Parathyroid Glands

The parathyroid glands develop from the endoderm: the superior glands from the fourth pharyngeal pouch, and the inferior glands from the third pharyngeal pouch. Parathyroid glands are usually found on the posterior surface of the thyroid gland. Chief cells secrete PTH, which has a half-life of 3 to 6 minutes. Primary HPT is most often asymptomatic and serendipitously found when the serum calcium value is increased on routine testing. The parathyroid glands can be evaluated with US, CT, MRI, or sestamibi scanning. Cervical exploration for primary HPT involves resection of a solitary adenoma in approximately 85% of patients. Injury to the RLN and superior laryngeal nerve does occur.

Download Full-text

Terminal branching of internal laryngeal nerve: a cadaveric study

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20213221 ◽

2021 ◽

Author(s):

Vijayalakshmi Madhavapillai ◽

Karthik Ganesh Mohanraj

Keyword(s):

Superior Laryngeal Nerve ◽

Local Anaesthetics ◽

Laryngeal Nerve ◽

Posterior Surface ◽

En Bloc ◽

Food Passage ◽

Medical College ◽

Point Of Entry ◽

Madras Medical College ◽

Intrinsic Muscles

Background: Innervation of larynx is much more complicated than previously been thought. Laryngopharynx is the common gateway for many specialists like oral surgeons, ENT surgeons, anaesthetists, UGI endoscopists and bronchoscopists. The sub-mucosal neural network can be anaesthetised by topical application or injection of local anaesthetics. In this study destination of the internal laryngeal nerve and its penetration into the intrinsic muscles of larynx are analysed.Methods: A total of 40 en bloc cadaveric specimens were investigated in the department of anatomy, Madras Medical College, Chennai and from Melmaruvathur Adhiparasakthi Institute of Medical Sciences and Research, Kanchipuram. Conventional anatomy dissection method was used in the identification of internal laryngeal branch of superior laryngeal nerve and its branches.Results: Irrespective of the number of divisions at the point of entry into thyrohyoid membrane, 4 branches were constantly traceable. The branches were traced by 2 approaches- (A) those supplying the mucus membrane- (i) to the junction of aryepiglottic fold and lateral border of epiglottis; (ii) to the posterior surface of interarytenoideus; (iii) to the posterior surface of posterior arytenoideus; and (iv) descending to apex of the pyriform fossa behind cricothyroid junction; (B) penetration into intrinsic muscles- (i) a branch terminated after entering interaryteoideus; and (ii) another terminated after entering the posterior cricoarytenoideus muscle.Conclusions: The knowledge of variation into branches and area of supply of internal laryngeal nerve is essential for anatomists and clinicians. It is not a nerve to be neglected as the knowledge of its branches is very much essential for the surgeons operating in this area of air and food passage.

Download Full-text

Preservation of the Laryngeal Nerves during Total Thyroid Lobectomy

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348947708600611 ◽

1977 ◽

Vol 86 (6) ◽

pp. 777-788 ◽

Cited By ~ 47

Author(s):

John M. Loré ◽

Duck J. Kim ◽

Samir Elias

Keyword(s):

Recurrent Laryngeal Nerve ◽

Total Thyroidectomy ◽

Vocal Cord ◽

Superior Laryngeal Nerve ◽

Laryngeal Nerve ◽

Parathyroid Glands ◽

External Branch ◽

Thyroid Lobectomy ◽

Maximum Protection

A technique of exposure and preservation of the recurrent laryngeal nerve at the very onset of thyroidectomy and preservation of the external branch of the superior laryngeal nerve at the close of the procedure is described, which is believed to afford maximum protection to these nerves during total thyroid lobectomy and isthmusectomy as well as total thyroidectomy. At the same time, preservation of the parathyroid glands is achieved. In 120 exposures and preservations of the recurrent laryngeal nerve there have been no instances of a single permanent paralysis of this nerve. In 111 total thyroid lobectomies in which the external branch of the superior laryngeal nerve was placed in jeopardy, only one patient had a slight bowing of the vocal cord with excellent voice function during a limited follow-up period.

Download Full-text

Parathyroid anatomy, hormone synthesis, secretion, action, and receptors

Oxford Textbook of Endocrinology and Diabetes ◽

10.1093/med/9780199235292.003.0404 ◽

2011 ◽

pp. 633-641

Author(s):

Geoffrey N. Hendy ◽

David Goltzman

Keyword(s):

Parathyroid Glands ◽

Cervical Region ◽

Pharyngeal Pouch ◽

Hormone Synthesis ◽

The Third ◽

Third Pharyngeal Pouch

Humans have two pairs of parathyroid glands lying in the anterior cervical region. The fetal parathyroid glands begin developing at 5 weeks from the third and fourth pharyngeal pouches. The third pharyngeal pouch, which contains tissue that will become the thymus and parathyroid, migrates downward and gives rise to the two inferior parathyroid glands normally located at the lower poles of the thyroid. The fourth pharyngeal pouch does not migrate and gives rise to the two upper parathyroid glands, which normally are attached to the upper poles of the thyroid (1).

Download Full-text