Abdomen & Anterior Abdominal Wall Learning Objectives Flashcards
Explain the function of the abdomen and its boundaries
Function: flexible container for the abdominal organs
Boundaries
- Anterior: abdominal wall
- Posterior: vertebral column
- Superior: diaphragm
- Inferior: pelvic inlet
Explain the functions of the anterior abdominal wall
Functions:
- Support the trunk
- Support the abdominal viscera
- Manage intra-abdominal pressure during respiration
- Move the trunk and maintain posture
Describe the organization of the greater and lesser sacs
Greater sac: “main abdominal cavity”
Lesser sac: “omental bursa”; diverticulum
- Posterior to stomach
Describe the organization of the mesenteries
Mesentery = double layer of peritoneum; provides conduit for neurovascular supply b/t organ and body wall
Peritoneal layers:
- visceral (innermost)
- parietal
Peritoneal ligaments of the greater omentum
Gastrophrenic ligament
Gastrosplenic ligament
Gastrocolic ligament
Peritoneal ligaments of the lesser omentum
Hepatogastric ligament
Hepatoduodenal ligament
Falciform ligament
Peritoneal ligament
Attaches liver to posterior surface of anterior abdominal wall
Inferiorly encloses the round ligament of the liver
Intraperitoneal
Enclosed by visceral peritoneum
Suspended by mesenteries
Primarily retroperitoneal
Kidneys
Suprarenal glands
never had mesentery, posterior to peritoneal cavity
Secondarily retroperitoneal
Duodenum (desc, horiz, ascend)
Colon (ascend, desc)
Pancreas
Rectum (upper 2/3)
were previous intraperitoneal, but mesentery fused during development
Explain the layers of the rectus sheath above the arcuate line
upper 2/3
Anterior rectus sheath: external oblique and internal oblique
Posterior rectus sheath: internal oblique and transversus abdominis (and transversalis fascia however not RS)
Explain the layers of the rectus sheath below the arcuate line
lower 1/3
Anterior rectus sheath: external oblique, internal oblique, transversus abdominis
Posterior (not considered rectus sheath): transversalis fascia
Explain the significance of the arcuate line
Demarcates the transition b/t the aponeurotic posterior rectus sheath (internal oblique and transversus abdominis) and the transversalis fascia
- When IO and TA transition to anterior rectus sheath
Inferior epigastric vessels perforate the rectus abdominis
Describe the anatomy of the inguinal canal including its contents in both males and females
4 cm long, parallel to inguinal ligament
Openings:
Deep inguinal ring
Superficial inguinal ring
Contents:
- ilioinguinal n.
- male: spermatic cord
- female: round ligament of uterus
Inguinal canal boundaries
Floor: inguinal ligament reinforced medially by lacunar ligament
Anterior wall: external oblique (aponeurosis) reinforced laterally by internal oblique
Posterior wall: transversalis fascia reinforced by conjoint tendon
List the layers of the anterior abdominal wall from superficial to deep
Skin
Camper’s fascia (fatty layer)
Scarpa’s fascia (membranous layer)
External abdominal oblique m.
Internal abdominal oblique m.
Transversus abdominis m.
Transversalis fascia
Extraperitoneal adipose
Parietal peritoneum
Describe the innervation of the skin of the abdomen via T7-T12 spinal nerves
Innervation corresponds with dermatomal striping pattern; no plexus
T7-11: thoracoabdominal nn.
T12: subcostal n.
