Thyroid, pancreas and parathyroid hormones Flashcards
What are the thyroid hormones?
T3 and T4 AND CALCITONIN . the thyroid is along the trachea in front of larynx
T3 and T4 are lipid soluble tyrosine derivatives
Calcitonin
peptide hormone released by the thyroid gland . it slightly decreases the blood calcium by dec the osteoclast number and activity. calcium levels can be effectively controlled in absence of calcitonin
The pancreas secretes what hormones?
insulin, glucagon
and somatostatin: which inhibits both insulin ad glucagon. role of somatostatin might be to extend the period of time over which nutrients are absorbed
insulin is released by which cells of the pancreas?
beta .
when is insulin released?
when the blood levels of carbs and proteins are high
what does insulin affect?
affects carbs- stored as glycogen in liver and muscles
fat is affected: its stored in adipose tissue
amino acids are affected: taken up by the cells of the body
What does glucagon do?
peptide hormone! , released by the alpha cells.
it stimulates glycogenolysis (breakdown of glycogen) and it stimulated gluconeogenesis in the liver. in high concentrations, it will break down adipose tissue increase the FA levels of the blood. the net effect of glucagon is opp of insulin - it raises the blood glucose levels.
How many parathyroid glands are there?
4
where are the parathyroid glands located?
attatched to the back of the thyroid
what do the parathyroid glands release?
parathyroid hormone
What does PTH (parathyroid hormone) do?
its a peptide , it will inc blood calcium. inc osteocyte abs of calcium and phosphate from the bone and stimulate proliferation of osteoclasts.
- it also increases renal calcium reabsorption and renal phosphate excretion.
- it will also inc calcium and phosphate uptake from the gut
what is PTH secretion regulated by?
by the calcium ion plasma concentration
