Lecture 2 - Inguinal Canal and Hernias Flashcards
Surface landmark locations: xiphoid process
Right under the sternum, at the top of the abdomen, between the costal margins
Surface landmark locations: costal margins
Formed by ribs 7-10
anterior superior iliac spine
bottom right of the stomach
Part of the pelvis
Pubic tubercle
Bottom middle (opposite the xiphoid process in the abdominal regions)
Inguinal ligament
bottom left of the abdomen(?)
Midclavicular lines
Divide the stomach vertically into an equal split of three parts
Subcostal line
Divides the stomach horizontally just below the costal margins, creating three regions above it (and three regions below with the intertubercular line)
Intertubercular line
Divides the stomach horizontally just above the inguinal ligament and the anterior superior iliac spine to form three regions above and below it
Abdominal region divisions
The abdomen is divided into nine equal parts formed by the midclavicular lines, subcostal line, and intertubercular line
The regions are numbered from 1-9 from the top right to the bottom left (correct POV)
Abdominal region 1: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
The right hypochondrium
The liver and the gallbladder are present here
Superior epigastric artery, intercostal arteries
Lateral thoracic vein
T8
Abdominal region 2: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
Epigastrium
The stomach, liver, pancreas, duodenum, and adrenal glands are present here
Superior epigastric artery
???
T7
Abdominal region 3: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
Left hypochondrium
The spleen, colon, and pancreas are present here
Superior epigastric artery, intercostal arteries
Lateral thoracic vein
T8
Abdominal region 4: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
Right lumbar/flank
The gallbladder, right kidney, part of the liver, and the ascending colon are present here
Inferior epigastric artery, lumbar arteries, intercostal arteries
Lumbar veins
T9
Abdominal region 5: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
Umbilicus region
Contains parts of the duodenum, jejunum, ileum, transverse colon (the section between the ascending and descending colons) and the bottom portions of both the left and right kidney
Inferior epigastric artery, maybe the intercostal and lumbar arteries too (not as significant tho)
Lumbar veins
T10
Abdominal region 6: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
Left lumbar/flank
Descending colon and the left kidney are present here
Inferior epigastric artery, lumbar arteries, intercostal arteries
Lumbar veins
T9
Abdominal region 7: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
Right iliac fossa
The cecum, vermiform appendix and terminal ileum are present here
Inferior epigastric arteries, deep circumflex iliac arteries, and lumbar arteries
Superficial epigastric vein
T11
Abdominal region 8: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
Hypogastrium/suprapubic region
The small intestine, bladder and uterus are present here
Inferior epigastric arteries, and deep circumflex iliac arteries
Superficial epigastric vein
T12
Abdominal region 9: what is it called, what organs are present here, what arteries are supplied here, what veins are present here, and what nerves innervate the region?
Left iliac fossa
The distal part of the descending colon and the proximal sigmoid colon are present here
Inferior epigastric arteries, deep circumflex iliac arteries, and lumbar arteries
Superficial epigastric vein
T11
Abdominal wall layers: outer layer - sixth outermost layer
Outer layer - skin
Second outermost layer - superficial fatty layer of subcutaneous tissue (Camper’s fascia)
Third outermost layer - Deep membraneous layer of subcutaneous tissue (Scarpa’s fascia)
Fourth outermost layer - Trilminar Abdominal muscles (external oblique-internal oblique-transversus abdominis)
Fifth outermost layer - Transervsalis (endo abdominal) fascia
Sixth outermost layer - Parietal peritoneum
External oblique muscles: origin, insertion, blood supply, innervation, and action
Lower 8 ribs
Xiphoid process, pubic crest, pubic tubercle, and anterior half iliac crest
Lower posterior intercostal arteries, subcostal artery, deep circumflex iliac artery
Motor: Intercostal nerves (T6- T12), Subcostal nerve (T12) Sensory: Iliohypogastric nerve (L1) and ilioinguinal
Flexion & rotation of trunk, increases intra abdominal pressure
Internal oblique muscles: origin, insertion, blood supply, innervation and action
Anterior 2/3rds iliac crest, lateral 2/3rds inguinal ligament
Ribs 10-12, Xiphoid process, Linea alba,
Lower posterior intercostal and subcostal arteries. Superior and inferior epigastric arteries. Superficial and deep circumflex iliac arteries
Motor: Intercostal nerves (T6- T12), Subcostal nerve (T12) Sensory: Iliohypogastric nerve (L1) and ilioinguinal
Flexion & rotation of trunk, increases intra abdominal pressure
Transversus abdominis muscles: origin, insertion, blood supply, innervation and action
lower 6 costal cartilages, anterior 2/3rds iliac crest, lateral 2/3rds inguinal ligament
Xiphoid process, Linea alba, pubic symphysis
Lower posterior intercostal arteries, arising from the descending thoracic aorta. Subcostal arteries, given off by the descending thoracic aorta. Superior epigastric artery, given off by the internal thoracic artery.
