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.

Symmetry

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 ArthropodsALLOWS 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

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