1. Animal Systems: Feeding and Digestion Chapter 27.1

2. Obtaining Food All animals are heterotrophs Filter feeders Modified gills filter food out of water Detritivores Feed on decaying bits of plant & animals Carnivores Eat other animals Herbivores – Eat plants

3. Nutritional Symbionts Parasites One organism benefits while the other is harmed Mutualism Both organisms benefit

4. Processing Food - Digestion Intracellular Digestion – Food is digested inside specialized cells that pass nutrients to other cells by diffusion. Extracellular Digestion - Food is broken down outside cells in a digestive system and is then absorbed.

5. Extracellular Digestion Gastrovascular Cavities Present in invertebrates Interior body space whose tissues carry out digestive functions Single opening for ingestion and excretion Cells lining the cavity absorb nutrients from food

7. Extracellular Digestion Digestive Tracts Most vertebrates but some invertebrates Digestion is through a tube with two separate openings Food moves in one direction (Mouth to anus) Intestines absorb nutrients

8. Specializations for Different Diets Specialized mouthparts Carnivores – Incisors, Canines Herbivores – Molars and Premolars

9. Specialized Digestive Tracts Carnivores Short intestines with meat digesting enzymes Herbivores Long intestines with microbial symbionts that digest cellulose

10. Animal Systems: Respiration Chapter 27.2

11. Respiratory System Function: Provide oxygen gas needed for cellular respiration and remove carbon dioxide from the body Invertebrate Organs: Gills and trachae Main Vertebrate Organs: Nose, mouth, pharynx, larynx, trachea, bronchi, bronchioles, lungs, gills, diaphragm

12. Respiration in animals Whether they live in water or on land, all animals must respire. To respire means to take in oxygen and give off carbon dioxide. Some animals rely of simple diffusion through their skin to respire. While others… Have developed large complex organ systems for respiration.

13. Respiratory Systems Respiration involves diffusion Respiration requires diffusion of O2 and CO2 across cell membranes Diffusion of O2 and CO2 is passive Occurs if different concentrations of O2 or CO2 on either side of membrane

14. Respiratory Systems Respiratory organs have Large surface areas Are in contact with air or water Moist Selectively permeable Balance the concentrations of oxygen and CO2 on either side of the respiratory membrane (diffusion)

15. Specialized structures Structures specialized for gas exchange include: gills (aquatic animals) spiracles (terrestrial insects) lungs (most terrestrial vertebrates)

16. Aquatic invertebrates Aquatic animals have naturally moist respiratory surfaces, and some animals simply allow gases to diffuse through their skins. Example: jellyfish and anemones

17. Aquatic invertebrates + vertebrates Some larger aquatic invertebrates and chordates (except reptiles and mammals) exchange O2 and CO2 through gills. Gills are organs that have lots of blood vessels that bring blood close to the surface for gas exchange.

18. Aquatic Gills Water flows through the mouth then over the gills where oxygen is removed Carbon dioxide and water are then pumped out through the operculum

19. Terrestrial Invertebrates Terrestrial invertebrates have respiratory surfaces covered with water or mucus. (Reduces water loss) There are many different specialized respiratory organs in terrestrial invertebrates. Spiders use parallel book lungs Insects use openings called spiracles where air enters the body and passes through a network of tracheal tubes for gas exchange Snails have a mantel cavity that is lined with moist tissue and an extensive surface area of blood vessels. How does respiration in aquatic invertebrates differ from that in terrestrial invertebrates?

20. Mollusk Insect Spider Gill Siphons Movement of water Book lung Airflow Tracheal tubes Spiracles Invertebrate Respiratory Systems

21. Vertebrate respiratory systems Chordates have one of two basic structures for respiration: Gills – for aquatic chordates Example: Tunicates, fish and amphibians Lungs - for terrestrial chordates Examples: Adult amphibians, reptiles, birds, and mammals

22. Vertebrate lungs As you move from amphibians to mammals the surface area of the lungs increases Insures a greater amount of gas exchange (or a two way flow of air). Birds, by contrast have lungs and air sacs which have only a one-way flow of air. This allows for them to have constant contact with fresh air. This adaptation enables them to fly at high altitudes where there is less oxygen.

