neuromuscular Flashcards
neuromuscular system
links central nervous system to peripheral nervous system. composed of neural circuit (motor neurons in spinal cord, sensory neurons in dorsal root ganglions, and skeletal muscle fibers)
functions
essential to movements of the body, the control of posture and breathing.
includes
muscles in the body and nerves serving them
nerves
long bundles of axons that transmit signals from the central nervous system. send and receive signals in the neuromuscular system.
sensory nerves
(afferent) send messages to the central nervous system
motor nerves
(efferent) send messages out to the muscles.
autonomic nervous system
(involuntary) controls involuntary actions involving cardiac and smooth muscle, such as heart rhythm, digestion, and breathing.
voluntary nerve signals
make skeletal muscles do a deliberate actions such as walking, throwing, or typing.
muscles
contain long myofibrils made of sarcomere units, each consisting of long strands of proteins called actin (thin filaments) and myosin (thick filaments).
skeletal muscles
work by contracting
proprioception
specialized sensory receptors that provide the central nervous system with information needed to maintain muscle tone and perform complex movements.
muscle spindles
proprioceptors that consist of several modified muscle fibers enclosed in a sheath of muscle tissue.
older muscle
muscle function is reduced in older adults
motor neuron
A neuron located in the central nervous system that projects its axon outside the CNS and directly or indirectly control muscles.
sensory neuron
These are typically classified as the neurons responsible for converting various external stimuli that come from the environment into corresponding internal stimuli.
reflex arc
A neural pathway that controls an action reflex. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This characteristic allows reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs. There are two types of reflex arcs: autonomic reflex arc (affecting inner organs) and somatic reflex arc (affecting muscles).
monosynaptic
reflex arcs that contain only two neurons (sensory neuron and motor neuron).
polysynaptic
multiple interneurons, interface between the sensory and motor neurons in the reflex pathway.
fight-or-flight response
in response to acute stress, the sympathetic nervous system is activated in response to the body releasing hormones.
