Parathyroid Glands

Greep, Roy O.

doi:10.1016/b978-0-12-395549-4.50014-4

Cited by 10 publications

(11 citation statements)

References 62 publications

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“…The rostral (cranial or parathyroid 111) parathyroids lie at the bifurcation of the carotid arteries near the angle of the jaws, whereas the caudal parathyroids (parathyroid IV) lie anterior to the heart between the anterior and posterior lobes of the thymus (Clark, 1970;Oguro, 1972;Warbhuwan, 1990-1991;Roth and Schiller, 1976), or they lie either dorsal to the anterior lobe of the thymus or embedded in it (Clark, 1971;Oguro, 1970;Singh and Kar, 1983b;Srivastav and Rani, 1992a). The parathyroids of snakes are not in intimate connection with the walls of the vessels along which they rest (Clark, 1970;Greep, 1963;Srivastav and Rani, 1992a,b).…”

Section: Ophidiamentioning

confidence: 97%

“…The caudal pair (parathyroid IV), if present, lies just posterior to the rostral pair located on either side of the neck near the aortic arch. It is characteristic of lizards that parathyroids are closely associated with the blood vessels (Akbarsha, 198513;Clark, 1970;Greep, 1963;Oguro, 1969;Senior, 1974).…”

Section: Ophidiamentioning

confidence: 98%

“…The four parathyroid glands of an individual are almost equal in size (Greep, 1963;Warbhuwan, 1990-1991;Padgaonkar et al, 1992;Singh and Kar, 1983a,b;Srivastav and Rani, 1992a,b) but vary between individuals from 0.5-0.6 mm in diameter (Padgaonkar et al, 1992) to 1-2 mm (Oguro, 1970;Singh and Kar, 198313). The rostral (cranial or parathyroid 111) parathyroids lie at the bifurcation of the carotid arteries near the angle of the jaws, whereas the caudal parathyroids (parathyroid IV) lie anterior to the heart between the anterior and posterior lobes of the thymus (Clark, 1970;Oguro, 1972;Warbhuwan, 1990-1991;Roth and Schiller, 1976), or they lie either dorsal to the anterior lobe of the thymus or embedded in it (Clark, 1971;Oguro, 1970;Singh and Kar, 1983b;Srivastav and Rani, 1992a).…”

Section: Ophidiamentioning

confidence: 99%

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Morphology and physiological significance of parathyroid glands in reptilia

Srivastav

Sasayama

Suzuki

1995

Microscopy Res & Technique

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Adult reptiles possess one or two pairs of parathyroid glands that have been shown in many species to derive from the third and fourth pharyngeal pouches, respectively. Up to five pairs may develop during early embryonic life. Excess glands may involute during late embryogenesis. The location of the parathyroid glands differs in the various species. As a general rule, they lie just anterior to the heart, the anterior pair (parathyroid III) being associated with the carotid artery, the posterior pair (parathyroid IV) with the aortic arch. In snakes, however, the anterior pair (parathyroid III) is associated with the carotid artery near the angle of the jaw. As shown by light microscopy and, to a lesser extent, by electron microscopy, the parathyroid parenchyma comprises secretory cells which may form dark and light variants, occasional oxyphil cells, and stellate cells. They are arranged in cords separated by connective tissue containing a capillary network. Parathyroid secretory cells often form follicles which might be the result of degeneration. Degeneration may occur as a form of involution during winter in species undergoing seasonal changes. The product of parathyroid cells, the parathyroid hormone, is responsible for the maintenance of blood calcium concentration. The sites of action--bones, kidneys, intestine, endolymphatics, and dermal skeleton--are not well understood or not investigated. In some turtles, parathyroid hormone is not the (main) factor for the regulation of calcium homeostasis.

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Section: Ophidiamentioning

confidence: 97%

Section: Ophidiamentioning

confidence: 98%

Section: Ophidiamentioning

confidence: 99%

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Morphology and physiological significance of parathyroid glands in reptilia

Srivastav

Sasayama

Suzuki

1995

Microscopy Res & Technique

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“…Parathyroid glands develop in most salamanders during adult life. Parathyroids never develop in some neotenic salamanders, which do not undergo metamorphosis-for example, Necturus maculata, Axolotl sp., Typhlomolge rathburni, and Proteus anguinas (Greep, 1963;Waggener, 1930). In Triturus cristatus, the glands lie medially between the second and fourth aortic arches.…”

Section: Urodelamentioning

confidence: 98%

“…There are a number of reviews dealing with the morphology of amphibian parathyroid glands (Clark, 1983;Clark et al, 1986;Greep, 1963;Isono et al, 1990;Pang et al, 1980;Roth and Schiller, 1976). The aim of this review is to summarize the data of reports on development, morphology, and seasonal changes on the parathyroid glands in caecilia, urodela, and anura.…”

Section: Introductionmentioning

confidence: 97%

Amphibian parathyroids: Morphological and functional aspects

Srivastav

Das²,

Das³

et al. 1995

Microscopy Res & Technique

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Amphibians living partially or totally in a terrestrial environment are the first tetrapods to possess parathyroid glands. Purely aquatic amphibians and amphibian larvae lack these endocrine glands. The parathyroids develop at the time of metamorphosis. The parathyroid glands in caecilians consist of a single cell type, that of urodeles may be composed of basal (supporting) cells and suprabasal (chief) cells, and that of anurans of small and large chief cells. Parathyroid glands of caecilians and anurans lack connective tissue, blood vessels, and nerves. The parathyroid cells become activated in response to decreased blood calcium concentration and undergo changes indicating increased parathyroid hormone secretion. Increased blood calcium concentration suppresses secretory activity. Usually, parathyroidectomy elicits hypocalcemia in most amphibians. Such operations have no effect in lower urodeles. Parathyroid hormone administration provokes hypercalcemia in most amphibians. The parathyroids of caecilians have not been studied in detail. The urodeles and anurans exhibit seasonal changes in the parathyroid glands. These changes may be initiated by environmental stimuli such as light, temperature, or alterations in blood calcium levels caused by natural hibernation.

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