Animal Architecture

Structure Hierarchy Cell  Tissue  Organ  Organ System

Cell Structure Plasma membrane –Isolates cytoplasm from environment –Regulates molecular movement into and out of cell –Interacts with other cells/environment Cytoplasm –Water, salts, organic monomers and polymers –Often contains organelles Genetic material –DNA

Epithelial Tissue Covers internal and external structures Purpose –Protection –Secretion –Gas exchange Basement membrane and connective tissue support epithelial tissue

Connective Tissue Very diverse functions –Support  Cartilage, bone, dense, loose –Energy storage  Adipose –Gas exchange  Red blood cells –Immune system  White blood cells

Muscle Tissue Contain contractile unit composed of actin and myosin fibers Smooth Striated –Skeletal –Cardiac

Smooth Muscle –Invertebrates Body wall, ducts, sphincter –Vertebrates Controls diameter of tubes (blood vessels and digestive system) Involuntary

Striated Densely packed actin/myosin fibers gives striated appearance Multinucleated cells – syncytial Skeletal –Found in both vertebrates and invertebrates –Attaches to bones and cartilage in vertebrates Cardiac –Only found in vertebrate heart

Nervous Tissue Neurons – send and receive signals Neuroglia – support and protection

Metazoa Multicellular Motile (at some point in life cycle) Heterotrophic (consumer) Diploid (two sets of chromosomes) Development proceeding via a blastula

Choanoflagellate Protozoan Simple colonial flagellates No specialization Precursor to Metazoa

Spherical Colonies of Choanoflagellates Reproduction of the whole cell aggregate through gametes Cell specialization

Metazoa Classification

Three Basic Tissues Ectoderm –Outer germ layer –Skin, nervous system, etc… Mesoderm –Forms between ectoderm and endoderm –Connective tissue, muscle, vascular etc… Endoderm –Innermost germ layer –Gastrointestinal tract

Eumetazoa

Animal Symmetry Spherical – Radiolarians (protists) Radial – Cnidarians (jellyfish) Bilateral – Acoelomates (flatworms)

Symmetry

Developmental Patterns Cleavage Pattern –Radial vs. Spiral –Regulative vs. Mosaic Blastopore formation Coelom formation

Mesoderm and Coelomic Formation

Protostomes Vs. Deuterostomes Protostomes –Molluscs –Annelids –Pseudocoelomates –Acoelomates Deuterostomes –Chordates –Echinoderms

Bilateria

Protostomes Body Plans

Segmentation Body divided into somites (segments) Phyla –Annelida –Arthropoda –Chordata

Cephalization Concentration of nervous tissue –Development of brain and senses –Movement toward stimulus

Overview of Body Plans