1. Embryongic Origin of GI tract
    Endoderm—epithelial, GI glands, (liver, gall badder, Pancreas)

    Splanchnic Mesoderm—Intrinsic Muscle, Conn Tiss, Peritoneal Linings

    Neural Crest—Enteric Nervous System
  2. Forming of Primitive Gut
    Coronal-Cuadal folding incorporates endodermal lining and splancnich mesoderm into embryo to for the Primitive Gut
  3. 4 Divisions of Primitive Gut @Day 28
    • Pharyngeal Gut|Foregut|Midgut|Hindgut
    • (Foregut, midgut, hindgut are considered as 3 abdominal division)

    Buccopharyngeal membrane-primitive mouth –part of phyrengeal gut

    Foregut – trachealbrochial diverticum (lung bud)

    Midgut – connect to the yolk sac by Vitilline Duct. bring vitamins to embryo—becomes umbilical chord

    Cloacal Membrane-primitive anus(closed) –part of hindgut
  4. Blood Supply to GI tract
    Each of the 3 abdominal divisions of the developing GI tract is associate with:
    with an Unpaired artery from aorta

    1. Celiac: supplies Foregut—Esophegus, stomach Duedonal Loop, spleen

    2. Superior Mesenteric Artery: supplies Midgut—small & large intestines

    3. Inferior Mesenteric artery: supplies Hind gut—Urogenital system, anus
  5. 3 paired arteries to Paired abdominal Glands
    Kidney—Renal Artery

    Adrenal Medulla—Suprarenal Artery

    Gonads—Gonadal Artery
  6. 3 UNPAIRED arteriesto UNPAIRED gastrointestainal Viscera
    Celiac Artery (first major branch of the abdominal aorta)

    Superior Mesenteric artery

    Inferior Mesenteric Artery
  7. Peritoneum
    Visceral: also called:
    Parietal: lines abdominal cavity

    • Visceral: reflected on to organs double fold also called mesentery
    • - Mesentery: suspends organs from posterior abdominal wall (always posterior)
    • - Omentum: loose support from one organ to another
    • - Ligament: double fold of peritoneum from organ to organ, or from organ
    • to abdominal wall
  8. Retroperitanel- outside peritoneum
    • S = Suprarenal glands (aka the adrenal glands)
    • A = Aorta/IVC
    • D = Duodenum (second and third segments [some also include the fourth segment] )
    • P = Pancreas (tail is intraperitoneal)
    • U= Ureters
    • C= Colon (only the ascending and descending branches)***
    • K = Kidneys
    • E = Esophagus
    • R = Rectum

    • ***transverse
    • colon is completely incased in visceral peritoneal to allow for free moving
  9. Outgrowths of Foregut (Supplied by Celiac)
    -Esophagus, Stomach, Liver, Duodenum, Dorsal/Ventral Pancreatic Outgrowth, Gall bladder
  10. Lesser Omentum can be divided into 2 divisions
    - Hepatoduodenal ligament-connects liver and Deuodenum

    - Gastohepatic Ligament- Stomach and liver

    FYI Stomach turns 90 deegrees during development
  11. Major branches of the Celiac Artery –3 branches
    Gastric: supplies the lesser curverature of the less side of stomach

    Splenic: supplies the spleen

    • Common Hepatic Artery: branches to supply the right side of stomach, liver,
    • gall bladder, part of the pancreas
    • - hepatic artery
    • - proper hepatic artery
    • - right gatric artery
  12. Falciform
    Falciform is double layered lining that connect liver to the body wall

    • --within falciform ligament is the ligamentum teres which is the reminence
    • of the obliterated umbilical vein
  13. Bare Area of the liver
    The portion of the area that is smashed up against the diaphragm not covered by the peritonium

    The bare area of the liver is clinically important because it represents a site where infection can spread from the abdominal cavity to the thoracic cavity
  14. Pancreas secretes
    • Bi-carbonate into the duondenum in order to
    • neutralize chyme
  15. Porta Hepatis
    • In free margin of lesser omentum (hepatodudenal ligament)
    • Place where vessels and bile duct lie
  16. SMA complication
    • Superior Mensentary Artery goes over the renal vein -- complication when SMA clamping renal vein during inflammation
    • Pancrea sits on top (pancreatic cancer gets it)
  17. Midgut derivatives
    from distal duodenum through 2/3 transverse colon:

    • Small intestine--duodenum (10”), jejunum (8’), ileum
    • (12’)

    caecum(blind sack) and appendix,

    Ascending colon

    2/3 of transverse colon
  18. Gall bladder's bile duct sent to:
  19. Omphalocele
    -Failure of Midgut to retract into abdomen
  20. Growth of Intestinal loop
    more rapid than developing abdomen

    Herniates out of abdominal cavity

    Rotation clockwise around the axis of superior mesenteric artery

    Will eventualy retract into abdomen

    Caudal limb subsequently retracts, undergoing further rotation
  21. Hindgut derivatives:
    Large Intestine

    distal 1/3 transverse colon

    descending colon

    sigmoid colon

    superior 2/3 anal canal [inferior 1/3 anal canal ectoderm]

    epithelium of bladder

    most of urethra
  22. Taenia Coli:
    thin strip of muscle that runs the length of the large intestine but not the entire length gives rise to the pouch formation (haustra)

    • Haustra-small pouches caused by saculation which gives colon segmented
    • appearance
  23. Hindgut Blood Supply
    • Inferior Mesenteric Artery supplies the distal 1/3 of transverse colon
    • to anal canal
    • Urorectal septum grows and divides hindgut
    • -rectum and anal canal are dorsal
    • -urogenital sinus is ventral

    Uroectal septum divides the hindgut into front and back. The posterior parts become structures of the GI tract, and the anterior parts become parts of the urinary system. This is why parts of the bladder and urinary system are supplied by the inferior mesenteric artery.
  24. Hepatic Portal System
    Blood will drain into liver first before entering inferior vena cave

    • does not want heart to receive toxins/
    • nutrients
  25. Enteric Nervous System
    From small Intestine to Large Intestine

    Can be innervated by Autonomic NS or on its own
  26. Extrinsic innervation vs. Intrinsic innervation
    • Ext: Autonomic (sympathetic and parasympathetic)
    • Int: Enteric
  27. Sympathetic
    • Sympathetic nerves have a general inhibitory action on digestion, inhibiting smooth muscle contraction and secretion.
    • Splanchnic nerves (preganglionic), synapse in celiac ganglion surrounding celiac artery, and in ganglia surrounding superior and inferior mesenteric arteries.
  28. Parasympathetic
    Parasympathetic nerves have a general stimulatory action. Vagal nerves (preganglionic) synapse in myenteric and submucous plexus within gut wall to innervate through transverse colon. Sacral outflow of parasympathetics supplies distal organs.
Card Set
D1 Fall MID1