Abdomen Overview (lecture 1) Flashcards
Where is the abdominal cavity?
between the diaphragm and pelvic inlet and is continuous with the pelvic cavity
What’s the superior boundary of the abdominal cavity?
diaphragm
What are the inferior boundaries of the ab cavity?
iliac crest, anterior superior iliac spine, inguinal ligament, pubic crest
What’s a central landmark of the abdominal cavity?
umbilicus
What’s the linea alba?
tendinous line and extends from xiphoid process to the pubic symphysis
Where is the transpyloric plane?
L1
Where is the transtubercular plane?
L4/L5
How many regions of the abdomen are there?
9 - 2 hypochondriacs, epigastric, 2 lumbars, umbilical, 2 inguinals, hypogastric
Does the organ hurt, or the subsequent inflammation from an organ in distress?
inflammation
What is in the superficial fascia?
camper’s fascia, scarpa’s facia, cutaneous nerves, superficial vessels
How is the anterior abdominal wall innervated?
lower 6 thoracic nerves (T7-T12”thoracoabdominal nerves” with T12 = subcostal nerve), lumbar plexus (ilioinguinal and iliohypogastric)
Where do the ilioinguinal and iliohypogastric come from?
anterior rami of the L1 lumbar plexus, with ilioinguinal running lower than iliohypogastric.
How does the ilioinguinal nerve enter the inguinal canal?
from the SIDE
What’s the difference between the iliohypogastric and ilioinguinal nerves?
ilioinguinal - becomes cutaneous
iliohypogastric - distributes to skin of pubic region
How is the skin near the midline supplied?
superior and inferior epigastric arteries
How is the skin near the flanks supplied?
lumbar, intercostal, and deep circumflex iliac arteries
How is the skin in the inguinal region supplied?
superficial epigastric, superficial circumflex iliac, superficial external pudendal arteries, and branches of the femoral artery
What are the branches of the internal thoracic artery?
pericardiophrenic, anterior mediastinal, pericardial, sternal, intercostal, perforating, musclophrenic, superior epigastric
Where does the musclophrenic artery supply?
branches of the aortic intercostal arteries (pericardium, diaphragm, abdominal muscles)
What does the superior epigastric artery anastomose with by entering sheath of rectus abdominus and going below it?
inferior epigastric artery
Where is the inferior epigastric artery?
immediatley below inguinal ligament and ascends between rectus abdominus and sheath to anastomose with superior epigastric artery above the umbilicus
What are the branches of the inferior epigastric artery?
external spermatic artery (accompanies spermatic cord supplying the cremaster), pubic (ana. with obturator) and muscular (abs, peritoneum, ana. w/ superficial epigastric artery)
What’s a safety mechanism in the abdomen and pelvis regarding blood supply?
anastomosases with other arteries to ensure blood flow
Where is the deep iliac circumflex?
behind inguinal ligament, ana. with lateral femoral circumflex, piercing transversalis fascia and transversus abdominus
What does the femoral artery give rise to?
superficial epigastric artery (1 cm below inguinal) and ascends in fascia to umbilicus, anastomosasing with inferior epigastric
superficial external pudendal
What does the superficial external pudendal supply?
lower ab wall, penis, scrotum, labium majorus
What is the dominant vascular supply to the anterior abdominal wall?
inferior epigastric arteries
What gives rise to the inferior epigastric artery?
external iliac artery (note: ABOVE inguinal ligament, so it’s the iliac artery, NOT femoral)
What is the superior epigastric artery a branch of?
Femoral artery
Where do the deep circumflex iliac arteries arise from?
external iliac artery
Where do the musculophrenic arteries arise from?
internal thoracic artery
What is the upper ab cavity vein system?
azygous, IVC
Where does the deep circumflex drain into?
external iliac veins
What drains into the great saphenous veins?
inferior and superficial epigastric, superficial external pudendal veins
What are paraumbilical veins?
branches of the left portal vein that lie in the ligament
(think: caput medusa is an illness that is located here)
What is caput medusa?
portal hypertension (often from cirrhosis of the liver (scarring)) caused by hepatitis, alcohol abuse, liver damage
What’s the solution to caput medusa?
