30 Questions
What stimulates β cells to release insulin?
Increased glucose levels
What is the role of α cells when blood glucose levels decrease?
Release glucagon
In Type 1 diabetes (IDDM), what causes the condition?
Loss of the β cells from autoimmune destruction
What is a characteristic feature of Type 2 diabetes (NIDDM)?
Failure to produce adequate insulin levels
What happens in Type 2 diabetes commonly associated with obesity?
Failure of peripheral target cells to respond to insulin
How do α and β cells contribute to the control of blood glucose concentration?
By opposing actions
What is the main component of pars distalis in the adenohypophysis?
Chromophils and chromophobes
Which type of cells are known as basophils and acidophils based on their staining affinities?
Chromophils
How are subtypes of basophilic and acidophilic cells usually identified?
By their granular morphology
What is the characteristic of chromophobes in the pars distalis?
They have clear cytoplasm without granules
Which part of the adenohypophysis accounts for 75% of its composition?
Pars Distalis
What are the two broad groups of cells suggested by common stains in the pars distalis?
"Chromophils and chromophobes"
What stimulates melatonin release in periods of darkness?
Sympathetic fibers
Which pancreatic cell type produces glucagon?
α
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
What is the main function of insulin in the body?
Decreases blood glucose content
What type of cells are found in the pineal gland that represent about 5% of the cells?
Interstitial glial cells
Which hormone inhibits the release of other islet cell hormones?
Somatostatin
What are the concretions of calcium and magnesium salts called in the pineal gland?
Corpora arenacea
Where are the glial cells found within the pineal gland?
In perivascular areas and between groups of pinealocytes
What is the hormone produced by PP cells in the pancreas?
Pancreatic polypeptide
What determines the diurnal rhythms of hormone release and physiologic activities throughout the body?
Levels of circulating melatonin
Which pancreatic cell type secretes a hormone that stimulates activity of gastric chief cells?
PP
What is the hormone structure of glucagon?
Polypeptide; 3500 Da
What is the role of thyroid peroxidase in the iodination of tyrosyl residues in thyroglobulin?
Catalyzing the oxidation of iodide to iodine
How are T3 and T4 formed within the colloidal thyroglobulin?
By coupling reactions between two iodinated tyrosines
What is the main mechanism through which endocytosis of iodinated thyroglobulin occurs in thyrocytes?
Both fluid-phase pinocytosis and receptormediated endocytosis
Where do C cells typically reside in relation to the follicular epithelium?
At the basement membrane of the follicle
Which organelle is involved in degrading thyroglobulin with lysosomal proteases?
Lysosomes
What differentiates C cells from thyrocytes in terms of size and staining characteristics?
C cells are larger and more pale stained than thyrocytes
Learn about how the activity of α and β cells is regulated by blood glucose levels, impacting the release of insulin, glucagon, and somatostatin. Understanding these hormonal interactions is crucial for maintaining blood glucose concentration in homeostasis.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
