Physio Ch 13 Vocab. Control of Body Movement:

Reflexes that involve somatic motor neurons and skeletal muscles

• Reflexes whose responses are controlled by autonomic neurons
• all ___ ___ are polysynaptic, with at least one synapse in the brain and another in the autonomic ganglion

integrated in the spinal cord

integrated in the brain

• born with them, genetically determined 
•  like the knee jerk

Pavlov's dogs salivating upon hearing a bell

• simplest of reflexes
• single synapse between the afferent and the efferent neuron

have two or more synapses

• located in skeletal muscles, joint capsules, and ligaments
• sense the body's position in space

• the somatic motor neuron that innervate skeletal contractile fibers
• ___ ___ ___ innervates extrafusal muscle fibers

• the effectors are contractile muscle fibers also known as ___ ___ ___
• action potentials alpha motor neurons cause ___ ___ ___ to contract

stretch receptors that send information to the spinal cord that brain about muscle length and changes in muscle length

-each muscle spindle consists of a connective tissue capsule that encloses a group of small muscle fibers 

-modified so that the ends are contractile but the center region lack myofibrils

• contractile ends of the intrafusal fibers have their own innervation from ___ ___ ___
• the non contractile central region of each intrafusal fiber is wrapped by sensory ending that are stimulated by stretch
• synapses directly to alpha motor neurons

because of tonic activity, even a mucsle at rest maintains a certain level of tension

the reflex pathway in which muscle stretch initiates a contraction response

• second type of proprioceptor
• found at the junction of muscle fibers and tendons.
• respond to tension created during isometric contraction
• ___ ___ ___ reflexes cause relaxation, opposite of the reflex contraction by muscle spindle

• collection of pathways controlling a single joint
• simplest ___ ___ is a monosynaptic stretch reflex like the knee jerk

For a muscle to extend the leg, the antagonistic flexor muscles must relax

• flexion reflexes, particularly the legs, are usually accompanied by ___ ___ ___
• -is a postural reflex that helps maintain balance when one  foot is lifted off the ground.

• 1 of 3 classifications of movement
• least complex 
• integrated primarily in the spinal cord

• help maintain body position ass we stand or move through space
• integrated in the brain
• require continuous sensory input from visual and vestibular

• 1 of 3 classifications of movement
• most complex
• requie integration at the cerebral cortex
• can be initiated at will without external stimuli

• 1 of 3 classifications of movement
• walking or running are a combination of rhythmic and voluntary movement.
• once activated, networks of CNS interneurons called ___ ___ ___ maintain the spontaneous repetitive activity

allow the body to prepare for a voluntary movement, and feedback mechanisms are used to create a smooth, continuous motion

• polysynaptic reflex pathways that cause an arm or leg to be pulled away from a noxious stimulus, such as a pinprick or hot stove.
• rely on divergent pathways in the spinal cord

a group of interneurons controlling voluntary movement that run from the motor cortex to the spinal cord, where they synapses directly onto somatic motor neurons