GI Flashcards
(143 cards)
Layers of GI
-Epithelium thrown into folds
-muscularis mucosa
-submucosa
-submucoasl pplexus
-Circular
Myenteric plexus
longitudinal
serosa
PANS
Vagal is a mixed nerve and supplies the mid and foregut
- Hindgut is supplied by pelvic nerves
- release Ach and active peptides (VIP and substance P)
- Synapse on enteric nervous system in two plexuses and modulates action
- Vasovagal responses and reflexes
SANS
short presynaptic and long postynaptic
- Celiac
- Superior Mesenteric
- Inferior Mesenteric
- Hypogastic (supplies GU for sexual response)
- Sensory and motor
Enteric
Intrinsic and can funtion in the absence of the other two
- Plexuses
- Also gets input from local receptors
Omphalocele
- Gut contents fail to return to gut after they extend into yolk sac through vitelling duct
- Covered by peritoneum
- Surgical Repair
- Commonly see elevated AFP on triple screen
- Can be associated with Beckwith Wiederman and other congenital anomalies
- Midline
Gastroschesis
- Failure of the lateral body folds to close, often associated with vascular injury during birth
- There will be no peritoneum covering gut contents
- Elevated AFP
- Occurs lateral to the umbilicus
Malrotations
Most commonly involves the cecum being located in the RUQ
- Adhesions that attempt to make it go secondarily retroperitoneal lead to LADD bands that compress duodenum
- Lad bands cause bilious vommiting
- Also can be a nidus for volvulus
Midgut Volvulus
- Winding of midgut around SMA leading to compresssion and ischemia
- Bilious vommiting and necrosis of bowel
- Necrosis with widespread air fluid levels in the bowel
Duodenal Atresia
- Failure to recanalize duodenum after endodermal proliferation
- Highly associated with Downs
- Bilious Vomitting and may present with polyydramnios from impaired swallowing
- Can also be non billious depending on location
- Associated with other defects
Pyloric Stenosis
Hypertrophy of pyloric sphincter that leads to inability to empty stomach
- Palpable olive commonly
- Nonbillious vommiting
- Polyhydramnios
- Seen more commonly in firstborn males
Pancreatic Divism
- Normally ventral bud migrates around to the back and joins with dorsal bud
- Most of organ is in the dorsal bud, but the main pancreatic duct is in the ventral bud
- Divisim can be assymptomatic or can lead to stenosis of the accessory duct and pancretittis
- Also, malrotation can lead to annular pancreas that compresses duodenum
TE fistula
- Esophagus ends in blind pouch and then fistualizes with traches
- Cyanosis, bubbling, and drooling at birth
- Emergency, risk of aspiration pneumonia and cyanosis
- Will also see air int he stomach
Arcuate Line
- Location where the transversalis fascia goes from passing posterior to passing anterior of the rectus
- Location where epigastrics enter rectus
Inguinal Canal
- Deep Ring is lateral to epigastrics and is formed with transversalis fascia
- Internal oblique forms the cremaster
- External oblique forms the superficial ring that is medial to the epigastrics
Femoral Canal
Inferior to inguinal ligament
- Contains femoral sheath with artery and vein (vein being medial) (venous by penis)
- Nerve passes laterally and outside of sheath
- Lymphatics and saphenous pierce
Retroperitoneal
- 2 (Descending), 3 transverse, and 4 (ascending) duodenum
- Head, body of pancreas
- rectum, ascending and descending colon
Intraperitoneal
1st duodenum (bulb)
tail of pancreas
Sigmoid (redundant mesentery that is liable to volvulus)
Lesser Sac
-Epiploi foramen that contain the common bile duct, portal vein, and hepatic artery
Lateral Hypothalamus
- Causes hunger and food seeking behaviors
- Is inhibited by leptin
- Destuction leads to apathy and anorexia
DM hypothalamus
- Causes satiety
- Destruction leads to aggression and hyperphagia
- Leptin stimulates
Salivary Glands
Stimulated by PANS (watery) and SANS (Viscous)
-Flow rate determines ioinic conentation
-Higher flow is more hypertonic
-Lower flow is mor hypotonic
-Major regualation by absortion of Na
-HCO3 is constant and rich in hypotonic souatin
-Normally Cl and Bicarb predominate
-Lipase can digest through stomah
-Amylase can’t
-CN7 controls submandibular (seromucous) and sublingual (mucous)
CN9 does parotid (serrous)
Esophagus
Superior is skeletal muscle from 4th pharyngeal pouch contraolled by vagus at ambiguus
- Inferior is smooth muscle controlled by vagus and dorsal motor 10
- Squamous epithelium
Swallowing
- Esophagus has negative rpessure, UES prevents air and LES prevents gastric
- Primary peristalsis is from overiding vagal
- Secondary is local reflex archs
- Retching is vomitting against closed UES so food returns to stomach
Stomach Anatomy
- Fundus is superior (Short gastrics)
- Cardia
- Body (Parietal and Chief Cells)
- Antrum: Mucous Cells and G Cells