Endocrine glands II Flashcards
How are the epithelial cells arranged in parathyroid glands?
Cords or clusters
What are the cells of the parathyroid gland?
- Chief cells2. Oxyphil cells3. Intermediate cells
Which parathyroid cells have secretory granules that contain PTH?
Chief cells
What are the effects of PTH?
Regulates calcium and phosphate levels in the blood
What is PTH’s function in bone?
Attaches to osteoblast receptors, causing them to release osteoclast stimulating factor, which triggers osteoclast activity. Calcium is freed from the bone to enter bloodstream (returning calcium levels to normal)
What is PTH’s function in the kidney?
- Conserves calcium (prevents loss in urine)2. Excretes phosphate (promotes loss in urine)
What is PTH’s role in the GI tract?
Controls formation of vitamin D in the kidneys, which facilitates calcium absorption in the GI tract
What does calcitonin do to blood calcium levels?
Decreases to normal
What happens during hypoparathyroidism (or removal of parathyroid glands)?
Hypocalcemia, Tetany
What happens during hyperparathyroidism?
Hypercalcemia, urinary tract stones
Which pancreatic cells produce glucagon?
Alpha
What do the alpha cells of the pancreas produce?
Glucagon
Which pancreatic cells produce insulin?
Beta
What do the beta cells of the pancreas produce?
Insulin
Which pancreatic cells produce somatostatin?
Delta
What do the delta cells of the pancreas produce?
Somatostatin
Which pancreatic cells produce gastrin?
G cells
What do the G cells of the pancreas produce?
Gastrin
Which pancreatic cells produce pancreatic polypeptide?
PP cells (F cells)
What do the PP (F) cells of the pancreas produce?
Pancreatic polypeptide
What is the function of somatostatin?
Reduces smooth muscle contraction of digestive tract and gall bladder
What is the function of gastrin?
Stimulates parietal cells of the stomach mucosa to produce HCl
What is the function of pancreatic polypeptide?
Inhibits pancreatic exocrine secretions (digestive juices)
Which adrenal region produces corticosteroids?
Cortex
What does the adrenal cortex produce?
Corticosteroids
Which adrenal region produces catecholamines?
Medulla
What does the adrenal medulla produce?
Catecholamines
How is the zona glomerulosa arranged?
Cords and clusters
What are the notable histological characteristics of the zona glomerulosa?
- Abundant sER2. Lipid droplets
What type of hormone is synthesized in the zona glomerulosa?
Mineralocorticoids
What is the main mineralocorticoid produced in the zona glomerulosa?
Aldosterone
What is the target of aldosterone?
Distal convoluted tubule of kidney
What is the function of aldosterone?
- Stimulate water balance2. Absorption of sodium3. Excretion of potassium
How are the cells arranged in the renal zona fasciculata?
Spongiocytes are arranged in radial columns with sinusoidal capillaries running in between
What are the notable histological characteristics of the zona fasciculata?
- Abundant sER2. Abundant Golgi3. Lipofuscin
What type of hormone is synthesized in the zona fasciculata?
Glucocorticoids
What are the glucocorticoids produced in the zona fasciculata?
- Cortisol2. Corticosterone
What is the function of the glucocorticoids?
Control of carbohydrate, fat, and protein metabolism
What causes Cushing’s syndrome?
Small tumors of the basophils in the anterior pituitary gland. Tumors produce excess ACTH which overstimulates the suprarenal cortex - excess cortisol is produced. Symptoms are obesity, impotency in males, amenorrhea in females
How are the cells of the zona reticularis arranged?
Anastomosing cords
What type of hormone is produced in the zona reticularis?
Androgens
What is the developmental derivation of the suprarenal medulla?
Neural crest cells
What are the cells of the suprarenal medulla?
- Chromaffin cells2. Sympathetic ganglion cells
What do chromaffin cells synthesize?
Catecholamines
What is the function of the sympathetic ganglion cells?
In CT of medulla; send axons to cortex where they modulate cortical activity and innervate blood vessels
