This paper seeks to give a basic look at the structure and physiology of those aspects of the nervous and respiratory systems most involved with the cycles of sleep. The brain is examined from the hindbrain (the medulla and the pons) to the midbrain up through the forebrain (the diencephalon and the telencephalon). Also noted are structures that may have a role in sleep and wake cycles, such as the reticular activating system, the red nucleus, basal ganglia, pineal gland, and the like. The respiratory system's structure and physiology is discussed in broad terms. Some of the other factors involved with the generation of slow wave sleep and rapid eye movement sleep are also briefly discussed including neurotransmitters, hormones, and circadian rhythms. The origins of some of the terms used are provided to help facilitate learning.