What are the four quadrants of the abdominal wall
Right upper quadrant
Left upper quadrant
Right lower quadrant
Left lower quadrant
List the structures found in the RUQ
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List the structures found in the LUQ
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List the structures found in the RLQ
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List the structures found in the left lower quadrant (LLQ)
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What are the nine regions the abdomen can be split into?
Right Hypochondriac (RH)
Epigastric (E)
Left Hypochondriac (LH)
Right Flank (RL)
Umbilical (U)
Left Flank (LL)
Right Inguinal (RI)
Pubic (P)
Left Inguinal (LI)
Where is the transpyloric plane found?
Level of L1: inferior border of rib 8
What structures are found at the transpyloric plane?
Gallbladder fundus
Pylorus of stomach
Pancreatic neck
SMA origin
Hepatic Portal Vein
Root of transverse mesocolon
Hila of kidneys
Where is the subcostal plane found?
L3 - Inferior border 10th costal cartilage
What structures are found at the subcostal plane?
Transverse Colon
Where is the transtubercular plane found?
Level of L5 - between iliac tubercles
What structures are found at the transtubercular plane?
Ileocecal junction
Where is the interspinous plane found?
Level of S2: between ASIS
What structures are found at the interspinous plane plane?
Appendix & Sigmoid Colon
What is the fatty outter layer of the superficial fascia
Camper’s fascia
What is the membranous underlying CT of the superficial fascia
Scarpa’s fascia
What is Scarpa’s fascia continuous with and what is it fused with?
What is the implication of this?
Continuous - Colle’s fascia of perineum
Fused - Fascia lata of lower limb
Implication - Fluid cannot go from abdomincal wall into leg but it can flow into or out of superficial perineum
From superficial to deep, how the muscles of the anterolateral abdominal wall organized?
External Oblique
Internal Oblique
Transversus abdominis
What is the origin and insertion of the external oblique muscle?
Origin: outer surface of lower 6 ribs Insertion: aponeurosis and linea alba & anterior iliac crest and pubic tubercle
What is the innervation of the external oblique muscles?
Ventral rami of T7-T12 of intercostal nerves
T7-T11: Thoracodabdominal nn.
T12: subcostal n.
What is the action of the external oblique muscles?
Compresses and supports abdominal viscera.
Flexes and rotates trunk.
Retains posture
The lower portion of the external oblique muscles are rolled under to make what?
Inguinal ligament
What is the origin and insertion of the internal oblique muscle?
Origin: iliac crest and some of thoracolumbar fascia
Insertion: lower part of ribs 10-12 , aponeurosis, linea alba and pubic crest
What is the innervation of the internal oblique muscles?
T7-T12 and L1
What is the action of the internal oblique muscles?
- Compresses and supports viscera
- Laterally flexes and rotates trunk
The lower portion of the internal oblique muscles make what?
Part of conjoint tendon
What is the origin and insertion of the transversus abdominis muscle?
Origin: lower 7-12 ribs, thoracolumbar fascia, iliac crest, and some even off upper inguinal ligament
Insertion: linea alba, pecten pubis and pubic crest
What is the innervation of the transversus abdominis muscles?
T7-T12
What is the action of the transversus abdominis muscles?
Compresses and supports visceral
What is the origin and insertion of the rectus abdominis muscle?
Origin: pubic symphysis and pubic crest
Insertion: xiphoid process and outer surface of 5-7th intercostal cartilages
What is the innervation of the rectus abdominis muscles?
Ventral rami of T7-T12
What is the action of the rectus abdominis muscles?
Flexes abdomen and compresses it
What are the layers of the anterior abdominal wall from superficial to deep
- Skin
- Camper’s fascia
- Scarpa’s fascia
- Deep fascia
- External abdominal oblique m. & deep fascia
- Internal abdominal oblique muscle & deep fascia
- Transversus Abdominis
- Transversalis fascia
- Extraperitoneal/Endoabdominal fat
- Parietal peritoneum
What is the arcuate line?
Sharp transition where all EO, IO & TA aponeurosis become anterior to rectus abdominis muscle.
Superior to the arcuate line, what structures are anterior and posterior to the rectus abdominis muscles?
Anterior: External Oblique & Internal Oblique
Posterior: Internal Oblique, Transversus Abdominis & Transversalis fascia
Inferior to the arcuate line, what structures are anterior and posterior to the rectus abdominis muscles?
Anterior: External Oblique, Internal Oblique & Transversus Abdominis
Posterior: Transversalis fascia
Where is the iliohypogastric nerve found?
L1: Runs between 2nd and 3rd muscle layers
(Superior to Ilio-inguinal nerve)
What is the function of the iliohypogastric nerve?
- Motor to Internal Oblique Muscle and Transversus Abdominis Muscle
- Sensory to upper inguinal and hypogastric region
Where is the ilioinguinal nerve found?
