Regulation of α and β Cells by Blood Glucose Levels

Play an AI-generated podcast conversation about this lesson

What stimulates β cells to release insulin?

Somatostatin from δ cells

Increased glucose levels (correct)

Decreased glucose levels

Loss of insulin effect

What is the role of α cells when blood glucose levels decrease?

Inhibit glucagon release

Release insulin

Release glucagon (correct)

Inhibit insulin release

In Type 1 diabetes (IDDM), what causes the condition?

Failure of somatostatin release

Loss of the β cells from autoimmune destruction (correct)

Loss of the α cells

Loss of the insulin effect

What is a characteristic feature of Type 2 diabetes (NIDDM)?

Failure to produce adequate insulin levels Signup and view all the answers

What happens in Type 2 diabetes commonly associated with obesity?

Failure of peripheral target cells to respond to insulin Signup and view all the answers

How do α and β cells contribute to the control of blood glucose concentration?

By opposing actions Signup and view all the answers

What is the main component of pars distalis in the adenohypophysis?

Chromophils and chromophobes Signup and view all the answers

Which type of cells are known as basophils and acidophils based on their staining affinities?

Chromophils Signup and view all the answers

How are subtypes of basophilic and acidophilic cells usually identified?

By their granular morphology Signup and view all the answers

What is the characteristic of chromophobes in the pars distalis?

They have clear cytoplasm without granules Signup and view all the answers

Which part of the adenohypophysis accounts for 75% of its composition?

Pars Distalis Signup and view all the answers

What are the two broad groups of cells suggested by common stains in the pars distalis?

"Chromophils and chromophobes" Signup and view all the answers

What stimulates melatonin release in periods of darkness?

Sympathetic fibers Signup and view all the answers

Which pancreatic cell type produces glucagon?

α Signup and view all the answers

What is the role of the pineal gland as described in the text?

Converting sensory input regarding light and darkness into variations in hormonal functions Signup and view all the answers

What is the main function of insulin in the body?

Decreases blood glucose content Signup and view all the answers

What type of cells are found in the pineal gland that represent about 5% of the cells?

Interstitial glial cells Signup and view all the answers

Which hormone inhibits the release of other islet cell hormones?

Somatostatin Signup and view all the answers

What are the concretions of calcium and magnesium salts called in the pineal gland?

Corpora arenacea Signup and view all the answers

Where are the glial cells found within the pineal gland?

In perivascular areas and between groups of pinealocytes Signup and view all the answers

What is the hormone produced by PP cells in the pancreas?

Pancreatic polypeptide Signup and view all the answers

What determines the diurnal rhythms of hormone release and physiologic activities throughout the body?

Levels of circulating melatonin Signup and view all the answers

Which pancreatic cell type secretes a hormone that stimulates activity of gastric chief cells?

PP Signup and view all the answers

What is the hormone structure of glucagon?

Polypeptide; 3500 Da Signup and view all the answers

What is the role of thyroid peroxidase in the iodination of tyrosyl residues in thyroglobulin?

Catalyzing the oxidation of iodide to iodine Signup and view all the answers

How are T3 and T4 formed within the colloidal thyroglobulin?

By coupling reactions between two iodinated tyrosines Signup and view all the answers

What is the main mechanism through which endocytosis of iodinated thyroglobulin occurs in thyrocytes?

Both fluid-phase pinocytosis and receptormediated endocytosis Signup and view all the answers

Where do C cells typically reside in relation to the follicular epithelium?

At the basement membrane of the follicle Signup and view all the answers

Which organelle is involved in degrading thyroglobulin with lysosomal proteases?

Lysosomes Signup and view all the answers

What differentiates C cells from thyrocytes in terms of size and staining characteristics?

C cells are larger and more pale stained than thyrocytes Signup and view all the answers