MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Ya.I. Fedoniuk 2010

BIOLOGY

CHAPTER 2. BIOGEOCENOTIC LEVEL OF ORGANIZATION OF LIFE AND THE PLACE OF MAN IN IT

2.5. MEDICAL ARACHNOENTOMOLOGY

Medical arachnoentomology is a branch of medical parasitology that studies Representatives of the phylum Arthropoda of medical importance.

Phylum Arthropoda

Phylum Arthropoda is the largest animal phylum, uniting over 1 million species. In the course of evolution, Arthropods originated from Annelids. Characteristic Features of the phylum include: 1) heteronomous body segmentation; 2) fusion of similar segments to form distinct body regions; 3) presence of segmented appendages consisting of several podomeres connected movably by joints; 4) body covered with a chitinous cuticle that performs protective and exoskeletal Functions; 5) musculature represented by separate striated Muscles rather than a continuous Skin-muscular sac; 6) formation of a mixed body cavity (mixocoel) during embryonic development, which houses Internal Organs; 7) Digestive System consisting of three sections (foregut, midgut, and hindgut), with associated glands that secrete digestive Enzymes; 8) Circulatory system characterized by the appearance of a pulsating Heart; the circulatory system is open, and the hemolymph filling the body cavity and vessels performs the function of Blood; 9) diverse respiratory organs (gills, book Lungs, tracheae); 10) Nervous system consisting of a paired cerebral ganglion (Brain), circumoesophageal connectives, and a ventral nerve cord; 11) excretory system represented by modified coelomoducts homologous to the metanephridia of annelids, or specialized organs unique to arthropods—Malpighian tubules; 12) reproduction is exclusively sexual, with most species being gonochoric (dioecious), often exhibiting Sexual Dimorphism.

Medical significance. Arthropods include human parasites, disease agents, disease reservoirs, vectors of infectious and parasitic diseases, intermediate and definitive hosts in the life cycles of parasites, as well as venomous animals.

Classification. The phylum Arthropoda is divided into several classes, of which the following are of medical importance: Crustacea, Arachnida, and Insecta.