Surgical anatomy of parathyroid glands

1. SURGICAL ANATOMY OF
PARATHYROID GLANDS
DR.SK.SALMA BEGUM
FIRST YEAR PG S – 3 UNIT
UNDERGUIDANCE OF
PROFESSOR DR.P.A. RAMANI
ASSOCIATE DR ABDUL SATTAR
ASSISTANT DR SRINIVAS
ASSISTANT DR MAHESH

3. HISTORY
• In 1850 Owen discovered the parathyroid glands in the Indian rhinoceros. He
referred to one of these glands as a small compact yellow glandular body
attached to the thyroid at the point where the veins emerged.
• Sandstrom rediscovered parathyroid glands in humans..He eloquently
described the glands as “glandulae parathyroidae” in his monograph “On a
New Gland in Man and Fellow animals.

4. • Gley documented the presumed function of the parathyroid glands in 1891 by
observing the development of tetany after their removal.
• In 1908 MacCallum discerned their role in calcium metabolism.
• Parathyroid harmone PTH was first isolated by Hanson in 1923, followed by Collip
in 1925 and subsequent studies by Guillemin,Schally and Yalow led to the
development of immunoassays to measure PTH levels.

6. EMBRYOLOGY
• The parathyroid glands - endodermal epithelial cells
-consist of combination of chief and oxyphil cells, adipose
tissue and fibrovascular stroma
• Superior parathyroid glands - fourth branchial pouch
-are closely associated with lateral aspects of thyroid
lobes .
- have a relatively abbreviated line of descent.

7. • Inferior parathyroid gland-third branchial pouch.
-closely associated with thymus
-have a longer line of Embryological descent.

8. • Normal parathyroid glands Weigh30-50 mg.
• Color varies ranging from golden to reddish brown and becoming more pale
yellow as the fat content increases. They are typically described as Portland
brick(yellow /brown ) in colour

9. ANATOMICAL LOCATION
• The superior parathyroid glands are normally located on the posteromedial
surface of the middle to superior thyroid lobe near the tracheoesophageal
groove.
• They may reside under the superficial fascia of thyroid, posterior to recurrent
laryngeal nerve
• When a tubercle of zuckerkandl of the thyroid lobe is present.these glands are
often found posteromedial to tubercle

10. • Inferior parathyroid glands usually lie at the inferior portion of the thyroid lobe
and anterior to recurrent laryngeal nerve.
• They demonstrate bilateral symmetry the superior and inferior glands are
symmetrical compared with contralateral side in 80% and 70% of patients
respectively.

13. BLOOD SUPPLY OF PARATHYROID GLANDS
• In 80% of cases they receive their blood supply from –
-inferior thyroid artery a branch of thyrocervical trunk from subclavian artery.
• Each gland has its own end arterial branch.
• Alternatively superior gland may receive blood supply from superior thyroid
artery in 20% of cases.
• Venous drainage parallels that of thyroid.

14. HISTOLOGY
1. Connective tissue capsule
2. Chief cells or principal cells
3. Oxyphil cells rich in mitochondria . The use of sestamibi scanning is based on
this. sestamibi accumulates in mitochondria.

16. PHYSIOLOGY
• PTH is synthesized as a 115 amino acid precursor that is subsequently cleaved to
84 as molecule secreted by parathyroid chief cells in response to a decrease in
serum calcium.
• It has a circulating plasma half life of 4.5 min(3-5 min) so introperative PTH can
be measured to distinguish between single adenoma and multigland disease.
• PTH1R- Bone and kidney.
-also present in breast, skin, heart and pancreatic tissue
• PTH2R- GI , cardiovascular , central nervous system.

17. • Kidney-it leads to increased calcium resorption.
-increased renal production of calcitriol.
• On bone-to release calcium in two phases
1. Immediate effect- to mobilize the calcium from readily available Skeletal stores
in equilibrium with extracellular fluid.
2. Later- the release of calcium and phosphate through the process of bone
resorption.

18. • Intestine- PTH increases calcium and phosphate absorption.