Type A-delta fibers conduct impulses at a very rapid rate and are responsible for transmitting acute sharp pain signals from the peripheral nerves to the spinal cord. Only type A-delta fibers transmit sharp. piercing pain. Somatic efferent fibers affect the voluntary movement of skeletal muscles and joints. Type C fibers transmit sensory input at a much slower rate and produce a slow. chronic type of pain. The autonomic system regulates involuntary vital functions and organ control such as breathing.