Motor: Intercostal nerves (T6- T12), Subcostal nerve (T12) Sensory: Iliohypogastric nerve (L1) and ilioinguinal
Flexion & rotation of trunk, increases intra abdominal pressure
Costal cartilages
Connects ribs 1-10 to the sternum
Tendon
Connects muscle to bone
Ligament
Connects bone to bone
Aponeurosis
A flat tendon - tendons are usually cylindrical
Tendons in the trilaminar muscles are all aponeurosis
Trilaminar abdominal muscles aponeurosis girdle mesh formation
EO aponeurosis - connect towards the midline, inferiorly
IO aponeurosis - connect towards the midline, superiorly
TA aponeurosis - connect towards the left side of the body, in a sideways direction
Tenderness raphe
Strong, fibrous connective tissue - Linea Alba
Inguinal ligament
The most inferior part of the external oblique aponeurosis, when folded back on itself
ASIS
Anterior superior iliac spine - The parts of the external oblique aponeurosis that do not fold back on itself
Rectus abdominis: its basics
Very long, strap-like muscles that span the entire length of the anterior abdominal wall
Needs tendinous intersections in between that tie it back to the underlying fascia
Rectus abdominis: origin, insertion, blood supply, innervation and action
Pubic symphysis and pubic crest
The xiphoid process and the 5ᵗʰ-7ᵗʰ costal cartilages
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T6-T12
Compresses abdominal contents, flexes vertebral column, accessory muscle of respiration
Rectus abdominis: what does the Linea alba do
Separate both Recti abdominus medially
Pyramidalis muscles: origin, insertion, blood supply, innervation and action
Front of the pubis and pubic symphysis
Linea alba
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T12
Tenses linea alba
The rectus sheath: above ASIS
Above anterior superior iliac spine - the layers are:
Skin -> Camper’s fascia -> Scarpa’s fascia -> External oblique muscles -> internal oblique muscles -> Rectus abdominis muscles -> internal oblique muscles -> transversus abdominis muscles 0> transversalis fascia
The aponeurosis for the internal oblique muscles runs both above and below the RA muscles.
The rectus sheath: below the ASIS
Below the anterior superior iliac spine - the layers are:
Skin -> Camper’s fascia -> Scarpa’s fascia -> External oblique muscles -> internal oblique muscles -> transversus abdominis muscles -> Rectus abdominis muscles -> transversalis fascia
The aponeurosis for the internal oblique muscles runs both above and below the RA muscles.
Difference between the rectus sheath above and below the ASIS
Above - Rectus abdominis muscles are superior to half of the IO aponeurosis as well as the TA aponeurosis
Below - Rectus abdominis muscles are inferior to the EO, IO, and RA muscles
Arcuate line
The point at which the IO and TA aponeurosis changes from being deep to the RA to being superficial to it
Inferior epigastric artery: what does it do and what potential weaknesses are there?
Supplies the rectus abdominis muscles as well as the sheath with blood after slipping through the arcuate line
Posterior stability decreased (?), the muscle may herniate as it’s not solely surrounded by fascia (?)
Spiegalien hernia
Hernia related to the rectus abdominis muscle or the rectus sheath
Abdominal lymph drainage
Above the umbilicus, lymph is moved to the anterior axillary lymph nodes
Below the umbilicus, lymph is moved to the superficial inguinal lymph nodes
The superficial inguinal ring
A defect located above and medial to the pubic tubercle and found within the EO aponeurosis
Triangular shape
Connects with the deep inguinal ring to form the inguinal canal
Deep inguinal ring
A defect found within the transversalis fascia
Circular shape
Connects with the superficial inguinal ring to form the inguinal canal
Inguinal canal: what is it, what is it made from, and what are its contents?
- natural opening
- Parallel to the inguinal ligament
- Extends from the DIR to the SIR (3-5cm long)
Roof - fibres from IO and TA
Anterior wall - EO aponeurosis reinforced by IO fibres
Posterior wall - transversalis fascia and conjoint tendon (formed from lower fibres of IO and TA)
Floor - inguinal and lacunar ligaments (formed from inguinal ligament and fascia lata fibres)
Contents:
Males - spermatic cord and ilioinguinal nerve
Females - round ligament of the uterus and ilioinguinal nerve
Hernia
The protrusion of part of the abdominal contents beyond the normal confines of the abdominal wall (Snell)
Epigastric hernia
Along the midline, above the umbilicus
Umbilical hernia
At the umbilicus
Inguinal hernia
At the Inguinal Canal, in the right and left areas of the suprapubic region, above where a femoral hernia would be
Femoral hernia
Roughly where the femoral artery will begin, in the left/right iliac fossa
Paracentesis: through which layers of the abdominal wall must the needle pass in order to reach the peritoneal cavity?
ns, ask someone?
Incisions: what structures are cut in a midline incision, to gain access to the abdominal cavity?
ns, ask soemone?
Incisions: how might you access intraabdominal structures without damaging the trilaminar muscles?
ns, ask someone?
