The parathyroid glands are small endocrine glands in the neck that produce parathyroid hormone (PTH), which regulates calcium and phosphate homeostasis. Conditions like hyperparathyroidism and hypoparathyroidism result from excess or decreased activity of these glands, respectively, leading to various health issues. Parathyroid tumors can cause hypercalcemia due to overproduction of PTH, which manifests in symptoms such as weakness and increased thirst in pets.

1. Topic :Parathyroid gland
By: Dr Iqra bano Chandio

2. Parathyroid gland
 The parathyroid glands are
small endocrine glands in the neck
of humans and other tetrapods that
produce parathyroid hormone.
 positioned behind the left and right
lobes of the thyroid.
 The size of the gland ranges from 2-
7 mm .

3. Parathyroid cells
 Two unique types of cells are
present in the parathyroid gland:
 Chief cells :which synthesise and
release parathyroid hormone.
 Oxyphil cells: which are lighter in
appearance and increase in number
with age,have an unknown function

4. Parathyroid hormone
 Parathyroid hormone (PTH, also known
as parathormone) is a small protein that
takes part in the control of calcium and
phosphate homeostasis, as well as bone
physiology.
 Parathyroid hormone has effects
antagonistic to those of calcitonin.

5. Calcium
 PTH increases blood calcium levels
by stimulating osteoclasts to break
down bone and release calcium.
 PTH also increases gastrointestinal
calcium absorption by the
activating vitamin D, and promotes
calcium conservation (reabsorption)
by the kidneys.

7. Hyperparathyroidism
 Hyperparathyroidism is the state in
which there is excess parathyroid
hormone circulating.
 This may cause bone pain and
tenderness, due to increased bone
reabsorption.
Hypoparathyroidism
•The state of decreased parathyroid activity
is known as hypoparathyroidism.
• This is most commonly associated with
damage to the glands or their blood supply
during thyroid surgery.

8. Symptoms of hypoparathyroidism
 Tingling in the lips, hands, fingers and toes
 Dental malformations (eg, misshapen teeth,
loss of enamel)
 Dry hair, dry skin, brittle nails, thinning hair
 Cataracts
 Headaches, memory loss, mental retardatio
 Tetany (severe muscle spasm)
 Impaired kidney function
 Seizures caused by calcium deposits in the
brain.
 Cardiac arrhythmias, fainting episodes

9. Parathyroid tumor
 A parathyroid tumor develops as a result
of replication or growth of cells in the
parathyroid gland.
 Parathyroid tumors tend to be benign
(non-cancerous). Benign tumors are called
adenomas.
 A malignant form of tumor, called
parathyroid carcinoma, has been
described, but is rare.
 Parathyroid tumors are common in cats
and dogs.

10. What are the signs of a parathyroid
tumor?
 The signs of a parathyroid tumor are related
to a condition known as hypercalcemia.
 Parathyroid tumors cause an
overproduction of parathyroid hormone
(PTH), a hormone that regulates the
circulating level of blood calcium, causing it
to rise. This condition is known as
hypercalcemia

11. What are the signs of a parathyroid
tumor?
 With hypercalcemia, your pet may become
anorexic, start vomiting, drink and urinate
more, and show signs of weakness, muscle
trembling, and general lethargy.

12. Normal parathyroid gland parathyroid gland cancer
Parathyroid tumor appearance

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