Quick Answer. The function of a synaptic knob is to change the action potential that is carried by axons into a chemical message. The chemical message then interacts with the recipient neuron or effector. This process is called synaptic transmission.
Over-the-counter (OTC) medicines that are recommended for head or pubic lice include: 1  Permethrin creme rinse 1% (such as Nix), which is a common first choice for treating head lice. 2  Shampoos containing pyrethrins and piperonyl butoxide (such as Rid), which are left on the hair for 10 minutes and then rinsed out.
Pyrethrin is used to treat head lice (Pediculus humanus var capitis) and crab lice (Pthirus pubis) and their nits or eggs. Permethrin is used to treat head lice (Pediculus humanus var capitis) and crab lice (Pthirus pubis) and their eggs.