Haritha

Abdominal Cavity And Peritoneum Question And Answers

Question 1. Give a brief description about the contents, attachments, and functions of greater Omentum and why is it called as policeman of abdomen.
Answer:

The Contents, Attachments, And Functions Of Greater Omentum

• Large thick fold of peritoneum
• Greater Omentum Hangs Down From:
  • Greater curvature of the stomach
  • The first part of the duodenum
  • Greater Omentum hangs down in the shape of an apron and covers the loops of intestine to a variable extent
  • Formed by 4 layers of peritoneum (anterior two layers and posterior two layers)
  • These 4 layers get fused to form a thin fenestrated membrane

Read And Learn More: Abdomen And Pelvis

Greater Omentum Contents:

• Adipose tissue or fat
• Right and left gastroepiploic vessels anastomoses between the first two layers
• Macrophage aggregates, seen as dense milky spots

Peritoneum Anatomy Important Questions

Greater Omentum Attachments:

• Anterior Two Layers
  • Hangs from greater curvature of the stomach to a variable extent
  • They fold upon themselves to form the posterior two layers
  • The Mode Of Folding Is Such That:
    • The first layer becomes the fourth layer
    • Second layer becomes the third layer
• Posterior Two Layers
  • They ascend up to the transverse mesocolon
  • The fourth layer loosely blends with the peritoneum on the anterior surfaces of the transverse colon and mesocolon.

Greater Omentum Functions

• When there is an infection in the peritoneal cavity, the greater omentum moves to the site of infection and seals it of from its surrounding thus limiting the spread of infection
• When there is any perforation of the gut, greater omentum plugs the gap to prevent the leakage of contents

For These Reasons, It Is Termed As Policeman Of Abdomen

• Storehouse of fat
• Macrophages present in the omentum protect the peritoneal cavity from infection.

Question 2. Describe Lesser Omentum.
Answer:

Lesser Omentum

• The double-layered fold of peritoneum
• Extent: From lesser curvature of the stomach and first part of the duodenum to the inferior surface of the liver

Lesser Omentum Attachments

• Superiorly
  • Attached to the liver (margins of fissure for ligamentum venosum and porta hepatis)
  • In an inverted L-shaped manner
• Inferiorly
  • Lesser curvature of the stomach
  • Upper border of first 2 cm of duodenum.

Lesser Omentum Parts

• Lesser Omentum Is Divided Into Two Parts, They Are:
  • Hepatogastric Ligament: Part of lesser omentum between the stomach and liver
  • Hepatoduodenal Ligament: Part of lesser omentum between duodenum and liver
• Right margin of lesser omentum is free and it forms the anterior boundary of the epiploic foramen
• The anterior and posterior layers of the peritoneum become continuous at the right margin.

Lesser Omentum Contents

Contents Of Right Free Margin

• Portal vein
• Hepatic artery
• Bile duct
• Hepatic plexus of nerves
• Lymphatics and lymph nodes

Contents Along The Lesser Curvature Of The Stomach

• Right and left gastric vessels
• Branches of left gastric nerve
• Gastric group of lymph nodes and lymphatics

Lesser Omentum DevelopmDent: derived from ventral mesogastrium.

Abdominal Cavity And Peritoneum Notes

Question 3. Write a note on the Mesentery of the small intestine. Describe root of the Mesentery and the free border of the mesentery.
Answer:

Mesentery Of The Small Intestine

• The broad fan-shaped fold of peritoneum
• Mesentery suspends the coils of the small intestine (jejunum and ileum) from the posterior abdominal wall
• Mesentery is wider at the central and narrow at the proximal and distal ends
• The average width of the mesentery is 6 inches and at the center, it is 8 inches
• Mesentery Presents With Two Borders:
  • The root of the mesentery or attached border
  • Intestinal border or free border.

Root Of Mesentery

• It is 15 cm long
• Attached to an oblique line across the posterior abdominal wall

Mesentery Extent: Duodenojejunal flexure (lies on the left side of L2) to an ileocecal junction (lies at the upper part of the right sacroiliac joint)

• Directed obliquely downwards and to the right
• Mesentery Crosses The Following Structures:
  • The third part of the duodenum
  • Abdominal aorta
  • Inferior vena cava
  • Right gonadal vessels
  • Right ureter
  • Right psoas major
• The root of mesentery divides the infrasonic compartment into two parts namely right and left
  • Right Part: Small, this part terminates in the right iliac fossa
  • Left Part: Large, this part passes into true pelvis.

Lesser Omentum Intestinal Border/Free Border

• Lesser Omentum Intestinal is 6 m long
• Thrown into pleats
• Lesser Omentum Intestinal covers the jejunum and ileum
• Lesser Omentum Intestinal is attached to the gut and forms a serous coat.

