# data[].attributes.body
The duodenum is a secondarily retroperitoneal organ. Except for the very first part, which is intraperitoneal, most of the duodenum is fused to the posterior abdominal wall. Because of this, only its anterior surface is covered by peritoneum, while the posterior surface is fixed. The duodenum lies just distal to the stomach, curves around the head of the pancreas, and then continues into the jejunum. This position makes it relatively immobile and closely related to the pancreas and biliary ducts in imaging.

# data[].attributes.body
The spleen is an intraperitoneal organ, lying posterior and lateral to the stomach, inferior to the diaphragm, and anterior to the left kidney. It is almost completely covered by visceral peritoneum, except at the hilum, where vessles enter and exit. Peritoneum reflects off the spleen to form gastrosplenic ligament, which connects it to the greater curvature of the stomach.

# data[].attributes.body
The abdominal muscle that I chose is the external oblique. The external oblique is the outermost of the abdominal muscles. It's superficial to the internal oblique, and it forms the lateral part of the abdominal wall. Moreover, its fibers run inferiorly (downward) and medially (inward) toward the linea alba. Also, the external oblique attaches superiorly on the iliac crest of the hip bone. Functionally, it helps flex the trunk and works with the rectus abdominis to create functional stability.

# data[].attributes.body
The Liver is an intraperitoneal organ and it's supported by: -the Faciform Ligament which anchors the Liver anteriorly. It divides theliver into Right and left halves

-the round ligament, which is a free-form of the Faciform ligament, attaches the liver to the remnants of the umbilicus anteriorly

-and the coronary ligament which attaches the liver superiorly to the diaphragm.

# data[].attributes.body
The rectus abdominis is deep to the external oblique and more anteriormedial than the Psoas muscle. External oblique, internal oblique and rectus abdominis aids in TRUNK FLEXION. The right and left sides are connected medially my the Linea Alba.

# data[].attributes.body
So many spaces and areas I never knew about. The deeper we dive into the abdomen, although it’s a lot of knowledge, the more it makes sense and I can combine my knowledge from other areas into this. We have the skin than the external oblique-internal oblique, transverse abdominus- rectus abdominus

which is decided by the lines Albee

Superior to the actuate line, On the posterior part of rectus sheath, It’s formed by the aponeuroses of the internal oblique as well as transversus abdominis but inferior to the actuate line the posterior recuts sheath is absent so it’s weaker and leads to hernias

# data[].attributes.body
The rectus abdominis is a crucial muscle involved in maintaining core stability. It primarily serves the function of trunk flexion, and aids in increasing intra-abdominal pressure. The anterior rectus sheath is one example of fascia that lies anterior/superficial to the rectus abdominis. It is a fibrous covering made up of aponeuroses serving as a form of support and protection to muscles. The quadratus lumborum is an example of a muscle that lies posterior and lateral to the rectus abdominis. It serves the purpose of allowing for lateral trunk flexion.

# data[].attributes.body
Pancreas is a retroperitoneal organ (behind the peritoneum). Pancreatic head is situated between duodenum on the right and Spleen on the left (pancreatic tail). The body of the pancreas is situated anterior to the head and the tail of the pancreas. Being a retroperitoneal organ, it is protected from blunt trauma. However, this can make it difficult in cases where surgery is required for pancreatic pathology (i.e. Tumors of Pancreatic head).

# data[].attributes.body
The appendix is an intraperitoneal organ. Both the anterior and posterior surfaces are covered by visceral peritoneum. It is suspended by the mesoappendix.

Clinical connection: Inflammation or rupture of the appendix can spread within the peritoneal cavity.

# data[].attributes.body
1. Camper's fascia

-Superficial fatty layer of the superficial fascia.

2. Scarpa's fascia

-Deeper membranous layer of the superficial fascia.

3. External oblique muscle

- run inferomedially ("hands in pockets" direction).

-Its aponeurosis contributes to the anterior rectus sheath.

4. Internal oblique muscle

-Fibres run superomedially, perpendicular to external oblique.

-Contributes to both anterior and posterior rectus sheaths (above arcuate line).

5. Transversus abdominis muscle

-Fibres run horizontally.

-Contributes to posterior rectus sheath (above arcuate line).

6. Transversalis fascia

-Thin, fibrous membrane deep to the transversus abdominis.

7. Extraperitoneal fat

-Loose connective tissue with fat.

