Structural anatomy of Parathyroid gland

• Parathyroid glands are tiny, lentil sized gland embeded in posterior of thyroid gland.
• two pairs of parathyroid glands are found.
• each thyroid lobe contains two parathyroid gland.
• The gland is composed of principal cells (secrete parathormone) and Oxyphilic cells (store parathormone)

Location: embedded on posterior of thyroid gland

Size: small lentil sized, 4 in number

Hormones of Parathyroid gland

1. Parathormone

• Regulate the concentration of calcium and phosphate level in blood
• Increase level of Ca++ in blood by reabsorption from intestine and kidney, Osteolysis
• Low Ca++ concentration in blood stimulate parathormone synthesis.
• Promote decalcification and demineralization of bone.
• stimulates Osteoclast to break (Osteolysis) to release Calcium from bone to blood.

* Improper balance of calcium and phosphate in blood causes faulty nerve impulse transmission, destruction of bone tissue, hamper bone growth and muscle tetany.

** when calcium level increases in blood, parathormone stimulates inhibition of reabasorption of calcium in kidney and inhibit osteolysis of bone.

 Disorder of Parathyroid gland:

1. Parathyroid tetany:

• deficiency of parathormone
• muscle spasms, sustained contractions of muscles
• may leads to death

2. Osteoporosis:

• over secretion of parathormone
• decalcification of bones
• bone becomes soft and porous

Parathyroid gland: structure, location and Hormones

The post what is Parathyroid gland? appeared first on Online Biology Notes.