Contents Of Mesentery

• Jejunal and ileal branches of superior mesenteric nartery and vein
• Autonomic nerve plexus
• Lacteals (lymphatics)
• Lymph nodes (100–200)
• Connective tissue and fat
• Jejunum and ileum.

Peritoneum And Abdominal Cavity MCQs

Question 4. Write a note on Transverse Mesocolon.
Answer:

Transverse Mesocolon

• Transverse Mesocolon is a broad transverse fold of the peritoneum
• Transverse Mesocolon suspends the transverse colon from the posterior abdominal wall.

Transverse Mesocolon Attachments

• Root of the transverse mesocolon is attached horizontally to the posterior abdominal wall, with an upward inclination towards the left
• Root Of Transverse Mesocolon Is Also Attached To:
  • Pancreas: Anterior surface of the head of the pancreas and anterior border of body of pancreas
  • Second part of the duodenum.

Transverse Mesocolon Contents

• Middle colic vessels
• Lymphatic and lymph nodes of the transverse mesocolon
• Nerves.

Question 5. Write a note on Sigmoid Mesocolon.
Answer:

Sigmoid Mesocolon

• Sigmoid Mesocolon is a triangular fold of the peritoneum
• Sigmoid Mesocolon suspends the sigmoid colon from the pelvic wall
• The root of the sigmoid mesocolon is attached to the pelvic wall in the shape of an inverted ‘V’
• The apex of inverted ‘V’ lies over the left ureter at the point of termination of left common iliac artery
• Left limb of inverted ’V’ has an attachment along the upper half of left external iliac artery
• Right limb is directed downwards and medially from the apex towards the median plane up to the level of S3 and is attached to the posterior pelvic wall.

Sigmoid Mesocolon Contents

• Right limb: Superior rectal vessels
• Left limb: Sigmoid vessels
• Lymphatics And Lymph Nodes Of Sigmoid Mesocolon
• Nerves.

Question 6. Describe in brief about the Peritoneal Cavity and write a note on its divisions.
Answer:

The Peritoneal Cavity

• Largest serous sac in the body, formed between the parietal and visceral layers of the peritoneum
• Secretes 30 ml of fluid/day
• Derived from coelomic cavity
• It is closed in males but open in female
• In females it communicates with the exterior through uterine tubes, uterus, and vagina
• Peritoneal Cavity Can Be Divided Into Two Parts:
• Greater Sac
• Lesser Sac.

Important Questions On Peritoneum

Peritoneal Cavity Greater Sac

• Main or larger compartment of the peritoneal cavity
• Extents across the entire area of the abdomen (from diaphragm to pelvic floor)
• Peritoneal Cavity Has 5 Recesses:
  • Hepatorenal Recess: It is the peritoneal pocket between liver and kidney
  • Subhepatic Recess: It is the peritoneal pocket between the liver and transverse colon
  • Subphrenic Recess: It is the peritoneal pocket between the diaphragm and the anterior part of the liver
  • Paracolic Recess: Lies lateral to ascending and descending colon
  • Morrison’s Pouch.

Peritoneal Cavity Subphrenic Spaces

• There are six recesses/spaces in the peritoneal cavity
• Situated between the diaphragm and the anterior part of the liver
• Three spaces are on the right and three are on the left
• On each side:
  • One space: Extraperitoneal
  • Two spaces: Intraperitoneal
• Peritoneal Cavity Are Namely:
  • Right anterior intraperitoneal compartment
  • Right posterior intraperitoneal compartment
  • Right extraperitoneal compartment
  • Left anterior intraperitoneal compartment
  • Left posterior intraperitoneal compartment
  • Left extraperitoneal compartment.

Peritoneal Cavity Lesser Sac

• Also known as omental bursa
• It is the left posterior intraperitoneal compartment
• This large recess of the peritoneal cavity is located behind:
  • Stomach
  • Lesser omentum
  • Caudate lobe of liver
• It is closed all around, except in the upper part of its right border
• Here, there is a slit-like opening called the epiploic foramen through which it communicates with the greater sac.