8. Parietal peritoneum

-The innermost serous membrane lining the abdominal cavity

# data[].attributes.body
Transverse Abdominis - Spatial relationships

It is the deepest of the flat muscles of the abdomen and is located anterolateral. It is deep or posterior to the internal oblique and is superficial or anterior to the transversalis fascia. It is one of the only abdomen muscles that has its fibers run transverse in direction around the abdomen. Clinical Connection: When it is not activated properly it can result in lower back pain and instability. Lower back pain after walking or standing for long periods can be due to a weak transverse abdominis.

Transversus abdominis. Physiopedia. (n.d.). https://www.physio-pedia.com/Transversus_Abdominis

# data[].attributes.body
From Superficial to Deep (above the arcuate line)

1. Skin

2. Superficial Facia

3. External Oblique

4. Internal Oblique

5. Transverse abdominis

6. Rectus sheath

7. Rectus abdominis

8. Rectus sheath

9. Transversalis fascia

10. Parietal peritoneum

From Superficial to Deep (below the arcuate line)

1. Skin

2. Superficial Facia

3. External Oblique

4. Internal Oblique

5. Transverse abdominis

6. Rectus sheath

7. Rectus abdominis

8. Transversalis fascia

9. Parietal peritoneum

The arcuate line is about midway between the umbilicus and the pubis symphysis. Superior to this line the rectus sheath is present both anterior and posterior to the rectus abdominis. The rectus abdominis is sandwiched between the rectus sheath. Inferior to this arcuate line the rectus sheath is not present posteriorly, rather it is only present anteriorly. This means the rectus abdominis lies on the transversalis fascia and that makes it a weaker posterior abdomen wall that has higher chances for herniation.

# data[].attributes.body
The organ I chose is the ureter. It is a retroperitoneal organ, meaning it lies posterior to the parietal peritoneum. The peritoneum is anterior to the ureter. The ureter is not suspended by a mesentery and has no peritoneal ligaments because it is embedded in the connective tissue of the retroperitoneal space.

# data[].attributes.body
The external oblique is situated on the lateral and anterior parts of the abdomen. It is superficial to internal oblique and superior to the leg muscle. It is also anterior to ribs deep to it. It is the most superficial between it, internal oblique and transversus abdominis. Fun fact is that the trasnversus abdominis is the 6-pack muscle :)

# data[].attributes.body
The order from superficial to deep is shown in the two sketches:

1. ﻿﻿﻿Skin

2. ﻿﻿﻿Superficial fascia

3. ﻿﻿﻿Camper's Fascia

4. ﻿﻿﻿Scarpa's fascia

5. ﻿﻿﻿External Oblique

6. ﻿﻿﻿Internal Oblique

7. ﻿﻿﻿Transversus Abdominis

8. ﻿﻿﻿Transversalis Fascia

9. ﻿﻿﻿Extra Peritoneal Fascia

10. ﻿﻿﻿﻿Parietal Peritoneum

An interesting idea is that the transversus abdominis is named for its fibers directions (horizontal)

# data[].attributes.body
The transverse abdominus is deep to the internal oblique and is superficial to the rectus abdominus muscle!

# data[].attributes.body
Understanding the accurate line is important as it is a weakness in the abdominal wall. This is a site where hernias are typically found; it is also a spot where the abdominal flap harvests are collected

# data[].attributes.body
The external oblique is the largest of the abdominal muscles. It is the most superficial abdominal muscle, lateral and anterior. Directly deep to to the external oblique is the rectus abdominis and internal oblique.

The function of the external oblique is to provide support to the core, twist and bend the torso, maintain pressure within the abdominal cavity to support the spine and aid in breathing

# data[].attributes.body
The rectus abdominis help with spinal flexion and posture. It is deep to the external obliques, and is enclosed by the rectus sheath. It is divided and located laterally to the linea alba but medially to the external and internal obliques. Together, they create intra abdominal pressure to stabilize the lumbar spine during movement.

# data[].attributes.body
The transverse abdominis is a deep muscle with its muscle fibres running horizontally. This muscle is located deep to the internal oblique and rectus abdominis muscles. The muscle fibers of the transverse abdominis end in an aponeurosis that contributes to the rectus sheath and inserts into the linea alba, which is medial to the transverse abdominis and extends from the sternum to the pubic bone. The transverse abdominis muscle provides significant core stability through tensing of the abdominal wall. It compresses the abdominal organs, which helps maintain intra-abdominal pressure.

# data[].attributes.body
The organ I chose is the Spleen.

The spleen is Intraperitoneal, this means it is surrounded by the peritoneum. From the anterior surface the spleen is adjacent to the stomach

# data[].attributes.body
The Internal Oblique is superficial to the transversus abdominis, which this, the transversus abdominis lies deep to the rectus abdominis helping to create a recuts stealth over it from the each obliques layer.

