Question

Which one of the following secretes Glucagon?
(a)Beta (β) cells of islets of Langerhans
(b)Alpha (α) cells of islets of Langerhans
(c)Acidophilic cells of the adenohypophysis
(d)Basophilic cells of the adenohypophysis

Answer 1

Hint: Two of the main hormones secreted by pancreas are insulin, which acts to lower blood sugar, and glucagon, which acts to raise blood sugar. This hormone is secreted by certain cells of the pancreas.

Complete answer:
Glucagon is a hormone which is secreted by the alpha cells of the islets of Langerhans in the pancreas. It is directly released into the bloodstream. Glucagon is involved in the activity of regulating sugar level in the blood.

Additional Information: The pancreas consists of both exocrine and endocrine parts and hence is known as a mixed gland. The exocrine part mainly secretes bicarbonate and enzymes. The endocrine part secretes hormones.
-The endocrine secretion of pancreas include the following:
-The endocrine hormones are synthesized, modified, and stored from a cluster of cells known as pancreatic islets or islets of Langerhans. They are named after Paul Langerhans who discovered the endocrine portion.
-Glucagon is produced from a group of cells known as alpha cells. Glucagon helps in raising blood glucose levels.
-Insulin is secreted by the beta cells it helps in lowering blood glucose levels. The beta cells are most numerous and are present at the centre of islets of Langerhans.
-Delta cells: These cells secrete the hormone somatostatin that is responsible for the inhibition of both insulin and glucagon secretion.
-F cells: These cells are responsible for the secretion of pancreatic polypeptide. It is found in the blood after the consumption of meals and helps in controlling the secretion of pancreatic enzymes.

So, the correct answer is, ‘Alpha (α) cells of islets of Langerhans.’

Note: Many digestive enzymes are secreted by the pancreas which includes pancreatic amylase which helps in breaking down of starch into disaccharide maltose, pancreatic lipase helps in degradation of triglyceride, proteases are a group of proenzymes including trypsin, chymotrypsin, carboxypeptidase, and elastase. Nucleases and peptidases are also secreted by the pancreas.