Revista de Morfología y Anatomía

The human ulnar nerve is one of the major nerves in the upper extremity, responsible for providing motor and sensory innervation to the hand and forearm. It originates from the brachial plexus, a network of nerves that emerge from the spinal cord in the neck. From there, it travels down the arm, passing through several important structures such as the axilla, the medial side of the upper arm, and the elbow joint.

The anterior cingulate cortex (ACC) is a region of the brain located in the frontal lobes, just behind the prefrontal cortex. It is part of the limbic system, which is involved in emotion regulation and the formation and retrieval of memories. The ACC has been implicated in a wide range of cognitive, emotional, and behavioral processes, including attention, decision making, conflict monitoring, empathy, and pain perception.

The human knee joint is one of the most complex and frequently used joints in the body. It plays a critical role in supporting the weight of the body, absorbing shock, and facilitating movement. The knee joint is composed of several key structures, including the femur, tibia, patella, and a network of ligaments, tendons, and muscles.

The carpal tunnel is a narrow passageway in the wrist that allows the median nerve and several tendons to pass from the forearm to the hand. The carpal tunnel retinaculum, also known as the flexor retinaculum, is a thick band of connective tissue that forms the roof of the carpal tunnel. It plays a crucial role in maintaining the stability of the wrist and ensuring the smooth movement of the tendons and nerves that pass through the carpal tunnel.

The human ear is a complex sensory organ responsible for detecting sound and maintaining balance. It is composed of three main parts: the outer ear, middle ear, and inner ear. Each part plays a critical role in the process of hearing and balance.

Introduction: Primary tumours associated with nerve cells are exceptionally rare whereupon the majority of these tumours present as benign. Neurons develop oncogenic mutations less than their supporting neuroglias which are transformed into glioma tumours.

Methods and materials: Using a multi-faceted approach, search strategies were generated using specific keywords and performed on selected scientific databases. Literature searches were performed and a shortlist of seven publications was generated following a strict criteria based selection process.

Results: Reduced number of proliferating cells: Early cell cycle exit results in the inability for nerve cells to regenerate as well as preventing malignancies from developing as no DNA is required to replicate. Additionally, post-mitotic Neurons have the ability to re-enter the cell cycle without producing two daughter cells to repair damaged DNA.

Tumour suppressor proteins: A high abundancy of PTEN and TP53 are present in the CNS and PNS (higher than most other areas of the body). These act as protective mechanisms for detection of damaged DNA to mark cells for immediate apoptosis.

Inhospitable environment created by the lymphatic system: An extensive network of lymphatic vessels channel tumour cell dissemination to cervical lymph nodes. This stimulates immune responses by the high abundancy of dendritic cells and the destruction of tumour cells.

Immunity in the nervous system: Natural Killer (NK) cells, seen in high abundancy in the CNS, are the most effective response factors against tumours and viral infections. NK cells express a large range of cellular receptors to tumour ligands which stimulates NK mediated cytotoxicity.

Hereditary: Li-Fraumeni syndrome, Cowden syndrome and neurofibromatosis 1 syndrome represent three genetic conditions with associated high risks of developing tumors such as glioblastoma, schwannoma and astrocytoma.

Geographic location: There is a correlation between countries with high Human Development Index (HDI) and the incidence and mortality of brain tumors.

Conclusions and future directions: Mutations are rare in nerve cells due to their inability to proliferate and regenerate. Mutated nerve cells are marked for DNA damage repair or apoptosis preventing passing on of oncogenic mutations. The high abundancy and range of immune cells surveilling the nervous system and lymphatic system mark cancerous growths for degradation. Germline mutations account for a small proportion of nerve cell tumors.