Endocrine Function II Part 3 Flashcards
This stimulates Sertoli cells to produce sperm and negatively feeds back on the anterior pit and hypothalamus
Testosterone
What are the 19 carbon androgen compounds responsible for?
Differentiation and maturation of the reproductive organs, secondary sexual characteristics, increased muscle mass and long bone growth
These cells produced inhibin that negatively feeds back on the anterior pit and hypothalamus.
Sertoli cells
What are three functions of vitamin D?
Stimulates the production of intestinal transport molecules specific for the absorption of calcium and phosphorus, works with PTH to enhance bone resorption, and enhances reabsorption of calcium and phosphorus.
What is the net effect of vitamin D?
To increase blood levels of both calcium and phosphorus
What are two names for biologically active form of vitamin D?
Calcitriol and 1,25-dihydroxycholecalciferaol (1,25-dihydroxy vitamin D)
Specific site of production of the parathyroid hormone.
Parathyroid gland
Specific stimulus for the release of parathyroid hormone?
Low ionized calcium levels in blood
Specific effects of the parathyroid hormone on the intestine, kidney, and bone
*
What is the net effect of the parathyroid hormone on blood, calcium and phosphorus concentrations?
Increased levels of calcium and decreased levels of phosphorus
What are four functions of the parathyroid hormone?
1 Increases intestinal absorption of calcium and phosphorus by stimulating the Renal formation of active vitamin D (calcitriol)
2 increases bone resorption (osteoclastic activity)
3 increases renal tubular reabsorption of calcium
4 decreases renal tubular reabsorption of phosphorus
What is the specific site of production of calcitonin?
Parafollicular cells of the thyroid gland
What are specific effects of calcitonin on the intestine kidney and bone?
Decreased intestinal reabsorption makes bone (osteoblast), decreases Renal reabsorption
What is the net effect of calcitonin on blood calcium and phosphorus?
Decrease in both serum calcium and phosphorous
Two functions of calcitonin.
Stimulate bone formation and enhances secretion of filtered calcium and phosphorus
What is the most common cause of hyperparathyroidism?
*adenoma, hyperplasia
What are the consequences of hyperparathyroidism on Renal and bone tissue due to hypercalcemia?
Bone resorption as calcium and phosphorus are released to the blood, kidney?
Typical serum calcium, ionized calcium, phosphorous, and PTH levels for hyperparathyroidism
Decreased PTH, increased phos, increased calcium, ionized calcium?
What is the most common primary cause of hypoparathyroidism?
Surgical Procedure
What are the blood/urine calcium and phosphorous levels seen in hypoparathyroidism?
Increased plasma phosphorous, Decreased plasma calcium, Decreased PTH, urine?
What are the blood calcium and phosphorus levels associated with hypervitaminosis D?
Increased calcium and increased phos
What are two diseases associated with vitamin D deficiency?
Cancer, autoimmune disease, lung disease, infections, schizophrenia, malabsorption dieases
Specific site of production of gastrin?
Peptide hormone secreted by G-cells of stomach antrum in response to contact with food (also produced in pancreas)
What is the function of gastrin?
Causes hydrochloric acid production by parietal cells in stomach; causes negative feedback as pH decreases
What are two diseases that cause hypergastrinemia?
achlorhydria, pernicious anemia, and gastrinomas
What is the syndrome associated with gastrinomas?
these cause Zollinger-Ellison Syndrome
What is the specific site of production of secretin?
Secreted by the duodenal and upper jejunal intestinal mucosa after contact with gastric HCl
What does secretin do?
It stimulates the pancreas and liver to secrete bicarbonate to counteract stomach acidity
What is the specific site of production of cholecystokinin-pancreozymin (CCK-PZ)?
Produced by the upper intestinal mucosal cells after contact with peptones, fatty acids, and HCl entering duodenum
What does CCK-PZ cause?
Gallbladder contraction and pancreatic enzyme secretion
What is the amine hormone derived from the hydroxylation and decarboxylation of tryptophan?
serotonin
What is the specific site of production of serotonin?
synthesized primarily by the enterchromaffin cells located in the GI tract
What are two physiological effects of serotonin?
smooth muscle stimulation and vasoconstriction (elevates the mood)
What is the syndrome associated with serotonin-producing tumors?
carcinoid syndrome
What is the urinary metabolite of serotonin commonly measured in the lab?
24-hour collection for 5-HIAA