# data[].attributes.body
The superficial to deep order of the abdominal wall muscles & fibres.

Starting with the superficial layers we have the Superficial fascia which is connective tissue, than the campers fascia which is a fatty layer (brings protection), after that we have the scarpas fascia which supports both connective tissue and the fatty layer. Than we have our External Oblique the superficial layer that has fibers run down and inward, our middle layer is the internal oblique which our fibers run perpendicular to the external fibers, after this layer we have our transversus abdominis known as the deep layer which fibers are horizontal. With our Transverse fascia it lines the abdominal wall. This leads us to our Parietal peritoneum..

# data[].attributes.body
The abdominal organ I chose is the spleen. The spleen is an intraperitoneal organ as it is almost completely surrounded by visceral peritoneum. The exception is the hilum of the spleen, where vessels and ligaments enter and exit. Due to the spleen being intraperitoneal, the spleen is held within the peritoneal cavity and has significantly more mobility when compared to retroperitoneal organs. In relation to some other organs, the spleen is posterior to the stomach and lateral to the left kidney. There are two ligaments that are connected to the spleen, the gastrosplenic and the splenorenal ligament, which are part of the greater omentum. The gastrosplenic connects the spleen to the stomach and lies anterior to the hilum of the spleen. The splenorenal ligament connects the spleen to the left kidney and lies posterior to the spleen's hilum.

# data[].attributes.body
The muscle I choose is the internal oblique muscle. It is a middle layer muscle of the lateral abdominal wall, running superiorly and medially, while aiding in trunk movement. The internal oblique muscle is superior and superficial to the iliac crest, part of the origin of the muscle. The inferior epigastric artery is posterior to the internal oblique muscle.

# data[].attributes.body
The abdominal wall is structured into several distinct muscular layers, which vary based on whether it is viewed from an anterior or posterior perspective.

The lateral abdominal wall consists of three muscles arranged from superficial to deep: the external oblique, internal oblique, and the transversus abdominis. Each of these muscles turns medially into an aponeurosis. The aponeuroses then meet to create the rectus sheath, which encloses the rectus abdominis. The rectus abdominis is a paired muscle, aligned vertically, and is located on either side of the midline. The rectus abdominis is separated by the linea alba.

The posterior abdominal wall consists of two muscles: the quadratus lumborum and the psoas major. The quadratus lumborum is the most superficial layer beginning at the iliac crest running up to about the 12th rib. Deep to the quadratus lumborum lies the psoas major, which extends downward from the lumbar spine to the pelvis.

An important feature is the arcuate line, which represents a transition point in the structure of the rectus sheath. It is typically located midway between the umbilicus and the pubic symphysis. Above the arcuate line, the rectus abdominis is surrounded both anteriorly and posteriorly by layers of aponeurosis, offering reinforced structural support. Below the arcuate line, however, all three aponeuroses pass anterior to the rectus abdominis, leaving only the transversalis fascia and the parietal peritoneum posteriorly. This results in a thinner and weaker posterior wall in the lower abdomen, which has important clinical implications, particularly regarding the increased risk of abdominal wall herniation in this region,

# data[].attributes.body
The kidneys are a retroperitoneal organ. it is classified as retroperitoneal because it sits behind or posterior to the peritoneum. the kidneys lie on the outside of the peritoneum but is still indirectly connected by the perirenal fascia and other connective tissues as well as the layer of perirenal fat. collectively these all help support and keep the kidneys in place. The kidneys are not attached to any mesenteries like the intraperitoneal organs are. the renal fascia acts as a road way or tunnel so that vessels, nerves ex... can enter and exit the kidneys even while being on the outside of the intraperitoneal space.

# data[].attributes.body
The rectus abdominus is a vertical muscle that sits at the front of the abdomen. it lies superficial to the transverse abdominus. The rectus abdominus lies inferior to the xiphoid process and superior to the pubic bone. the rectus abdominus is split into two by the linea alba and lies laterally to the linea alba .

# data[].attributes.body
The most superficial of the abdominal muscles is the external obliques which is the largest of the 3 flat muscles and lies lateral/anterior. Next is the internal obliques which lies deeper to the external obliques followed by the transverse abdominus. The rectus abdominus is medial and extends across the whole length of the front of the abdomen. the rectus abdominus is separated down the middle by a band of fibrinous connective tissue and is enclosed in a rectus sheath made from the aponeurosis of the external and internal obliques and the transverse abdominus. deeper to this you have the transversalis fascia and then the parietal peritoneum.

