Welcome to my video tutorial on boundaries of inguinal canal. We will consider the right sided inguinal canal to understand its boundaries. Imagine a box as right sided inguinal canal.
Here it's medial side towards pubic symphysis and here it's lateral side towards anterior superior iliac spine. So the box has four walls, anterior wall, posterior wall, roof and floor. The arrow indicates here the direction of inguinal canal which is downwards, forwards and medially. Let's look into the anterior wall.
It shows a deficiency towards medially known as superficial inguinal ring. The details of which we will consider in further slides. So the rest of the anterior wall is made up of external oblique aponeurosis throughout its length and lateral one third of it reinforced by fleshy fibers of internal oblique muscle which lies deeper in plane.
So these two major structures form the anterior wall apart from skin and superficial fascia. Posterior wall, like the anterior wall, it also shows an opening but towards the lateral side, known as deep inguinal ring. The rest of the wall is formed by transversalis fascia throughout its length and medial one third of it reinforced by conjoined tendon, which is formed by the fusion of aponeuritic layers of transversus abdominis and internal oblique muscles.
So, these two major structures form the posterior wall, fasciae transversalis and conjoined tendon. The inguinal rings are nothing but the opening seen in the inguinal canal. The superficial inguinal ring seen on the anterior wall whereas the deep inguinal ring seen on the posterior wall.
These rings allow few major structures to pass through the inguinal canal from abdominal cavity towards the external genitalia and vice versa. These structures are spermatic cord in males and round ligament of uterus in females. Let's look into the roof. It is formed by the arched fibers of transversus abdominis and internal oblique muscles.
It is completely fleshy. The internal oblique fleshy fibers after forming the anterior wall they arch over the inguinal canal accompanying the fleshy fibers of transversus abdominis. So the roof is formed by arched fleshy fibers of these two muscles.
They connect the anterior and posterior walls from lateral to medial side. Where they are converted into their aponeuritic layers and fuse with each other to form conjoined tendon. And the conjoined tendon forms a part of posterior wall of inguinal canal. Lastly, the floor is formed by inguinal ligament with its upper curved or concave surface.
Inguinal ligament is nothing but the lower interned portion of external oblique aponeurosis, which extends from anterior spine to anterior spine. superior iliac spine towards pubic tubercle but only the medial half of inguinal ligament forms the floor of inguinal canal. Inguinal ligament internally continues with the fascia transversalis so that external oblique aponeurosis, inguinal ligament upper curved surface and fascia transversalis they together form a continuous boundary for inguinal canal.
Let's quickly revise the boundaries on dissected right inguinal canal. Here is the right-sided inguinal region. Here is the inguinal ligament, which is nothing but the modification of external oblique aponeurosis.
It extends from anterior superior iliac spine towards pubic tubercle. Its medial half forms the floor of inguinal canal. Internally, the inguinal ligament continues with fascia transversalis, which forms the posterior wall of inguinal canal. Towards medially, the posterior wall is supported by conjoined tendon.
Let's see the roof. It is formed by the arched fleshy fibers of transversus abdominis here, which lies deeper in plane. It is supported by fleshy fibers of internal oblique muscle superficially which also forms the lateral part of anterior wall. After forming the roof both the muscles become aponeurotic fuse with each other to form conjoined tendon which gets attached to pectin pubis.
Anterior wall is formed by aponeurosis of external oblique muscle throughout its length. Medially it shows a deficiency, an opening called superficial inguinal ring, which is bounded by aponeuritic fibers called as cruric, inferior crust and superior crust. They gets attached to pubic tubercle and pubic crest respectively.
So here it is the right sided inguinal canal occupying the middle half of the inguinal region roofed by arched fleshy fibers of transversus abdominis and internal oblique muscles. Floor is formed by middle half of inguinal ligament. So it extends between superficial and deep inguinal rings.
The canal allows the passage of few major structures which enter or leave the abdominal cavity. They are spermatic cord in males. round ligament of uterus in females. So that is all about the boundaries of inguinal canal with the concept of a box between two openings.
Thanks for watching.