PSYCH261 Lecture Notes - Lecture 8: Extrafusal Muscle Fiber, Golgi Tendon Organ, Alpha Motor Neuron

• School: University of Waterloo
• Department: Psychology
• Course: PSYCH261
• Professor: Roxane Itier Itier

Document Summary

Types of vertebrate muscles: smooth muscles control digestive system and other organs, skeletal (striated) muscles movement of the body in relation to the environment, cardiac muscles control the heart. Effectors: e. g. , the hands (distal) or neck (proximal: eyes effectors for vision. Extrafusal muscle fiber responsible for force exerted by contraction skeletal muscle. Alpha motor neuron serves several fibers (from 10 to 100) Alpha motor neuron originates in the brainstem and spinal cord; exits via the ventral root. It synapses with muscle fiber at the motor endplate the synapse is the neuromuscular junction. Terminal button releases ach endplate potential (depolarization) . 1 myofibril = overlapping strands of actin and myosin filaments (striated muscle) sarcomere = contractile unit of striated muscle tissue actin attached to myosin cross bridges rowing movements contraction of. Intrafusal muscle fibers (muscle spindles) are specialized sensory organs and functions as muscle length detector: fibers are stretched when muscle lengthens, sensory ending is stretch receptors.