4.1 Digestive System part 2 (Submucosal secretions) Flashcards
Submucosal secretions into the GI tract are from the…
Glandular epithelium in (salivary glands, stomach, pancreas, liver, small intestine, large intestine…)
Are the glands that produce submucosal secretions considered exocrine or endocrine glands?
Exocrine
What two types of saliva do the salivary glands produce?
Serous and mucous
Serous saliva
Solubilizes food
Mucous saliva
Lubricates passage of food
What counteracts acidic foods? (Salivary gland secretions)
Buffers (sodium bicarbonate)
Salivary amylase
Initiates carbohydrate digestion by chemical digestion of food
-Breaks starch into disaccharides
4 layers of stomach lining
Mucosa
Submucosa
Muscularis
Serosa
Mucousal cells of the gastric pits
Mucous cells
Parietal cells
Chief cells
Endocrine (G) cells
Mucous cells
Secrete mucus on surface and in neck of glands, protect stomach wall from damage by acid and enzymes
Parietal cells
Secrete HCl
Chief cells
Produce pepsinogen enzyme, converted to active pepsin by stomach acidity (works best at pH less than 3)
Endocrine (G) cells
Produce hormones (Gastrin, histamine)
What enzyme takes carbon dioxide and water to make bicarbonate?
Carbonic anyhydrase
Net effect of HCl production by parietal cells
Stomach pH drops
Blood pH rises
Is the H+ going into the stomach active or passive transport?
Active
Is the HCO3 going into the blood active or passive transport?
Passive
Cells make up ____ but they themselves have _____
Villi, microvilli
Lacteal in small intestine
Lymph tissue, fat absorption
Enterocyte
Often called S cells because they are secreting