Basic Principles of Animal Form and Function Chapter 40 Basic Principles of Animal Form and Function

Overview: Diverse Forms, Common Challenges Anatomy is the study of the biological form of an organism Physiology is the study of the biological functions an organism performs The comparative study of animals reveals that form and function are closely correlated Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig. 40-1 Figure 40.1 How does a jackrabbit keep from overheating? For the Discovery Video Human Body, go to Animation and Video Files.

Size and shape affect the way an animal interacts with its environment Concept 40.1: Animal form and function are correlated at all levels of organization 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 Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Physical Constraints on Animal Size and Shape The ability to perform certain actions depends on : an animal’s shape, size, and environment Evolutionary convergence reflects: Different species’ adaptations to a similar environmental challenge Physical laws impose: constraints on animal size and shape Video: Shark Eating Seal Video: Galápagos Sea Lion Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

(a) Tuna (b) Penguin (c) Seal Fig. 40-2 Figure 40.2 Convergent evolution in fast swimmers (b) Penguin (c) Seal

Exchange with the Environment An animal’s size & shape: directly affect how it exchanges energy and materials with its surroundings Exchange occurs: As substances dissolved in the aqueous medium diffuse and are transported across the cells’ plasma membranes A single-celled protist living in water: Has a sufficient surface area of plasma membrane to service its entire volume of cytoplasm Video: Hydra Eating Daphnia Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Mouth Gastrovascular cavity Exchange Exchange Exchange 0.15 mm 1.5 mm Fig. 40-3 Mouth Gastrovascular cavity Exchange Exchange Exchange Figure 40.3 Contact with the environment 0.15 mm 1.5 mm (a) Single cell (b) Two layers of cells

Multicellular organisms with a sac body plan have: Body walls that are only two cells thick, facilitating diffusion of materials Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

More complex organisms have: Highly folded internal surfaces for exchanging materials Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 40.4 Internal exchange surfaces of complex animals External environment CO2 Food O2 Mouth Animal body Respiratory system Blood 50 µm 0.5 cm Lung tissue Nutrients Cells Heart Circulatory system 10 µm Interstitial fluid Digestive system Figure 40.4 Internal exchange surfaces of complex animals Lining of small intestine Excretory system Kidney tubules Anus Unabsorbed matter (feces) Metabolic waste products (nitrogenous waste)

Metabolic waste products (nitrogenous waste) Fig. 40-4a External environment CO2 Food O2 Mouth Animal body Respiratory system Blood Nutrients Cells Heart Circulatory system Interstitial fluid Digestive system Figure 40.4 Internal exchange surfaces of complex animals Excretory system Anus Unabsorbed matter (feces) Metabolic waste products (nitrogenous waste)

Lining of small intestine Fig. 40-4b 0.5 cm Figure 40.4 Internal exchange surfaces of complex animals Lining of small intestine

Fig. 40-4c 50 µm Lung tissue Figure 40.4 Internal exchange surfaces of complex animals

Kidney tubules 10 µm Fig. 40-4d Figure 40.4 Internal exchange surfaces of complex animals Kidney tubules

In vertebrates, the space between cells is filled with: Interstitial fluid Such fluid allows for the movement of material into and out of cells A complex body plan: Helps an animal to maintain a relatively stable internal environment in a variable environment Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Hierarchical Organization of Body Plans Most animals are composed of: Specialized cells Cells are organized into tissues Tissues have different functions Tissues make up: Organs Organs together make up: organ systems Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Table 40-1

Tissue Structure and Function Different tissues: have different structures Such structures are suited to their functions Tissues are classified into four main categories: Epithelial Connective Muscle Nervous Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

covers the outside of the body Epithelial Tissue Epithelial tissue: covers the outside of the body Lines the organs and cavities 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) Squamous (like floor tiles) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

