Today’s Objectives TSW be able to recognize and give examples of the three types of symmetry found in animals. TSW be able to properly use directional terms for anatomical position. TSW be able to draw the three types of triploblastic body plans.

Asymmetry Radial Symmetry Bilateral Symmetry

Asymmetrical animals Sponges

Radially Symmetrical Animals Cnidarians Coelenterates Nematodes Annelids Ctenophorans Echinoderms

Bilaterally Symmetrical Animals Platyhelminths Chordates Fishes Herps Birds Rotifers Molluscs Arthropods ALLOWS FOR CEPHALIZATION!

Directional Orientation Anterior vs. Posterior Dorsal vs. Ventral Medial vs. Lateral Distal vs. Proximal Inferior vs. Superior Cephalic vs. Caudal Aboral vs. Oral

Acoelomate Pseudocoelomate Eucoelomate Body Plans Acoelomate Pseudocoelomate Eucoelomate

Tissue Layer Body Plans Diploblastic – ectoderm and gastroderm separated by mesoglea Triploblastic - ectoderm, mesoderm and endoderm Acoelomate Pseudocoelomate Eucoelomate

Acoelomate Body Plans Solid mass of cells between endoderm and ectoderm (parenchyma)

Pseudocoelomate Body Plans Body cavity not entirely lined with mesoderm Pseudocoelom comes from blastocoel

Eucoelomate Body Plans Cavity completely lined with mesoderm (peritoneum and serosa) Visceral structures suspended

Review Items Draw each type of triploblastic body plan and label each germ layer. Name at least one phylum of animals that falls into each category of symmetry.

Anatomical Position Review Use the proper terms to describe the relationship between the following body parts: A) hand is ____ to the elbow B) knee is ____ to the head C) bellybutton is ____ to the spinal cord D) heart is ____ to the lungs E) head is ____ to the neck (2 terms fit here) F) wrist is ____ to the fingers