Essential Functions All animals carry out the following: Feeding: obtain food from the environment Respiration: exchange O2 and CO2 Circulation: move materials around body Excretion: get rid of wastes Respond: process information with nerves Move: all animals are motile at some point Reproduce: most sexually, some asexually

Animal Circulatory Systems The circulatory system is the animal body system that moves (circulates) blood, oxygen and nutrients throughout the body.

Open Versus Closed Circulatory System Open circulatory system – blood is not always contained in vessels; instead blood is pumped into body cavities and diffuses directly to organs. Found in simpler organisms such as arthropods and mollusks. Closed Circulatory System: blood moves throughout body in blood vessels. Found in larger, more active animals Prompt students to think about whether or not they think older organisms are more simple or more complex – segway into open circulatory systems as being simpler than closed A trend with evolution/life is that the more primitive an animal is, the simpler the body design. Why are closed circ. Systems found in more active animals? Can be circulated more efficiently due to blood pressure across small vessels

Hearts can be 2, 3, or 4 chambered Reptile/Amphibian heart Fish heart Mammal Heart Explain what a chamber is Have them color?

Hearts can be 2, 3, or 4 chambered The heart is the pump of the circulatory system: it moves blood through the body The number of chambers defines the 3 major heart types The more complex they are, the more efficiently (better) they work Explain what a chamber is Fish have a 2 chambered system where blood must pass through 2 capillary beds before returning to the heart. §        Lowers blood pressure o       Reptiles have a 3 chambered system which increases blood flow/pressure since blood must pass through only 1 capillary bed per cycle. §        Disadvantage: mixes oxygenated & deoxygenated blood o       Mammals have a more efficient system with a 4 chambered heart. Blood pressure is increased and there is no mixing of blood. Talk about getting oxygen from lungs Have them color oxygenated vs deoxygenated blood

Higher blood pressure, no mixing of blood 3 chambers = higher blood pressure, bad thing is that oxygenated and deoxygenated blood mix. 2 chambers = low blood pressure 4 chambers = Higher blood pressure, no mixing of blood

Endotherms Animals that can control their own body temperature Warm-blooded  All Endotherms have a 4 chambered heart Mammals and birds Along with the complete separation of oxygenated blood from deoxygenated blood, the evolutionary development of a four chambered heart also allowed these organisms to generate their own body heat. This is called endothermy (or endothermic).

Ectotherms Animals that need external energy to control body temperature Cold-blooded Reptiles, ambhibians, and fish

Annelid - earthworm Segmented body = body is divided into sections Closed Circulatory system Consistes of earthworms, leeches, and marine worms

Annelid Digestion and Nutrition Complete digestion Variety of feeding methods: Filter feeders, predators, parasites

Annelid Excretion Complete excretion system (mouth and anus) Digestive waste Each segment has a special part that collects waste and transports it out of the body

Annelid Respiration and Regulation Annelids exchange gases through their moist skin

Annelid Reproduction Can reproduce asexually or sexually: Most reproduce sexually Earthworms and leeches are hermaphrodites; they produce both sperm and eggs

Annelid Circulation Annelids have a closed circulatory system Blood is pumped to head & body transporting oxygen and carbon dioxide Have clusters of nerves that act as “hearts” that pump blood, really enlarged, muscular blood vessels

Insects Phylum Arthropoda Arthropods are organisms with a segmented body, a tough exoskeleton, and jointed appendages

Insect Diagram

Insect Digestion and Nutrition some insects feed on plants, while others feed on animals

Insect Excretion Excretion – Insects have structures called Malipghian tubules through which they get rid of waste materials

Insect Respiration and Regulation Insects have tiny holes and internal tubes through which gases are exchanged (no lungs). Regulation – Insects have a nervous system, composed of a brain

Insect Reproduction Most insects hatch from eggs. Insects go through several growth phases because of their exoskeleton (no room to grow)

Insect Circulation Open circulatory system