The arrangement of epithelial cells may be: Simple (single cell layer) Stratified (multiple tiers of cells) Seudostratified (a single layer of cells of varying length) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Epithelial Tissue Cuboidal epithelium Simple columnar epithelium Fig. 40-5a Epithelial Tissue Cuboidal epithelium Simple columnar epithelium Pseudostratified ciliated columnar epithelium Stratified squamous epithelium Figure 40.5 Structure and function in animal tissues Simple squamous epithelium

Apical surface Basal surface Basal lamina 40 µm Fig. 40-5b Figure 40.5 Structure and function in animal tissues 40 µm

Mainly binds and supports other tissues It contains: Connective Tissue Connective tissue Mainly binds and supports other tissues It contains: Sparsely packed cells scattered throughout An extracellular matrix The matrix consists of: Fibers in A liquid, jellylike, or solid foundation Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

There are three types of connective tissue fiber, all made of protein: Collagenous fibers: provide strength and flexibility Elastic fibers stretch & snap back to their original length Reticular fibers: join connective tissue to adjacent tissues Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Connective tissue contains cells, including Fibroblasts: secrete the protein of extracellular fibers Macrophages are involved in the immune system Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

In vertebrates, the fibers foundation combine to form six major types of connective tissue: Loose connective tissue : binds epithelia to underlying tissues holds organs in place Fibrous connective tissue found in: Tendons: attach muscles to bones Ligaments: which connect bones at joints Cartilage: a strong and flexible support material Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

stores fat for insulation and fuel Blood: Adipose tissue stores fat for insulation and fuel Blood: composed of blood cells and cell fragments in blood plasma Bone: mineralized and forms the skeleton Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Connective Tissue Loose connective tissue Cartilage Fibrous connective Fig. 40-5c Connective Tissue Collagenous fiber Loose connective tissue Chondrocytes Cartilage 120 µm 100 µm Elastic fiber Chondroitin sulfate Nuclei Fat droplets Fibrous connective tissue Adipose tissue 30 µm 150 µm Figure 40.5 Structure and function in animal tissues Osteon White blood cells Bone Blood 700 µm 55 µm Central canal Plasma Red blood cells

Loose connective tissue Fig. 40-5d Collagenous fiber 120 µm Figure 40.5 Structure and function in animal tissues Elastic fiber Loose connective tissue

Fibrous connective tissue Fig. 40-5e Nuclei 30 µm Figure 40.5 Structure and function in animal tissues Fibrous connective tissue

Bone Osteon 700 µm Central canal Fig. 40-5f Figure 40.5 Structure and function in animal tissues Central canal Bone

Cartilage Chondrocytes 100 µm Chondroitin sulfate Fig. 40-5g Figure 40.5 Structure and function in animal tissues Chondroitin sulfate Cartilage

Adipose tissue Fat droplets 150 µm Fig. 40-5h Figure 40.5 Structure and function in animal tissues Adipose tissue

Blood White blood cells 55 µm Plasma Red blood cells Fig. 40-5i Figure 40.5 Structure and function in animal tissues Plasma Red blood cells Blood

It is divided in the vertebrate body into three types: Muscle Tissue Muscle tissue consists of long cells called muscle fibers, which contract in response to nerve signals 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 activities Cardiac muscle is responsible for contraction of the heart Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Muscle Tissue Skeletal muscle Cardiac muscle Smooth muscle Multiple Fig. 40-5j Muscle Tissue Multiple nuclei Muscle fiber Sarcomere Skeletal muscle Nucleus 100 µm Intercalated disk 50 µm Cardiac muscle Figure 40.5 Structure and function in animal tissues Smooth muscle Nucleus Muscle fibers 25 µm

Skeletal muscle Multiple nuclei Muscle fiber Sarcomere 100 µm Fig. 40-5k Multiple nuclei Muscle fiber Sarcomere Figure 40.5 Structure and function in animal tissues 100 µm Skeletal muscle

