Post on 18-Dec-2015
transcript
LOCATION
Parathyroid glands are 4 small glands of the
endocrine system which are embedded in posterior
surface of the thyroid gland.
HORMONES THAT ARE PRODUCED
The parathyroid glands release a hormone called parathyroid hormone (PTH). This hormone controls the levels of: calcium, phosphorus and magnesium. Parathyroid hormone has a number of effects in the body.
AFFECTS OF HORMONES ON BODY
It causes the release of calcium from bones.
It causes calcium to be absorbed (taken up into the
blood) from the intestine.
It stops the kidneys from excreting (getting rid of)
calcium in the urine.
It causes the kidneys to excrete phosphate in the urine.
It increases blood levels of magnesium.
HOMEOSTASIS
PTH has many effects on the bones and the kidneys.
It stimulates osteoblasts to pump Ca++ ions out of the fluid. Over a
longer time course, PTH stimulates bone reabsorption
Stimulates [Ca++] on the kidney. First, it decreases the loss of Ca+
+ ions in the urine by stimulating Ca++ reabsorption. "Reabsorption"
means the transfer of substances from the forming urine back into
the ECF. Reabsorption, which is performed by the cells of the kidney
tubules, allows the recovery of those useful small molecules such as
sugars, amino acids, and Ca++ ions. As well as stimulating Ca+
+ reabsorption, PTH also inhibits phosphate reabsorption in the
kidney.
FEEDBACK MECHANISMS AND ANTAGONISTIC HORMONES
A negative feedback system involving 2
antagonistic hormones, calcitonin and parathyroid
hormone (PTH), play the major roles in calcium
(Ca2+) in order to maintain homeostasis in
mammals.
RELEASING HORMONES AND GLANDS
Hormone Released: Parathyroid hormone (PTH)
Hormone Structure: Peptide
Hormone Function: Increases blood calcium
concentrations by stimulating calcium release from bone,
promoting calcium uptake from intestinal tract and
decreasing calcium excretion by the kidney; Decreases
blood phosphate level
Hormone Regulator: Calcium concentrations in blood
IMPROPER FUNCTION
Hyperparathyroidism occurs when the parathyroid
hormone is produced by an overactive parathyroid
gland. This is called hyperparathyroidism.
Hyperparathyroidism occurs when one or four
parathyroid glands grows into a tumor and behaves
inappropriately by making excess parathyroid hormone
which harms the body. Too much calcium in the
bloodstream causes damage to the nervous system, and
cause higher risk of cancer.
TREATMENTS
There are no pills nor drugs to cure this disease.
The only way to solve/remove hyperparathyroidism is
by having surgery.
The average operative time to remove the diseased
parathyroid gland using this technique is about 25
minutes
PARATHYROID VIDEO
http://www.youtube.com
/watch?v=sD9st1ZPFrQ
#t=302
SOURCES
http://courses.washington.edu
www.parathyroid.com
http://classes.biology.ucsd.edu
http://faculty.clintoncc.suny.edu