To consider a sperm cell as normal in terms of morphology, it must have particular characteristics as regards its main parts: head, neck, and tail.
It should have an oval head and be composed of two, well-defined regions: the nucleus, which contains the 23 chromosomes of the father, and the acrosome, a deposit of hydrolases found on the distal edge.
The neck or midpiece, which is the part that connects the head with the tail and contains the sperm's mitochondria, must be longer than the head.
Finally, the tail is the longest and thinnest part of the sperm cell. In order for it to be able to move forward, its back and forth movement must have a rhythmical longitudinal sliding motion.