Session 4 Flashcards
From what embryological structure is the scrotum derived from?
Labioscrotal folds
What three structures are contained within the scrotum?
Testis
Epididymis
First part of the spermatic cord
What name is given to the double layer of peritoneal membrane that surrounds the testis?
Tunica vaginalis
What name is given to the thick fibrous layer surrounding the testis?
Tunica albuginea
Where do the testes develop?
Within the mesonephric ridge
Which arteries supply blood to the testes and where do they arise?
Left and right testicular arteries
Branches of the abdominal aorta at the level of L2 (just inferior to the renal arteries)
Where do the left and right testicular veins drain?
Left: left renal vein
Right: IVC
Via which two structures does the epididymis connect to the seminiferous tubules?
Efferent ductules
Rete testis
What are the contents of the spermatic cord?
Testicular artery
Cremasteric artery
Artery of the vas deferens
Genital branch of the genitofemoral nerve
Cremasteric nerve
Sympathetic fibres
Vas deferens
Pampiniform plexus
Lymphatics
Describe the route of the spermatic cord.
From the deep inguinal ring, lateral to the inferior epigastric vessels
Via the inguinal canal and superficial inguinal ring
To the posterior bored of the testis
What is the pampiniform plexus and why is this clinically important?
A plexus of veins surrounding the testicular artery, draining into the testicular vein
This is a morphological adaptation that cools the blood entering the testis, helping to maintain the temperature of the gonads below that of the rest of the body
What are the different layers of the spermatic cord and from where do they derive?
External spermatic fascia (from the aponeurosis of external oblique) Cremasteric muscle and fascia (from internal oblique) Internal spermatic fascia (from the transversalis fascia) Tunica vaginalis (from the processus vaginalis)
What is a hydrocoele?
Serous fluid within the tunica vaginalis
What is a haematocoele?
Blood within the tunica vaginalis
What is a varicocoele?
Varicosities of the pampiniform plexus
What is a spermatocoele?
An epididymal cyst
What simple technique can be utilised in clinic to distinguish between fluid and solid (tumour) masses within the scrotum?
Transillumination
Describe the developmental basis of an indirect inguinal hernia.
Reopening of the processus vaginalis allowing for continuity between the peritoneal cavity (abdomen) and the tunica vaginalis (scrotum)
What is testicular torsion and what can occur as a consequence?
Twisting of the spermatic cord (usually just above the upper pole) leading to loss of blood supply and necrosis
How does innervation differ between the anterior and posterior/inferior surfaces of the testis?
Anterior: innervated by the lumbar plexus
Posterior/inferior: innervated by the sacral plexus
Describe the lymphatic drainage of the testis and scrotum and explain the distinction between the two.
Testis drain to paraaortic nodes
Scrotum drains to superficial inguinal nodes
Difference in lymphatic drainage due to difference in embryological origin
Describe the course of the vas (ductus) deferens?
Ascends in spermatic cord Traverses inguinal canal Tracks around pelvic side wall Passes between bladder and ureter Forms dilated ampulla Opens into ejaculatory duct
Where can the seminal vesicles be found anatomically?
Between the bladder and the rectum
What is the function of seminal vesicles?
Ejaculatory secretions (account for 70-80% volume of ejaculate)
The ejaculatory duct is formed by the merging of which two ducts?
Vas deferens
Duct of the seminal vesicle
Give two routes via which prostate malignancy can metastasise.
Via lymphatics (internal iliac and sacral nodes) Via venous system (internal vertebral plexus to the brain and vertebrae)
By what method can the prostate be easily examined?
Digital rectal examination (DRE)
Branches of which artery supply blood to the penis?
Internal pudendal arteries
What are the constituents of the internal structure of the penis?
Dorsally: pair of corpora cavernosa
Ventrally: corpus spongiosum
Which is the least distensible portion of the male urethra and why is this clinically relevant?
