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.
Whereas the interneurons all lie within the CNS, portions of the afferent and efferent neurons project out of the CNS and constitute the nerves of the PNS. The cell bodies of afferent neurons reside in discrete structures called ganglia located near the CNS.Thus, the cell bodies of the afferent spinal nerves are located in dorsal root ganglia, present on either side of the spinal cord.he sensory impulse that is generated here travels along afferent fibers to cell bodies located in a dorsal root ganglion and from there to the spinal cord. Within the spinal cord, the afferent fibers synapse on the cell bodies of efferent neurons, whose long axons extend to innervate muscles in the leg.