Question

describe gastric factors that promote emptying of stomach

Answer 1

Gastric emptying is the process by which the contents of the stomach are moved into the duodenum.This mainly accomplished by, Peristaltic waves, systolic contraction of antrum and reduction in size of stomach.

The antrum is the lower part of the stomach. The antrum holds the broken-down food until it is ready to be released into the small intestine, so this antrum pumps gastric contents from the stomach to the duodenum, so emptying of stomach is a coordinated function by intense peristaltic contractions in the antrum. At the same time, the emptying is opposed by varying degrees of resistance to passage of chyme at the pylorus end. Rate of stomach emptying depends on pressure generated by antrum against pylorus resistance. Antral distension stimulates vasovagal excitatory reflexes leading to increased antral pump activity

Gastric emptying is due to muscular activity of the stomach on which neural and hormonal mechanisms operate to modify it..Hormomal factors, many gastrointestinal hormones like gastrin, secretin and cholocystokinen can affect the rate of stomach emptying.Gastrin has mild to moderate stimulatory effects on motor functions in the body of the stomach. Enhances activity of pyloric pump, other two hormone delay stomach emptying. Secretin released from the duodenum in response to acid, has a direct inhibitory effect on the gastric smooth muscles

Neural mechanism,  Parasympathetic innervation via vagus nerve stimulates motility

Other factors which affect emptying of stomach include,

Increased food volume in stomach promotes increased emptying.

Solids stay in stomach longer,while Clear fluids empty rapidly

  Protein empties fastest, followed by carbohydrates. Fats take longest to empty, high protein food especially meat stimulate release of gastrin from antral mucosa