L34: Inguinal Region and Spermatic Cord Flashcards
(33 cards)
Reason testes are held outside body cavity?
- ) Lower temp = more effective sperm production
2. ) Sperm is activated when moved from cooler to warmer conditions in female repro tract
Layers of the testes
- inner layer = tunica albuginea
- outer layer = tunica vaginalis
Where in the testes is sperm formed?
- Seminiferous tubules
Pathway of sperm to vas/ductus deferens
- Seminiferous tubules
- Straight tubules
- Rete testes
- Efferent ductules
- Epididymis (head, body, tail)
Layers of spermatic cord and abdominal wall derivatives
- ) Skin = skin of scrotum
- ) Camper’s fascia = (not present)
- ) Scarpa’s fascia = Dartos muscle and fascia
- ) External oblique m. = external spermatic fascia
- ) Internal oblique m. = cremasteric muscle and fascia
- ) Transversus abdominis m. = (not present)
- ) Transversalis fascia = inner spermatic fascia
- ) Parietal peritoneum = tunica vaginalis of testes, not layer of spermatic cord
Is the transversus abdominis muscle part of the spermatic cord? What layer?
- Not part of the spermatic cord
Contents of inguinal canal in females
- Round ligament
Origin of cremasteric muscle
- Internal oblique muscle
Origin of Dartos muscle
- Scarpa’s fascia
Contents of inguinal canal in males
- Ductus deferens
- Vessels (testicular a, cremasteric a, ductus deferens a, pampiniform plexus v)
- Nerves (genital branch of genitofemoral, sympathetics with testicular a and ductus, sympathetics with ilioinguinal and posterior scrotal, parasympathetics from pelvic splanchnics with ductus deferens)
- Lymphatics
- Vestige of processus vaginalis
Innervation of cremasteric muscle
- Genital branch of genitofemoral nerve
Function of cremasteric and Dartos muscles
- Dartos: wrinkling of scrotum to reduce surface area and therefore heat loss
- Cremaster: elevation of scrotum to bring testes closer to body to reduce heat loss
Where to palpate the inguinal rings?
- Superficial ring is on lateral edge of pubis
- Deep ring is half way between superficial ring and ASIS
3 arches present in inguinal canal
- Transversus abdominis (not pierced)
- Internal oblique
- External oblique
What forms the deep and superficial rings of the inguinal canal?
- Deep ring = transversalis fascia
- Superficial ring = external oblique m
Borders of inguinal canal
- Anteriorly: aponeurosis of external oblique
- Posteriorly: transversalis fascia
- Posterior medially: conjoint tendon
- Floor: inguinal ligament
- Floor medially: lacunar ligament
Innervation of pyramidalis muscle
- Subcostal (T12)
Vasculature of testicles
- testicular artery (off aorta)
Vasculature to cremaster muscle
- cremasteric artery (from inferior epigastric a, which comes off external iliac a)
Vasculature to ductus deferens
- ductus deferens artery (from inferior vesicular a, from internal iliac artery)
Venous drainage of testicles/spermatic cord and pathway
- Pampiniform plexus, converge as left/right testicular veins
- Right testicular vein directly onto IVC
- Left testicular vein directly onto left renal vein
Scrotal branch of ilioinguinal branch runs within the spermatic cord – true / false
- False, outside, but within inguinal canal
Describe embryological descent of ovaries and testes and formation of inguinal canal
- Gubernaculum (ligamentous structure) attaches the ovaries/testes to scrotal/labial folds. This structures courses through the abdominal wall, marking future site of inguinal canal
- 7th week: projection of parietal peritoneum (processus vaginalis) invaginates through body wall next to gubernaculum. This continues til the 9th month just until before birth. Meanwhile, as body grows, testes move along gubernaculum towards scrotum. Ovaries stop descent short of pelvic brim
Remnant of gubernaculum in adult males and females
- In males: upper part degenerates, lower part tethers testis to scrotum (scrotal ligament)
- In females: upper part as ovarian ligament, lower part as round ligament
