Motility & secretion of the GIT Flashcards Preview

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Flashcards in Motility & secretion of the GIT Deck (17):
1

4 functions of motility?

Propel
Retain
Breakdown
Circulate

2

Mastication involves...?

1st act of digestion
Mechanical breakdown
Moistens/lubricates
Abnormal teeth common cause of GIT disturbances

3

Pharyngeal phase involves...?

Breathing stops momentarily -> soft palate closes nasopharynx -> tongue closes pharynx opening -> epiglottis folds over glottis -> closes laryngeal opening

4

Motility in the proximal stomach...?

Food storage
Little mixing
Wall relaxes to accomodate meal
Then contracts -> push food & empty

5

Motility in the distal stomach...?

Thick muscle
Vigorous contractions
Grinding, mixing
Emptying function
Peristaltic waves push food -> pylorus

6

2 primary patterns in SI motility...?

Propulsive - peristalsis
Segmentation - mixes digesta with digestive juices -> mucosal surface

7

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

8

Secondary contractions in the rumen...?

Eructation
Produces CO2, O2, methane, nitrogen
Gases pushed cranially

9

3 steps in rumination...?

Regurgitate - via reticular contractions & low pressure in thorax -> material into oesophagus -> antiperistalsis -> mouth
Remasticate - some matter -> resalivation
Reswallow

10

Oral secretions from which glands?

Parotid
Mandibular
Sublingual

11

2 types of saliva secretion?

Serous - parotids
Viscous - small glands

12

Saliva contains...?

98% water
Mucin - lubrication
Amylase - Starch ->maltose (NOT in ruminants)
Bicarb
Lysozyme & antibodies - antibacterial
Urea - important N source for protein synthesis in ruminants

13

Ruminant saliva vs monogastric...?

Ruminant - higher volume produced; higher pH; higher [bicarb], [phosphate] & [Na]

14

Gastric secretion...?

Stomach lined with surface mucous cells
Protects stomach from acid
If injured -> stomach ulcers

15

Gastric mucous properties?

From crypt & surface epithelial cells
Glycoproteins & mucopolysaccharides
Protects against HCl & pepsin
Barrier against bugs & endotoxins
Lubrication

16

Pancreatic enzyme properties?

Secreted by EXOCRINE pancreas
2 types - potent enzymes & bicarb
Important in monogastrics (carry out most digestion)
Synthesised as zymogens (inactive)

17

Main types of pancreatic enzymes...?

Proteolytic -> protein digestion
Pancreatic amylase & chitinase -> CHO digestion
Pancreatic lipase -> lipid digestion