BIO310H5 Lecture Notes - Lecture 6: Acetyl-Coa, Sliding Filament Theory, Neuromuscular Junction
Document Summary
Simple neuronal circuit: sensory neuron (afferent neuron, interneuron, motoneuron (efferent neuron) Myelin is segmented to prevent current from ending. Nodes of ranvier: short, unmyelinated gaps that sit between myelinated axons. Saltatory conduction: a series of discontinuous and regenerative depolarizations that take place only at the nodes of ranvier: voltage gated na channels occur only at the gaps of the myelin sheath called nodes of ranvier. Thus depolarization can occur only at the nodes causing the ap to jump from node to node along the axon. Two major types of muscles (2 main types based on the arrangement of actin and myosin): striated: (striated appearance) skeletal & cardiac. Actin and myosin arranged in parallel (sarcomeres: smooth: (not striated) Actin and myosin are not organized and do not have sarcomeres: muscles consist of long, cylindrical, multinucleated muscle fibers arranged in. Each fiber arises from many individual embryonic muscle cells called myoblasts, which fuse during embryonic development to form a myotube.