Peritoneal Cavity Boundaries

• Anterior Wall
  • Anterior two layers of greater omentum
  • Stomach
  • Lesser omentum
  • Caudate lobe of liver
• Posterior Wall
  • Diaphragm
  • Left suprarenal gland
  • Upper part of left kidney
  • Pancreas
  • Transverse mesocolon
  • Transverse colon (How to remember: Structures forming stomach bed—spleen)
  • Posterior two layers of greater omentum
• Upper Border
  • Peritoneal reflction (from esophagus to diaphragm)
  • Fissure for ligamentum venosum (its upper end)
  • Caudate lobe of liver (its upper border)
• Lower Border
  • Continuation of 2nd layer with the 3rd layer of greater omentum

Peritoneum Anatomy Viva Questions

Lesser Sac Has 3 Recesses

• Superior Recess: Lies posterior to lesser omentum and liver
• Inferior Recess: Lies between anterior two layers and posterior two layers of greater omentum
• Splenic Recess: Lies between lienorenal ligaments and gastrosplenic ligaments.

Question 7. Write a note on epiploic foramen.
Answer:

Epiploic Foramen

• Also known as foramen of Winslow
• Epiploic Foramen is a vertical slit like opening of the lesser sac through which it communicates with the greater sac
• Epiploic Foramen is located at the level of T12 vertebrae
• Situated behind the right free margin of lesser omentum.

Epiploic Foramen Boundaries

• Anteriorly
  • Right free margin of lesser omentum and its contents
• Posteriorly
  • Inferior vena cava
  • Right suprarenal gland
  • T12 vertebrae
• Superiorly
  • Caudate process of liver
• Inferiorly
  • First part of the duodenum
  • Horizontal part of hepatic artery

Question 8. Describe about Morrison’s pouch or hepatorenal pouch.
Answer:

Morrison’s Pouch

• Right posterior intraperitoneal compartment
• The most dependent part of the peritoneal cavity
• Morrison’s Pouch Is Situated Between:
  • Anterior aspect of right kidney
  • The posteroinferior surface of the liver.

Morrison’s Pouch Or Hepatorenal Pouch Boundaries

• Anteriorly
  • Visceral surface of the liver
  • Gallbladder
• Posteriorly
  • The second part of the duodenum
  • Hepatic flexure of colon
  • Transverse mesocolon
  • Right suprarenal gland
  • The upper part of right kidney
  • Head of the pancreas
• Superiorly
  • Inferior layer of coronary ligament
• Inferiorly
  • Opens into the general peritoneal cavity

Morrison’s Pouch Or Hepatorenal Pouch Applied Anatomy

• It is the common site for subphrenic abscess
• Since it is open inferiorly to the general peritoneal cavity, infections from this pouch can easily enter the peritoneal cavity
• Usually, this recess is not filled with fluid but during conditions like hemoperitoneum, flids can get collected in this space or recess.

Abdominal Cavity And Peritoneum PDF

Question 9. Describe Rectouterine Pouch (pouch of Douglas).
Answer:

Rectouterine Pouch (pouch of Douglas)

• Peritoneal pouch present in females
• Situated behind the rectum and uterus

Rectouterine Pouch Features:

• In The Upright Position: Most dependent part of the peritoneal cavity
• In The Supine Position: Most dependent part of the pelvic cavity

Rectouterine Pouch Boundaries

• Anteriorly: Uterus and upper 1/3rd of vagina
• Posteriorly: Rectum
• Floor: Rectovaginal fold of peritoneum.

Abdominal Cavity And Peritoneum Multiple Choice Questions

Question 1. Which ligament is NOT part of the greater omentum?

1. Gastrocolic ligament
2. Hepatogastric ligament
3. Gastrosplenic ligament
4. Splenorenal ligament

Answer: 2. Hepatogastric ligament

Question 2. Which structure is the remnant of the umbilical vein?

• Ligament of Treitz
• Falciform ligament
• Round ligament (Teres)
• Coronary ligament

Answer: 3. Round ligament (Teres)

Question 3. Which of the following structures is most likely to get affected by a posteriorly perforating peptic ulcer?

1. Hepatorenal pouch
2. Greater sac
3. Lesser sac
4. Pouch of Douglas

Answer: 3. Lesser sac

Question 4. What is the posterior boundary of the epiploic foramen?

1. Caudate lobe of the liver
2. First part of the duodenum
3. Common bile duct
4. Inferior vena cava

Answer: 4. Inferior vena cava

Abdominal Cavity And Peritoneum Questions And Answers

Question 5. Foramen of Winslow is bounded:

1. Superiorly by the left lobe of liver
2. Anteriorly by lesser omentum
3. Posteriorly by the inferior vena cava
4. Inferiorly by the pylorus of stomach

Answer: 4. Inferiorly by the pylorus of stomach

Testis

The External Features Of The Testis And Explain In Detail The Coverings Of The Testis

• Male gonad
• Homologous with ovary in female
• It is suspended in the scrotal sac by spermatic cord
• Lies obliquely in both half of the scrotum, such that the upper pole is tilted forwards and medially
• Function: Secretion of testosterone, production of spermatozoa
• Oval in shape, weight: 10–15 g
• Measurements
  • Length: 4–5 cm
  • Breadth: 2.5 cm
  • Anteroposterior Diameter: 3 cm

