Gastro hormones Flashcards
What is the function of the enteric endocrine system?
Secretions
Motility
Appetite
Describe the role of gastrin/ where it is produced and the stimuli for its release
Produced: G cells in duodenum and stomach
Stimulated by: Presence of peptides and Aa in gut lumen/ distended stomach/ vagal stimulation/ hypercalcaemia
Role: stimulates release from gastric acid from parietal cells and stimulates release of pepsinogen from chief cells
What are the main GI hormones?
- Insulin
- Glucagon
- Gastrin (local)
- Ghrelin
- GIP
- Secretin
- Cholecystokinin (local)
At what pH does gastrin secretion stop?
~3
What do tumours of the gastrin secreting cells cause?
Stomach ulcers
Discuss secretin
- Produced in duodenum
- Stimulated by presence of H+ in small intestine
- Stimulates release of pancreatic juices and bile.
Discuss CCK
- Produced in the duodenum
- Stimulated by presence of fatty acids, monoglycerides, Aa in small intestine
- Stimulates release of pancreatic enzymes (lipase) and contraction of the gall bladder (bile)
What gastric hormones enables insulin release?
GIP
GLP-1 promotes its secretion and it also suppresses glucagon driven gluconeogenesis
Which gastric hormones promotes satiety?
-GLP-1
Discuss motilin
Produced in Mo cells of SI
Maintains motility in stomach and SI
Stimulate production of pepsin
What hormone causes satiety and which causes appetite?
- Leptin= satiety
- Ghrelin= appetite
What does the satiety and appetite centres respond to?
- Satiety= high glucose
- Appetite= Low glucose
Why do some Labradors have an endless appetite?
-The Ghrelin that stimulates appetite should block MSH BUT in some Labradors the MSH doesn’t work properly so they have no appetite suppression
What is the lipostat hypothesis?
- Adipose tissue produced leptin
- Amount of leptin produced is proportional to amount of fat so if you have more fat then more leptin is produced to should have stronger appetite suppression
Give an example of an anorexinergic hormone
Leptin
