Question

Insulin is a peptide hormone secreted by the beta cells of the pancreas in response to elevated levels of blood glucose. Locally, insulin will inhibit the release of glucagon from alpha cells in the pancreas, and it will also impact the metabolism of many peripheral tissues. The actions of insulin are best described as which of the following?

	a.	autocrine only
	b.	paracrine and autocrine
	c.	endocrine only
	d.	Paracrine and endocrine