Read And Learn More: Abdomen And Pelvis

Testis External Features: Testis has

• Two Poles: Upper and lower
• Two Borders: Anterior and posterior
• Two Surfaces: Medial and lateral
  • Two poles are convex and smooth
  • The upper pole provides attachment to the spermatic cord

Testis Borders

1. Anterior Border
   • Convex and smooth
   • Completely covered by tunica vaginalis
2. Posterior Border
   • Straight
   • Partially covered by tunica vaginalis

Testis Relations:

• Epididymis lies on its lateral aspect
• Both are separated by an extension of the cavity of tunica vaginalis known as the sinus of the epididymis
  • Two Surfaces (Medial And Lateral): Convex and smooth.

Anatomy Of Testes

Appendix Of The Testis:

• Small oval body attached to the upper pole of the testis
• It is the remnant of the paramesonephric duct.

Coverings of Testis

1. Tunica Vaginalis

• Tunica Vaginalis is a serous sac
• Represents the lower persistent portion of processus vaginalis
• Tunica Vaginalis is invaginated by the testis from behind
• As a result, it has two layers (parietal and visceral) with a cavity between them
• Tunica vaginalis completely covers the testis, except for its posterior border.

2. Tunica Albuginea

• The thick, dense, white fibrous layer
• Tunica Albuginea completely covers the testis
• Tunica Albuginea is enclosed by the visceral layer of tunica vaginalis except posteriorly where testicular nerves and vessels enter into testis
• Mediastinum Testis: Vertical septum formed by the thickened posterior border of the tunica albuginea
• Numerous incomplete fibrous septa extend from the mediastinum into the inner aspect of Tunica albuginea
• These septa divide testis in to 200–300 lobules.

3. Tunica Vasculosa

• Innermost vascular layer
• It lines the lobules.

Testis Blood Supply

1. Arterial Supply
   • Testicular Artery
     • Branch of abdominal aorta given of at level of L2 vertebrae
     • Descends through posterior abdominal wall
     • Reach deep inguinal ring
     • Enters spermatic cord
     • Reaches posterior border of testis
     • Divides Into:
       • Two large branches—medial and lateral
       • Small branches
     • Medial and lateral branches Pierces the tunica albuginea
     • Ramify in tunica vasculosa.
   • Artery To Vas (Sometimes)
2. Venous Drainage
   • By pampiniform plexus of veins
   • Thy condenses into two veins at the deep inguinal ring and accompanies testicular artery
   • Finally, two veins fuse together forming one vein which drains into the inferior vena cava.

Testis Lymphatic Drainage: Preaortic and para-aortic lymph nodes.

Testis Nerve Supply: By sympathetic fibers from the T10 segment.

Function Of Testes

Development of Testis

The Development Of Testis

The development of the testis and ovaries begins in a similar manner but parts way at a particular point.

Development Of Testis

• Sex cords increase in length and extend into the medulla of the developing gonad. Sex cords are now called as medullary cords
• The sex cords anastomose with each other and canalize resulting in the formation of seminiferous tubules
• The ends of seminiferous tubules anastomoses with one another giving rise to rete testis
• Two Types Of Cells Line The Seminiferous Tubules:
  • Spermatogenic cells: Formed from primordial germ cells
  • Sertoli cells: Formed from coelomic epithelium
• A dense fibrous layer is formed by mesoderm which separates the sex cords from coelomic epithelium, known as the tunica albuginea.
• Mesoderm Also Gives Rise To:
  • Leydig cells
  • The connective tissue around seminiferous tubules
  • Mediastinum testis
• The canal of the epididymis and vas deferens develop from the mesonephric duct. The development of the testis and ovaries begins in a similar manner but parts way at a particular point
• Gonads develop from three sources:
  • Intermediate mesoderm—which is present medial to the middle part of the mesonephros
  • Coelomic epithelium—which covers the intermediate mesoderm
  • Primordial germ cells from the wall of the yolk sac near the allantois
• Coelomic epithelium begins to proliferate and it gets thickened
• Mesoderm below the coelomic epithelium condenses due to the thickening of coelomic epithelium
• Both these processes lead to the formation of the genital ridge
• Coelomic epithelial cells continue to proliferate and they invade the condensed mesoderm in the form of solid cords, known as the ‘sex cords’
• Primordial germ cells from the wall of the yolk sac migrate along the dorsal mesentery of the hindgut toward the developing gonad
• Sex cords and primordial germ cells get intermixed
• Till this point, the development of the testis and ovaries are the same.

