Repro - male repro and pelvis osteology Flashcards
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?
Scrotal ligament
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:
- Testes-> pampiniform venous plexus -> right testicular vein-> IVC
- 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:
Neurovascular: 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 2. Lymphatics
What are the coverings of the spermatic cord from superficial to deep? What are their origins in the anterolateral abdominal wall?
- External spermatic fascia - aponeurosis of external oblique
- Cremasteric muscle and fascia - internal oblique and transversalis
- Internal spermatic fascia - transversalis fascia
- 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:
Urethral sphincter
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:
Levator ani
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.