Membranous urethra
Most difficult portion to catheterise
What is the function of bulbospongiosus in the male perineum?
Helps expel the last drops of urine from the urethra
Helps maintain erection
What is the function of ischiocavernosus in the male perineum?
Compresses veins, helping to maintain erection
Which three structures make up the linea terminalis?
Arcuate line
Pectineal line
Pubic crest
Describe a “gynecoid” pelvis.
Round inlet Straight sidewalls Ischia spines not too prominent Well-rounded greater sciatic notch Well-curved sacrum Sub-pubic arch >90 degrees
What name is given to a pelvis that is “good”for childbirth?
Gynecoid
How is the obstetric conjugate measured?
From the sacral promontory to the midpoint of the pubic symphisis
How is the diagonal conjugate measured?
From the sacral promontory to the inferior border of the pubic symphisis
What name is given to the type of pelvis seen in the male?
Android
What two types of cells make up the epithelium of the seminiferous tubules?
Sertoli cells
Cells of germ cell lineage
Which cell type is responsible for forming the blood-testis barrier?
Sertoli cells
What hormone stimulates the activity of Sertoli cells and what do they secrete?
Sensitive to FSH
Secrete inhibin
As well as germ cells and Sertoli cells, what other cell type is found in the seminiferous tubules? What do they secrete?
Leydig cells
Testosterone
What type of neoplasm accounts for 90-95% of all testicular neoplasms?
Germ cell tumours (seminomas and teratomas)
Which structures merge within the prostate?
Ejaculatory ducts and the prostatic urethra
What structure is found at eh convergence of the seminiferous tubules?
Rete testis
What is the epithelial type of the rete testis?
Simple cuboidal
Describe the epithelium of the efferent ductules.
Characteristic ‘scalloped’ epithelium with cilia
By what mechanisms are sperm transported through the efferent ductules?
Ciliary action
Myoid contraction
Describe the histological appearance of the epididymis.
Smooth muscle tube lined by pseudostratified ciliated epithelium
Where do sperm reach maturation (i.e. become motile)?
Within the epididymis
Describe the histological appearance of the vas deferens.
Pseudostratified columnar epithelium
A longitudinal layer of smooth muscle
A circular layer of smooth muscle
A second longitudinal layer of smooth muscle
What is the function of the vas deferens?
Connect the epididymis to the ejaculatory duct
Its smooth muscle contracts powerfully during ejactulation
Describe the histological appearance of the seminal vesicle.
Secretory (columnar) epithelium
Smooth muscle layer
What type of nervous control stimulates the discharge of the contents of the seminal vesicle into the ejaculatory duct?
Sympathetic innervation
Which zone of the prostate is most commonly seen to be enlarged in benign prostatic hyperplasia (BPH)?
Transition zone
Which zone of the prostate is most commonly seen to be enlarged in prostatic carcinoma?
Peripheral zone
Why does BPH often present earlier than prostatic malignancy?
Enlargement of the transition zone of the prostate in BPH will obstruct the internal urethral orifice leading to early symptoms of dysuria, nocturia and urgency.
Enlargement of the peripheral zone of the prostate in malignancy is less likely to obstruct the internal urethral orifice, thus fewer, or no symptoms appear until later stages of the disease.
From the ovary to the uterus, what are the different sections of the Fallopian tube?
Fimbriae
Infundibulum
Ampulla
Isthmus
What are the two layers of the uterus?
Endometrium
Myometrium
What are the two layers of the endometrium?
Stratum functionalis
Stratum basalis
What are the two segments of the cervix and what are their corresponding epithelia?
Endocervical canal (mucus-secreting, simple columnar epithelium) Ectocervix (non-keratinised, stratified squamous epithelium)
At what point on the cervix is the squamocolumnar junction (SCJ) located?
SCJ can be located at any point across the cervix
What type of epithelium lines the vagina?
Non-keratinised, stratified squamous epithelium (glycogen-producing)
