Chapter 40: Basic Principles of Animal Form & Function Cell size limited by Cell size limited by surface area :volume surface area :volume Cells must be in aqueous solution for nutrient & waste exchange Cells must be in aqueous solution for nutrient & waste exchange

tissues Groups of cells with common structure & function Groups of cells with common structure & function Types: Types: Epithelial Epithelial Cover body, line organs, & body cavities Cover body, line organs, & body cavities Tightly packed; held together by tight junctions Tightly packed; held together by tight junctions Barrier against microbes, fluid loss, or mechanical injury Barrier against microbes, fluid loss, or mechanical injury Categorized by numbers of layers & shape Categorized by numbers of layers & shape Shape Shape Cuboidal- dice-like Cuboidal- dice-like Columnar- brick-like Columnar- brick-like Squamous- floor tile-like Squamous- floor tile-like Types: Types: Simple epithelium Simple epithelium Single layer Single layer “leaky”- allows for diffusion “leaky”- allows for diffusion Ex. Alveoli, capillaries Ex. Alveoli, capillaries Stratified epithelium Stratified epithelium Multiple tiers of cells Multiple tiers of cells Glandular epithelia Glandular epithelia Absorb or secrete solutions Absorb or secrete solutions Ciliated- lining of respiratory system Ciliated- lining of respiratory system Mucus membrane- oral cavity, nasal passages; moisten & lubricate Mucus membrane- oral cavity, nasal passages; moisten & lubricate

Connective tissue Connective tissue Bind to & support other tissues Bind to & support other tissues Sparse number of cells scattered through an extra-cellular matrix Sparse number of cells scattered through an extra-cellular matrix Consist of 3 protein fibers Consist of 3 protein fibers Collagen: non-elastic; strength; resists stretching Collagen: non-elastic; strength; resists stretching Elastin: rubbery; retain shape Elastin: rubbery; retain shape Reticular: branched to connect adjacent tissues Reticular: branched to connect adjacent tissues

Types of connective tissue Types of connective tissue Loose connective Loose connective Fibroblasts- secrete proteins of extracellular fibers Fibroblasts- secrete proteins of extracellular fibers Macrophages- immune response Macrophages- immune response Adipose Adipose Storage of fat Storage of fat For energy & insulation For energy & insulation Fibrous connective Fibrous connective Tendons- attach muscle to bone Tendons- attach muscle to bone Ligaments- attach bone to bone Ligaments- attach bone to bone Cartilage Cartilage Part of all of skeleton in vertebrates Part of all of skeleton in vertebrates Bone Bone Mineralized connective tissue Mineralized connective tissue Blood Blood Plasma- liquid matrix of water, salts, & proteins Plasma- liquid matrix of water, salts, & proteins Leukocytes- white blood cells Leukocytes- white blood cells Erythrocytes- red blood cells Erythrocytes- red blood cells Platelets- blood clotting Platelets- blood clotting Form in red bone marrow at ends of long bone Form in red bone marrow at ends of long bone

Nervous tissue Nervous tissue Sense stimuli & transmit signals within the animal Sense stimuli & transmit signals within the animal Neuron=nerve cell specialized to conduct impulses Neuron=nerve cell specialized to conduct impulses dendrites= extensions that conduct impulses to the cell body dendrites= extensions that conduct impulses to the cell body Axons= extensions that transmit impulses away from the cell body Axons= extensions that transmit impulses away from the cell body Muscle tissue Muscle tissue Capable of contraction when stimulated Capable of contraction when stimulated Consists of contractile proteins actin & myosin Consists of contractile proteins actin & myosin Types: Types: Skeletal muscle Skeletal muscle Attached to bone by tendons Attached to bone by tendons Voluntary Voluntary Striated pattern Striated pattern Cardiac muscle Cardiac muscle Contractile walls of heart Contractile walls of heart Striated pattern Striated pattern Smooth muscle Smooth muscle Lines walls of internal organs Lines walls of internal organs Involuntary Involuntary Tapered, non-striated appearance Tapered, non-striated appearance

Organ systems Are inter-dependant; organs with separate functions act in coordinated manner Are inter-dependant; organs with separate functions act in coordinated manner Tissues organized into organs except in simple organisms Tissues organized into organs except in simple organisms Some organs are layered (ex. Vertebrate stomach) Some organs are layered (ex. Vertebrate stomach) Mesentery=sheets of connective tissue in which organs are suspended Mesentery=sheets of connective tissue in which organs are suspended

