Paramyxoviridae AND Orthomyxoviridae

Family Orthomyxoviridae

Orthomyxoviruses are spherical, enveloped viruses containing a segmented RNA.Viruses in this family infect humans, and animal. Orthomyxoviruses are divided into 3 types: influenza A, B, and C. Only types A and B are of medical importance.
Structure: Influenza virions are spherical, enveloped. Two types of spikes project from the surface: one is composed of hemagglutinin (H protein) and the second of neuraminidase (N protein). The RNA is composed of eight distinct segments of RNA.

Paramyxoviridae
The genera include; parainfluenza viruses (which cause upper respiratory tract infections), the mumps virus, the measles virus, and respiratory syncytial virus (a major respiratory tract pathogen). Paramyxoviruses are spherical, enveloped particles that contain a nonsegmented, and have envelope. The first, the HN protein (H, and N), is involved in the binding of the virus to a cell; measles virus lacks the neuraminidase activity. The second, the F protein (fusion), functions to fuse viral and cellular membranes, thus facilitating virus entry into the cytoplasm where viral replication occurs.