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.
Figure 6. Location of the brain and the spinal cord in the human body. Afferent and efferent nerves make up the peripheral nervous system. There are two types of peripheral nerve fibers, afferent and efferent. 1  Afferent fibers are those that carry neural impulses toward the central nervous system.2  Efferent fibers carry impulses from the central nervous system to effectors such as muscles and glands.fferent and efferent nerves make up the peripheral nervous system. There are two types of peripheral nerve fibers, afferent and efferent. 1  Afferent fibers are those that carry neural impulses toward the central nervous system. ( 2 Afferent nerves ascend to or approach the central nervous system.).