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.
1 Nerves that carry information from sensory receptors to the central nervous system only are called afferent nerves. 2  Other neurons, known as efferent nerves, carry signals only from the central nervous system to effectors such as muscles and glands. Afferent, Efferent, and Mixed Nerves. 2  Some of the nerves in the body are specialized for carrying information in only one direction, similar to a one-way street. 3  Nerves that carry information from sensory receptors to the central nervous system only are called afferent nerves.