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.
The reflex arc is the nerve pathway that the signal follows. For example, the knee jerk reflex arc has a stimulus going to an interneuron in the spine and a motor neuron compl â¦ etes the arc by causing the knee to jerk. A reflex is just the action itself.he somatic reflex arc is a neural circuit that travels through the spinal cord. It allows the body to respond to the stimulus before the brain interprets the message/ impulse â¦ . For example, when you burn yourself, you automatically pull your hand away without even thinking about it.