5-Digestive system Flashcards
Mouth, pharynx, esophagus and anal canal are lined with – – epithelium : protective function
Stratified squamous epithelium
Function of Simple Columnar cells in stomach and intestines
Secrete and absorb nutrients
In the mucosa, the layer of connective tissue that contains blood and lymph vessels
Lamina propria
What the muscularis mucosae does
Create folds and increase surface area
Layers of GI tract from Innermost to Outermost
Mucosa, submucosa (connective tissue binding mucosa to muscularis), serosa
– neuron is located bw smooth m layers of muscularis mucosae and controls movement
Myenteric
Purpose of submucosal plexus (nervous control)
Control secretions of secretory cells of epithelium
– Innervation consisting of VAGUS nerve INCREASES secretion and motility (increase activity of enteric neurons)
Parasympathetic Innervation
Salivary amylase (breaks down carbohydrates) is – by stomach acids and lingual lipase (breaks down fats) is – by stomach acids
Salivary amylase is DEactivated by stomach acids
Lingual lipase is Activated by stomach acids
What 3 things does the stomach secrete?
HCl
Pepsin - protein enzyme, activated by hcl
Gastric lipase
What is the absorption in stomach limited to?
Water, certain ions, short chain fatty acids, drugs, alcohol
The exocrine pancreas consists of – cells that secrete pancreatic juice OUT thru duct and into duodenum
Acini cells - exocrine - duct
The endocrine pancreas consists of – cells and secretes glucagon and insulin into blood
Islet cells
islet is like INlet for endocrone
Name the pancreatic enzymes
- Pancreatic amylase
- Protective protein enzyme secreted in inactive form
- pancreatic lipase
- nucleic acid enzymes
Purpose of sodium bicarbonate in pancreatic juice
- buffer acidic gastric juice in chyme
- Create proper, more basic pH for enzymes in small intestine
– are functional cells in liver that produce bile
Hepatocytes
What happens to iron, globin, and bilirubin after phagocytosis of aged RBC liberates them?
Iron and globin are recycled
Bilirubin broken down in intestine, excreted in bile and urine
Purpose of bile salts
Aide in absorption of lipids
Significance of pancreatic lipase
Principal triglyceride digestion
8!!! Functions of liver
- Production of bile
- Carb metabolism - glycogen storage
- Lipid metabolism
- Protein metabolism - ATP & blood proteins
- Processing of drugs and hormones - detox
- Excrete bilirubin from heme
- Storage of vitamins and minerals
- Activation of vitamin D
4 cells of small intestine and what they do
- absorptive cells absorb nutrient
- goblet cells secrete mucosa
- goblet of mucus*
- paneth cells secrete lysozyme
- enteroENDOCRINE cells secrete hormones
Digestion of what occurs in small intestines
- carbs to monosaccharides
- proteins to amino acids
- lipids to fatty acid and glycerol
- nucleic acids to nucleotides
– of all absorption occurs in small intestine
90%
What is secreted by LARGE intestine
Mucus but no enzymes