Male Reproductive System Anatomy

 Descent of Testis

Descent Of Testis

• Testis which develops in relation to the lumbar region of the posterior abdominal wall starts to descend
• It gradually descends to the scrotum through the iliac fossa (3rd month) and the inguinal canal (7th month), finally reaching the scrotum by the end of 8th month.
• It is a mandatory developmental process to ensure that the mature testis promotes normal spermatogenesis
• Some Factors Responsible For The Descent Of The Testis Are:
  • Increased intra-abdominal pressure
  • Gubernaculum: A guiding force for the descent
  • Differential growth of body wall.

Vas Deferens

The Features And Course Of Vas Deferens

• Also known as ductus deferens
• Thick-walled muscular tubes
• Two in number
• Length: 45 cm
• Lumen: Narrow, but the terminal part (ampulla) is sacculated.

Vas Deferens Course: It has

• External course
• Internal course.

Vas Deferens  External Course

Vas Deferens Internal Course

Testes Structure And Function

Vas Deferens Blood Supply

1. Arterial Supply

• From artery to vas deferens
• This artery can arise from either
  • Superior vesical artery (common)
  • Inferior vesical artery or
  • Middle vesical artery.

2. Vas Deferens Venous Drainage

3. Vas Deferens Nerve Supply

Pelvic splanchnic nerves—parasympathetic.

Male Internal Genital Organs

• Penis
• Scrotum

Male External Genital Organs

• Testis
• Epididymis
• Vas deferens
• Prostate
• Seminal vesicles
• Bulbourethral glands

Male Reproductive System Anatomy

Layers Of The Scrotum From Outside To Inside

The Layers Of The Scrotum From Outside To Inside

1. Skin
2. Dartos muscle (which replaces the superficial fascia)
3. External spermatic fascia
4. Cremasteric muscle and fascia
5. Internal spermatic fascia.

Mnemonics: ‘Some Damn Englishman Called It scrotum’

Male Genital Organs Multiple Choice Questions

Question 1. The coverings of the testis are:

1. Tunica vasculosa
2. Tunica albuginea
3. Tunica vaginalis
4. All of the above

Answer: 4. All of the above

Question 2. Which of the following arteries gives blood supply to vas deferens?

1. Middle rectal artery
2. Inferior epigastric artery
3. Cremasteric artery
4. Superior vesical artery

Answer: 4. Superior vesical artery

Question 3. Which of the following statements are true about testis?

1. It has no parasympathetic supply T cannot find it in books but Blitz reckons it has a vagal supply
2. Appendix is inferior
3. Vas deferens in somewhere
4. Epididymis is somewhere else
5. Drains to para-aortic and inguinal nodes

Answer: 1. It has no parasympathetic supply T cannot find it in books but Blitz reckons it has a vagal supply

Question 4. Lymph from the vas deferens drains into nodes:

1. Superficial inguinal
2. External iliac
3. Internal iliac
4. Lumbar

Answer: 2. External iliac

Testes Location In Body

Question 5. All of the following statements regarding ductus deferens are true, except:

1. It is separated from the base of the bladder by the peritoneum
2. It passes lateral to inferior epigastric artery at deep inguinal ring
3. It crosses the ureter in the region of the ischial spine
4. The terminal part is dilated to form an ampulla

Answer: 1. It is separated from the base of the bladder by the peritoneum

Anterior Abdominal Wall Question And Answers

Question 1. Describe about abdominal cavity and briefly mention its contents.
Answer:

• Abdominal Cavity  is the lower part of the trunk, below the diaphragm
• Walls surrounding the abdomen forms the abdominal cavity
• Boundaries Of The Abdominal Cavity
  • Superiorly: Diaphragm
  • Inferiorly: Pelvic diaphragm
  • Anteriorly: Anterior abdominal wall (muscles)
  • Posteriorly: Posterior abdominal wall (muscles and lumbar vertebrae)
  • Both Sides: Lateral ends of muscles of anterior abdominal wall, lower ribs.

Anatomy Of Anterior Abdominal Wall

Read And Learn More: Abdomen And Pelvis

Abdominal Cavity Contents

• Liver and gallbladder
• Pancreas
• Stomach
• Small intestine and major portion of large intestine
• Kidneys and upper part of ureters
• Suprarenal glands
• Spleen
• Arteries, veins, lymphatics, nerves, etc.

Question 2. Describe about the various abdominal planes and mention the abdominal quadrants.
Answer:

The Various Abdominal Planes And Mention The Abdominal Quadrants

Transumbilical Plane

• A transverse plane passing through the umbilicus
• Lies between L3 and L4 vertebrae.

