Chapter 20 Unifying Concepts of Animal Structure and

Chapter 20: Unifying Concepts of Animal Structure and Function What is the difference between the terms Structure and Function? • The purpose of animal function is ultimately related to the animal’s reproductive success (think of function as a ‘concept’) • Animal structure relates to the suite of physical characteristics that accomplish a function (or functions) pp. 414

Concepts of Animal Structure and Function Examples of Structure and Function 1) Function: Feeding (a concept) 2) Structure: Tooth structure in carnivores (ex. carnassials) pp. 414

Concepts of Animal Structure and Function Examples of Structure and Function 1) Function: Catalyzing a reaction (a concept) 2) Structure: Active site of enzyme pp. 414

Concepts of Animal Structure and Function Structures of a Bird Wing is Related to its Function Fig. 20. 1 pp. 414

Concepts of Animal Structure and Function Basic Hierarchy of Biological Structure Cell Tissue Organ System Individual pp. 414 Fig. 20. 1

Concepts of Animal Structure and Function Basic Hierarchy of Biological Structure A tissue is defined as: • a group of similar cells that interact to perform a specific function 4 Major Animal Tissue Types - Epithelial - Connective - Muscle - Nervous pp. 415

Structure and Function of Epithelial Tissues that line the outside of the body, organs, and body cavities Fig. 20. 4 pp. 416

Types of Epithelial Tissue in the Body Two general ways of defining epithelial tissue structure: 1) Number of layers • Simple = single layer of epithelial cells • Stratified = 2 or more layers of epithelial cells pp. 416

Types of Epithelial Tissue in the Body Two general ways of defining epithelial tissue structure: 2) Epithelial cell shape • Squamous = flattened cells • Cuboidal = ‘dice’ or cube shaped • Columnar = elongated cells (like a brick stacked vertical) pp. 416

Types of Epithelial Tissue in the Body Simple Squamous Epithelium Structure: Flat cells arranged in single layer Function: Forms layers where diffusion of ‘materials’ must occur • Ex. lining of alveoli for diffusion of O 2 / CO 2 Fig. 20. 4 pp. 416

Types of Epithelial Tissue in the Body Stratified Squamous Epithelium Structure: Flat cells arranged in multiple layers Function: Occurs in areas where abrasion wears away cell layers • Ex. lining of esophagus, Fig. 20. 4 skin pp. 416

Types of Epithelial Tissue in the Body Simple Columnar Epithelium Fig. 20. 4 Structure: Elongated cells arranged in single layer Function: Form layers where absorption of nutrients and secretion occur • Ex. lining of intestine pp. 416 Fig. 20. 4

Structure and Function of Connective Tissue Functions in support and binding of other tissues Fig. 20. 5 pp. 417

Structure and Function of Connective Tissue General Structure: A sparse population of cells found in an extracellular Fig. 20. 5 matrix pp. 417

An Example of a Connective Tissue Matrix Blood vessel Red Blood Cells pp. 417 Blood Plasma (Matrix)

Structure and Function of Connective Tissue Collagen is a Major (Protein) Fiber in the Matrix Secreted by Cells of Many Connective Tissues (Fig. not in text) pp. 417

Types of Connective Tissue in the Body Loose Connective Tissue Structure: Low number of cells with a loose matrix of fibers (collagen, elastin, reticular Function: Forms a binding material to hold organs and tissues in place pp. 417 Fig. 20. 5

Types of Connective Tissue in the Body Cartilage Structure: Cells secrete a matrix of dense collagen fibers and a rubbery material (chondroitin sulfate) Function: Creates a flexible skeletal material: e. g. ears, nose, between vertebrae, support Fig. 20. 5 windpipe pp. 417

Types of Connective Tissue in the Body Bone Structure: A rigid connective tissue – matrix is collagen fibers – with a hardened mineral base of calcium, phosphate, and magnesium (hard) Function: Major support structure and attachment site for muscle + protects Fig. 20. 5 major organs pp. 417

Structure and Function of Muscle Tissue Fig. 20. 6 pp. 418

Types of Muscle Tissue in the Body Skeletal Muscle Structure: Striated muscle cells with actin/myosin filaments responsible for contractions Function: Voluntary muscular movement Fig. 20. 6 pp. 418

General Mechanism of Muscle Contraction Actin pp. 418 Myosin

Types of Muscle Tissue in the Body Cardiac Muscle Structure: Cells are striated, branched ; Intercalated disks join adjacent cells Function: Involuntary muscular movement, short contractions + quick communication between adjacent cells pp. 418 Intercalated disk Fig. 20. 6

Types of Muscle Tissue in the Body Smooth Muscle Structure: Cells are non-striated – muscle fibers arranged in spirals Function: Involuntary muscular movement + long continuous contractions pp. 418 Fig. 20. 6

Structure and Function of Nervous Tissue Neurons (nerve cells) are the basic unit of the nervous system Fig. 20. 7 pp. 419

Basic Structure of a Neuron Fig. 48. 2 Cell Body Dendrites pp. 419 Axon Synaptic Knobs

Basic Structure of a Neuron Fig. 28. 7

Concepts of Animal Structure and Function Basic Hierarchy of Biological Structure Cell Tissue Organ System Individual pp. 414 Fig. 20. 1

Tying the Tissues Together: Organs - Each main tissue type is found in the small intestine - The result is proper functioning of the intestine (absorption of nutrients) pp. 419 Fig. 20. 8