1. Chapter 9 Architectural Patterns of An Animal
Zoology
Chapter 9
Architectural Patterns of An Animal

2. Five Major Grades of Organization
Unicellular Protozoans
Metazoans
Tissues
Organs
Organ Systems

3. Unicellular Protozoans
Simplest eukaryote
Complete organisms
All life functions
Organization of labor
Distinct support and locomotor devices, fibrils and sensory structures

4. Metazoa- multicellular animals, greater structural complexity by combining cells into larger units
Cells-specialized part of whole organism, not capable of independent existence
Cells-specialized for performing various tasks
Cellular organization-division of labor

5. Tissue- group of similar cells
Perform common functions as a highly organized unit
Types of tissue-epithelial, connective, nervous
Special roles of tissue-parenchyma-chief functional cells, stroma-supportive tissue

6. Organs Made of similar tissues Specialized for certain functions
Carries burden of organ’s chief function

7. Organ Systems Different organs work together
Eleven different organ systems in metazoans: skeletal, muscular, integumentary, digestive, respiratory, circulatory, excretory, nervous, endocrine, immune and reproductive

8. Animal Body Plans Grade of organization Body symmetry
Number of embryonic germ layers
Number of body cavities

9. Symmetry
Balanced proportions that correspond to size and shape of parts on opposite sides of median plane.
Types-spherical, radial, bilateral

10. Spherical Symmetry
Plan divides body into mirrored halves, like in unicellular organisms

11. Radial Symmetry
Divided into similar halves by more than two planes passing through longitudinal axis.
Biradial-some part is single or paired with only 2 planes.

12. Bilateral Symmetry
Divides along sagittal plane into two mirrored portions, right and left halves, animals are better fitted for forward movement-has cephalization-head, nervous tissue, sense organs and mouth

13. Anatomy Terms Anterior-head Posterior-tail Dorsal-back Ventral-belly
Median-midline
Lateral-side
Distal-farther from medial
Proximal –nearer to medial
Pectoral-chest
Pelvic-hip region and hind legs

14. Body Planes Frontal Plane- divided into dorsal and ventral
Sagittal Plane- divided into right and left
Transverse Plane- divided into anterior and posterior

15. Body Cavities-Internal Space
Metazoans-zygoteblastulagastrula.
One side of blastula pushes inward and makes a depression(gastrocoel or archenteron) external opening is blastopore that becomes the adult mouth, endoderm is the outer cell layers. Mesoderm is the third germ layer

16. Three Methods of Mesoderm Formation
Acoelomate-mesodermal cells fill blastocoel, gut only body cavity and parenchyma are the spongy cells.
Pseudocoleomate-false coelom with mesodermal cells that line outer blastocoel edge and leaves two body cavities. The mesoderm only partially surrounds it.

17. Mesoderm Formation
Schizocoelous-mesodermal cells fill blastocoel form a solid band of tissue around gut and through programmed cell death space opens inside this band to form a coelom, ends up with two body cavities: gut and coelom.
Enterocoleous-cells from gut lining grow outward as pouches and expand into blastocoel , the pouch walls form a mesodermal ring, enclose space and becomes a coelom, pouches close off to enclose coelom bounded by mesoderm on all sides.

18. Developmental Layers- determine body plans
Diploblastic-two germ layers
Triploblstic-three germ layers
Blind gut-incomplete gut, food and waste enter and leave through same opening
Complete gut-one way flow of food from mouth to anus, complex tube within a tube
Segmentation(metamerism)serial repetitions of similar body segments along longitudinal axis of body, each segment is called a metamere or somite

19. Metazoan Body Components
Cellular components-derived from three embryonic germ layers
Body Fluids- located in intracellular space and extracellular space
Extracellular structural elements-supportive material of organism: loose connective tissue, cartilage, cuticle, provide mechanical stability and protection

20. Cellular Components- tissue group of similar specialized cells
Epithelial-sheet of cells that cover an external or internal surface: lines organs of body cavities, ducts and passageways, classified by cell form and number of cell layers
Connective-bind, support functions, widespread in the body, loose connective tissue fibers or dense fibers made of tendons and ligaments, also includes cartilage a semi-rigid tissue and bone a calcified connective tissue.

21. Cellular Components
3. Muscular-most abundant tissue specialized for contraction striated, skeletal and cardiac)
4. Nervous-specialized for reception of stimuli and conduction of impulses from one region to another made of two cell types neurons the basic functional unit and neuroglia a variety of nonnervous cells that insulate neuron membranes and serve support functions.