Micro of Endocrine Glands - Pancreatic Islets and Pineal Gland

Question 1

Pancreatic Islets are also called _____.

Answer 1

Islets of Langerhans

Question 2

List four cell types found in pancreatic islets.

Answer 2

1. A (alpha) cells
2. B (beta) cells
3. D (delta) cells
4. F cells

Question 3

A (alpha cells) of pancreatic islets

Answer 3

Produce glucagon (polypeptide) –> stimulates liver glycogenolysis –> increases blood glucose level

Question 4

B (beta cells) of pancreatic islets

Answer 4

Produce insulin (polypeptide) –> facilitates glycogen storage in liver and skeletal muscle –> lowers blood glucose

Question 5

D (delta) cells of pancreatic islets

Answer 5

Produce somatostatin (peptide) --> inhibits glucagon release and decreases pancreatic exocrine secretion
Acting opposite of CCK

Question 6

F cells of pancreatic islets

Answer 6

Produce pancreatic polypeptide –> inhibits pancreatic bicarbonate and enzyme secretion; causes relaxation of gall bladder; decreases bile secretion

Question 7

Another name for pineal gland

Answer 7

Epiphysis cerebri

Question 8

Gross anatomy of pineal gland

Answer 8

1. Part of epithalamus (diencephalon)
2. Innervated mainly by sympathetic (postganglionic) fibers from cranial cervical ganglia
3. Shaped like a pine cone

Question 9

Parenchyma of pineal gland

Answer 9

1. Pinealocytes - main cell type, fuzzy nucleus
2. Glial cells (fibrous astrocytes)
3. Corpora arenacea (brain sand) - calcium carbonate deposits, signifiance is unkown

Question 10

Function of pineal gland

Answer 10

1. Largely unkown
2. Secretes melatonin (derivative of serotonin) - produced only during dark periods; suppresses or stimulates gonadotropin (FSH, LH) secretion
3. Prevents precocious puberty in humans