Sengstaken-Blakemore tube
What’s the lymphatic drainage above the umbilicus?
pectoral lymph nodes in the axilla
What’s the lymphatic drainage below the umbilicus?
superficial inguinal lymph nodes
What are the 5 bilaterally paired muscles in anterolateral abdominal wall?
external and internal obliques, transversus abdominus, external and internal aponeuroses
What’s the purpose of ab muscles?
support and protection, flexion, lateral bending, increasing ab pressure
What’s the innervation of the ab muscles?
intercostal nerves (T7-11), subcostal (T12), ilihypogastric (L1) and ilioguinal (L1)
What’s the straight muscle of the abdomen and where does it connect?
rectus abdominus; pubis to xiphoid process and cartilage of ribs 5-7
How is the rectus abdominus arranged?
tendinous intersections laterally from linea alba “linea semilunaris”
What is the rectus sheath?
“sandwich” that encloses the upper 3/4 of the rectus abdominus with the “bread” being external, internal, and transversus that come together and go on either side, which make up the linea alba!
Note: this changes a bit around the ribs, and towards the pelvis, it isn’t squished in as tight
Is there a posterior rectus sheath?
No
What is the arcuate line?
where inferior epigastric vessels enter the rectus sheath and converge with superior epigastric vessels (may be absent)
Essentially separates the rectus sheath into inferior and superior portions
How is the arcuate line significant for the rectus sheath?
above the arcuate line, its a full sandwich. Below the arcuate line, there is only the top part of the “bun” so that it is strong anteriorly, but weak posteriorly between the muscle and abdominal viscera
What is the origin and insertion of the internal oblique?
o: lumbar fascia, iliac crest, lateral 2/3 of inguinal ligament
i: ribs 10, 11, 12, xiphoid process, linea alba, symphysis pubis
What is the internal oblique involved in?
lateral 1/2 of the inguinal canal, portion of rectus sheath, inguinal falx, cremasteric muscle fascia, and has an upward and forward angle
What does the external obilque do?
flexes vertebral column; forward and downward angle
What’s the origin and insertion of the external oblique?
o: ribs 5-12
i: aponeurosis, iliac crest, linea alba, rectus sheath
What’s the transverse abdominus do?
flexes and laterally bends trunk, support, increases intra-abdominal pressure
What’s the origin and insertion of the transverse abdominus?
o: lower 6 ribs, thoracolumbar fascia, iliac crest, inguinal ligament
i: linea alba, pubic crest, pecten of the pubis
What’s the innervation of the transverse abdominus?
anterior primary rami (T7-12), conjoint tendon ilioinguinal nerve (L1)
What are the different types of abdominal incisions?
Midline, transverse (horizontal w/o fear of nerve damage), subcostal (exposing gallbladder/spleen to avoid nerve), muscle splitting incisions (avoid cutting muscle fibers)
What is the umbilicus?
remnant attachment of umbilical cord, located in linea alba, if scarring is incomplete, it causes an umbilical hernia
How many umbilical ligaments are there?
3, two of which are paired
What’s the median umbilical ligament?
runs from apex of bladder to the umbilicus, complications can lead to urine leakage
What are the paired medial umbilical ligaments?
lies on each side of the midline, remnants of umbilical arteries, running from internal iliac arteries in pelvis to the umbilicus
What are the paired lateral umbilical ligaments?
ridges raised by existing and functioning inferior epigastric arteries
What do the lumbar vertebrae do in the abdominal wall?
form posterior wall of abdomen allowing flexion and extension, convex curvature or lordosis, and can be a site of fracture
What are the five muscles of the posterior abdominal wall?
iliacus, psoas major, psoas minor, quadratus lumborum, diaphragm
What is the quadratus lumborum?
laterally in the posterior abdominal wall, a thick muscular sheet in quadrilateral shape positioned superficially to psoas major
- includes extension and lateral flexion of vertebral column (fixing 12 rib during inspiration)
What is the quadratus lumborum innervation?
