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.
The dorsal root contains afferent (sensory) fibers that transmit information to the spinal cord from the sensory receptors. The ventral root contains efferent (motor) fibers that carry messages from the spinal cord to the effectors. Cell bodies of the efferent fibers reside in the spinal cord gray matter. These roots become nerves that innervate (transmit nerve impulses to) muscles and organs throughout the body.