Animal Architecture Structure Hierarchy Cell Tissue Organ System

Animal Architecture

Structure Hierarchy • Cell Tissue 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 – Energy storage – Gas exchange – Immune system Cartilage, bone, dense, loose Adipose Red blood cells 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