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.
Quick Answer. Afferent neurons carry signals to the brain and spinal cord as sensory data, and efferent neurons send signals from the brain to the muscles, glands and organs of the body in response to sensory input. The main cell bodies of afferent neurons are located near the brain and spinal column, which comprise the central nervous system.