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.
Sensory neurons (afferent neurons) are unipolar, bipolar, or multipolar shaped cells that conduct action potentials toward or into the central nervous system. They carry somatic nervous system signals from the skin, joints, skeletal muscles, sensory organs (eyes, ears, mouth, and nose). They also carry autonomic nerous system signals from the visceral organs (heart, lungs, vessels, etc).