Introduction to the world of Invertebrates

9/3/2015 Essential Functions for all organisms: 1. Respiration 2. Feeding/Digestive System 3. Response/Nervous System 4. Circulatory System 5. Reproduction System 6. Excretory System 7. Movement These lead to diversity in all living organisms

The Animal Kingdom is the most diverse kingdom in appearance. –Each phylum has its own typical body plan / arrangement. –We will examine the physiology and anatomy of all the Animal Kingdom phyla: Physiology is the study of the function of the organs Anatomy is the structure and location of the organs. 9/3/2015

FEEDING: 9/3/2015 -all animals are heterotrophic - must obtain their food from another source. Types of feeding: Herbivore: Eats only plants Carnivores: Eats only animals

9/3/2015 Omnivores: Eats both plants and animals. Filter Feeders: Do not move Must filter out food from water Detritovores: Eat dead and decaying plants and animals Parasites: Feed off another organism (host) and harms the host.

9/3/2015 Types of Digestive Systems: Simplest: Two way digestive system Enters and exits out the same opening.

9/3/2015 More complex system: One way digestive system Enters and exits out different openings.

9/3/2015 Respiratory System: All animals must: -take in oxygen -give off carbon dioxide Small and aquatic (water) animals must: -respire through moist skin -called cutaneous respiration -rely on the process of diffusion Larger animals: -have various forms of complex modes of respiration

Circulatory System: 9/3/2015 Used to transport items throughout the body. -oxygen -carbon dioxide -food molecules Small aquatic organisms simply transport items from water into their body by diffusion.

9/3/2015 Two types of circulatory systems: Open Circulatory Systems -Blood is only partially contained within a system of blood vessels. -One or more hearts or heartlike organs pump blood through vessels into surrounding tissues.

9/3/2015 Closed Circulatory Systems -A heart or heart like organ forces blood through vessels that extend throughout the body. -Closed circulatory systems are characteristic of larger, more active animals.

Excretory System: 9/3/2015 To rid the body of toxic, nitrogenous cellular waste -main nitrogenous waste is ammonia -ammonia must be eliminated OR -convert ammonia into a less toxic substance that can then be removed.

Response : 9/3/2015 Receptors used for detecting touch, sound and light. -utilizes the nervous system Some organisms have netlike arrangement of nerve nets which consist of individual nerve cells

9/3/2015 Cephalization: -concentration of sense organs and nerve cells in the front of the body forming a “head region”.

Movement: 9/3/2015 -some animals are sessile - nonmoving -most are mobile -uses a set of muscles to coordinate the motion. -muscles must be attached to the skeletal system.

Types of skeletal systems: 9/3/2015 Exoskeletons -An external skeleton - is a hard body covering - made up of chitin.

Endoskeleton: 9/3/2015 -Is a structural support located inside the body.

Reproduction: 9/3/2015 -Most animals reproduce sexually -requires what two things? -sperm -egg

Two types of sexual reproduction: 9/3/ Internal Fertilization:

2. External Fertilization: 9/3/2015 FISH

9/3/2015 Frogs

9/3/2015 Some simpler animals may reproduce asexually -one organism divides into 2 new identical organisms. Hydra and Planarians :

9/3/2015 Some organisms are hermaphrodites. -one organism has both male and female organs and sex cells. Hermaphrodites:

Trends in animal evolution: Cell specialization: –cells, tissues, organs, organ systems Early development: –Zygote Fertilized egg –Blastula A hollow ball of cells –Blastopore The blastula folds in creating this opening –Protostome Mouth is formed from blastopore –Deuterosome Anus is formed from blastopore –Anus Opening for solid waste to exit from digestive system 9/3/2015

Cells of most animal embryos differentiates into three layers called germ layers. Ectoderm: –Outermost layer –Develops into sense organs, nerves, outer skin layer Mesoderm: –Middle layer –Develops into muscles, circulatory system, reproductive system and excretory system Endoderm: –Innermost layer –Develops into digestive and respiratory systems. 9/3/2015

Cephalization: –An anterior concentration of sense organs To have a head region The more complex the animals become the more pronounced their cephalization. 9/3/2015

Segmentation: –“Advanced animals have body segments, and specialization of tissues. 9/3/2015