The Arcuate lies halfway between the umbilicus and the pubis synthesis and is located in the lower portion of the rectus sheath. Above the line there is both anterior and posterior layers making this portion of the wall stronger and better anchored while below the line there is not that anterior and posterior support. below the line the anterior portion has the aponeurosis for support but does not posteriorly making this area weaker and more prone. to herniation

# data[].attributes.body
The pancreas is a secondary retroperitoneal organ, meaning the organ began intraperitoneal but became retroperitoneal later in development.

Retroperitoneal organs are located posteriorly to the peritoneum, so the organ is covered by the parietal peritoneum on the anterior side and is attached to the abdominal wall posteriorly along with its mesentery.

It is located within the anterior pararenal space between the anterior renal fascia and posterior peritoneum.

# data[].attributes.body
This weakness can lead to hernias, particularly when increased abdominal pressure is present. For example, from pregnancy, obesity, or poor surgical closure.

# data[].attributes.body
The internal oblique is also deep to the external oblique.

# data[].attributes.body
The Stomach:

The stomach is an intraperitoneal organ. The visceral peritoneal completely wraps the stomach making in intraperitoneal.

The lesser omentum attaches the stomach to the superior liver while the greater omentum attaches the stomach to the inferior transverse colon.

# data[].attributes.body
The rectus abdominus is midline. It is a vertical muscle and the most superficial of the abdominal muscles.

The rectus abdominus is lateral to the linea alba. The linea alba separates the rectus abdominus into two equal sections.

The transverse abdominus is a horizontal muscle compared to the rectus abdominus, which is vertical.

# data[].attributes.body
I think this image is a great representation of the layers of the anterior abdominal wall. (Citation in caption)

Changes Above Vs. Below Arcuate Line:

1) The rectus sheath is present above the arcuate line and is absent below the arcuate line.

2) The aponeuroses of the external and internal obliques and transverse abdominus are anterior and posterior above the arcuate line while the aponeuroses of these muscles are only anterior below the arcuate line.

# data[].attributes.body
The liver is an intraperitoneal organ of the abdomen. This means it is completely surrounded by the peritoneum, making it more anchored. The ligaments associated with the live include the round ligament, falciform ligament, and coronary ligament. The liver is suspended by them to attach to the diaphragm and abdominal wall. It is adjacent to the diaphragm and stomach.

# data[].attributes.body
The rectus abdominis is deep to the external oblique and is a bilateral muscle. It is inferior to the xiphoid process, but superior to the pubic symphysis.

# data[].attributes.body
The abdominal wall consists of 4 muscle. The most superficial are the external obliques located lateral and anterior to the abdomen. Deep to them are the internal obliques, that are smaller and thinner. The rectus abdominis is deep relative to the external obliques and extends the length of the front of the abdomen. The most internal muscle is the transverse abdominis, deep to the internal obliques.

The linea alba is the vertical line running medially through the abdomen separating the rectus abdominis muscle. Midway from the umbilicus and pubis is the arcuate line, acting as a transition point. Above it are the anterior and posterior aspects of the rectus sheath, strengthening and anchoring the abdominal wall. Below it only has anterior support, making it a weaker area more prone to herniation.

# data[].attributes.body
The internal oblique is positioned lateral and superficial to the rectus abdominis. As well as inferiorly to the diaphragm.

The internal oblique aids in lateral trunk flexion as well as load distribution, and prevents the body from spinal strain.

# data[].attributes.body
In an anterior view of the abdominal wall, the most superficial muscle of the lateral wall(s) is the external oblique, just deep to that is the internal oblique, and deep to that is the transversus abdominis. Each of these three muscles consist of an aponeurosis, which together form the rectus sheath that encases the rectus abdominis. The rectus abdominis is deep to the external and internal obliques, and medial to the transverse abdominis.

In a posterior view of the abdominal wall, the quadratus lumborum is the most superficial layer, deep to that is the psoas major and then the psoas minor.

Above the arcuate line, the rectus abdominis is covered by the rectus sheath and superficial muscles anteriorly, and posteriorly. Below the arcuate line, the rectus abdominis is covered anteriorly by the aponeuroses of the external oblique, internal oblique and transverse abdominis, however, posteriorly it's only 'protection' is the transversalis fascia and the peritoneum making this area more prone to herniation.

# data[].attributes.body
The transverse colon is classified as an intraperitoneal organ because the visceral peritoneum surrounds its anterior and posterior surfaces. It connects to the superior greater curvature of the stomach. Positioned superior to the ileum, the transverse colon is located posterior to the jejunum. Additionally, it lies inferior to the stomach and anterior to the small intestine.

