BIOL 111 Lecture Notes - Lecture 14: Hydrostatic Skeleton, Neuromuscular Junction, Moulting

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: Rudiger Krahe

Document Summary

Biol 111 lecture 14 arthropods: skeletons, moulting, & muscles & arthropods ii: Lecture date/time: oct 27th, 2015 / 10:35-11:25 am. Because of exoskeleton which doesn"t change shape, the mass can grow continuously but the size has to change in a stepwise manner, until it moults and can grow again. Hydrostatic skeleton: ex. cnidarians, worms , shell-less mollusks. Musculo-skeletal system: allows muscles to attach to skeleton. Skeletal muscles: need a resistor to act against (ex. a skeleton) ; are often found in antagonistic pairs, meaning that they act in opposite directions (muscles only pull not push ex. biceps/triceps) (see image) Muscles are organs that consist of muscle tissue and connective tissues that wraps the muscle, shaping them into muscle fibers. Muscle fibers are long cells, with multiple nuclei for constant protein production = multinucleate cell. Muscle fibres contain many myofibrils (which have a striped/striated pattern) Motor neuron spikes drive muscle contractions from nervous system that sends commands.