Blog #4 ::::: Cranial Nerves

In my last blog I talked about spinal nerves, now I am going to talk about cranial nerves. The difference between cranial and spinal nerves is that cranial nerves emerge directly from the brain stem while spinal nerves are nerves that emerge from segments of the spinal cord. There are twelve different cranial nerves. The twelve cranial nerves can be divided into different groups. These groups being motor, sensory or mixed nerves. Sensory nerves tend to be located in the lateral brain stem. While motor nerves are located medially.

The function of the cranial nerves is for the most part similar to the spinal nerves, the nerves that are associated with the spinal cord. The motor components of the cranial nerves are derived from cells that are located in the brain. These cells send their axons out of the cranium where they will control muscles. , glandular tissue or specialized muscle. The sensory components of cranial nerves originate from groups of cells that are located outside of the brain. These collections of nerve cell bodies are called sensory ganglia. They have the same role as the dorsal root ganglia which are associated with the spinal cord.

In general, sensory ganglia of the cranial nerves send out a branch that divides into two branches. The motor components of cranial nerves transmit nerve impulses from the brain to target tissue outside of the brain while sensory components send nerve impulses from sensory organs to the brain. Without cranial nerves, we would be unable to chew, smell or see. These twelve nerves help to control many muscles of the body. All of them have their own purpose. Who knew one little nerve could control your mouth and how you chew.