# data[].attributes.body
The abdominal organ that I chose is the stomach. The stomach is an intraperitoneal organ. This is because it is completely surrounded by peritoneum, making it more visible and anchored. The stomach is covered by peritoneum on both the anterior and posterior surface. The stomach is suspended by the greater omentum from its greater curve to connect the stomach with the spleen and transverse colon. The stomach is also suspended by the lesser omentum from its lesser curve to attach to the liver.

# data[].attributes.body
The abdominal muscle I chose is the external oblique. The external oblique is superficial to the internal oblique muscle. It is also lateral to the rectus abdominis.

# data[].attributes.body
The Abdominal Wall:

1. Skin

2. Superficial fascia (camper's and scarpa's)

3. External Oblique

4. Internal Oblique

5. Transversus abdominis

6. Transversalis fascia

7. Extraperitoneal fat

8. Parietal peritoneum

A change I noticed above and below the arcuate line is that above the arcuate line the rectus abdominis is covered anteriorly and posteriorly. This creates a stronger posterior wall. Whereas below the arcuate line, it is only covered by an anterior sheath. This makes the abdominal wall weaker and the body more prone to herniations.

# data[].attributes.body
The External Oblique is superior to the Internal Oblique and is situated on the lateral and anterior part of the abdomen.

Clinical connection: The External Oblique compresses the abdomen and bends the spine. It's also the largest and most superficial of the three abdominal muscles.

Also, if the External Oblique is weak or has an injury, it can affect coughing.

# data[].attributes.body
Abdominal Wall

1. Skin

2. Superficial fascia

3. Camper's Fascia

4. Scarpa's fascia

5. External Oblique

6. Internal Oblique

7. Transversus Abdominis

8. Transversalis Fascia

9. Extra Peritoneal Fascia

10. Parietal Peritoneum

The difference between the muscles above and below the Arcuate line is that the abdominal wall below the Arcuate line is weaker, making it prone to hernias.

# data[].attributes.body
The kidneys are an abdominal organ which is considered to be retroperitoneal. This is because the organ is partially surrounded by the peritoneum. Additionally, the kidneys are posterior to the peritoneum, making them more anchored and less variable.The kidneys are suspended by the renal fascia. Adjacent to the right kidneys is the Hepatorenal recess (pouch of Morison), as discussed in our lectures!

# data[].attributes.body
One abdominal muscle we have discussed is the rectus abdominis. Superiorly and slightly medially to the rectus abdominis, is the sternum, a bone in the thoracic cage. Deeper than the rectus abdominis is another muscle, the psoas major. Some sections of the psoas major muscle, the inferior end, extend more laterally than the rectus abdominis.

# data[].attributes.body
he abdominal muscles that we have learnt about thus far have multiple different layers from superficial to deep. The external oblique muscle is the most superficial layer. The internal oblique is deeper than the external oblique, it is a middle layer. The rectus abdominis is located medially, and is deep relative to the external oblique. The transverse abdominis is the most internal layer, and deepest of these muscles. Discussing fascia, the linea alba is the vertical line of the abdomen, located medially and separating the rectus abdominis muscles. The arcuate line is a transitional point midway between the umbilicus and pubis. Above the arcuate there are both anterior and posterior layers on the rectus sheath, thus providing the abdominal wall with strength and anchoring it effectively. Below the arcuate line however, there is only anterior support, making things below the line weaker and more prone to herniation.

# data[].attributes.body
Choose one abdominal organ and explain whether it is intraperitoneal, retroperitoneal, or secondarily retroperitoneal.
Then describe how the peritoneum relates to that organ—which surfaces are covered, and what structures (like ligaments or mesenteries) are connected to it? Use directional terms like posterior to, suspended by, or adjacent to in your description.

Reply to at least one peer’s post

Ask a follow-up question

Add a detail or clinical connection

Offer a helpful clarification or encouragement

# data[].attributes.body
Choose one of the abdominal muscles (external oblique, internal oblique, transversus abdominis, rectus abdominis) and describe its spatial relationships to two other nearby structures (e.g., vessels, bones, other muscles).
Use terms like superficial to, lateral to, or deep to in your description. You can use text, audio or video. Be creative!

Reply to at least one peer’s post

Ask a follow-up question

Add a detail or clinical connection

Offer a helpful clarification or encouragement

# data[].attributes.body
Post a brief explanation (or a drawing/photo of your sketch) showing the superficial-to-deep order of the abdominal wall muscles and fascia. You can include a video or a voice over of an image or text with an image. Include any changes you notice above vs. below the arcuate line.

Reply to at least one peer’s post

Ask a follow-up question

Add a detail or clinical connection

Offer a helpful clarification or encouragement