Animal Systems 18/04/12. Overview: Diverse Forms, Common Challenges. Organization & Functions BIOL212

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1 Animal Systems Organization & Functions BIOL212 Overview: Diverse Forms, Common Challenges Anatomy is the study of the biological form of an organism Physiology is the study of the biological funcdons an organism performs The comparadve study of animals reveals that form and funcdon are closely correlated Figure

2 Concept 40.1: Animal form and funcdon are correlated at all levels of organizadon Size and shape affect the way an animal interacts with its environment Many different animal body plans have evolved and are determined by the genome EvoluDon of Animal Size and Shape Physical laws constrain strength, diffusion, movement, and heat exchange As animals increase in size, their skeletons must be propordonately larger to support their mass EvoluDonary convergence reflects different species adaptadons to a similar environmental challenge Video: Shark EaDng Seal Video: Galápagos Sea Lion Figure 40.2 Seal Penguin Tuna 2

3 Exchange with the Environment Materials such as nutrients, waste products, and gases must be exchanged across the cell membranes of animal cells Rate of exchange is propordonal to a cell s surface area while amount of exchange material is propordonal to a cell s volume Video: Hydra EaDng Daphnia A single- celled prodst living in water has a sufficient surface area of plasma membrane to service its endre volume of cytoplasm MulDcellular organisms with a saclike body plan have body walls that are only two cells thick, facilitadng diffusion of materials Figure 40.3 Mouth Exchange Gastrovascular cavity Exchange Exchange 0.1 mm 1 mm (a) Single cell (b) Two layers of cells 3

4 In flat animals such as tapeworms, the distance between cells and the environment is minimized More complex organisms have highly folded internal surfaces for exchanging materials Figure 40.4 External environment Lining of small intestine (SEM) Digestive system 100 µm Mouth Nutrients Anus Unabsorbed matter (feces) Food Animal body Bl o o d Heart CO 2 O2 Circulatory system Respiratory system Excretory system Metabolic waste products (nitrogenous waste) Cells Lung tissue (SEM) Interstitial fluid Blood vessels in kidney (SEM) 50 µm 250 µm Figure 40.4a External environment Food CO 2 O2 Mouth Animal body Bl o o d Respiratory system Digestive system Nutrients Heart Circulatory system Cells Interstitial fluid Excretory system Anus Unabsorbed matter (feces) Metabolic waste products (nitrogenous waste) 4

5 Fjords increase shoreline: Milford Sound, New Zealand Figure 40.4b Lining of small intestine (SEM) 100 µm 5

6 Figure 40.4c Lung tissue (SEM) 250 µm Figure 40.4d Blood vessels in kidney (SEM) 50 µm In vertebrates, the space between cells is filled with inters11al fluid, which allows for the movement of material into and out of cells A complex body plan helps an animal living in a variable environment to maintain a reladvely stable internal environment 6

7 Hierarchical OrganizaDon of Body Plans Most animals are composed of specialized cells organized into 1ssues that have different funcdons Tissues make up organs, which together make up organ systems Some organs, such as the pancreas, belong to more than one organ system Subatomic pardcles Atoms Molecules Organelles Cells Tissues Organs Organ Systems Organism PopulaDon Community Ecosystems The Biosphere Heirarchy Table

8 Exploring Structure and Function in Animal Tissues Different Dssues have different structures that are suited to their funcdons Tissues are classified into four main categories: epithelial, connecdve, muscle, and nervous Epithelial Tissue Epithelial 1ssue covers the outside of the body and lines the organs and cavides within the body It contains cells that are closely joined The shape of epithelial cells may be cuboidal (like dice), columnar (like bricks on end), or squamous (like floor Dles) The arrangement of epithelial cells may be simple (single cell layer), stradfied (muldple Ders of cells), or pseudostradfied (a single layer of cells of varying length) 8

