis.
Describe the passage of an indirect inguinal hernia:
Through the deep inguinal ring (lateral to the inferior epigastric vessels) and into the inguinal canal.
What are the potential consequences of an indirect inguinal hernia on the tunica vaginalis?
Reopening of the processus vaginalis potentially can give continuity between the peritoneal cavity and the tunica vaginalis.
What is testicular torsion?
It is twisting of the spermatic cord - usually just above the upper pole of the testis. This gives the risk of testicular necrosis due to constriction of vasculature in the spermatic cord.
What is benign prostatic hyperplasia? Where in the prostate is it most likely to affect?
It is a benign increase in the size of the prostate which occurs mainyl in the central zone of the prostate.
What can be consequences of benign prostatic hyperplasia?
Due to the central zone's proximity to the urethra, it can cause: dysuria, nocturia and urgency.
Where do prostatic malignancies occur mainly?
In the peripheral zone of the prostate.
What is the clinical significance of the location of the prostate where prostatic malignancies tend to occur?
The peripheral zone is further away from the central zone (zone affected by benign prostatic hyperplasia), therefore the malignancies need to get very large before they compress the urethra and cause symptoms. These malignancies therefore present late.
Where do prostatic malignancies metastasise via the lymphatic route?
Internal iliac and sacral nodes.
Where do prostatic malignancies metastasise via the venous route?
Internal vertebral plexus. From there they can metastasise to vertebrae and the brain.
What blood test is used to help diagnose a prostatic disorder?
Prostatic-specific Antigen (PSA) is produced normally by the prostate and is often elevated in prostatic disorders. This is one of a range of tests that is used to assess and differentiate between prostate hyperplasia, prostatitis and carcinoma.
How can the prostate be examined?
It can be examined via Digital Rectal Examination (DRE) - this exploits the close anatomical relation between the prostate and the rectum.
Which three bones make up the pelvic girdle?
Ilium, ischium and pubis
What makes up the sacrum?
It is formed from the fusion 5 originally separate sacral vertebrae.
Where do the pelvic bones articulate with each other?
Where do the pelvic bones articular with sacrum?
What does the sacrospinous ligament attach?
The ischial spine to the coccyx and sacrium.
What does the sacrotuberous ligament attach?
Sacrum and coccyx to ischial tuberosity.
How does the general structure of the female pelvis differ from that of a male's?
Females' is thinner and lighter
How does the greater pelvis of the female pelvis differ from that of a male's?
How does the lesser pelvis of the female pelvis differ from that of a male's?
Male - narrow and deep, tapering
Female - wide and shallow, cyclindrical
How does the pelvic inlet of the female pelvis differ from that of a male's?
Male - heart-shaped, narrow
Female - oval and rounded, wide
How does the pelvic outlet of the female pelvis differ from that of a male's?
Females' comparatively larger
How does the Pubic arch and subpubic angle of the female pelvis differ from that of a male's?
It is wider (>80 rather than
How does the obturator foramen of the female pelvis differ from that of a male's?
Oval rather than round
How does the acetabulum of the female pelvis differ from that of a male's?
Smaller than males'
How does the greater sciatic notch of the female pelvis differ from that of a male's?
Almost 90 degrees compared to ~70 degrees (narrower) in the males - males' look like an inverted V.
What is a 'good' pelvis for childbirth?
Round inlet, straight side walls, ischial spines not too prominent, well-rounded greater sciatic notch, well-curved sacrum (to fit foetal head), sub-pubic arch >90 degrees.
What forms the pelvic inlet?
Posteriorly - promontory and ala of sacrum
Anteriorly - Right and left linea terminalis (arculate lines of inner ilium, pectineal line of pubis and pubic crest)
What does the clinical assessment of the pelvic inlet, 'anatomic conjugate' mean?
Measurement from the sacral promontory to the superior border of the pubic symphysis
What is the sacral promontory?
Prominent anterior edge of the first sacral vertebrae - palpable on posterior of the vagina.
What does the clinical assessment of the pelvic inlet, 'obstetric conjugate' mean? What is its significance?
Measured from the sacral promontory to the midpoint of the pubic symphysis. This is the minimum diameter of the pelvic canal (as this is where the pubic bone is thickest). Can be measured by X-ray.
What does the clinical assessment of the pelvic inlet, 'diagonal conjugate' mean?
Measured from the sacral promontory to the inferior border of the pubic sympthysis.
What are the borders of the pelvic outlet?
Anteriorly - pubic arch
Laterally -ischial tuberosities
Posterolaterally - inferior margin of sacrotuberous ligaments
Posteriorly - tip of coccyx
How is the pelvic outlet enlarged during pregnancy?
The posterolateral border of the pelvic outlet is made up of the sacrotuberous ligament which is softened by progesterone during pregnancy,