L1
(exits superficial ring)
What is the function of the ilioinguinal nerve?
- Motor to lower Internal Oblique Muscle and Transversus Abdominis Muscle
- Sensory to lower inguinal, anterior scrotum/labia, and near medial thigh
Where is Thoraco-abdominal N. located, what is it a continuation of & what is it’s function?
T7-T11
It is the continuation of the intercostal n.
Has both motor and sensory innervation
Where is the subcostal n. located
T12. Runs along inferior 12th rib
What is the function of the subcostal n.
motor - innervates muscles of anterior abdominal wall
sensory - superior to the iliac crest
Superficial lymphatic vessels superior to the umbilicus drain where?
Superiorly into the Axillary lymph nodes with a few going to parasternal nodes
Superficial lymphatic vessels inferior to the umbilicus drain where?
Inferiorly into the Superficial inguinal lymph nodes
Deep lymphatic vessels drain where?
Deep veins of abdominal walls (e.g., external and internal iliac veins)
What structure is formed by the combined aponeurosis of inferior/medial margins of internal oblique and transversus abdominal m. inserting onto the pubis
Conjoint tendon (inguinal falx)
What is the inguinal ligament
Basically the rolled-under inferior border of external oblique muscle aponeurosis that is attached ti the ASIS and pubic tubercle
What is the ligament between the pubic rami and inguinal ligament and anchors the inguinal ligament to the pubis
Lacunar ligament
List the crural fibers
Medial crus
Lateral crus
Intercrural fibers
What ligament is the continuation of fibers from the lacunar ligament that runs along pectin pubis
Pectineal ligament
What is the external opening of the inguinal canal that serves as an exit for the spermatic cord or round ligament
Superficial inguinal ring
(Ring is really a partial split in the external oblique m. aponeurosis)
What structure is the entrance to the inguinal canal and beginning of the invagination of the peritoneum into tranversalis fascia
Deep Inguinal Ring
What structures pass through the deep inguinal ring in males vs females
Males - Vas deferens and gonadal vessels/nerves
Females - Round ligament
Where does the femoral canal/ring lie
Immediately lateral to the lacunar ligament
Where do gonads originally form
Near T10 axial level
What connects gonads to the future scrotal swellings and helps them to descend
Gubernaculum
What is the outpocketing of the parietal peritoneum that descends with the gonads
Process vaginalis
What represents the remains of processus vaginalis around the testes when the connection to the peritoneum is closed
Tunica Vaginalis
What layers of the abdominal wall are carried along as the male gonad descends and help form the spermatic cord. What are they called in the spermatic cord?
Transversalis fascia - Internal spermatic fascia
Internal oblique m. - Cremasteric m.
External oblique m. - External spermatic fascia
What are the contents of the spermatic cord
- Vas deferens (ductus deferens)
- Testicular artery
- Testicular veins
- Pampiniform plexus
- Gonadal nerves
- Gonadal lymphatics
What is Cryptorchid testis
Undescended testis (increases risk of developing cancer)
What is it called when there’s an open connection between tunica vaginalis and the abdomen
Persistent processus vaginalis
What is hydrocele
Peritoneal fluid accumulation within tunica vaginalis. More common in babies.
(When illuminated will see light glow through it)
What is an Hematocele
Accumulation of blood in the tunica vaginalis
(Opaque when illuminated)
What does the guberculum become as ovaries descenend
It becomes attached to the developing uterus and forms the ovarian ligament and round ligament of the uterus.
What is the course of the round ligament of the uterus
Enters deep ring and exists superficial ring attaching to labial swellings
What are the contents of the female inguinal canal
Round ligament of the uterus
Iliolingual nerve
Genitofemoral nerve
What lymph nodes do the scrotum drain into
Superficial inguinal nodes and eventually travel into iliac and lumbar lymph nodes
What lymph nodes do the testes drain into
Lumbar and pre-aortic lymph nodes
What results in the median umbilical fold?
Fold due to obliterated urachus
What results in the medial umbilical fold?
Fold due to obliterated umbilical arteries
What results in the lateral umbilical fold?
Fold due to inferior epigastric artery
What are the boundaries of Inguinal (Hesselbach’s) Triangle?
Medial: lateral border of the rectus abdominis muscle (linea semilunaris)
Lateral: inferior epigastric vessels
Inferior: inguinal ligament
Describe a direct hernia.
- Bulges through weakness in tranversalis fascia in Hesselbach’s triangles and pushes directly through the fascia and bulges out due to weak abdomincal structures next to the spermatic cord (in males)
- Medial to epigastric artery
Describe an indirect hernia.
- Through deep inguinal ring and out superficial inguinal ring
- Lateral to inferior epigastric vessels
Describe a femoral hernia.
- Hernia below inguinal ligament
- more common in women