Lecture 20 : Comparative anatomy

1. Eukaryoticcells Heterotrophs Essentialfunctions Feeding Respiration Circulation Excretion Response Movement Reproduction Lecture 20: Comparative anatomy All Animals What do animals do to survive? have are carry out with such as No cell walls

2. Invertebrate feeding and digestion: • Invertebrates can either have intracellular or extracellular digestion: • Intracellular meaning that food is digested within each individual cell of the organism. • Examples: Sponges • Extracellular means that digestion occurs inside a digestive tract or cavity, then absorbed into the body. • Examples: mollusks, chordates, arthropods, echinoderms

3. Invertebrate digestive systems: Section 29-2 Intestine Gizzard Crop Mouth/anus Pharynx Mouth Gastrovascularcavity Anus Gastrovascularcavity Annelida Coelenterata Crop Pharynx Anus Pharynx Mouth Rectum Mouth/anus Stomachanddigestive glands Intestine Flatworm Arthropoda

4. Vertebrate digestive systems: • The digestive systems of many vertebrates have organs that are well adapted for different feeding habits. • Carnivores, such as sharks have short digestive tracts that produce fast-acting digestive enzymes. • Herbivores have long intestines that have large colonies of bacteria that help in digesting the cellulose fibers in plant tissues.

5. The Digestive Systems of Vertebrates Section 33-3 Shark Salamander Lizard Pigeon Cow Esophagus Stomach Intestine Liver Gallbladder Pancreas Cloaca Crop Gizzard Cecum Rectum

6. Respiration in animals: Aquatic invertebrates: • Aquatic animals have natural moist respiratory surfaces. some respire through diffusion through their skin and others use gills. Terrestrial Invertebrates: • There are many different respiratory specialized organs in terrestrial invertebrates. • Spiders use parallel book lungs. • Insects use openings called spiracles where air enters the body and passes through tracheal tubes for gas exchange. • Snails have a mantel cavity that is lined with moist tissue and an extensive surface area of blood vessels.

7. Invertebrate respiratory systems: Trachealtubes Gill Siphons Movement of water Spiracles Mollusk Insect Airflow Booklung Spider

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

9. Vertebrate 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. Vertebrate Lungs: Nostrils, mouth, and throat Trachea Lung Air sac Salamander Lizard Primate Pigeon

10. Invertebrate circulatory systems: Open circulatory systems: • Invertebrate circulatory system can range from a system where cells simply do diffusion to take in oxygen or systems with many hearts and even systems with one heart. • The blood is pumped through open cavities. • This system is found in arthropods and mollusks. Closed circulatory systems: • A closed system forces blood through vessels that extend throughout the body of the organism. Since the system is “closed” the blood never leaves the vessels. • This system is found in Annelids and chordates.

11. Invertebrate Circulatory Systems: Section 29-2 Heart like structure Hearts Small vessels in tissues Heart Bloodvessels Sinusesand organs Bloodvessels Heart likestructures Insect:Open Circulatory System Annelid:Closed Circulatory System

12. Vertebrate circulatory systems: • Chordate circulatory systems range from a single loop system (found in organisms with gills) to double loop systems. Single-Loop Circulatory System Double-Loop Circulatory System Fishes Most Reptiles Crocodilians, Birds, and Mammals

13. Aquatic Invertebrate excretion: • Some aquatic invertebrates diffuse ammonia out their bodies into the surrounding water where it is diluted and carried away. • Example: sponges, coelenterate, and some round worms. • Other aquatic invertebrates swell up with water, dilute the wastes and excrete the wastes through tiny pores in their skin. Terrestrial Invertebrate excretion: • Many terrestrial invertebrates convert ammonia into urea. • Urea is a simpler nitrogenous compound that is much less toxic than ammonia. • This urea is eliminated from the body in urine.

14. Invertebrate Excretory Systems Section 29-2 Flatworm Flame cells Excretory tubules Excretory pore Flame cell Excretory tubule Nephridia Digestive tract Annelid Malpighian tubules Arthropod

15. Vertebrate Excretion: • Aquatic vertebrates kidneys and rely on gill slits to release excretory wastes into surrounding water for dilution • Terrestrial vertebrates rely on the kidney’s to filter out the ammonia and change it into urea and send it to be released in urine.

16. Nervous system • All animals respond to their environment through specialized cells called nerve cells. • In most animals, nerve cells hook together to form the nervous system. • Nervous systems can range from fairly simple to extremely complex. • The arrangement of nerve cells from phylum to phylum can be dramatically different.

17. Invertebrate Nervous Systems Vertebrate Nervous Systems Section 29-2 Arthropod Brain Ganglia Ganglia Brain Flatworm Mollusk