Smith: Skeletal Muscle Physiology Flashcards Preview

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Flashcards in Smith: Skeletal Muscle Physiology Deck (10):

Most reflexes have 6 basic components. What are they?

1. A sensory receptor2. An afferent neuron3. An integration center (CNS)4. An interneuron5. A motor (efferent) neuron6. An effector (muscle)


What are the receptors called on stretch reflexes?

muscle spindles


When an antagonistic muscle is inhibited in a reflex what is this called?

reciprocal innervation or reciprocal inhibition


What are the 4 steps of the patellar reflex?

1. muscle spindles detect stretch2. sensory neurons conduct action potentials to the spinal cord3. Sensory neurons synapse directly with alpha motor neurons4. Alpha motor neurons conduct action potentials to the same muscle that was stretched, causing it to contract


What are the two subtypes of skeletal muscle fibers?

1. Extrafusal fibers (alpha motor neurons) these make up the bulk of the muscle2. Intrafusal fibers (gamma-motor neurons) these form the muscle spindle


Intrafusal fibers are subdivided into:

1. Nuclear bag fibers (fast and innervated by group 1a afferents)2. Nuclear chain fibers (slower group II afferents and fast group Ia afferents. These detect static changes in length and tension)


What is a big difference between a patellar reflex and a golgi tendon reflex?

In a patellar reflex, the alpha motor neuron is stimulated to contract a muscle, in a golgi tendon reflex the alpha motor neuron is inhibited to relax the muscle.


What is the purpose of the golgi tendon reflex?

To prevent tendon damage


Muscle tone is fine tuned by two sensory organs. What organs are they?

1. Muscle Spindle2. Golgi Tendon Organ


What makes an area vary in the number of muscle spindle fibers?

The finer the movement required, the moore muscle spindles in a muscle.