Exocrine and Endocrine Glands

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Glands in Insect


1. AGR 254 ENTOMOLOGY EXOCRINE GLANDS AND ENDOCRINE GLANDS 2. Types of glands 1. Exocrine glands system 2. Endocrine glands system 3. Exocrine Glands Send chemicals/signals outside body-cuticle layer. They may be single cells or small aggregates of secretory cells; or can be complex glands Exocrine glands are generally of ectodermal origin and are widely scattered over the insect. Examples of exocrine glands: A. Simple unicellular gland B. Unicellular cell with ductule cell C. Simple aggregations of gland cells D. Aggregation of gland cells with common duct E. Complex aggregation of glands with common duct Glands that secrete their products into ducts that lead directly into the external or lumens of various organs. 4. Examples of Exocrine Glands Simple unicellular Unicellular with ductule Simple aggregation Aggregation same duct Complex- same duct SITI NURAREFANIE,SUHANAH,SYAMRIZAL,WILFRED 5. Function of exocrine 1. Defense venoms, alarm pheremones Nastute soldiers of termite produce sticky defensive material from the enlarged frontal gland 2. Intraspecific Communication Glands in many insects produce chemicals that serve as signals of various sorts for other members of the same species These are called pheromones 6. Function of exocrine 3. Building Structural Material Structural materials include wax and silk In honeybee wax is secreted by epidermal glands to construct honey combs 4. Transport of Materials in Liquid State Salivary glands Accessory gland and spermathecal gland assist transport of spermatozoa 7. Endocrine Gland Typically ductless and their secretions are usually released directly into the Hemolymph(like blood of human). Endocrine system involved with the secretion of hormones . Commonly function in close coordination with one another. In insects, the largest and most obvious endocrine glands are found in the Prothorax-just behind the head. 8. Endocrine Gland & The Nervous system-(coordinate) Hormones are involved with long term adjustments to changes in the external and/or internal environment Nerves system only provide short-term adjustments to changes in the external and/or internal environment 9. Major endocrine structures are: Corpora allata Corpora cardiaca Thoracic glands Insects have special cells called Neurosecretory cells that secrete neurohormones. act as the link between the nervous and endocrine systems 10. Neurosecretory cells location: Protocerebrum Subesophageal and other ventral chain ganglia Corpus cardiacum 11. Corpora allata produces and secretes juvenile hormones-it plays a crucial role in metamorphosis. The thoracic gland or Prothoracic gland secrete hormones that initiate the molting process- Ecdysal Hormone. Prothoracic glands are only found in immature insects. In many Diptera species, the corpus allatum is fused with the corpus cardiacum, forming a "ring gland", also known as Weismann's ring.-wiki In Lepidoptera species, the corpus allatum acts a release site for prothoracicotropic hormone which is generated by the brain.-wiki 12. Corpora allata Thoracic gland SITI NURAREFANIE,SUHANAH,SYAMRIZAL,WILFRED 13. Function Of the endocrine glands: Regulation of molting Determination of form at metamorphosis Polymorphism Regulation of diapause Involvement in reproduction Regulation of metabolic activities and general body functions Regulation of behavior Regulation of preprogrammed cell death 14. THE END... THANKS FOR YOUR ATTENTION


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