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Form and Function in Invertebrates. Section 19-3. Lecture Outline. Support and Movement Feeding and Digestion Internal Transport Respiration Excretion Response Reproduction. Support and Movement. Hydrostatic skeletons Exoskeletons Endoskeletons.
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Form and Function in Invertebrates Section 19-3
Lecture Outline • Support and Movement • Feeding and Digestion • Internal Transport • Respiration • Excretion • Response • Reproduction
Support and Movement • Hydrostatic skeletons • Exoskeletons • Endoskeletons
Support is provided by water-filled body cavities muscles contract and push against water in the body cavities Use circular and longitudinal muscles Earthworm Sea anemone (figure 19-16) Hydrostatic skeletons
Made of chitin Jointed excellent mechanical advantage but heavy growth involves shedding Arthropods insects spiders crustaceans Exoskeletons
Lighter Easier growth Vertebrates-bones Sponges Some echinoderms Endoskeleton
Feeding and Digestion • Intracellular • Extracellular • See figure 19-17 In the Hydra...
Intracellular Digestion Endocytosis! A lysosome with digestive enzymes combines with a food vacuole allowing intracellular digestion. Where is endocytosis?
Intracellular Digestion • “gastro” – digestion • “vascular” - circulation • A gastro vascular cavity not only helps with digestion, but also with the circulation (It gives access to the internal layer of cells!) Feeding?
Intracellular Digestion • Sponges by filter feeding • Cnidarians and flatworms use gastrovascular cavity • Small food particles are consumed – limiting!
Extracellular digestion • More advanced • Tube-within-a-tube body plan • One-way movement • Mouth and anus • Food moves into blood vessels lining digestive cavity
Internal transport • Open Circulatory Systems • Closed Circulatory Systems
Blood from the heart is NOT entirely contained in blood vessels Blood released into sinuses GRASSHOPPER Location of Heart? See figure 19-18 Open Circulatory Systems
Blood always enclosed in blood vessels diffusion occurs through walls of capillaries EARTHWORM # of hearts? Pumping direction? Closed Circulatory System
RespirationGetting Oxygen! • Needs • Solutions
Respiration: Needs • Large surface area • moist respiratory surface • protected • contact with environment
Respiration: Solutions • Live in water …or use • Skin • Gills • Book lungs • Trachea
Respiration: Solutions • Live in water …or use • Skin - Earthworm • Gills – (Fish), Lobster: gills attached to legs • Book lungs – Spider, pages of a book • Trachea – Insects use tracheal tubes!
Trachea means a tube with air The oxygen is not in the blood. Humans carry oxygen in the blood. Insects use tracheal tubes! oxygen Trachea in a Grasshopper
Excretion • Water • Nitrogen • Ammonia • Urea • Uric acid • What type of nitrogen-containing compound is used if the animal lives in water? NH3 - Ammonia
PLANARIA excretory pore flame cells EARTHWORM nephridia excretory pore segmented GRASSHOPPER Malpighian tubules Lots of water ammonia Some water Urea Little water Uric Acid Excretion in …
Centralization nerves concentrated in ganglia or nerve rings Cephalization Brains in anterior region Specialized sensory cells in anterior region Bilateral symmetry Response
Reproduction • Great variety • Sexual: increase genetic diversity • Asexual
1 b 2 d 3 c 4 a 5 c 6 b 7 a 8 c Recalling main ideas, page 465
1 f 2 e 3 d 4 j 5 b 6 h 7 d 8 g 9 g 10 i 11 k 12 c 13 b 14 a Section Review
Continued… • 15. does • 16. chitin • 17. Segmented worms • 18. Closed • 19. Water-dwelling • 20. True • 21. Nerve cord • 22. True • 23. Capable
24 and 25 • Sexual reproduction increase genetic diversity. This is illustrated by the large differences seen in invertebrates. • Planaria drawing and roundworm drawing.
Test Items Most MissedBlood Pressure • The grasshopper has low pressure • Blood trickles through sinus cavities • Worm has high pressure • Blood pressure only exists in a closed circulatory system
Nervous System Ideas • Ganglia are in each segment • Centralization • Nerve net in Hydra • Low centralization • Ganglia in grasshopper • higher centralization • Nerve net to nerve cord • Example of centralization • Ganglia to brain • Example of cephalization