The brain stem is the region between the diencephalon and the spinal cord. It consists of three parts: midbrain, pons, and medulla oblongata. The midbrain is the most superior portion of the brain stem. The pons is the bulging middle portion of the brain stem. This region primarily consists of nerve fibers that form conduction tracts between the higher brain centers and spinal cord. The medulla oblongata, or simply medulla, extends inferiorly from the pons. It is continuous with the spinal cord at the foramen magnum. All the ascending (sensory) and descending (motor) nerve fibers connecting the brain and spinal cord pass through the medulla.
In in general, authors often create triplets or structures in three parts. In its simplest form, this is merely , from 's . wrote a popular handbook of , in which he touted the advantages of over the more traditional used by and many other famous play-writers.
The sternum, commonly referred to as the breastbone, is a flat elongated bone at front of the chest. It is the bone to which the ribs attach to through the costal cartilages and the clavicle (collarbone) meets with at the sternoclavicular joint . The sternum is a natural ‘shield’ that protects the important organs in the thoracic cavity – the heart and great blood vessels. It has three parts known as the manubrium (top), body of the sternum (middle) and xiphoid process (bottom).
The first type of neuron studied was the (or motoneuron), which stimulates muscle fibers to produce movement. Because it was the first type studied, the motor neuron became the prototypical textbook neuron, used to illustrate the three basic parts of neurons: dendrites, cell body, and axon.