BSC-2085 Lecture Notes - Lecture 17: Patellar Reflex, Intrafusal Muscle Fiber, Extrafusal Muscle Fiber
Document Summary
Explain what is a reflex and the components of the reflex arc. Automatic responses coordinated within spinal cord through interconnected sensory neurons, motor neurons, and interneurons. Preserve homeostasis by making rapid adjustments in the function of organs/organ systems. Each time a particular reflex is activated, it produces the same motor response. Neural reflexes: rapid, automatic responses to specific stimuli, basic building blocks of neural function, one neural reflex produces one motor response. Reflex arc: the wiring of a single reflex, beginning at receptor, ending at peripheral effector, generally opposes original stimulus (negative feedback) Integration and control of spinal reflexes: reflex behaviors are automatic. But processing centers in brain can facilitate or inhibit reflex motor patterns based in spinal cord. Brain can override some reflexes through descending tracts. Describe the five steps in a neural reflex. Step 1: arrival of stimulus, activation of receptor: physical or chemical changes. Step 2: activation of sensory neuron: graded depolarization leads to action potential.
