Prof. Viktor Matej¿ík graduated in 1975 at the Medical Faculty of the Comenius University in Bratislava, Slovakia. In 1982 he took the 1st Degree Qualification in Surgery, followed by a Degree in Neurosurgery and a Professor degree at Comenius University. He worked as lecturer and as professor at the Department of Neurosurgery at the Faculty of Medicine at the Comenius University and University Hospital, while nowadays he is Deputy of the Head of this Department. His main interest areas are: neurosurgery, craniocerebral injuries, and peripheral nerves. Prof. Matej¿ík is author and co-author of several monographs and nearly 200 publications with more than 200 citations.

Ass. Prof. Zora Haviarová graduated at the Medical Faculty of the Comenius University in Bratislava, Slovakia. In 1995 she took a Degree Qualification in Internal Medicine. She is associate professor of anatomy, histology and embryology, working basically at the Institute of Anatomy of the Comenius University, Comenius University, Bratislava. Since 2013, she has worked at the dispensary of the Institute of Tropical Diseases (Bratislava, Slovakia). Her main areas of interest are: research on the structure of the varicose vein wall, clinical anatomy (cardiovascular system, peripheral nerves), and infectology. Dr. Haviarová is author and co-author of more than 130 publications (including 3 monographs) with more than 220 citations.

Ass. Prof. Roman Kuruc graduated at the Medical Faculty of Comenius University, Bratislava (General Medicine branch), then he got a Degree Qualification in Pathological anatomy and one in Forensic Medicine. With a special interest on forensic medicine, cranio-cerebral injuries and traffic injuries, he is author and co-author of more than 120 publications with more than 50 citations.

Chapter 1 Variability in the peripheral nervous system.- Chapter 2 Definition of the terms about the peripheral nervous system.- Chapter 3 Differences in the structure of the autonomic nervous system and the structure of the followed material.- Chapter 4 Differences in the structure of the brachial plexus.- Chapter 5 Variations and lesions of the brachial plexus at the level of nerve trunks.- Chapter 6 Variations and lesions of the brachial plexus at the level of nerve fascicles.- Chapter 7 Variations and lesions at the level of the terminal branches of the brachial plexus.- Chapter 8 Differences in the structure of the lumbosacral plexus.- Chapter 9 Intraspinal (extradural and intradural) spinal nerve variations.- Chapter 10 Intracranial intradural variations of the cranial nerves.- Chapter 11 The autonomic ganglia of the cranial nerves.- Chapter 12 Sources of nerve supply to the vessels of the extremities and peculiarities of the deep vessels of the lower limb innervation.- Chapter 13 Sources of innervation of the upper limb superficial and deep veins.-Chapter 14 Signs of the spinal nerve lesions on the extremities.- Chapter 15 Sources of the nerve veins.- Chapter 16 Hematomas of Peripheral Nerves.- Chapter 17 Summary of our contribution.- Chapter 18 Supplementary figures.