BIOL 2030 Lecture Notes - Lecture 7: Harpoon, Gastrodermis, Peristalsis
Document Summary
Phylum cnidaria-jelly sh, sea anemones: cnidae (ex. nematocysts), nerve net; phylum platyhelminthes- Nematocyst: the most common type of cnida, a stinging organelle contained within a cnidocyte. Polyp body will not have many cnidocytes because its the tentacles that go out and grab the prey. Discharge stimulated by chemical and/or physical contact. Operculum is like a lid or cap on the cnida. Cnidocil is like the trigger; when something touches the cnidocil, it signals the operculum to open and send out the nematocysts. In the white space around is where toxins are ( uid that contains toxins that is produced by cnidocyte. When cnidocil comes in contact with something, operculum opens. Nematocyst is packaged inside, and when operculum opens, nematocyst. !1 inverts and stinging thread comes out so toxins in uid area have contact with the thread and now have access to the outside of the cell. Stinging thread is like a little harpoon.
