Parathyroid gland
There
are four parathyroid glands. They are small, light-colored lumps that stick out
from the surface of the thyroid gland. All four glands are located on the
thyroid gland.
They
are butterfly-shaped and located inside the neck, more specifically on both
sides of the windpipe.
One
of the parathyroid glands most important functions is to regulate the body's
calcium and phosphorus levels. Another function of the parathyroid glands is
to secrete parathyroid hormone, which causes the release of the calcium present
in bone to extracellular fluid.
PTH
does this by depressing the production of osteoblasts, special cells of the
body involved in the production of bone and activating osteoclasts, other
specialized cells involved in the removal of bone.
Receptors bind a specific hormone
and the result is a specific physiologic response, meaning a normal response of
the body.
PTH finds its major target cells in bone,
kidneys, and the gastrointestinal system.
Calcitonin, a hormone produced by the
thyroid gland that also regulates ECF calcium levels and serves to counteract
the calcium-producing effects of PTH.
The adult body contains as much as
1 kg of calcium. Most of this calcium is found in bone and teeth. The
four parathyroid glands secrete the parathyroid hormone (PTH). It opposes the effect of
thyrocalcitonin. It does this by removing calcium from its storage sites in
bones, releasing it into the bloodstream. It also signals the kidneys to
reabsorb more of this mineral, transporting it into the blood. It also signals
the small intestine to absorb more of this mineral, transporting it from the
diet into the blood.
Calcium is important for steps of
body metabolism. Blood cannot clot without sufficient calcium. Skeletal muscles
require this mineral in order to contract. A deficiency of PTH can lead to
tetany, muscle weakness due to lack of available calcium in the blood.
Sumber : Bpk. Dr. Iskandar Zulkarnain
#posting tugas cyberprenership
ahmad baihaqi
NIM 1112503964
Tidak ada komentar:
Posting Komentar