subcostal nerve L1-L3
What are the attachments of the quadratus lumborum?
o: iliac crest and iliolumbar ligament
i: transverse process of L1-L4 and 12th rib
What’s the psoas major?
located near midline of posterior abdominal wall, flexes thigh at hip and lateral flexing of vertebral column. Covered by fascia (transversalis fascia, psoas fascia)
What are the attachments for the psoas major?
o: transverse processes and vertebral bodies of T12-L5
i: lesser trochanter of femur
What’s the innervation for the psoas major?
anterior rami of L1-L3 nerves
What’s the psoas minor?
anterior to the psoas major (present in 60% of people), flexes vertebral column
What’s the attachments of psoas minor?
o: T12 and L1 and attaches to superior ramus of pubic bone “pectineal line”
what’s the innervation of the psoas minor?
anterior rami of L1 spinal nerve
What’s the illiacus?
fan-shaped muscle stationed on posterior abdominal wall that assists with flexion of thigh at hip joint
What does the psoas major and iliacus major together make?
iliopsoas, major flexor of thigh
What are the attachments of the iliacus?
o: surface of iliac fossa and anterior inferior iliac spine
i: lesser trochanter of the femur
What’s the innervation of the iliacus?
femoral nerve (L2-L4)
What’s the lumbar plexus?
innervates the structures of the lower abdomen as well as the anterior and medial segments of the lower extremity
What do the posterior branches of the lumbar dorsal rami supply?
back muscles, vertebral bodies and intervertebral discs, periosteum, vertebral body, annulus fibrosis, dura mater and nerve root sleeves, femoral nerve
What is the most important nerve from the lumbar plexus?
femoral nerve
What does the femoral nerve supply?
anterior and lateral thigh muscles, medial leg and foot, quadratus femoris, iliopsoas, sartorius
What do the ventral rami supply?
quadratus lumborum, psoas major, obturator nerve (medial thigh, abductor hip)
How is the lumbar plexus formed?
ventral rami of L1-L4 with contributions from T12 and L5 and forms within the psoas muscle
What are the peripheral branches of the lumbar plexus?
iliohypogastric, ilioinguinal, genitofemoral, lateral femoral, femoral, obturator
What is the peritoneum?
single layer of mesothelial cells resting on a thin layer of connective tissue with a parietal and visceral layer (they are continuous at one point) with a cavity in between
What are the peritoneum functions?
location of blood and lymph vessels, nerves, lubrication, serous fluid production, suspension of organs, limit spread of infection, adhesions
What is mesentary?
double layer of peritoneum connecting viscera to abdominal wall
What is the omentum?
double layer attached to stomach
What is the peritoneal ligament?
layers that connect viscera to abdominal wall
What ligaments hold the stomach in place?
hepatoduodenal ligament, gastrohepatic ligament, gastrophrenic ligament, gastrosplenic ligament
review this slide for where these ligaments are
Where is the retrocecal recess?
posterior to appendix
Where is the hepatorenal recess?
Morrison’s pouch - lowest point in peritoneal cavity when supine (where fluid goes); below the liver and above the kidney
Where are the paracolic gutters?
lateral to ascending and descending colon and forms a “gutter”
Where is the subphrenic abscess?
below diaphragm and above liver, where fluid can accumulate as well
What is peritonitis?
inflammation and generation of a sticky fluid containing fibrin that glues the greater omentum to the inflamed areas (limiting spread)
Where is referred pain for the liver, gallbladder, and duodenum?
right shoulder and neck area
Where is referred pain for the stomach?
middle upper back, front middle abdomen and left a bit
Where is referred pain for the gall bladder?
inferior border of scapula wrapping upwards
Where is referred pain for the liver?
making a U from front to back along the side in middle abdomen, right shoulder
Where is referred pain for the kidney/ureter?
wraps around side from back to groin area
Where is referred pain for the spleen?
left pocket where it’s located
Where is referred pain for the cecum/ascending colon?
subrapubic
Where is referred pain for the small intestine?
center abdomen
