1B Anatomy of the GI Tract Wall Flashcards
T/F The GI tract is continuous w/ the external environment
T
What is one of the most common problems with GI tracts in the US?
Peptic ulcer disease (PUD)
What is PUD?
Gastric juice penetrates the gastric mucosal barrier, injuring the gastric wall w/ its acidic and enzymatic contents
What is acute pancreatitis?
Pancreatic juice escapes the pancreas and/or duodenum. Pathology usually involves an obstructed pancreatic duct at its entrance into the duodenum
What happens during a ruptured appendix?
The colon wall tears open, allowing intestinal bacteria to escape to the abdominal and pelvic cavities, causing peritonitis or even death
What are the four layers of the GI tract wall?
Mucosa, submucosa, muscularis externa, and serosa
What are smooth muscle pacemaker cells?
Smooth muscle cells that display rhythmic, spontaneous variations in membrane potential
What is the prominent type of self-induced electrical activity in digestive smooth muscle called?
Slow-wave potential
What is the slow-wave potential also referred to as?
Basal electrical rhythm (BER) or pacemaker potential
What is the enteric nervous system?
The neurons of the submucosal and myenteric plexuses. AKA intrinsic nerve plexus
What are extrinsic nerves and how do they differ from the intrinsic nerves?
Extrinsic nerves originate outside the GI tract and innervate the various GI organs. Intrinsic nerves are inside the walls of the GI tract
T/F The extrinsic nerves have both paraSNS and SNS
T
What part of the GI tract does the Vagus nerve innervate?
The upper GI tract - esophagus, stomach, small intestine, and ascending colon
What percentage of the vagus nerves are afferent vs. efferent?
75% are afferent
25% are efferent
What pelvic nerves innervate the lower GI tract?
S2, S3, and S4