BIOL 204 Lecture Notes - Lecture 15: Myotome, Smooth Muscle Tissue, Pharyngeal Slit
Document Summary
Slime glands in myxinoidea: myx- multicellular smile glands that rapidly release a stream of mucins and protein threads, rapidly expands in seawater to produce a thick mucus slime that coats the gills of a potential predator. Epidermal glands- amphibians: most in tetrapods are multicellular, amphibians have, abundant multicellular mucus glands to produce the mucus cuticle, multicellular granular glands (poison) for defense, amphibian larvae, unicellular leydig cells produce aniviral and antibacterial substances. Functions of muscles: primary role- provide force for movement. Insertions and orgins: muscle has 2 points of attachment, orgin, relatively fixed structure. Muscle actions: skeletal muscles work in antagonistic pair, flexion: to bend one part relative to one another about a joint (decrease angle between. Embryological origins- skeletal muscles: trunk; epimere mesoderm becomes segmentally arranged into somites, mytotome of trunk somites develops into axial and appendicular muscles, myotome of some anterior somites also grows ventrally and anteriorly to form hypobranchial muscles.
