IIC. Respiratory System of Insects 2023-2024 PDF

GENERAL PHYSIOLOGY AND TOXICOLOGY l AG-MC312 1st Semester, 2023-2024 l BSA 3-Animal Science, Agronomy, Crop Protection & Horticulture IIC. Respiratory system ILO l Identify the insect metabolic systems as to its parts/structures and functions on insect’s various life proc...

GENERAL PHYSIOLOGY AND TOXICOLOGY l AG-MC312 1st Semester, 2023-2024 l BSA 3-Animal Science, Agronomy, Crop Protection & Horticulture IIC. Respiratory system ILO l Identify the insect metabolic systems as to its parts/structures and functions on insect’s various life processes MARIA LIMA D. PASCUAL Professor, Dept. of Agriculture and Food Science (DAFS) College of Agriculture, Food Science, Agribusiness and Development Communications (CAFBC) CTU-Barili Campus Insect Respiratory System 2  ▪ All insects are aerobic organisms Content ▪ Insect respiration is accomplished without lungs using a system of internal spiracles tracheal Respiratory system tubes tubes and sacs through which gases Functions either diffuse or are Components of actively pumped, delivering oxygen respiratory system directly to tissues that need oxygen and Spiracle eliminate carbon dioxide via their cells Trachea ▪ Process of interchange of gases Tracheoles between environment and the blood or Air sacs cellular tissues Content Functions Respiratory system ▪ Provide the cells and tissues with oxygen Functions Components of ▪ Eliminate CO2, a product of cell respiration respiratory system Spiracle ▪ Conjunction with circulatory system Trachea Tracheoles Air sacs  Components of respiratory system Content ▪ Spiracle Respiratory system ▪ Trachea Functions ▪ Tracheoles Components of ▪ Air sacs respiratory system Spiracle Trachea Tracheoles Air sacs Content Spiracle - external opening through which Respiratory system air enters into the trachea Functions - they are lateral in position and only one pair of spiracles on a Components of segment respiratory system - has a chamber or atrium with an opening and closing Spiracle mechanism called atrial valve Trachea - in Dipterans, Coleopterans, Tracheoles Lepidopterans, spiracles consist of sieve plate Air sacs - has peristigmatic glands that prevents the wetting of organs  Number and distribution of the functional spiracles Content ▪ the largest number of spiracles found in insects is ten pairs Respiratory system (2 thoracic and 8 abdominal) Functions ▪ in most insect, the first spiracle is on the prothorax, but is Components of mesotharacic in origin ▪ spiracles are never present on the head respiratory system ▪ respiratory system can be classified on the basis of the Spiracle number and distribution of the functional spiracles Trachea Tracheoles Air sacs  Number and distribution of the functional spiracles 1. Polypneustic respiratory system - at least 8 pairs of functional spiracles Content a. Holopneustic - 10 pairs of spiracles (1 meso, 1 meta, 8 abdomen) b. Peripneustic - 9 pairs of spiracles (1 meso, 8 abdomen) c. Hemipneustic - 8 pairs of spiracles (1 meso, 7 abdominal) Respiratory system Functions 2. Oligopneustic respiratory system - 1 or 2 pairs of functional spiracles a. Amphipneustic - 2 pairs of spiracles (1 meso, 1 abdominal) Components of b. Metapneustic - 1 pair of post abdominal spiracle respiratory system c. Propneustic - 1 pair of mesothoracic spiracle (ex. dipterous larvae) Spiracle 3. Apneustic respiratory system - no functional spiracles Trachea Tracheoles Closed Air sacs The tracheal system does not open to the outside. Ex. Chironomid larvae plate gills Rectal gills Holopneustic Metapneustic Cuticular  Types of Spiracles Content ▪ Simple or non-atriate Respiratory system - an opening with no lip Functions closure or filter chamber Components of ▪ Atriate with lip closure respiratory system - slit-like apparatus with Spiracle two movable valves/lips Trachea Tracheoles ▪ Atriate with filter- Air sacs apparatus - atrium is lined with tiny hairs  Trachea Content - are the larger tubes of the tracheal system Respiratory system - ectodermal in origin Functions - consist of epithelial Components of cells and cuticular respiratory system lining called intima Spiracle - helical folds of Trachea cuticular lining is Tracheoles known as taenidia Air sacs - where air passes through from the spiracles Content Tracheoles - each trachea ends in Respiratory system microscopic tubes called Functions tracheoles Components of - lie within individual cell respiratory system and sit in a pool of fluid Spiracle which allows diffusion of oxygen and carbon Trachea dioxide in and out of the Tracheoles cells Air sacs  Air sacs Content - balloon-like structures that acts as oxygen Respiratory system reservoir Functions - provides buoyancy to Components of swimming in aquatic respiratory system insects Spiracle - in dry terrestrial Trachea environment, it allows an insect to conserve Tracheoles water by closing its Air sacs spiracle during the periods of high evaporative stress 15 Source: https://www.youtube.com/watch?v=1WzcJXZy-Y0 16