T4: nipple
T6: xyphoid process
T10: umbilicus
Describe the division of the abdomen into quadrants
Vertical: midline
Horizontal: through umbilicus
Right upper quadrant (RUQ)
– superior border is costal margin
Left upper quadrant (LUQ)
– superior border is costal margin
Right lower quadrant (RLQ)
Left lower quadrant (LLQ)
Direct hernia
Acquired
Medial to inferior epigastric vessels
Least common (<33%)
Indirect hernia
Congenital
Lateral to inferior epigastric vessels
Enters scrotum
Most common (>66%)
Name the composition of the portal triad
Hepatic artery proper
Hepatic portal vein
Common bile duct
Components of digestive system
Oral cavity
Pharynx
Esophagus
Stomach
Small intestine
- duodenum
- jejunum
- ileum
Large intestine
- cecum/appendix
- ascending colon
- transverse colon
- descending colon
- sigmoid colon
- rectum
- anus
Stomach: surface and internal features
Surface features:
o Fundus
o Body
o Greater and lesser curvatures
Internal features:
o Folds
o Cardiac and pyloric orifices
o Cardiac and pyloric sphincters
Small intestine function
enzymatic digestion of food; absorption of nutrients
Small intestine features
Duodenum
o Superior
o Descending
– Duodenal papillae (major and minor)
o Horizontal
o Ascending
Jejunum
o Duodenojejunal flexure
Ileum
Large intestine features
Surface features:
o Teniae coli
o Haustra
o Appendices epiploicae
Cecum
o Ileocecal junction
o Vermiform appendix
Ascending colon
o Right colic flexure
Transverse colon
Descending colon
o Left colic flexure
Sigmoid colon
Rectum
Anus
Explain the three layers of the thoracolumbar fascia including what attaches to each
Anterior layer: (not considered thoracolumbar fascia)
- Anterior to quadratus lumborum
Middle layer:
- Between quadratus lumborum and erector spinae
- Attachment for external/internal obliques
Posterior layer:
- Posterior to erector spinae
- Attachment for latissimus dorsi
Muscles of posterior abdominal wall
Psoas major/minor
Iliacus
Quadratus lumborum
Attachments for psoas major/minor
from transverse processes of T12-L4 to lesser trochanter of femur
Attachments for iliacus
from iliac fossa to lesser trochanter of femur
Attachments for quadratus lumborum
from 12th rib & transverse processes of L1-4 to iliolumbar ligament & iliac crest
Attachments for diaphragm
from xiphoid process, inner surface of the lower ribs & costal cartilages, medial & lateral arcuate ligaments & lumbar vertebrae via the crura to the central tendon
Name the openings in the diaphragm and the structures that pass through them
Left crus (“leg”)
Right crus
Median arcuate ligament
- Aortic hiatus passes through here
Medial arcuate ligament
- Psoas major/minor pass through here
Lateral arcuate ligament
- Quadratus lumborum passes through here
Parasympathetic innervation of kidney
Vagus >
Esophageal plexus >
Post vagal trunk >
Celiac ganglion and plexus >
Renal nerve plexus >
Kidney
Sympathetic innervation of kidney
Lesser/least splanchnic (T10-11; T12) >
Aorticorenal ganglion (synapse) >
Renal nerve plexus >
Kidney
Parasympathetic innervation of urinary bladder
S2-4 >
Pelvic splanchnic >
Inferior hypogastric plexus >
Wall (synapse; contraction)
Sympathetic innervation of urinary bladder
T10-12, L1-2 >
Lumbar splanchnic >
Superior/inferior hypogastric plexus >
Inferior hypogastric plexus (synapse) >
Wall relaxation
Define the trigone of the urinary bladder
Triangular surface at base of bladder
- Shaped by openings of ureter and urethra to form triangle
Urinary stones can form here
Contrast the anatomy of the male and female urethra
Male urethra
- 20 cm in length
- Prostatic, membranous, spongy segments
Female urethra
- 4 cm in length
Portal hypertension pathways
A) HPV > L gastric > esophageal > azygos > IVC
B) HPV > IMV > superior rectal > mid/inf rectal > internal iliac > common iliac > IVC
C) HPV > paraumbilical > sup/inf epigastric > IVC
D) HPV > splenic > IMV > L. colic > lumbars > IVC
Foregut
Liver, gallbladder, spleen, stomach, pancreas, duodenum
Midgut
Supplied by SMA
Small intestine, cecum, appendix, ascending colon, transverse colon
Hindgut
Supplied by IMA
transverse colon, descending colon, sigmoid colon, rectum