9 Figure 40.5aa Epithelial Tissue Stratified squamous epithelium Cuboidal epithelium Simple columnar epithelium Simple squamous epithelium Pseudostratified columnar epithelium Figure 40.5ab Apical surface Basal surface Basal lamina 40 µm Polarity of epithelia Connective Tissue Connec1ve 1ssue mainly binds and supports other Dssues It contains sparsely packed cells scagered throughout an extracellular matrix The matrix consists of fibers in a liquid, jellylike, or solid foundadon 9

10 There are three types of connecdve Dssue fiber, all made of protein: Collagenous fibers provide strength and flexibility ElasDc fibers stretch and snap back to their original length ReDcular fibers join connecdve Dssue to adjacent Dssues ConnecDve Dssue contains cells, including Fibroblasts that secrete the protein of extracellular fibers Macrophages that are involved in the immune system In vertebrates, the fibers and foundadon combine to form six major types of connecdve Dssue: Loose connecdve Dssue binds epithelia to underlying Dssues and holds organs in place Car1lage is a strong and flexible support material Fibrous connecdve Dssue is found in tendons, which agach muscles to bones, and ligaments, which connect bones at joints 10

11 Adipose 1ssue stores fat for insuladon and fuel Blood is composed of blood cells and cell fragments in blood plasma Bone is mineralized and forms the skeleton Figure 40.5ba Loose connective tissue Collagenous fiber Connective Tissue Blood Plasma White blood cells 30 µm 120 µm Elastic fiber Fibrous connective tissue Nuclei Bone Cartilage Chondroitin sulfate Adipose tissue 100 µm 55 µm Red blood cells Chondrocytes Central canal Fat droplets 700 µm Osteon 150 µm Figure 40.5bb Loose connective tissue Collagenous fiber 120 µm Elastic fiber 11

12 Figure 40.5bc Fibrous connective tissue 30 µm Nuclei Figure 40.5bd Bone Central canal 700 µm Osteon Figure 40.5be Adipose tissue Fat droplets 150 µm 12

13 Figure 40.5bf Cartilage Chondrocytes Chondroitin sulfate 100 µm Figure 40.5bg Blood Plasma White blood cells 55 µm Red blood cells Muscle Tissue Muscle 1ssue consists of long cells called muscle fibers, which contract in response to nerve signals 13

14 It is divided in the vertebrate body into three types: Skeletal muscle, or striated muscle, is responsible for voluntary movement Smooth muscle is responsible for involuntary body acdvides Cardiac muscle is responsible for contracdon of the heart Figure 40.5ca Muscle Tissue Skeletal muscle Nuclei Muscle fiber Sarcomere 100 µm Smooth muscle Cardiac muscle Nucleus Muscle fibers 25 µm Nucleus Intercalated disk 50 µm Figure 40.5cb Skeletal muscle Nuclei Muscle fiber Sarcomere 100 µm 14

15 Figure 40.5cc Smooth muscle Nucleus Muscle fibers 25 µm Figure 40.5cd Cardiac muscle Nucleus Intercalated disk 50 µm Nervous Tissue Nervous 1ssue senses sdmuli and transmits signals throughout the animal Nervous Dssue contains Neurons, or nerve cells, that transmit nerve impulses Glial cells, or glia, that help nourish, insulate, and replenish neurons 15

16 Figure 40.5da Nervous Tissue Neurons Glia Glia 15 µm Neuron: Dendrites Cell body Axon Axons of neurons 40 µm Blood vessel (Fluorescent LM) (Confocal LM) Figure 40.5db Figure 40.5dc 16

17 CoordinaDon and Control Control and coordinadon within a body depend on the endocrine system and the nervous system The endocrine system transmits chemical signals called hormones to recepdve cells throughout the body via blood A hormone may affect one or more regions throughout the body Hormones are reladvely slow acdng, but can have long- lasdng effects Figure 40.6 Figure 40.6a 17

18 The nervous system transmits informadon between specific locadons The informadon conveyed depends on a signal s pathway, not the type of signal Nerve signal transmission is very fast Nerve impulses can be received by neurons, muscle cells, endocrine cells, and exocrine cells Figure 40.6b Concept 40.2: Feedback control maintains the internal environment in many animals Animals manage their internal environment by reguladng or conforming to the external environment 18