23. SalamanderLizardPigeonPrimate Nostrils, mouth, and throat Trachea Lung Air sac Vertebrate Lungs

24. Human respiratory system Parts of the respiratory system include: Trachea Bronchi Bronchioles Alveoli

25. The Human Respiratory System

26. Respiration and the respiratory System Alveoli Air sacs in the lungs that allow the exchange of oxygen and carbon dioxide so oxygen can enter the blood stream.

28. Circulation and Gas Exchange Recall the interconnection between circulation and the respiratory system. Gas exchange at the lungs and in the body cells moves oxygen into cells and carbon dioxide out.

29. Oxygen and carbon dioxide exchange at alveoli Oxygen-rich air from environment Bronchioles Nasal cavities PharynxTrachea Bronchi Bronchioles Alveoli Pharynx Nasal cavities Carbon dioxide-rich air to the environment Bronchi Trachea Movement of Oxygen and Carbon Dioxide In and Out of the Respiratory System BIG QUESTION … WHY DO ANIMALS BREATHE?

30. Gills exchange gases in fish. What is the site of gas exchange in mammals? 1.Alveoli 2.Tracheids 3.Bronchi 4.Esophagus

31. Animal Systems: Circulation Chapter 27.3

32. Functions of the circulatory system  Transports materials  Nutrients from digested food  Respiratory gases: CO 2 and O 2  Waste materials: Toxins and nitrogenous wastes  Antibodies  Hormones  Enzymes  Immune functions  Maintains homeostasis  Blood pH  Heat transport

33. Animal Circulatory Systems Types of circulatory systems: gastrovascular, open, closed. Vascular system: arteries, veins, capillaries. Capillary - tissue fluid exchange.

34. Cnidarian Gastrovascular Systems Some larger animals such as hydras, sea anemones, jellyfish, and flatworms lack a true circulatory system. The gastrovascular cavity extends to most areas of the body in these animals and serves as a circulatory system as well as a digestive cavity. Larger Animals Without a Separate Circulatory System

35. Gastrovascular cavity  No system is required  Single opening: exchange of materials with the environment  Central cavity for digestion and distribution of substances throughout the body  Body walls are two cell layers thick  materials undergo diffusion  Cnidarians (e.g. Hydra) and flatworms (e.g. planarians) Circulation in Simple Invertebrates

36. Flatworm and Hydra Gastrovascular System

37. Circulatory Systems For larger or more active animals, some form of more efficient circulatory systems are necessary for internal transport. Two types of circulatory system are found: Open Circulatory Systems Closed Circulatory Systems

38. Open Circulatory System  Phylum Arthropoda, Phylum Mollusca (with one exception)  Heart(s) pumps blood  empties into spongy cavities (sinuses)  contacts tissues to supply with oxygen  blood then travels back to heart(s) ( without blood vessels)  Blood - Hemolymph

39. Open Circulatory System

40. Advantage - Exchange of materials is direct between the hemolymph and tissues. There is no diffusion barrier. Disadvantage - Little fine control over distribution of the hemolymph to body regions. No mechanism for reducing flow to a specific part of an organ.

41. Open Circulatory System Open circulatory systems tend to be found in more inactive animals. Most molluscs have an open system, but the highly active cephalopods (squid and octopus) have evolved a closed system.

42. Closed Circulatory System The blood is contained within a completely closed system of vessels. Vessels form a closed loop, usually with some sort of pumping organ like a heart or contractile vessels. Vessels branch into smaller and smaller tubes that penetrate among the cells of tissues.

43. Closed Circulatory System Fine-scale control over the distribution of blood to different body regions is possible. Muscular walls of vessels can constrict and dilate to vary the amount of flow through specific vessels. Blood pressures are fairly high and the circulation can be vigorous. Advantages:

44. Closed Circulatory System: Single Loop Circulation Blood circulates through the body in one direction Heart contains 1 ventricle & atrium Ventricle pumps blood out of heart to gills Gills exchange CO2 w/ O2 and bring oxygenated blood to body tissues and then back to heart Atrium receives deoxygenated blood from tissues

45. (and capillaries)

46. Closed Circulatory System: Double Loop Circulation As vertebrates evolved one pump was not enough to deliver blood to organs. Double Loop Circulation: Lungs for respiration Double loop Two pump circulatory system

47. Closed Circulatory System: Double Loop Circulation Oxygen poor blood is pumped from right side of the heart to the lungs. The lungs undergo gas exchange so the oxygen rich blood can be transported back to the left side of the heart. The oxygenated blood transports to body tissues, which undergo gas exchange. Deoxygenated blood (CO2) is transported back to the right side of the heart and the process starts over.