Median Vertical Plane

The Median Vertical Plane is a plane passing through the suprasternal notch and pubic symphysis.

The lateral Vertical Plane is a plane passing through, the midway between mid inguinal point and middle of the clavicle.

Anterior Abdominal Wall Layers

Transpyloric Plane of Addison

• A plane passing through the tip of 9th costal cartilage and midway between median vertical plane
• Anteriorly it passes through tip of 9th costal cartilage and posteriorly it passes through lower part of body of L1 vertebra
• The Pylorus, inferior margin of liver, neck of the gallbladder, anterior end of spleen, hilum of kidney, portal vein, etc. lie at this level.

Subcostal Plane

• A transverse plane passing just below 10th rib
• Lies at the upper border of L3 vertebra.

Transtubercular Plane

• Transverse passing through the level of tubercle on the iliac crest
• Lies at the upper border of L5 vertebra

The Abdominal Cavity Is Divided Into Nine Regions By

• Two transverse planes
• Two vertical planes
  • Upper Transverse Plane: Transpyloric plane
  • Lower Transverse Plane: Transtubercular plane
  • Vertical Planes: Right and left lateral vertical planes.
• Nine regions from above to downwards and from right to left are:
  • Right hypochondrium
  • Right lumbar
  • Right iliac fossa
  • Epigastrium
  • Umbilical
  • Hypogastrium
  • Left hypochondrium
  • Left lumbar
  • Left iliac fossa

Question 4. Describe about the features, formation, and contents of the rectus sheath.
Answer:

Rectus Sheath

• Rectus Sheath is an aponeurotic sheath formed from the aponeurosis of felt muscles of the anterior abdominal wall
• Rectus Sheath encloses:
  • Rectus abdominis muscle
  • Pyramidalis muscle
• Rectus Sheath Has Two Walls: Anterior And Posterior
  • Anterior Wall:
    • Rectus Sheath Anterior Wall  is complete, and covers the entire extend of muscle from the upper end to the lower end
    • Rectus Sheath AnteriorWall fimly adheres to tendinous intersections of the rectus abdominis muscle
  • Posterior Wall
    • Rectus Sheath Posterior Wall is incomplete, it is deficient above and below
    • Rectus Sheath Posterior Wall is free from the Rectus abdominis muscle.

Anterior Abdominal Wall Muscles

Rectus Sheath Formation

• AboveThe Costal Margin
  • Anterior Wall: By external oblique aponeurosis
  • Posterior Wall: It is deficient (here rectus abdominis lies directly on 5th 6th and 7th costal cartilages)
• Between The Costal Margin And Arcuate Line (Lies At The Level Of The Anterior Superior Iliac Spine).
  • Anterior Wall:
    • By external oblique aponeurosis
    • Anterior lamina of aponeurosis of internal oblique
  • Posterior Wall:
    • Transversus abdominis aponeurosis
    • Posterior lamina of aponeurosis of internal oblique
• Below The Arcuate Line
  • Anterior Wall:
    • By the aponeurosis of all three flt muscles of anterior abdominal wall (internal oblique, external oblique, transversus abdominis)
    • External oblique aponeurosis contributes separately whereas aponeurosis of internal oblique and transversus abdominis fuses with each other
  • Posterior Wall: It is deficient.

Rectus Sheath Contents

• Muscles: Rectus abdominis and pyramidalis
• Blood Vessels: Superior and inferior epigastric arteries and veins
• Nerves: Terminal parts of:
  • Lower fie intercostal nerves
  • Subcostal nerves.

Rectus Sheath Applied Anatomy

• Rectus sheath maintains the strength of the anterior abdominal wall
• Rectus sheath also checks the boing of the rectus abdominis muscle, thus increasing the efficiency of the rectus muscle.

Question 5. What is fascia transversalis, Briefly describe its extent and modifications.
Answer:

Fascia Transversalis

• Fascia lining the inner surface of the transversus abdominis muscle
• Fascia transversal is separated from the peritoneum by the extraperitoneal connective tissue

Anterior Abdominal Wall Nerve Supply

Fascia Transversalis Extent:

• Superiorly: Continuous with the diaphragmatic fascia
• Inferiorly: Continuous with fascia iliaca
• Anteriorly: Adherent to linea alba at a level above the umbilicus
• Posteriorly: Continuous with an anterior layer of the thoracolumbar fascia

Modifiations Of Fascia Transversalis

• In the fascia transversalis there is an oval opening of about 1.2 cm above the midinguinal point, known as deep inguinal ring.
  • Mid Inguinal Point: Midpoint between the anterior superior iliac spine and the symphysis pubis.
  • MidPoint Of Inguinal Ligament: Midpoint of the anterior superior iliac spine and pubic tubercle.
• Two Prolongations:
  • Internal Spermatic Fascia: Tubular prolongation of fascia transversalis, which surrounds the spermatic cord
  • The Anterior Wall Of Femoral Sheath: Prolongation of fascia transversalis into the thigh over the femoral vessels
• Iliopubic tract: Thckened inferior margin of fascia transversalis.

