Flashcards in Motility & secretion of the GIT Deck (17):
4 functions of motility?
1st act of digestion
Abnormal teeth common cause of GIT disturbances
Pharyngeal phase involves...?
Breathing stops momentarily -> soft palate closes nasopharynx -> tongue closes pharynx opening -> epiglottis folds over glottis -> closes laryngeal opening
Motility in the proximal stomach...?
Wall relaxes to accomodate meal
Then contracts -> push food & empty
Motility in the distal stomach...?
Peristaltic waves push food -> pylorus
2 primary patterns in SI motility...?
Propulsive - peristalsis
Segmentation - mixes digesta with digestive juices -> mucosal surface
Describe the primary contractions (mixing) in the rumen
1st Reticulum contracts -> material to atrium & dorsal rumen
2nd contraction -> empties reticulum ->omasum
3. Rumen contractions cycles digesta round dorsal & ventral sac
4. Digesta moves back & forth -> ending up in omasum
Secondary contractions in the rumen...?
Produces CO2, O2, methane, nitrogen
Gases pushed cranially
3 steps in rumination...?
Regurgitate - via reticular contractions & low pressure in thorax -> material into oesophagus -> antiperistalsis -> mouth
Remasticate - some matter -> resalivation
Oral secretions from which glands?
2 types of saliva secretion?
Serous - parotids
Viscous - small glands
Mucin - lubrication
Amylase - Starch ->maltose (NOT in ruminants)
Lysozyme & antibodies - antibacterial
Urea - important N source for protein synthesis in ruminants
Ruminant saliva vs monogastric...?
Ruminant - higher volume produced; higher pH; higher [bicarb], [phosphate] & [Na]
Stomach lined with surface mucous cells
Protects stomach from acid
If injured -> stomach ulcers
Gastric mucous properties?
From crypt & surface epithelial cells
Glycoproteins & mucopolysaccharides
Protects against HCl & pepsin
Barrier against bugs & endotoxins
Pancreatic enzyme properties?
Secreted by EXOCRINE pancreas
2 types - potent enzymes & bicarb
Important in monogastrics (carry out most digestion)
Synthesised as zymogens (inactive)