Chapter 40 : Introduction to Animal Structure and Function

4 Hierarchal levels of organization Cells Cells Tissues Tissues Organs Organs Organ systems Organ systems

Tissues: groups of cells with a common structure and function. 4 Principal Anatomy Anatomy Structure Structure Function Function

Outside of body and lines organs and cavities Outside of body and lines organs and cavities Held together by tight junctions Held together by tight junctions Protect; secretion Protect; secretion Organization: Organization: Basement membrane: dense mat of extracellular matrix Basement membrane: dense mat of extracellular matrix Free Surface determines how classified : Free Surface determines how classified : a) By # of layers: a) By # of layers: Simple: single layer of cells Simple: single layer of cells Stratified: multiple tiers of cells Stratified: multiple tiers of cells b) By shape : Cuboidal (like dice) Cuboidal (like dice) Columnar (like bricks on end) Columnar (like bricks on end) Squamous (like floor tiles) Squamous (like floor tiles) 1. Epithelial Tissue

2. Connective Tissue bind and support other tissues; sparsely scattered cells throughout a matrix of protein fibers in a watery, jelly-like, or solid foundation bind and support other tissues; sparsely scattered cells throughout a matrix of protein fibers in a watery, jelly-like, or solid foundation 3 kinds of fibers: 3 kinds of fibers: A-Collagenous fibers (collagen protein-non- elastic)A-Collagenous fibers (collagen protein-non- elastic) B-Elastic fibers (elastin protein-long threads; rubbery)B-Elastic fibers (elastin protein-long threads; rubbery) C-Reticular fibers (very thin & branched collagen fibers)C-Reticular fibers (very thin & branched collagen fibers)

6 Different Types of Connective Tissue: 1. Loose connective tissue: 1. Loose connective tissue: Most widespread C.T.. binds epithelia to underlying tissue; holds organs in place Most widespread C.T.. binds epithelia to underlying tissue; holds organs in place Two types of cells predominate in the matrix: Two types of cells predominate in the matrix: 1-Fibroblasts- secretes the extracellular proteins1-Fibroblasts- secretes the extracellular proteins 2-Macrophages- amoeboid WBC’s; phagocytosis2-Macrophages- amoeboid WBC’s; phagocytosis

2. Adipose tissue- fat storage; insulation 2. Adipose tissue- fat storage; insulation 3. Fibrous connective tissue: 3. Fibrous connective tissue: Dense-lots of collagenous fibers arranged in parallel Dense-lots of collagenous fibers arranged in parallel Found in: Found in: 1-Tendons- muscles to bones1-Tendons- muscles to bones 2-Ligaments- bones to bones; joints (BOBOLI)2-Ligaments- bones to bones; joints (BOBOLI)

4. Cartilage: collagen in a rubbery matrix (chondroitin); flexible support. 4. Cartilage: collagen in a rubbery matrix (chondroitin); flexible support. Collagen secreted by chondrocytes (cells) Collagen secreted by chondrocytes (cells) 5. Bone: mineralized tissue ; 5. Bone: mineralized tissue ; Calcium, Magnesium, Phosphorous Calcium, Magnesium, Phosphorous osteoblasts-cells the collagen osteoblasts-cells the collagen 6. Blood: liquid plasma matrix; erythrocytes (RBC’s) carry O2; leukocytes (WBC’s) immunity, platelets 9 blood clotting) 6. Blood: liquid plasma matrix; erythrocytes (RBC’s) carry O2; leukocytes (WBC’s) immunity, platelets 9 blood clotting)

3. NervousTissue 3. NervousTissue Neurons & supporting cells (neuroglia). Neurons & supporting cells (neuroglia). Sense stimuli and transmit signals from 1 part of the animal to another. Sense stimuli and transmit signals from 1 part of the animal to another. Neuron: (nerve cell)functional unit that transmits impulses Neuron: (nerve cell)functional unit that transmits impulses Cell BodyCell Body Dendrites: transmit impulses from tips to rest of neuronDendrites: transmit impulses from tips to rest of neuron Axons: transmit impulses toward another neuron or effectorAxons: transmit impulses toward another neuron or effector

4.Muscle Tissue Most abundant tissue. Most abundant tissue. Consists of long cells called muscle fibers that are capable of contracting when stimulated by nerve impulses Consists of long cells called muscle fibers that are capable of contracting when stimulated by nerve impulses Contain myofibrils made of proteins actin & myosin Contain myofibrils made of proteins actin & myosin

Body Plans and the External Environment Size & Shape Size & Shape Fusiform shape of penguins, sharks arose via convergent evolution; adaptations. Fusiform shape of penguins, sharks arose via convergent evolution; adaptations. Surface area: volume limits size Surface area: volume limits size Adaptations via complexity of body plans Adaptations via complexity of body plans Tapeworm—long thin Tapeworm—long thin Hydra—sac body Hydra—sac body

Regulating the Internal Environment Interstitial fluid: internal fluid environment of vertebrates; exchanges nutrients and wastes Interstitial fluid: internal fluid environment of vertebrates; exchanges nutrients and wastes Claude Bernard: “constant internal milieu” Claude Bernard: “constant internal milieu” Homeostasis: “steady state” or internal balance Homeostasis: “steady state” or internal balance Depends on Feedback Circuits: Depends on Feedback Circuits: Negative feedback: change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation; i.e., body temperatureNegative feedback: change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation; i.e., body temperature Positive feedback: physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change; i.e., uterine contractions at childbirthPositive feedback: physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change; i.e., uterine contractions at childbirth

Bioenergetics of Animals The flow of energy through an animal The flow of energy through an animal Sets limits on an animal’s behavior, growth, reproduction and determines how much food it needs. Sets limits on an animal’s behavior, growth, reproduction and determines how much food it needs.

2 Basic Bioenergetic Strategies 1. Endothermic: birds, mammals 1. Endothermic: birds, mammals Requires more energyRequires more energy capable of intense activity over long periods of time.capable of intense activity over long periods of time. 2. Ectothermic: reptiles, amphibians, most fish 2. Ectothermic: reptiles, amphibians, most fish Requires less energyRequires less energy Generally incapable of intense activity over long periods of time.Generally incapable of intense activity over long periods of time.

Metabolism: sum of all energy- requiring biochemical reactions Catabolic processes of cellular respiration Catabolic processes of cellular respiration Calorie; kilocalorie/C Calorie; kilocalorie/C Endotherms: bodies warmed by metabolic heat Endotherms: bodies warmed by metabolic heat Ectotherms: bodies warmed by environment Ectotherms: bodies warmed by environment Basal Metabolic Rate (BMR): minimal rate powering basic functions of life (endotherms) Basal Metabolic Rate (BMR): minimal rate powering basic functions of life (endotherms) Standard Metabolic Rate (SMR): minimal rate powering basic functions of life (ectotherms) Standard Metabolic Rate (SMR): minimal rate powering basic functions of life (ectotherms)

Maximum Metabolic Rate Inversely related to duration of activity Inversely related to duration of activity Endotherm’s respiration rate is 10X higher than ectotherm—make long duration activity possible Endotherm’s respiration rate is 10X higher than ectotherm—make long duration activity possible

Metabolic Rate Rate Per gram of body weight is inversely related. Rate Per gram of body weight is inversely related. Energy Expenditure comparisons: Energy Expenditure comparisons: 2 animals of same taxonomic class, a smaller animal has a greater energy demand than does a larger one2 animals of same taxonomic class, a smaller animal has a greater energy demand than does a larger one An endotherm and ectotherm of the same weight: the endotherm has greater energy requirementAn endotherm and ectotherm of the same weight: the endotherm has greater energy requirement