Digestive System Flashcards
Peritoneum: layers
Parietal peritoneum: lines wall of abdominopelvic cavity Visceral peritoneum (serosa): covers some organs Space between: peritoneal cavity- contains serous fluid
Ascites
Abnormal accumulation of serous fluid in peritoneal cavity
Peritoneum: what is it, what’s it made of
Largest serous membrane in body
Made of a layer of simple squamous epithelium (mesothelium) and underlying layer of areolar connective tissue
Retroperitoneal organ
When peritoneum only covers anterior surface.
Kidneys, L intestines, duodenum, pancreas
Peritoneal folds
Greater omentum Lesser omentum Falciform lig Mesentery Mesocolon
Greater omentum
Largest peritoneal fold
2 sheets, folds on itself
Covers transverse colon and small intestine
Responsible for beer belly
Falciform ligament
Attaches liver to ant abdominal wall and diaphragm
Lesser omentum
Suspends stomach and duodenum from liver
Pathway for BV entering liver
Mesentery
Fans out from post abdominal wall, wraps around S intestine and returns
Double layered. BVs and LVs and nodes in between
Mesocolon
2 sep folds
Bind transverse colon and sigmoid colon to post abdominal wall
Carries BVs and LVs to post abdominal wall
What activates then inactivates salivary amylase?
Chloride ions activate it, stomach acids inactivate it
Salivary amylase
Digestive enzyme
Initiates breakdown of starch into smaller molecules
Works for about an hour
Stomach acids will inactivate it.
Lingual lipase
Digestive enzyme
Becomes activated by stomach acid
Breaks down triglycerides into diglycerides and fatty acids
Movement of food from mouth into stomach by swallowing
Deglutition
Deglutition stages
Voluntary
Pharyngeal
Esophageal
Deglutition voluntary stage
Bolus into oropharynx via tongue
Deglutition pharyngeal stage
Involuntary
Bolus moves through pharynx to esophagus
Deglutition centre in medulla cause uvula and soft palate to block nasopharynx, epiglottis to block larynx
Esophageal stage of Deglutition
Involuntary passage of bolus
From esophagus to stomach
Peristalsis
Mucous secretion from esophageal glands
Layers of GI tract
Mucousa
Submucousa
Muscularis
Serosa
Mucosa layers
1) Epithelium
- some exocrine cells among them: secrete mucous and fluid
2) Lamina propria
- has BVs&LVs: distribute nutrients from GI to other parts
- has most of MALT cells (immune cells)
3) Muscularis mucosae
- has folds in stomach and S intestine for more surface area
GI tract mucosa: Epithelium of mouth, pharynx, esophagus, anal canal
Non-keratinized stratified squamous.
Protective function
GI tract mucosa: epithelium of stomach and intestines
Simple columnar.
Secretes, absorbs
MALT of GI tract
Mucosa-associated lymphatic tissue: In Lamina propria Lymphatic tissue containing immune cells Along entire tract, esp: Tonsils Appendix S intestine L intestine
GI tract layer: submucosa
Binds mucosa layer to muscularis
Has BVs and LVs
Submucosa Plexus