48. Circulatory Systems The cardiovascular system consists of the heart and the 3 types of blood vessels that carry blood throughout your body. The blood vessels—arteries, capillaries, and veins—carry blood pumped by the heart. Arteries are blood vessels that carry blood away from the heart and to the body’s organs. Capillaries are tiny blood vessels that allow the gas exchange between body cells and blood. Veins carry blood back to heart

49. Evolution of Circulatory Systems

51. Mammalian Circulatory System Mammalian hearts have 2 sides separated by a partition Right: Oxygen poor blood Left: Oxygen rich blood Each side has an upper chamber (atrium) and a lower chamber (ventricle) This is called a 4 chamber heart

54. Cardiac cycle

55. Evolution of Circulatory Systems in Vertebrates

56. Animal Systems: Excretion Chapter 27.4

57. Essential Questions How do animals manage toxic nitrogenous waste? How do aquatic animals eliminate wastes? How do land animals remove wastes while conserving water?

58. Excretion Nitrogenous wastes are produced as a result of cellular respiration (exchanging O2 + CO2) Nitrogenous wastes can be secreted as: Ammonia – water soluble and toxic Usually released by aquatic organisms Urea – ammonia combined with CO2 in the liver Less toxic and conserves water Most vertebrates Released diluted as urine Uric acid – excreted as a paste or crystals Produced by birds and reptiles

59. Excretion The excretory system collects wastes and delivers them to organs that will be released from the body. Small animals in wet environments get rid of ammonia by allowing it to diffuse out of their body fluids across their skin. Most larger animals have excretory systems that process ammonia and eliminate it from the body.

60. Excretion Most complex excretory organs are the kidneys in vertebrates Other structures for excretion Nephredia/Excretory pores Flat worms, Annelids Malpighian tubules Arthropods All involve a type of tubular system

62. Maintaining Water Balance Excretory systems are extremely important in maintaining the proper balance of water in blood and body tissues May also excrete excess water or have to conserve water.

63. Kidneys Separate wastes and excess water from blood to form urine Usually cannot excrete excess salt.

64. Freshwater Animals Freshwater invertebrates lose ammonia to their environment by simple diffusion across their skin. Freshwater fishes and amphibians eliminate ammonia by diffusion across the same gill membranes they use for respiration.

65. Saltwater Animals Typically release ammonia by diffusion across their body surfaces or gill membranes. Many marine invertebrates have body fluids with water concentrations similar to that of the seawater around them.

67. Excretion in Terrestrial Animals Land animals can lose large amounts of water from respiratory membranes that must be kept moist. And must eliminate nitrogenous wastes in ways that require disposing of water. Therefore, terrestrial animals have to have adaptations to conserve water loss.

68. Terrestrial Invertebrates Some produce urine in nephridia Annelids, Mollusks Nephridia Tubelike excretory structures that filter body fluid. Leaves the body through excretory pores.

69. Terrestrial Invertebrates Insects and arachnids convert ammonia into uric acid Malpighian tubules Absorb uric acid from body fluids Concentrate the wastes and add them to digestive wastes.

70. Terrestrial Invertebrates Water is absorbed from wastes Crystals form a thick paste which leaves the body through the anus Paste contains little water Minimizes water loss

71. Terrestrial Vertebrates Mammals and land amphibians convert ammonia into urea Excreted in urine by the kidneys. Reptiles and birds convert ammonia into uric acid, which leaves the body as a thick white milky paste (bird droppings)

73. Terrestrial Vertebrates Most vertebrate kidneys cannot excrete concentrated salt Most vertebrates cannot survive by drinking seawater All that extra salt would overwhelm the kidneys, and the animal would die of dehydration.