Describe two central reflexes triggered by stimulation of the stretch receptors in the stomach wall. (Module 22.15B) Describe two central reflexes triggered by stimulation of the stretch receptors in the stomach wall. (Module 22.15B) The gastric reflex opens the cardiac sphincter and the enteric reflex opens the pyloric sphincter. The enterogastric reflex closes the pyloric sphincter and the gastroenteric reflex stimulates motility and secretion in the small intestine. The cephalic reflex opens the esophagus during swallowing and the gastric reflex opens the cardiac sphincter. The gastroileal reflex opens the ileocecal valve and the colonic reflex closes the ileocecal valve. The gastroenteric reflex stimulates motility and secretion in the small intestine and the gastroileal reflex opens the ileocecal valve.

The gastroenteric reflex stimulates motility and secretion in the small intestine and the gastroileal reflex opens the ileocecal valve.

Explanation:

The gastroenteric reflex is triggered by stomach distension which increases the glandular secretion and peristaltic activity in the duodenum and the small intestine. This reflex is mediated by the activation of baroreceptors in the stomach in order to increase motility and secretion along the small intestine. Moreover, the gastroileal reflex is an extrinsic reflex that acts together with the gastrocolic reflex to stimulate the process of defecation. This reflex is caused by the increase in levels of gastrin hormone, which in turn is caused by the entry of food into the stomach. The gastroileal reflex induces peristaltic activity in the final section of the small intestine (i.e., ileum) and the opening of the ileocecal valve.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.