Form and Function in Invertebrates Section 19-3 Use Side Four of the laserdisc, chapters 11 and 12

Lecture Outline Support and Movement Feeding and Digestion Internal Transport Respiration Excretion Response Reproduction

Support and Movement Hydrostatic skeletons Exoskeletons Endoskeletons

Hydrostatic skeletons 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)

Show the gianat Earth worm and the Flatworm on Side Four, LT, chapter 12

Setae grip soil and for allow movement

Sea Anemone

Exoskeletons Made of chitin Arthropods Jointed excellent mechanical advantage but heavy growth involves shedding Arthropods insects spiders crustaceans

Endoskeleton Lighter Easier growth Vertebrates-bones Sponges Some echinoderms

Feeding and Digestion Intracellular Extracellular See figure 19-17 In the Hydra...

Protista – In the cell!

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?

Nematocyst: – a stinging cell (Cnidoblast)

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

Setae grip soil and for allow movement

Internal transport Open Circulatory Systems Closed Circulatory Systems

Open 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

Dorsal Heart in Grasshopper

Closed Circulatory System Blood always enclosed in blood vessels diffusion occurs through walls of capillaries EARTHWORM # of hearts? Pumping direction?

Respiration Getting 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 BOOK LUNG: terrestrial respiratory organ characteristic of arachnids such as scorpions and primitive spiders. Each book lung consists of hollow flat plates. Air bathes the outer surface of the plates and blood circulates within them, facilitating the exchange of gases. In most species, adequate gas exchange occurs without any muscular movement to ventilate the lung.

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!

Book Lungs in a Spider

Trachea in a Grasshopper

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

Excretion in … PLANARIA EARTHWORM GRASSHOPPER Lots of water ammonia excretory pore flame cells EARTHWORM nephridia segmented GRASSHOPPER Malpighian tubules Lots of water ammonia Some water Urea Little water Uric Acid

Nephridia – two per segment

UREA

Response Centralization Cephalization nerves concentrated in ganglia or nerve rings Cephalization Brains in anterior region Specialized sensory cells in anterior region Bilateral symmetry

Reproduction Great variety Sexual: increase genetic diversity Asexual Chapter 11 on side four of the LT lasardisc on Flukes is a good place to show this.

Recalling main ideas, page 465 1 b 2 d 3 c 4 a 5 c 6 b 7 a 8 c

Section Review 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

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 Missed Blood 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 Nerve net in Hydra 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

Humans use nephrons in the kidney Round worms (Nematodes) have the most primitive tube-like digestive system Humans use nephrons in the kidney Similar to nephridia located separately in segments Cnidarians have a gastrovascular cavity

Earthworm Nephridia similar to kidney Crop similar to stomach Gizzard similar to teeth Aortic arch similar to heart Intestine used extra cellular digestion.