Chapter 111 Testes, Epididymides and Scrotum Flashcards
Label the diagram
Where does the vas deferens (=ductus deferens) insert?
Prostatic urethra
What structures are contained in spermatic cord?
- Vas fererens (+ a. & v.)
- Testicular artery
- Pampiniform plexus
- Lymphatic vessels
- Nerves
- Cremaster muscle
What muscle is the cremaster muscle formed from?
Where does it insert
Internal abdominal oblique
Inserts on spermatic fascia and travels along external surface of parietal vaginal tunic
What is the arterial supply to the testicle?
And epididymis?
Testicular artery (from aorta at level of L4. ≈ovarian artery)
Ductus deferens artery (=branch of prostatic = branch of internal iliac. ≈vaginal artery)
Where do the R and L testicular veins drain into
R into CVC
L into L renal vein
List the 3 layers of the scrotum
Skin
Tunica dartos
Scrotal fascia
What is the name of the shiny white capsule covering testis?
Tunica albuginea
What is principal arterial supply to scrotum?
External pudendal (≈ vuvla)
What nerve supplies scrotum?
Pudendal
What 3 cell types form the seminiferous tubules?
Leydig/interstitial cells --> testosterone production. stimulated by LH (from anterior pituitary)
Sertoli cells –> support spermatozoa. Stimulated by FSH
Spermatogenic cells
What are the accessory sex glands in dogs?
And cats?
Dog = prostate
Cat = prostate + bulbourethral gland
Name a particular property of prostatic fluid and its function
Alkaline to support spermatozoa survival in acidic female reproductive tract
Name the fibrous connection that puls testis into scrotum
Gubernaculum
Name 5 features of scrotum that help maintain low temp:
- Thin scrotal skin
- Sparse hair (dogs)
- Abundant sweat glands
- Little sc fat
- Cremaster m. and tunica dratos can control proximity to body
- Pampiniform plexus -wrapped around artery–> countercurrent heat exchange
Compared with body temp, what should testicular temp be
2-3ºC lower
How can bilateral cryptorchid be differentiated from anorchid
- Imaging
- Ex-lap
- Testosterone concentration (give human chorionic gonadotrophin)
- Check for presence of penile spines in cats (they are testosterone dependent. Disappear 6 weeks after castration)
List 2 potential secondary complications of cryptorchid testicle
- Neoplasia
- Torsion
- (Concurrent congenital anomalies)
- (Urine spraying in cats)
What is incidence fo neoplasti transformation of retained testicle in dogs?
10%
unknown in cats
Increased rates of which 4 concurrent abnormalities have been noted in cryptorchid dogs?
- Hip dysplasia
- Patella lux
- Penile/prepuce defects
- Umbilical hernia
What is the name of the hyperechoic central linear structure seen on US of testis
Mediastinum testis
Give an example of each potential cause for orchitis/epididymitis
Bacterial
Viral
Fungal
Rickettsial
Bacterial: Brucella, Kleb
Viral: Distemper
Fungal: Rhodotorula glutinis
Rickettsial: Rocky Mountain spotted fever
List 3 primary tumours of testis. With what relative frequency do they occur?
How does frequency change if testicle is inguinal?
Leydig/interstitial cell
Sertoli (sustentacular) cell
Seminoma
Represented in near equal frequency
If inguinal testicle –> Sertoli cell and seminoma twice as likely vs abdominal cryptorchid)
What type of testicular tumour most commonly –> feminization?
Sertoli cell tumour
(but feminization also reporetd with leydig/interstitial cell tumour and seminomas)
Sertoli cells can also produce excess progesterone
What % of dogs with sertoli cell tumour present with feminization?
15-40%
Name 3 potential haematological changes that result from excesss oestrogen
Anaemia, leukopaenia, thrombocytopaenia
i.e. myelosuppression
Guarded prognosis if present
What is metastitic rate of sertoli cell tumour?
2.5 - 10%
What is metastitic rate for seminoma?
Sites?
6-11%
Epididymis, tunica albuginea, lungs, LNs
What paraneoplastic syndrome are Leydic (/intersitial) cell tumours associated with?
increased testosterone
–> perianal adenoma (37%)
–> perianal gland adenocarcinoma (9%)
–> perineal hernia (15%)
Metastatic testicular tumours rare. What type has been reported? where should you look for primary?
Adenocarcinoma
Primary in GI tarct
What hormonal change in sertoli cell tumours is thought to result in feminization?
Increase in oestradiol:testosterone ration
(rather than increase in peripheral oestradiol 17β)
List 10 ddx for testicular tumour
- Torsion
- Orchitis
- Epididymitis
- Scrotal hernia
- Haematoma
- Abcess
- Sperm granuloma
- Spermatocoele
- Varicoele
- Hydrocoele
What is incidence of bilateral involvement in:
Leyding/interstitial cell tumour
Sertoli cell tumour
Seminoma
Leyding/interstitial cell tumour 43%
Sertoli cell tumour 11%
Seminoma 18%
What is a hydrocoele
Fluid accumulation around testis
WHat may be cause ofa spermiostatic granuloma/cyst
Epididymal occlusion (congenital aplasia or aquired duct occlusion)
List 2 secondary scrotal neoplasms
Sertoli cell tumour
Leydig (/interstitial cell) tumour
How do caudal castration complication rates compare to prescrotal?
Similar
4% inflammation
2% scrotal swelling
Delayed (36-48h) post-op breeding has been reported in what % of greyhounds undergoing neutering?
26%
How soon after castration do dogs become aspermic?
5d
Up to 21d after vasectomy
Adv o no mating for 2 weeks warn re small risk