Bioenergetics Flow of energy through an organism Flow of energy through an organism Limits animal’s behavior, growth, & reproduction Limits animal’s behavior, growth, & reproduction Determines food requirements Determines food requirements

Animals are heterotrophs Animals are heterotrophs Energy Input (ingested food) Digestion (enzymatic hydrolysis of food) Absorption (small energy molecules by body cells) Catabolism (cellular respiration & fermentation harvest chemical energy from food molecules) some Energy Stored in ATPsome Energy Lost as heat is to surroundings Energy Used - chemical energy of ATP powers cellular work. Energy Used - chemical energy of ATP powers cellular work. After the needs of staying alive are met, leftover chemical energy and carbon skeletons from food molecules can be used in biosynthesis. Energy Lost - cellular work generates heat, which is lost to surroundings or used to maintain body temperature (endotherms) Energy Lost - cellular work generates heat, which is lost to surroundings or used to maintain body temperature (endotherms)

Metabolic rate Total amount of energy an animal uses to stay alive Total amount of energy an animal uses to stay alive Measured in Calories (kilocalories) Measured in Calories (kilocalories) Calculated by measuring: Calculated by measuring: oxygen used oxygen used Amount of heat loss per unit of time Amount of heat loss per unit of time Heat loss is by-product of cellular work Heat loss is by-product of cellular work Heat loss is measured with calorimeter Heat loss is measured with calorimeter Range of metabolic rates Range of metabolic rates Minimal rate for life support (breathing, sleeping….) Minimal rate for life support (breathing, sleeping….) Maximal rates occur during peak activity (all out exercise) Maximal rates occur during peak activity (all out exercise) Vary depending on: Vary depending on: Age, sex, size Age, sex, size Body and environmental temperature Body and environmental temperature Food quality & quantity Food quality & quantity Amount of available oxygen Amount of available oxygen Hormonal balance Hormonal balance Time of day & activity level Time of day & activity level

Endotherms Animals that generate their own body heat metabolically Animals that generate their own body heat metabolically Includes birds, mammals Includes birds, mammals Many endotherms are homeothermic Many endotherms are homeothermic Maintain temperature within narrow limits Maintain temperature within narrow limits Basal metabolic rate Basal metabolic rate Endothermic animal’s metabolic rate measured under resting, fasting, & stress-free conditions Endothermic animal’s metabolic rate measured under resting, fasting, & stress-free conditions Average BMR for humans: Average BMR for humans: Males… kcal/day Males… kcal/day Females… kcal/day Females… kcal/day

Ectotherms Animals that acquire most of their body heat from the environment Animals that acquire most of their body heat from the environment Includes fish, amphibian, reptiles, & invertebrates Includes fish, amphibian, reptiles, & invertebrates Minimal metabolic rate must be determined at a specific temperature Minimal metabolic rate must be determined at a specific temperature Standard metabolic rate (SMR) Standard metabolic rate (SMR) Ectotherm’s minimal metabolic rate measured under controlled temperature as well as resting, fasting, & stress-free conditions Ectotherm’s minimal metabolic rate measured under controlled temperature as well as resting, fasting, & stress-free conditions

Metabolic rate/gram is inversely related to body size among similar animals Metabolic rate/gram is inversely related to body size among similar animals Smaller animals consume more calories/gram than larger animals Smaller animals consume more calories/gram than larger animals Correlated to higher metabolic rate & need for faster oxygen delivery to tissues Correlated to higher metabolic rate & need for faster oxygen delivery to tissues Small animals have a higher Small animals have a higher Breathing rate Breathing rate Blood volume Blood volume Heart rate Heart rate Inverse relationship holds true for both endotherms & ectotherms Inverse relationship holds true for both endotherms & ectotherms

Body plans & the external environment single celled organisms single celled organisms must have sufficient surface area of plasma membrane to service the entire volume of cytoplasm must have sufficient surface area of plasma membrane to service the entire volume of cytoplasm Multi-cellular animals body plan Multi-cellular animals body plan two-layered sac... e.g. coelenterates / cnideria two-layered sac... e.g. coelenterates / cnideria flat-shaped body... max. surface area exposed to water (e.g. the flat worms) flat-shaped body... max. surface area exposed to water (e.g. the flat worms) most complex animals have a small SA : volume and lack adequate exchange area on the outer surface but….. most complex animals have a small SA : volume and lack adequate exchange area on the outer surface but….. Highly folded, moist, internal surfaces for material exchange. Highly folded, moist, internal surfaces for material exchange. Circulatory system shuttles materials between the inner & outer surfaces Circulatory system shuttles materials between the inner & outer surfaces

