Cervical effacement (also called cervical ripening) refers to a thinning of the cervix. It is a component of the Bishop score. It can be expressed as a percentage. Prior to effacement, the cervix is like a long bottleneck, usually about four centimeters in length. Throughout pregnancy, the cervix is tightly closed and protected by a plug of mucus. When the cervix effaces, the mucus plug is loosened and passes out of the vagina.
A reflex arc is a neural pathway that controls a reflex action. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord.hen the patellar tendon is tapped just below the knee, the patellar reflex is initiated and the lower leg kicks forward (via contraction of the quadriceps). The tap initiates an action potential in a specialized structure known as a muscle spindle located within the quadriceps.
reÂ·flex arc. 1. the route followed by nerve impulses in the production of a reflex act, from the peripheral receptor organ through the afferent nerve to the central nervous system synapse and then through the efferent nerve to the effector organ.2. a neural pathway that involes both the peripheral and central nervous systems.eÂ·flex arc. 1. the route followed by nerve impulses in the production of a reflex act, from the peripheral receptor organ through the afferent nerve to the central nervous system synapse and then through the efferent nerve to the effector organ.