Anal pore
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The anal pore or cytoproct is a structure in various single-celled eukaryotes where waste is ejected after the nutrients from food have been absorbed into the cytoplasm.[1]
In ciliates, the anal pore (cytopyge) and
Location
The anal pore is an exterior opening of microscopic organisms through which undigested food waste, water, or gas are expelled from the body. The anal pore is located on the
This structure is found in different unicellular eukaryotes like paramecium organelles.
Function
Digested nutrients from the vacuole pass into the cytoplasm, making the vacuole shrink and moves to the anal pore, where it ruptures to release the waste content to the environment outside of the cell. The cytoproct is used for the excretion of indigestible debris contained in the food vacuoles.
Most
In
In ciliates, the anal cytostomes and cytopyge pore regions are not covered by either ridges or cilia or hard coatings like the other parts of the organism. As a food vacuole approaches the cytoproct region it actually starts to flatten out the surrounding cells, and a thin-membrane vacuole allows it to be combined in the cell wall. Once the vacuole attaches to the plasma membrane of the cell wall, the vacuole is emptied. The waste excreted by the cell can come as a membrane-bound packaged ball, or as a stream of debris behind the organism.
Directly after secretion of the waste products, deep invagination (deep, canyon-like structure that was the vacuole) is still present. About 10 to 30 seconds after secretion, the vacuole detaches, and a new thin plasma membrane is formed. After a minute has gone by the organisms cytoproct is closed up again and the process is ready to be repeated.
In marine animals
References
- ISBN 978-0471497547. Retrieved 16 January 2018.
Bibliography
- “Introduction to Ctenophora.” Introduction to the Ctenophora, https://ucmp.berkeley.edu/cnidaria/ctenophora.html.
- Pang, Kevin; Martindale, Mark Q. (December 2008). "Ctenophores". Current Biology. 18 (24): R1119–R1120. PMID 19108762.
- Presnell, Jason S.; Vandepas, Lauren E.; Warren, Kaitlyn J.; Swalla, Billie J.; Amemiya, Chris T.; Browne, William E. (October 2016). "The Presence of a Functionally Tripartite Through-Gut in Ctenophora Has Implications for Metazoan Character Trait Evolution". Current Biology. 26 (20): 2814–2820. PMID 27568594.