Regulating the internal environment Mechanisms Mechanisms interstitial fluid interstitial fluid Regulators: Regulators: Internal controls used to maintain homeostasis if external environment changes Internal controls used to maintain homeostasis if external environment changes Conformers: Conformers: internal conditions vary with external environmental changes internal conditions vary with external environmental changes **animal may be regulate according to 1 variable & conform to another Homeostasis depends on feedback circuits (i.e. nervous system) Homeostasis depends on feedback circuits (i.e. nervous system) receptors - detects internal change receptors - detects internal change control center - processes information from receptors & directs the effectors to respond control center - processes information from receptors & directs the effectors to respond effector provides a response effector provides a response

feedback (common method of regulation in animals) feedback (common method of regulation in animals) positive feedback positive feedback enhancement of a response enhancement of a response Rare Rare Ex. Blood clotting, childbirth contractions Ex. Blood clotting, childbirth contractions negative feedback negative feedback reduced response reduced response examples: insulin regulation in mammal, body temp. regulation examples: insulin regulation in mammal, body temp. regulation hypothalamus... detects high blood temperature  impulse to sweat gland  sweat gland increases output  evaporative cooling  normal temperature obtained  stops sending impulse hypothalamus... detects high blood temperature  impulse to sweat gland  sweat gland increases output  evaporative cooling  normal temperature obtained  stops sending impulse

Thermo-regulators Animal maintains internal temperature within a tolerable range Animal maintains internal temperature within a tolerable range Can be ectotherm or endotherm Can be ectotherm or endotherm Poikilotherm Poikilotherm Internal temps vary widely Internal temps vary widely Homeotherm Homeotherm Relatively stable internal temps Relatively stable internal temps Modes of heat exchange between organism & the environment: Modes of heat exchange between organism & the environment: Conduction Conduction Convection Convection Radiation Radiation Evaporation Evaporation

Adaptations for thermo-regulation Insulation Insulation Hair, feathers, & fat layers Hair, feathers, & fat layers Reduce flow of heat between organism & the environment Reduce flow of heat between organism & the environment Circulatory adaptations Circulatory adaptations Vaso-dilation Vaso-dilation Increase diameter of surface blood vessels Increase diameter of surface blood vessels Warms skin & transfers heat to environment by radiation, convection, & conduction Warms skin & transfers heat to environment by radiation, convection, & conduction Vasoconstriction Vasoconstriction Decreases diameter of surface blood cells Decreases diameter of surface blood cells Reduces blood flow to the surface Reduces blood flow to the surface Retain heat Retain heat Countercurrent heat exchange Countercurrent heat exchange Arrangement of blood vessels to help trap heat in body core Arrangement of blood vessels to help trap heat in body core Reduces heat loss Reduces heat loss

Cooling by evaporative heat loss Cooling by evaporative heat loss Sweating Sweating Breathing Breathing Panting Panting Increase mucus production Increase mucus production Spread of saliva on body surface Spread of saliva on body surface Behavioral responses Behavioral responses Move between shaded & sunny locales Move between shaded & sunny locales Huddling Huddling Shivering Shivering Torpor Torpor Hibernation- long term (cold) Hibernation- long term (cold) Estivation/summer torpor- slow in summer to survive high temps & low water levels Estivation/summer torpor- slow in summer to survive high temps & low water levels Daily torpor- based on feeding times Daily torpor- based on feeding times

Acclimatization Acclimatization Physiological response occurring over days or weeks to environmental temperature change Physiological response occurring over days or weeks to environmental temperature change Occurs by: Occurs by: Increasing or decreasing insulation (fur or fat) Increasing or decreasing insulation (fur or fat) Changing functional enzymes Changing functional enzymes Changing proportions of unsaturated fats & cholesterol in the cell membrane Changing proportions of unsaturated fats & cholesterol in the cell membrane Rapid adjustments to temperature change involve stress-induced proteins Rapid adjustments to temperature change involve stress-induced proteins i.e. heat shock proteins- protect other proteins from denaturization at high temperatures i.e. heat shock proteins- protect other proteins from denaturization at high temperatures