Exam #4: Inguinal Canal Flashcards
Why are the testes outside of the body?
1) Sperm production is more effective at lower temperatures
2) Sperm are “re-activated” by entering a warm enviornment
Describe the layers of the fascia & muscles surrounding the testes from inside to outside.
- Tunica Albugenia
- Visceral Layer of the Tunica Vaginalis
- Parietal Layer of Tunica Vaginalis
- Internal Spermatic Fascia
- Cremaster Muscle & Fascia
- External Spermatic Fascia
- Dartos Fascia
What is the tunica albugenia?
Tough white fibrous covering on the testicle
Where are sperm formed?
Seminiferous tubules
Where are sperm stored?
Epididymis
What carries sperm from the epididymis to the urethra?
Ductus (vas) Deferens
Describe the path that sperm takes from the seminiferous tubules to the penis.
- Seminiferous tubules
- Straight tubules
- Rete testes
- Efferent ductules
- Epididymis (head, body, & tail)
- Ductus Deferens (Vas Deferens)
- Urethra
- Penis
What fascial layer forms the deep ring?
Transversalis fascia
What fascial layer forms the superficial ring?
External oblique fascia
What three abdominal muscle layers form the arches of the inguinal canal? Which are pierced by the spermatic cord & which is not?
- Transversus abdominus (NOT pierced by the spermatic cord)
- Internal oblique
- External oblique
Developmentally, what pulls the testis through the body wall?
Gubernaculum
What does the parietal peritoneum become in the spermatic cord?
Tunica vaginalis
What does the transversalis fascia become in the spermatic cord?
Inner spermatic fascia
What does the transversus abdominus become in the spermatic cord?
Nothing
What does the internal oblique become in the spermatic cord?
Cremasteric muscle & fascia
What does the external oblique become in the spermatic cord?
External spermatic fascia
What does Scarpa’s fascia become in the spermatic cord?
Dartos muscle & fascia
What does Camper’s fascia become in the spermatic cord?
Nothing
What does the skin of the abdominal wall become?
Skin of the scrotum
What are the borders of the inguinal canal?
- Anterior= aponeurosis of external oblique m.
- Floor= inguinal ligament (from external oblique)
- Floor Medially= lacunar ligament
- Posteriorly= trasnversalis fascia
- Posterior Medially= conjoint tendon (fused aponeurosis of the internal oblique & tranverse abdominis)
How do the functions of the cremaster muscle & dartos muscle differ?
Cremaster m.= pulls testicles into body
Dartos m.= wrinkles the scrotum
What artery oxygenates the testicles? What artery does it branch from?
Testicular artery, a branch off the aorta
What artery oxygenates the cremaster m.? What artery does it branch from?
Cremaster artery, a branch off the inferior epigastric artery
What artery oxygenates the ductus deferens? What artery does it branch from?
Ductus deferens artery, a branch off the inferior vesicular artery
What is the pampiniform plexus?
Venous network formed by ~12 veins that functions to cool the blood in the testicles (counter-current heat exchange)
What nerve innervates the pyramidalis m.?
Subcostal (T12)
What nerve innervates the cremaster m.?
Genital branch of the genitofemoral nerve
What nerve innervates the dartos m.?
Sympathetics running with the ilioinguinal & posterior scrotal nerves
What artery is homologous to the Testicular Artery, which is present in females? Does this artery pass through the inguinal canal?
Ovarian Artery; NO
What is the difference between the right & left testicular veins?
Right drains into the IVC
Left drains into the left renal artery
In females, what does the gubernaculum become?
Cranially= ovarian ligament Caudally= round ligament
Describe the formation of the inguinal canal in males.
- Begins during the 7th week of development
- Projection of parietal peritoneum called the processus vaginalis begins to invaginate through the body wall next to the gubernaculum
- As the body grows, the gubernaculum is pulled down
- 8th month, testicle is starting into the inguinal canal but the scrotum is empty
- 9th month, testicles descend into the scrotum
Direct Hernia
- Hernia through an acquired weakening in the body wall
- Through Hasselbach’s triangle
- Goes through superficial ring but NOT into spermatic cord
Indirect Hernia
- Hernia through weak processes vaginalis INTO spermatic cord
- More common in younger males
Femoral Hernia
Hernia below the inguinal ligament where the femoral vessels push through
Hydrocele/ Hematocele
Serous fluid or blood build up in the tunica vaginalis
Sebaceous cyst
General condition of cyst within the epidermis; often related to infection of a hair follicle
Spermatocele
Cyst within the head of the epididymis; patient may confuse for testicular cancer
Cryptorchidism
Failure of testes to properly descend; more common in premature babies (9th month descent of testicles)
Monorchidism
Single testicle
Polyorchidism
More than 2 testicles
Ectopic testes
Testes that deviate from the normal path & lodge somewhere in the abdominal cavity
Vasectomy
Vas Deferens is cut & can be tied or not
