Chapter 40: Basic Principles Chapter 40: Basic Principles of Animal Form & Functionof Animal Form & Function

Cell size limited byCell size limited by surface area :volumesurface area :volume

Cells must be in aqueous solution for Cells must be in aqueous solution for nutrient & waste exchangenutrient & waste exchange

tissuestissues Groups of cells with common structure & functionGroups of cells with common structure & function Types:Types:

Epithelial Epithelial Cover body, line organs, & body cavitiesCover body, line organs, & body cavities Tightly packed; held together by tight junctionsTightly packed; held together by tight junctions Barrier against microbes, fluid loss, or mechanical Barrier against microbes, fluid loss, or mechanical

injuryinjury Categorized by numbers of layers & shape Categorized by numbers of layers & shape

ShapeShape Cuboidal- dice-likeCuboidal- dice-like Columnar- brick-likeColumnar- brick-like Squamous- floor tile-likeSquamous- floor tile-like

Types:Types: Simple epitheliumSimple epithelium

Single layer Single layer ““leaky”- allows for diffusionleaky”- allows for diffusion Ex. Alveoli, capillariesEx. Alveoli, capillaries

Stratified epitheliumStratified epithelium Multiple tiers of cellsMultiple tiers of cells

Glandular epithelia Glandular epithelia Absorb or secrete solutionsAbsorb or secrete solutions Ciliated- lining of respiratory systemCiliated- lining of respiratory system Mucus membrane- oral cavity, nasal passages; Mucus membrane- oral cavity, nasal passages;

moisten & lubricatemoisten & lubricate

Connective tissueConnective tissue Bind to & support other tissuesBind to & support other tissues Sparse number of cells scattered Sparse number of cells scattered

through an extra-cellular matrixthrough an extra-cellular matrix Consist of 3 protein fibersConsist of 3 protein fibers

Collagen: non-elastic; strength; resists Collagen: non-elastic; strength; resists stretchingstretching

Elastin: rubbery; retain shapeElastin: rubbery; retain shape Reticular: branched to connect adjacent Reticular: branched to connect adjacent

tissuestissues

Types of connective tissueTypes of connective tissue Loose connectiveLoose connective

Fibroblasts- secrete proteins of extracellular Fibroblasts- secrete proteins of extracellular fibersfibers

Macrophages- immune responseMacrophages- immune response AdiposeAdipose

Storage of fatStorage of fat For energy & insulationFor energy & insulation

Fibrous connectiveFibrous connective Tendons- attach muscle to boneTendons- attach muscle to bone Ligaments- attach bone to boneLigaments- attach bone to bone

CartilageCartilage Part of all of skeleton in vertebratesPart of all of skeleton in vertebrates

BoneBone Mineralized connective tissueMineralized connective tissue

BloodBlood Plasma- liquid matrix of water, salts, & Plasma- liquid matrix of water, salts, &

proteinsproteins Leukocytes- white blood cellsLeukocytes- white blood cells Erythrocytes- red blood cellsErythrocytes- red blood cells Platelets- blood clottingPlatelets- blood clotting Form in red bone marrow at ends of long Form in red bone marrow at ends of long

bonebone

Nervous tissueNervous tissue Sense stimuli & transmit signals within the animalSense stimuli & transmit signals within the animal Neuron=nerve cell specialized to conduct impulsesNeuron=nerve cell specialized to conduct impulses

dendrites= extensions that conduct impulses to dendrites= extensions that conduct impulses to the cell bodythe cell body

Axons= extensions that transmit impulses away Axons= extensions that transmit impulses away from the cell bodyfrom the cell body

Muscle tissueMuscle tissue Capable of contraction when stimulatedCapable of contraction when stimulated Consists of contractile proteins actin & myosinConsists of contractile proteins actin & myosin Types:Types:

Skeletal muscleSkeletal muscle Attached to bone by tendons Attached to bone by tendons VoluntaryVoluntary Striated patternStriated pattern

Cardiac muscleCardiac muscle Contractile walls of heartContractile walls of heart Striated patternStriated pattern

Smooth muscleSmooth muscle Lines walls of internal organsLines walls of internal organs InvoluntaryInvoluntary Tapered, non-striated appearanceTapered, non-striated appearance

Organ systemsOrgan systems Are inter-dependant; organs with Are inter-dependant; organs with

separate functions act in coordinated separate functions act in coordinated mannermanner

Tissues organized into organs except Tissues organized into organs except in simple organismsin simple organisms

