#arahn
- Arachnoiditis — A progressive neurological disorder characterized by the chronic inflammation of the arachnoid mater, the middle meningeal membrane surrounding the brain and spinal cord. This pathology leads to the development of scar tissue and fibrous adhesions that can trap and compress spinal nerve roots, causing severe chronic pain, numbness, muscle spasms, and motor impairments, often triggered by infections, spinal surgeries, or irritating chemical substances.
- Arachnologist — A scholar or specialist in arachnology; a biologist dedicated to the methodical and scientific study of organisms within the class Arachnida, including spiders, scorpions, harvestmen, and mites. This specialist investigates the taxonomy, evolutionary anatomy, behavioral ecology, and biochemical composition of these invertebrate arthropods' venoms, playing an important role in monitoring global biodiversity.
- Arachnologist — A woman who specializes in arachnology; a female biologist or zoologist dedicated to the scientific and methodical study of organisms within the class Arachnida, such as spiders, scorpions, mites, and harvestmen. Her activity encompasses field work for collecting specimens, laboratory taxonomic analysis, describing new species, and studying the ecological or biochemical impact of these invertebrates venoms.
- Arachnological — Pertaining to arachnology, relating to the scientific study of spiders and other arachnids; specific to research analyzing the taxonomy, ecology, behavior, or biology of the class Arachnida. The term describes elements associated with this field, such as a specimen collection, a specialized journal, an international congress, or a field sampling method.
- Arachnology — A specialized branch of zoology that deals with the scientific, systematic, and methodical study of organisms classified within the class Arachnida, including spiders, scorpions, harvestmen, and mites. Unlike entomology, which analyzes insects, this discipline focuses on the structural biology, phylogenetic taxonomy, behavioral ecology, and biochemical properties of venoms and silks specific to terrestrial chelicerates.
- Arachnosis — A parasitic disease or infectious condition specific to honeybees or other beneficial insects, caused by the massive infestation of various mites or other small parasitic arachnids (such as the genus Acarapis). The disease affects the respiratory system or cutaneous integrity of the host insect, leading to a severe weakening of the colony and major economic losses in apiculture if not treated in time with specific acaricides.
- Argas — A genus of soft-bodied parasitic ticks in the family Argasidae, lacking a chitinous dorsal shield, which primarily attack domestic and wild birds, but also accidentally mammals or humans. These hematophagous arachnids are nocturnal, hiding in the cracks of shelters during the day, and represent major biological vectors for transmitting dangerous pathogens, such as bacteria and viruses.