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AN INTRODUCTION TO ANIMAL STRUCTURE AND FUNCTION Structure verses Function n Anatomy – study of structure n Physiology – study of function n Functional anatomy n Tissues – groups of cells that share a common function. EPITHELIAL TISSUE n Body covering and lines inner body cavities. n Attached to the basement membrane n Basement membrane is an extra cellular matrix. n Function primarily protection and some secretion. Classification Can Be Based on Number of layers n Simple epithelium – single layer n Found on surfaces that participate in gas and nutrient exchange. n Stratified epithelium – several layers n Found on surfaces that undergo frequent abrasion. n Psuedostratified epithelium – Appear to be more than one layer but are not. n Found on surfaces that are ciliated. Classified by Cell Shape n Squamous – Flat “tile like” cells. n Meant for covering large areas. n Glandular or Cuboidal – Cube shaped cells n Involved in storage and secretion. n line glands and mucous membranes. n Columnar – brick shaped cells. n Involved in storage and secretion. Chuck and Me Psuedostratified columnar Simple Columnar Simple Cuboidal Columnar Ciliated Connective Tissue n Bind and support other tissues. n Sparse population of cells scattered through and extra cellular matrix. n Matrix usually secreted by the cells that make up the tissue. n Matrix may be – web like fibers, gelatinous or fluid. Connective Tissue Fibers Composition n Collagenous Fibers – Tensile Strength n Elastic Fibers – Elasticity n Reticular Fibers – Connects layers of tissue together. Major Types of Connective Tissue n Loose - Packing material that holds organs in place and has all types of fibers. n Cells scattered throughout this type of tissue are macrophages and fibroblasts. n Adipose – Stores fat and provides insulation. n Fibrous – Dense and mostly collagenous fibers. n Tendons - attach muscle to bone. n Ligaments – join bones together. n Cartilage – Collagenous fibers embedded in a rubbery matrix made of condroitin sulfate. n Secreted by chondrocytes n Strong but flexible Adipose Tissue Loose Connective Tissue Connective Tissue n Bone – Mineralized connective tissue. n Osteoblasts - deposit a matrix of collagen that is flexible but more brittle than cartilage. n Hydroxyapatite - calcium, magnesium and phosphorous matrix. n Osteons (Haversian systems) are subunits of bone that contain blood vessels and is innervated. n When and osteoblast gets caught in its own secretion it is called an osteocyte. Cartilage n Blood – Cells suspended in a fluid matrix called plasma. n Plasma contains water salt and a variety of proteins. n Erythrocyte – Red blood cells. Carry O2 and CO2 to and from tissues via hemoglobin. Leucocytes – White blood cells involved in the immune system. Platelets – Proteins involved in the clotting of blood. Nervous Tissue n Senses Stimuli. Electrically activated. n Axons transmit impulses toward another neuron. n Composed of Neurons. Neuron Muscle Tissue n Myofibrils made up of contracting proteins called actin and myosin. n Individual units are called sacromeres. n Most animals are primarily composed of muscle tissue. n Three primary types of muscle tissue: n Striated - skeletal, voluntary n Cardiac - intercalated discs, involuntary n Smooth – peristalsis, involuntary Skeletal Muscle Smooth Muscle Cardiac Muscle Organs are made up of many layers of different tissues Serosa, Sub Mucosa, Mucosa and Muscularis Body Plan n Size and shape of the body depends on how the animal interacts with its environment. n All cells must be bathed in an aqueous environment for nutrient and gas exchange. n Amoebas have a large surface area relative to their volume. n Tape worms are flat. n Hydra are gastric sacs exposed to water on all sides. n Multicellular organisms have complex folds with small tightly packed cells that are bathed in interstitial fluid. Fusiform shape conducive for swimming fast Body plan of Amoeba and Hydra Small Intestine Regulating the Internal Environment n Homeostasis maintained through positive and negative feedback systems. n Receptor Control center Effector n Receptor senses stimuli n Control Center processes and directs a command to the effector. n Effector carries out the response. Bioenergetics n Metabolic Rate – Amount of energy an animal uses in a unit of time. n Measured in Kilocalories or Calories. n Can be measured by: n Amount of heat given off n O2 consumption n CO2 emission. n Endotherms need more energy to maintain basic metabolic functions than ectotherms n Basal Metabolic Rate – minimal amount of energy needed to maintain cellular functions for an endotherm under no stress. n Standard Metabolic Rate - minimal amount of energy needed to maintain cellular functions for an ectotherm under no stress. n Amount of energy to maintain each gram of body weight is inversely proportional to body size. n Due to greater surface to volume ratio in smaller animals. n Dissipate heat much more rapidly. Ghost Crab on a Treadmill
"AN INTRODUCTION TO ANIMAL STRUCTURE AND FUNCTION"