Smooth muscle Nucleus Muscle fibers 25 µm Fig. 40-5l Figure 40.5 Structure and function in animal tissues 25 µm Smooth muscle

Cardiac muscle Nucleus Intercalated disk 50 µm Fig. 40-5m Figure 40.5 Structure and function in animal tissues Nucleus Intercalated disk 50 µm Cardiac muscle

Nervous tissue contains: Nervous tissue senses stimuli and transmits signals throughout the animal Nervous tissue contains: Neurons, or nerve cells, that transmit nerve impulses Glial cells, or glia, that help nourish, insulate, and replenish neurons Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Nervous Tissue Neuron 40 µm Axons Blood vessel Dendrites Cell body Fig. 40-5n Nervous Tissue 40 µm Dendrites Cell body Axon Glial cells Neuron Figure 40.5 Structure and function in animal tissues Axons Blood vessel 15 µm

Neuron 40 µm Dendrites Cell body Axon Fig. 40-5o Figure 40.5 Structure and function in animal tissues Neuron

Glial cells and axons Glial cells Axons Blood vessel 15 µm Fig. 40-5p Figure 40.5 Structure and function in animal tissues Blood vessel Glial cells and axons 15 µm

Coordination and Control Control coordination within a body depend on: he endocrine system The nervous system The endocrine system: transmits chemical signals called hormones Signals carried throughout the body to receptive cells via blood A hormone may affect one or more regions throughout the body Hormones are relatively slow acting, but can have long-lasting effects Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

(a) Signaling by hormones (b) Signaling by neurons Fig. 40-6 Stimulus Stimulus Endocrine cell Neuron Axon Signal Hormone Signal travels along axon to a specific location. Signal travels everywhere via the bloodstream. Blood vessel Signal Axons Figure 40.6 Signaling in the endocrine and nervous systems Response Response (a) Signaling by hormones (b) Signaling by neurons

cell via the bloodstream. Stimulus Endocrine Hormone Signal travels Fig. 40-6a Stimulus Endocrine cell Hormone Signal travels everywhere via the bloodstream. Blood vessel Figure 40.6a Signaling in the endocrine and nervous systems Response (a) Signaling by hormones

The nervous system transmits information between specific locations The information 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, and endocrine cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

(b) Signaling by neurons Fig. 40-6b Stimulus Neuron Axon Signal Signal travels along axon to a specific location. Signal Axons Figure 40.6b Signaling in the endocrine and nervous systems Response (b) Signaling by neurons

Concept 40.2: Feedback control loops maintain the internal environment in many animals Animals manage their internal environment by regulating or conforming to the external environment Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Regulating and Conforming A regulator uses internal control mechanisms to moderate internal change in the face of external, environmental fluctuation A conformer allows its internal condition to vary with certain external changes Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

(temperature conformer) Fig. 40-7 40 River otter (temperature regulator) 30 Body temperature (°C) 20 Largemouth bass (temperature conformer) 10 Figure 40.7 The relationship between body and environmental temperatures in an aquatic temperature regulator and an aquatic temperature conformer 10 20 30 40 Ambient (environmental) temperature (ºC)

Homeostasis Organisms use homeostasis to maintain a “steady state” or internal balance regardless of external environment In humans, body temperature, blood pH, and glucose concentration are each maintained at a constant level Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Mechanisms of Homeostasis Mechanisms of homeostasis moderate changes in the internal environment For a given variable, fluctuations above or below a set point serve as a stimulus; these are detected by a sensor and trigger a response The response returns the variable to the set point Animation: Negative Feedback Animation: Positive Feedback Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Response: Heater turned off Room temperature decreases Stimulus: Fig. 40-8 Response: Heater turned off Room temperature decreases Stimulus: Control center (thermostat) reads too hot Set point: 20ºC Figure 40.8 A nonliving example of negative feedback: control of room temperature Stimulus: Control center (thermostat) reads too cold Room temperature increases Response: Heater turned on