Question 6. Describe the inguinal canal including its boundaries, contents, and inguinal rings, and also give a brief description about the spermatic cord and its contents.
Answer:

Inguinal Canal

• Inguinal Canal is an oblique intermuscular passage in the lower part of anterior abdominal wall (site of potential weakness in the lower part of anterior abdominal wall)
• Lies just above the medial half of the inguinal ligament
• The inguinal Canal is larger in males than in females
• The inguinal Canal allows the passage of structures, from the testis to the abdomen in males and round ligament in females
• Inguinal Canal Length: 4 cm
• Inguinal Canal Extent: From deep inguinal ring to superficial inguinal ring
• Inguinal Canal Direction: Downwards, forwards, and medially.

Deep Inguinal Ring: Oval opening in the fascia transversalis, 1.25 cm above the mid inguinal point.

Anterior Abdominal Wall Blood Supply

Superfiial Inguinal Ring

• The triangular gap in the external oblique aponeurosis
• Lies above and lateral to the pubic crest
• Base of the triangle is formed by the pubic crest
• Lateral or medial margins or crura form the sides of triangle
• Length – 2.5 cm, breadth – 1.25 cm.

Inguinal Canal Boundaries

1. Anterior Wall
   • In The Whole Extent 
     • Skin
     • Superficial fascia
     • External oblique aponeurosis
   • Lateral  2/3 rd
     • Internal oblique muscle
2. Posterior Wall
   • In The Whole Wxtent 
     • Fascia transversal
     • Extraperitoneal tissue
     • Parietal peritoneum
   • Medial 2/3 rd
     • Conjoint tendon
     • Reflcted part of inguinal ligament
   • Lateral 1/3 rd
     • Interfoveolar ligament
3. Roof: Arched fiers of internal oblique and transversus abdominis muscle.
4. Floor: Inguinal ligament and lacunar ligament.

Inguinal Canal Contents

• Male: Spermatic cord, ilioinguinal nerve
• Female: Round ligament of uterus, ilioinguinal nerve.

Coverings Of The Spermatic Cord

• Internal Spermatic Fascia: Derived from fascia transversalis, covers the cord completely
• Cremasteric Fascia: Derived from internal oblique and transversus abdominis muscles, covers the cord above the level of the above-mentioned muscles
• External Spermatic Fascia: Derived from external oblique aponeurosis, covers the cord below the superficial inguinal ring.

Contents Of The Spermatic Cord

• Ductus deferens
• Arteries: Testicular artery, cremasteric artery, artery to ductus deferens
• Pampiniform plexus of veins
• Nerves:
  • Genital branch of genitofemoral nerve
  • Sympathetic nerve plexus around the artery to ductus deferens
  • Lymphatics from the testis
  • Remnants of processus vaginalis.

Mnemonics: Inguinal canal walls: ‘MALT: 2M, 2A, 2L, 2T’:

• Starting from the superior, moving around in order to posterior
• Superior Wall (Roof): 2 Muscles:
  • Internal oblique Muscle
  • Transverse abdominis Muscle
• Anterior Wall: 2 Aponeuroses:
  • Aponeurosis of external oblique
  • Aponeurosis of internal oblique
• Lower Wall (Flor): 2 Ligaments:
  • Inguinal Ligament
  • Lacunar Ligament
• Posterior Wall: 2Ts:
  • Transversalis fascia
  • Conjoint Tendon

Anterior Abdominal Wall Landmarks

Question 7. Describe about the mechanism of the inguinal canal preventing inguinal herniation and write a note on the inguinal hernia and Hesselbach’s triangle.
Answer:

The Mechanism Of The Inguinal Canal Preventing Inguinal Herniation:

• The presence of the inguinal canal causes a weakness in the lower part of the anterior abdominal wall as a result there is a chance of herniation of abdominal viscera into the inguinal canal
• But this is prevented by the following mechanisms:

