Introduction to the Abdomen and Inguinal Canal

Question 1

Name the nine abdominal regions

Answer 1

• Epigastric Region
• Right and Left Hyperchondriac Region
• Right and Left Lumbar Region (Right and Left Lateral Regions)
• Right and Left Iliac Region (Right and Left Inguinal Regions)
• Hypogastric Region (Pubic Region)
• Umbilical Region

Question 2

Organs within the Left Hypochondraic Region

Answer 2

o Spleen, stomach, splenic flexure of the colon, tail of pancreas, may have extension of liver

Question 3

Organs within the Right Hypochondriac Region

Answer 3

o Liver and Gallbladder

Question 4

Organs within the Epigastric Region

Answer 4

o Liver, stomach, body of pancreas, oesophagus, abdominal aorta, IVC

Question 5

Organs within the Right Lumbar Lateral Region

Answer 5

o Right kidney, right suprarenal gland, hepatic flexure of colon, ascending colon

Question 6

Organs within the Umbilical Region

Answer 6

o Duodenum, jejunum, head of pancreas, abdominal aorta, IVC, Stomach, transverse colon

Question 7

Organs within the Left Lumbar Region

Answer 7

o Left kidney, Left Suprarenal Gland, descending colon

Question 8

Organs within the Right Iliac/Inguinal Region

Answer 8

o Caecum, Vermiform appendix, ileum

Question 9

Organs within the Hypogastric/Pubic Region

Answer 9

o Sigmoid Colon, rectum, urinary bladder (when distended), ileum

Question 10

Organs within the Left Iliac/Inguinal Region

Answer 10

o Sigmoid Colon

Question 11

How to Identify the Transpyloric Plane

Answer 11

Find the Superior Landmark
 Jugular Notch of the Manubrium

Find the Inferior Landmark
 Pubic Symphysis

Midpoint between these two landmarks (approx. L1 vertebrae) is the location of the horizontal plane

Question 12

What does the Transpyloric Plane pass through

Answer 12

 Passes through L1, the pyloris of the stomach, neck of the pancreas, the gall bladder, and the hepatic portal vein

Question 13

How to Identify the Transtubercular Plane

Answer 13

Estimate position of the tubercle of the right and left iliac crests

Draw a horizontal line between the two points passing through L5

Question 14

What does the Transtubercular Plane pass through

Answer 14

 Passes through L5 and the tubercles of the iliac crest

Question 15

How to Identify the Midclavicular Plane

Answer 15

Find the Superior Landmark
 Midpoint of the Clavicle

Find the Inferior Landmark
 Midinguinal Point
 Midpoint between the ASIS and the Pubic Symphysis

Question 16

How to Identify the Subcostal Plane

Answer 16

Palpate and locate the most inferior region of the Right and Left Costal Margins

Question 17

What are the Quadrants of the Abdominal Regions

Answer 17

• Right and Left Upper Quadrant

* Right and Left Lower Quadrants

Question 18

What are the Quadrants of the Abdominal Regions separated by?

Answer 18

• Divided by a midsagittal plane and a transumbilical plane passing through the umbilical

Question 19

What are the lines of division of the abdominal regions?

Answer 19

• Paired vertical right and left midclavicular planes and two horizontal planes

Question 20

Peritoneal Cavity

Answer 20

• Consists of organs located within the abdomen
• Cavity is lined with parietal peritoneum
• Superficial organ surfaces are lined with visceral peritoneum

Question 21

Superior and Inferior Border of the Peritoneal Cavity

Answer 21

• Superior Boundary – Thoracic Diaphragm
• Inferior Boundary – Imaginary plane dividing the abdomen from the pelvis through the superior pelvic aperture (at the pelvic brim)

Question 22

Classification of Abdominopelvic Organs

Answer 22

• Abdominopelvic organs are classified as either extraperitoneal or intraperitoneal

Question 23

Extraperitoneal Organ

Answer 23

o Located along the walls of the abdomen and pelvis

o Majority are located posteriorly are referred to as retroperitoneal organs

Question 24

Extraperitoneal Organ Examples

Answer 24

o Urinary Bladder – Located on the anterior pelvic wall

Question 25

Intraperitoneal Organs

Answer 25

o Suspended inside the peritoneal cavity by peritoneal folds such as the jejunum and liver

Question 26

Skeletal Structures of the Abdominal Wall

Answer 26

* Inferior Thoracic Cage * Hip Bones * Pelvic Brim/Superior Pelvic Aperture (of lesser or true pelvis) * Lumbar Vertebrae Due to the lack of skeletal protections in the anterolateral abdominal wall, the anterolateral abdominal muscles from strong expandable support for this region

Question 27

Boundaries of the Anterolateral Abdominal Wall

Answer 27

* Xiphisternum * Costal Margins * Hip Bones * Inguinal Ligament

Question 28

What are the Hip Bones and Important Landmarks?

