Anterior Abdominal Wall/ Inguinal Canal Flashcards
Basic Layers of the Anterior Abdominal Wall
(1) Skin
(2) Superficial Fascia
(3) Muscles
(4) Transversalis fascia
(5) Extrapertioneal connective tissue
(6) Peritoneum
The layers of the superificial fascia of the Anterior Abdominal wall, above the umbilicus. Below the umbilicus?
Above- only fat
Below (2 layers):
- The superficial fatty fascia [Fascia of Camper’s which is replaced by the subcutaneous Dartos muscle in the scrotum]
- The deep membranous fascia [Fascia of Scarpa’s which is continuous with the fascia of the perineum (Colles’ Facia)]
The Antero-Lateral Muscles of the Anterior Abdominal Wall
(3):
External Oblique
Internal Oblique
Transversus abdominis
The midline muscles of the Anterior Abdominal Wall
(3):
Rectus Abdominis
Pyramidalis
Cremaster Muscle
What innervates the Oblique muscles and the Transversus Abdominis
The Ventral Rami of the six inferior thoracic nerves + the first lumbar nerves (No lumbar nerves for the external oblique)
What innervates the Pyramidalis muscle?
Iliohypogastric nerve
What innervates Rectus Abdominis?
Ventral rami of the six inferior thoracic nerves
Derivation and insertion of the Cremaster muscle
Derived from the lower arched fibers of internal oblique. The muscle fibers descend on the spermatic cord to form loops around it.
Inserted into the Pubic Tubercle
Innervation of the Cremaster Muscle
The Genitofemoral Nerve
Function of the Cremaster Muscle
To suspend the Testes and to pull them closer to the body in cold temperature (Cremasteric Reflex)
What is the Rectus Sheath and what are its contents?
-An aponeurotic sheath formed by the fusion of the aponeuroses of the external oblique, internal oblique and transverse muscle of the abdomen.
CONTENTS:
- 2 Muscles (rectus abdominis, pyramidalis)
- 2 Vessels (superior and inferior epigastric vessels)
- Lower 6 intercostal nerves
The 3 lines which the Rectus Abdominis is related to
- Line Alba
- Linea Semilunaris
- Arcuate Line
What defines a Direct vs and Indirect Hernia
Direct- Exit abdominal wall medial to the INFERIOR EPIGASTRIC ARTERY via Hesselbech’s Triangle
Indirect- Exit abdominal wall lateral to the inferior epigastric artery, through the deep inguinal ring
Line Alba
Tendinous median raphe between the two rectus abdominis muscles, formed by the fusion of the aponeuroses of the external oblique, internal oblique and transverse abdominal muscles. Extends from the Xiphoid process to the pubic symphysis.
Linea Semilunaris
A curved line along the lateral border of the rectus abdominis
Arcuate line
Cresent-shaped line marking the inferior limit of the posterior layer of the rectus sheath. Anterior to that line, the inferior epigastric artery ascends to enter the sheath.
At 26 weeks, what process generally begins?
The descent of testicles from their position in the posterior abdominal wall to the deep inguinal rings. This change occurs as the fetal pelvis enlarges and the body or trunk of the embryo elongates
Gubernaculum Testis
A mesenchymal band that extends from the caudal part of the testis along the course of its descent in the inguinal canal. Functions like a rubberband, anchoring the testis to the scrotum and guiding its descent into the scrotum. Forms a path through the anterior abdominal wall for the processus vaginalis to follow during formation of the inguinal canal
Processus Vaginalis
An outpouching of the peritoneum which develops ventral to the gubernaculum
As the testis and ductus deferens descend, they are ensheathed by the fascial extensions of the abdominal wall. What are these extensions and what do they become?
- The extension of transversalis fascia becomes internal spermatic fascia
- The extension of internal oblique muscle becomes Cremasteric muscle
- The extension of external oblique aponeurosis becomes external spermatic fascia