Abdominal Wall And Cavity Flashcards
What does a median incision go through?
Linea alba
Which incision would you use to access the gallbladder?
Subcostal
What would you use a pfannenstiel incision for?
C section
What happens to the rectus sheath at the arcuate line?
Above line, rectus abdominis covered anterior and posterior by aponeuroses of flat muscles of abdo wall
Below line, all 3 aponeuroses are anterior to muscle and so only fascia behind. This leaves region vulnerable to herniation
Which vessels are contained in rectus sheath?
Superior and inferior epigastric artery and veins
What are the 5 layers of the anterior abdominal wall?
Skin Superficial fascia Muscles and aponeuroses Transversalis fascia Parietal peritoneum
Where does the inguinal ligament run?
From ASIS to pubic tubercle
Which muscle runs from rib 5-12 to anterior iliac crest, linea alba and pubic tubercle?
External oblique
What is an aponeurosis?
Broad flat sheet of tendon
What is the linea alba?
Midline fibrous aponeuroses
Why can you safely inject a needle or cannula into linea alba?
Avascular
Where does lymph of the anterior abdominal wall drain to?
Above umbilicus - axillary nodes
Below umbilicus - inguinal nodes
What is a hernia?
Protrusion of tissue or organ through its retaining tissue
Name 3 sites for an anterior abdominal wall hernia
Umbilical
Inguinal
Femoral
What is hesselbachs triangle?
Area of bulging of direct hernia. Medial to inferior epigastric artery. Bordered by rectus abdominis and inguinal ligament
Which type of anterior abdo wall hernia are women and men most likely to get?
Men - indirect inguinal
Women - femoral
What are the differences in contents of inguinal canal in males and females?
Males - spermatic cord and contents
Females - round ligament of uterus and lymphatics from uterus
What are the boundaries of the abdomen?
Diaphragm to pelvic girdle
What vertebral level is the Subcostal plane on?
L3
What vertebral level is the supracristal plane on?
L4
What vertebral level is the transtubercular plane on?
L5
What planes divide the abdomen into the 9 regions?
Mid clavicular lines
Subcostal plane
Transtubercular plane
What does the external oblique aponeurosis lower free border form?
Inguinal ligament
Where does the internal oblique run from and to?
From iliac crest and inguinal ligament
To linea alba, pubic bone and ribs 9-12
What do the lower aponeurosis of the internal oblique form?
Part of the conjoint tendon
Which arteries are united by the epigastric arteries?
Subclavian artery and external iliac artery
What can the vascular supply of the abdominal wall provide a bypass for?
Descending aorta
What nerve is at risk from a gridiron incision?
Ilioinguinal
What serves as a reference point to differentiate between an inguinal and a femoral hernia?
Pubic tubercle
Above and medial - inguinal
Below and lateral - femoral
What are the borders of the lumbar (petit) triangle?
External oblique
Latissimus dorsi
Iliac crest
What is the deep inguinal ring?
Invagination of transversalis fascia
Lies between the midpoint of inguinal ligament and the midinguinal point (1cm above the inguinal ligament)
What is the superficial inguinal ring?
Lies supero-lateral to the pubic tubercle
Point of emergence of spermatic cord (male) or round ligament and coverings (female)
What forms the tunica vaginalis?
Testicle is retroperitoneal and descends through the anterior abdominal wall and pulls a fold of peritoneum with it that forms the tunica vaginalis
What forms the posterior wall of the inguinal canal?
Transversalis fascia
What level does the coeliac trunk, SMA and IMA branch from the aorta?
T12
L1
L3
What pain modalities are viscera not sensitive to?
Cutting or thermal stimuli
What are the 2 compartments of the greater sac?
Supracolic and infracolic
Why does the lesser sac become sectioned off?
Pancreas, liver, duodenum and gallbladder become secondarily retroperitoneal
How does the stomach rotate to reach its adult position?
Rotates to right about longitudinal axis & clockwise about sagittal axis
What does the ventral mesentery become?
Lesser omentum
What does the dorsal mesentery become?
Greater omentum
Describe the surface anatomy of the liver
Right costal margin
Follows upper limit of diaphragm
5th rib at mid clavicular line
Associated with costodiaphragmatic recess
What holds the liver in place?
Peritoneum
Which part of the liver is in contact with the diaphragm?
Bare area
What are the 4 lobes of the liver?
Left
Right
Caudate
Quadrate
What is the porta hepatis?
Entry and exit point for portal vein, bile duct, hepatic artery and autonomics from liver
What structures form a H shape on the posterior of the liver?
Ligamentum venosum Ligamentum teres Porta hepatis IVC Gallbladder
Which peritoneal recesses can accumulate fluid / be a focus for abscess formation?
Sub-phrenic space
Hepato-renal space - Morison’s pouch
What are the functions of the peritoneum?
Facilitate movement between abdominal organs and between organs and the abdominal wall
Produce peritoneal fluid which contains leukocytes and antibodies
What is the difference between intraperitoneal and retroperitoneal organs?
Intraperitoneal organs are almost completely covered by peritoneum and suspended by a mesentery whereas retroperitoneal organs are only partially covered by peritoneum
What is the dermatome supply of the following regions – epigastric, umbilicus and suprapubic?
Epigastric: T7
Umbilicus: T10
Suprapubic: L1
In a paramedial incision, which way would you displace the muscle and why?
Laterally, towards its nerve supply