Answer 28

o Iliac Crest, ASIS, Pubic Tubercle, Pubic Crest, Pubic Symphysis

Question 29

What is the Inguinal Ligament attached to?

Answer 29

o Attaches to the Pubic Tubercle

Question 30

Rectus Abdominis

Answer 30

o Divided into differing sections | o Surrounded by a CT sheath – Rectus Sheath

Question 31

Three Muscles Compose the Anterolateral Abdominal Wall

Answer 31

o External Oblique Abdominis, Internal Oblique Abdominis, Transversus Abdominis

Question 32

External Oblique Abdominis: Direction of Fibres

Answer 32

 Fibres run in an inferomedial direction

Question 33

Internal Oblique Abdominis: Location and Direction of Fibres

Answer 33

 Deep to the External Oblique Abdominis  Fibres run in a superomedial direction

Question 34

Transversus Abdominis: Location and Direction of Fibres

Answer 34

 Muscle fibres run horizontally |  Deep to the Internal Oblique Abdominus

Question 35

Linea Alba: Location and what does it form?

Answer 35

o Located between the Rectus Abdominis muscles | o Forms a vertical line which runs down the midline of the abdomen

Question 36

Tendinous Intersections

Answer 36

o Separate the rectus abdominus muscles o Seen on the surface of the skin

Question 37

Supportive Structures of the Abdominal Wall

Answer 37

o Transversalis Fascia o Parietal Peritoneum o Extraperitoneal Fat o Inguinal Ligament

Question 38

Supportive Structures of the Abdominal Wall: Inguinal Ligament

Answer 38

 CT layer which attaches to the anterior superior iliac spine and the pubic tubercle  Forms a surface landmark – inguinal groove

Question 39

What does the Inguinal Canal Pass Through?

Answer 39

o Passes through the three muscle layers, transversalis fascia, parietal peritoneum and extraperitoneal fat o Approximately 4cm long

Question 40

Opening of the Deep Inguinal Ring

Answer 40

 Opening in the deep abdominal wall

Question 41

Superficial Inguinal Ring

Answer 41

 Exit from the inguinal canal  Inferomedial opening in aponeurosis of external obliquus abdominis (superolateral to the pubic tubercle)  Triangular shaped

Question 42

Major Structures in the Male Inguinal Canal

Answer 42

 Ductus Deferens, Testicular blood vessels, Spermatic Cord

Question 43

Male Inguinal Canal from Superficial to Deep

Answer 43

* Superficial inguinal ring with aponeurosis of external obliquus abdominis * Belly of internal obliquus abdominis * Belly and aponeurosis of transversus abdominis * Deep inguinal ring with transversalis fascia

Question 44

Female Inguinal Canal

Answer 44

 Shorter than male inguinal canal  Round ligament of the uterus, fat pad, blood vessels and nerves

Question 45

Inguinal Hernia

Answer 45

* Protrusion or passage of a peritoneal sac, with or without abdominal contents, through a weakened part of abdominal wall of inguinal region/groin * More common in males due to the larger size of the inguinal canal

Question 46

Two Types of Inguinal Hernia

Answer 46

Direct or Indirect

Question 47

Direct Inguinal Hernia

Answer 47

o Through peritoneum and transversalis fascia in posterior wall of inguinal canal o Does not use deep inguinal ring o 25-33% incidence o Only traverses medial 1/3 of inguinal canal o Rarely enters scrotum

Question 48

Indirect Inguinal Hernia

Answer 48

o Through deep inguinal ring o 66-75% incidence o Transverses entire inguinal canal o Exits through superficial inguinal ring inside spermatic cord o Commonly enters scrotum

Question 49

Psoas Major

Answer 49

o Attaches to the bodies of vertebrae T12-L5 superior and the lesser trochanter of the femur inferiorly o In the posterior abdominal wall

Question 50

Iliacus

Answer 50

o Within the iliac fossa in the posterior abdominal wall

Question 51

Iliopsoas

Answer 51

o When the iliacus muscle joins the psoas major and passes into the thigh, the combined muscles are referred to as the iliopsoas muscle o In the posterior abdominal wall

Question 52

quadratus lumborum

Answer 52

o Square shaped muscle attaching to the 12th rib and the iliac crest o in the posterior abdominal wall