Changes

==Thymus==

==Thymus==

Reptiles usually have two pairs of thymus glands located cranial to the [[Snake Cardiovascular System|heart]]. They are closely associated with the common carotid artery, jugular vein and vagus nerve.  In [[Snake|snakes]] there are significant [[:Category:Snake Species|species]] differences with some [[Boidae|boids]], [[Colubridae|colubrids]] and crotalids having only a single bilateral lobe.  The thymus decreases in weight with age.

Reptiles usually have two pairs of thymus glands located cranial to the [[Snake Cardiovascular System|heart]]. They are closely associated with the common carotid artery, jugular vein and vagus nerve.  In snakes there are significant species differences with some [[Boidae|boids]], [[Colubridae|colubrids]] and crotalids having only a single bilateral lobe.  The thymus decreases in weight with age.

 

==Parathyroids==

==Parathyroids==

There are usually two pairs of parathyroid glands. They measure about 0.5-1.0 mm in diameter and are located cranial to the [[Snake Cardiovascular System|heart]].  The caudal parathyroids are often associated with thymic tissue. The parathyroids play a very important role in calcium metabolism and accidental [[Lizard and Snake Surgery|surgical]] removal will result in hypocalcaemia and tetanic convulsions.

There are usually two pairs of parathyroid glands. They measure about 0.5-1.0 mm in diameter and are located cranial to the [[Snake Cardiovascular System|heart]].  The caudal parathyroids are often associated with thymic tissue. The parathyroids play a very important role in calcium metabolism and accidental [[Lizard and Snake Surgery|surgical]] removal will result in hypocalcaemia and tetanic convulsions.