1. Flap Valve Mechanism:
   • The inguinal canal is oblique (in children it is straight)
   • Deep and superficial inguinal rings do not lie opposite to each other
   • So when the intra-abdominal pressure increases, the anterior and posterior walls of the canal get approximated, like a flip obliterating the passage
2. Guarding Of Inguinal Rings:
   • Deep Inguinal Ring: Guarded by internal oblique muscle
   • Superfiial Inguinal Ring: Guarded by conjoint tendon and reflcted part of inguinal ligament
3. Shutter Mechanism:
   • Internal oblique muscle forms the anterior wall, roof, and posterior wall of the canal
   • When it is contracted the roof is pulled and gets approximated on the floor, like a shutter— obliterating the passage
4. Ball Valve Mechanism:
   • Contraction of cremasteric muscle pulls the testis up and this helps the spermatic cord to plug the superficial inguinal ring
5. Slit Valve Mechanism:
   • Contraction of the external oblique approximates the two crura of the superficial inguinal ring (like a slit valve).

Hesselbach’s Triangle Or Inguinal Triangle: Situated on the posterior wall of inguinal canal

Anterior Abdominal Wall Hernias

Hesselbach’s Triangle Or Inguinal Triangle Boundaries

• Medially: Lateral border of rectus abdominis muscle (lower 5 cm)
• Laterally: Inferior epigastric artery
• Inferiorly: Medial half of the inguinal ligament
• Floor:
  • Fascia transversalis
  • Peritoneum
  • Extraperitoneal tissue.

Hesselbach’s Triangle Or Inguinal Triangle Applied Anatomy

Direct hernias occur commonly through Hesselbach’s triangle.

Inguinal Hernia

• It is the abnormal protrusion of a viscus or a part of it through the inguinal canal
• There Are Two Types Of Inguinal Hernias:
  • Direct
  • Indirect

Indirect Inguinal Hernia

• Most common type of hernia
• In an indirect inguinal hernia, the hernia sac enters the inguinal canal through the deep inguinal ring into the inguinal canal
• Common in children and young adults, male > female
• Commonly occurs due to persistent processus vaginalis sac
• It Can Be:
  • Congenital: Persistent processus vaginalis sac
  • Acquired: Increased intra-abdominal pressure, for example, weight lifting.

Types Of Indirect Hernia

• Complete Hernia: Hernial sac extent from deep inguinal ring to superficial inguinal ring to bottom of scrotum
• Funicular: Hernial sac extent from deep inguinal ring to root of scrotum
• Bubonocele: Hernial sac is present in the inguinal canal only.

Direct Inguinal Hernia

• Occurs through Hesselbach’s triangle (due to weakness in the posterior wall of the inguinal canal)
• Always congenital
• The precipitating factor is the weakness of fiers of transversus abdominis
• Occurs in elderly due to chronic cough, in smokers (decreased strength of abdominal muscles due to decreased elastin).

Boundaries Of Anterior Abdominal Wall

Coverings of Hernial Sac (outside to inside)

1. Indirect hernia
   • Skin
   • Superfiial fascia (campers and scarpas)
   • External spermatic fascia
   • Cremaster muscle and fascia
   • Internal spermatic fascia
   • Extraperitoneal fat
   • Peritoneum
2. Direct hernia
   • Skin
   • Superfiial fascia (campers and scarpas)
   • External oblique aponeurosis
   • Conjoint tendon
   • Fascia transversalis
   • Peritoneum

Anterior Abdominal Wall Multiple Choice Questions And Answers

Question 1. All the following structures pass through the inguinal canal except:

1. Inferior epigastric artery
2. Ilioinguinal nerve
3. Spermatic cord
4. Genital branch of genitofemoral nerve

Answer: 1. Inferior epigastric artery

Question 2. The posterior wall of the inguinal canal is mainly formed by:

1. Fascia transversalis and conjoint tendon
2. Internal oblique
3. External oblique
4. All of the above

Answer: 1. Fascia transversal and conjoint tendon

Question 3. Which of the following is a common structure in Hesselbach’s triangle and femoral (scarps) triangle?

1. Conjoint tendon
2. Rectus femoris
3. Inguinal ligament
4. Inferior epigastric artery

Answer: 3. Inguinal ligament

Anterior Abdominal Wall Examination

Question 4. The superior ¾ of the posterior rectus sheath is comprised of what layers?

1. Aponeurosis of external abdominal oblique and internal abdominal oblique
2. The aponeurosis of internal abdominal oblique and transverse abdominal muscle
3. The aponeurosis of external and internal abdominal oblique and transverse abdominal muscle
4. Transversalis fascia

Answer: 2. Aponeurosis of internal abdominal oblique and transverse abdominal muscle

Question 5. The median umbilical fold contains which of the following embryonic remnant(s)?

1. Urachus
2. Umbilical arteries
3. Superior epigastric arteries
4. Inferior epigastric arteries

Answer: 1. Urachus