Endostyle

The Endostyle (gr. Stylos "pillar"), also called hypobranchial is a ventral in the gills intestine located Flimmerrinne with glandular epithelium of lancelet , the lamprey larvae ( Ammocoetes ) and tunicates (all the chordates belong). The glandular epithelium produces a web of mucus which is placed over the gill slits and with which food particles filtered in the gill intestine are captured. This is collected in the epibranchial groove and releases the nutrients it contains to the overlying dorsal vessel.

Transverse section through a lancet fish, the endostyle is marked with number 18

The cells of the endostyle accumulate iodine from the environment and incorporate this into molecules of the hormone thyroxine . Because of this ability, the hypobranchial is a homologue of the thyroid gland of vertebrates considered, which means you can thyroid phylogenetically derived from Endostyle.

literature

Alfred Goldschmid: Chordata, chordates. In: W. Westheide, R. Rieger (Ed.): Special Zoology. Part 1: Protozoa and invertebrates. Gustav Fischer, Stuttgart / Jena 1997, 2004, ISBN 3-8274-1482-2 , p. 835ff.
Alfred F. Romer, Thomas S. Parsons: Comparative anatomy of the vertebrate animal. 5th edition. Paul Parey Verlag, Hamburg / Berlin 1991, ISBN 3-490-11218-0 , p. 534 ff.

Individual evidence

↑ JE Dumont, B. Corvilain, C. Maenhaut: The Phylogeny, Ontogeny, Anatomy, and Metabolic regulation of the thyroid. ( Memento from September 28, 2011 in the Internet Archive ) In: Thyroid Disease Manager. 2002.

[1] JE Dumont, B. Corvilain, C. Maenhaut: The Phylogeny, Ontogeny, Anatomy, and Metabolic regulation of the thyroid. ( Memento from September 28, 2011 in the Internet Archive ) In: Thyroid Disease Manager. 2002.