BIO 2135 Lecture Notes - Lecture 5: Zygote, Scyphozoa, Mesoglea
31 Jan 2017
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Document Summary
Loss of choanocytes the microvilli from this structure are persistent though, we inherit the microvillar surface. Connexins can change their conformation to open or close a hole in the cell information can be shared when the connection pore opens. There will now be tight junctions, a base membrane, cells are now isolated they can only communicate with each other true tissue. Inside the nematocyst capsule is a coiled spring that is under tension. If anything touches the cnidocil (trigger), the operculum pops up and the spring fires. It shoots out, pierces the skin of a prey, releases toxins, immobilizes prey. The prey can then be pulled in. Polyp body = oral opening, but no anal opening. Epidermis = epitheliomuscular cells (can contract, arranged longitudinally) Gastrodermis = nutritive muscular cells (absorbs, can contract, arranged circularly) Circular contraction + longitudinal contraction, works as a skeletal system that can move the body both ways.
