Additional causes of bleeding in early pregnancy include: 1  Cervical changes. During pregnancy, extra blood flows to the cervix. 2  Infection. Any infection of the cervix, vagina, or a sexually transmitted infection (such as chlamydia, gonorrhea, or herpes) can cause bleeding in the first trimester.
A: Afferent neurons are special nerve cells that are responsible for carrying nerve impulses from the receptors to the central nervous system. Efferent neurons carry nerve impulses from the central nervous system to the muscles and glands. Continue Reading.
(April 2014). In the peripheral nervous system, an afferent nerve fiber is the nerve fiber (axon) of an afferent neuron (sensory neuron). It is a long process (projection) extending far from the nerve cell body that carries nerve impulses from sensory receptors or sense organs toward the central nervous system.he opposite direction of neural activity is efferent conduction. In the nervous system there is a closed loop system of sensation, decision, and reactions. This process is carried out through the activity of afferent neurons (sensory neurons), interneurons, and efferent neurons (motor neurons).