Anatomy Flashcards
What nerve(s) innervates the anterior abdominal wall muscles (external and internal oblique, transversus abdominis)?
Thoracoabdominal T7-T11 and subcostal nerve T12 (and branches of lumbar plexus for internal oblique + transversus abdominis)
The internal oblique muscle inserts into ___
Ribs 10-12
The linea semilunaris demarcates the ____ and runs from the 9th rib to the ____
Lateral border of the rectus abdominis muscles; pubic tubercle
The trans pyloric plane is at approximately what vertebral level?
L1
The deep inguinal ring is located where along the inguinal ligament? It is an oval defect in which structure?
Mid-point (between ASIS and pubic tubercle); transversalis fascia
The superficial inguinal ring sits MEDIALLY/ LATERALLY to the inferior epigastric artery? It is a defect in which structure?
Medially; external oblique aponeurosis
True or false: the ilioinguinal nerve passes through the deep inguinal ring into the inguinal canal?
False - it is a structure contained in the inguinal canal but gains access via the anterior wall/ piercing the roof midway along the canal (it is NOT transmitted through the deep ring)
Describe the fascial linings of the spermatic cord and their origins?
External spermatic fascia - from external oblique aponeurosis
Cremasteric muscle/ fascia - from internal oblique muscle and fascia
Internal spermatic fascia - from transversalis fascia
The cremaster artery arises from the ____
inferior epigastric artery
List the retroperitoneal structures
SAD PUCKER - Suprarenal glands, Aorta/ IVC, D2/3, Pancreas (except the tail), Ureters, Colon (ascending + descending), Kidneys, Esophagus, Rectum
The inguinal ligament is formed by ____
The free inferior border of the external oblique aponeurosis. It extends from the ASIS to pubic tubercle
What is the approximate length of the inguinal canal? What are its contents?
4cm (6cm in Last’s); Spermatic cord (males) / round ligament (females) and ilioinguinal nerve
The arcuate line is the horizontal delineation of the lower posterior rectus sheath. Where is it usually positioned?
Approx 2.5cm below the umbilicus. It is also known as the Semicircular line of Douglas
Describe the aponeurotic layers of the rectus sheath superior and inferior to the arcuate line
SUPERIOR: external oblique aponeurosis is anterior, the internal oblique aponeurosis splits and has a ‘laminae’ anterior and posterior to rectus muscle, transverses aponeurosis lies deep
INFERIOR: external, internal oblique aponeurosis and transversus aponeurosis lie anteriorly (transversalis fascia lies deep)
The median umbilical ligament runs from ____ to ____ and contains the ____
Superior bladder to midline of internal anterior abdominal wall. Urachal remnant
The medial umbilical ligaments (x2) are formed due to ___
The obliterated umbilical artery
The lateral umbilical folds (NOT ligamentous structures) are formed by ____
The inferior epigastric arteries
(the epigastric vessels sit post to rectus abdominis, in the post rectus sheath (above arcuate line) or superficial to transversalis fascia (below))
The foregut is from mouth to ____ (supplied by X), midgut from ____ to _____ (supplied by Y) and hindgut from ____ to anus (supplied by Z)
The foregut is from mouth to D1 (coeliac artery), midgut from D1 to L colic (splenic) flexure (SMA) and hindgut from L colic (splenic flexure) to anus (IMA)
The duodenum sits anterior/ posterior to the bile duct, portal vein and pancreas
Anterior
The major duodenal papilla empties into which part of the duodenum?
D2 (descending)
Psoas major, the IVC, aorta, right ureter and gonadal vessels pass anteriorly/posteriorly to the duodenum, and the SMA/ SMV pass anteriorly/ posteriorly
posteriorly; anteriorly
Which structures suspends the duodenojejunal flexure from the posterior body wall?
Ligament of Treitz
The jejunum is usually thicker/ thinner walled than the ileum, has more/ less plicae circulares and single/ multiple layers of vascular arcades with short/ long vasa recta
Thicker walls; more; single; long (allows for ‘windows’ in mesentery - thinner between vasa rectae)
Where are Peyer’s patches located?
Ileum.
These are palpable lymphatic nodules part of the MALT (mucosa associated lymphoid tissue), and distinguish ileum from jejunum