Structure of abdomen Flashcards
four diaphragm primordia and what they form
septum transversum: most of central tendon. Mesentery of esophagus: muscular crura and middle central tendon. Pleuroperitoneal membranes: part of central tendon. Body wall: muscle
structures perforating diaphragm and at what levels
T8: vena cava, T10: esophagus, T12: aortic hiatus (aorta, thoracic duct, azygos vein)
three types of diaphragmatic hernia
congenital: failure of pleuropeitoneal membranes to fuse (posterolataral defect with abdominal organs in thorax). Sliding hiatal: is most common. GE
junction is displaced ^; “hourglass stomach.”. Paraesophageal hernia—GE junction is normal.
Fundus protrudes into the thorax.
omphalocele vs gastroschisis
midgut fails to return from umbilical cord (covered by peritoneum). Failure of left and right somatopleure to fuse, abdominal contents extrude thru folds (not covered by peritoneum)
nine regions of abdomen
Epigastric, umbilical, suprapubic flanked by L and R hypochondriac, lumbar, inguinal
what primordial tissue do the organs develop from
splanchnopleure. Parenchyma (epithelium of GI tract) from endoderm and stroma (SM, CT, vasculature, visceral peritoneum) from lateral plate mesoderm
3 branches of celiac trunk
splenic, L gastric, common hepatic (then divides into hepatic proper and gastroduodenal). All give blood supply to foregut.
Branches of S Mesenteric
ileocolic, R colic, Middle colic, intestinal branches All give blood supply to midgut.
branches of I mesenteric
L colic, sigmoid branches, S rectal. All give blood supply to hindgut
define: arcade, vasa recta, marginal artery
looping anastomoses. Go straight to intestine from arcades. Follow contour of colon
parasympathetic path to gut
foregut and midgut: vagus. Hindgut: pelvic splanchnic nerves (S2,3,4). Presynaptics synapse in Myenteric (auerbach’s) plexus for SM and submucosal (meissner’s) plexus for glandular secretion and muscularis mucosase
path of sympathetics
thoracic (abdominal) and lumbar (pelvic) splanchnics synapse on collateral (prevertebral) ganglia and innervate arteries and adrenal glands
spinal cord segments for visceral sensory of: heart, stomach, appendix, left colic flexure to sigmoid colon
T1, T7-T9, T10, L1-L5
somatic pain, visceral pain, referred pain.
intense sensation carried by general sensory neurons in body wall. Mostly dull sensation carried by visceral sensory neurons in organs (except: stones, appendicitis, spasm, ulcers). Originates in one location and felt in another supplied by same spinal segment (peritonitis under diaphragm felt in C3,4,5 dermatomes of shoulder)
four lobes of liver
left, right, caudate, quadrate