Some organs are layered (ex. Some organs are layered (ex. Vertebrate stomach)Vertebrate stomach)

Mesentery=sheets of connective Mesentery=sheets of connective tissue in which organs are suspendedtissue in which organs are suspended

BioenergeticsBioenergetics

Flow of energy through an organismFlow of energy through an organism Limits animal’s behavior, growth, & Limits animal’s behavior, growth, &

reproductionreproduction Determines food requirementsDetermines food requirements

Animals are heterotrophsAnimals are heterotrophsEnergy InputEnergy Input(ingested food)(ingested food)

DigestionDigestion(enzymatic hydrolysis of food)(enzymatic hydrolysis of food)

AbsorptionAbsorption(small energy molecules by body cells)(small energy molecules by body cells)

CatabolismCatabolism(cellular respiration & fermentation harvest chemical (cellular respiration & fermentation harvest chemical

energy from food molecules)energy from food molecules)

some some Energy Stored Energy Stored in ATPin ATP some some Energy Lost Energy Lost as heat as heat is to is to surroundingssurroundings

Energy UsedEnergy Used - chemical energy of ATP powers cellular work. - chemical energy of ATP powers cellular work. After the needs of staying alive are met, leftover chemical After the needs of staying alive are met, leftover chemical energy and carbon skeletons from food molecules can be energy and carbon skeletons from food molecules can be used in biosynthesis. used in biosynthesis.

Energy LostEnergy Lost - cellular work generates heat, which is lost to - cellular work generates heat, which is lost to surroundings or used to maintain body temperature surroundings or used to maintain body temperature (endotherms)(endotherms)

Metabolic rateMetabolic rate Total amount of energy an animal uses to stay Total amount of energy an animal uses to stay

alivealive 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 timeAmount of heat loss per unit of time

Heat loss is by-product of cellular workHeat loss is by-product of cellular work Heat loss is measured with calorimeterHeat loss is measured with calorimeter

Range of metabolic ratesRange 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 Maximal rates occur during peak activity (all out

exercise)exercise) Vary depending on:Vary depending on:

Age, sex, sizeAge, sex, size Body and environmental temperatureBody and environmental temperature Food quality & quantityFood quality & quantity Amount of available oxygenAmount of available oxygen Hormonal balanceHormonal balance Time of day & activity levelTime of day & activity level

EndothermsEndotherms Animals that generate their own Animals that generate their own

body heat metabolicallybody heat metabolically Includes birds, mammalsIncludes birds, mammals Many endotherms are homeothermicMany endotherms are homeothermic

Maintain temperature within narrow Maintain temperature within narrow limitslimits

Basal metabolic rateBasal metabolic rate Endothermic animal’s metabolic rate Endothermic animal’s metabolic rate

measured under resting, fasting, & measured under resting, fasting, & stress-free conditionsstress-free conditions

Average BMR for humans:Average BMR for humans: Males….1600-1800 kcal/dayMales….1600-1800 kcal/day Females….1300-1500 kcal/dayFemales….1300-1500 kcal/day

EctothermsEctotherms Animals that acquire most of their Animals that acquire most of their

body heat from the environment body heat from the environment Includes fish, amphibian, reptiles, & Includes fish, amphibian, reptiles, &

invertebratesinvertebrates Minimal metabolic rate must be Minimal metabolic rate must be

determined at a specific temperaturedetermined at a specific temperature Standard metabolic rate (SMR)Standard metabolic rate (SMR)

Ectotherm’s minimal metabolic rate Ectotherm’s minimal metabolic rate measured under controlled temperature as measured under controlled temperature as well as resting, fasting, & stress-free well as resting, fasting, & stress-free conditionsconditions

Metabolic rate/gram is inversely Metabolic rate/gram is inversely related to body size among similar related to body size among similar animalsanimals Smaller animals consume more Smaller animals consume more

calories/gram than larger animalscalories/gram than larger animals Correlated to higher metabolic rate & Correlated to higher metabolic rate &

need for faster oxygen delivery to need for faster oxygen delivery to tissuestissues

Small animals have a higherSmall animals have a higher Breathing rateBreathing rate Blood volumeBlood volume Heart rateHeart rate

Inverse relationship holds true for both Inverse relationship holds true for both endotherms & ectothermsendotherms & ectotherms

Body plans & the external Body plans & the external environmentenvironment

single celled organismssingle celled organisms must have sufficient surface area of plasma must have sufficient surface area of plasma

membrane to service the entire volume of membrane to service the entire volume of cytoplasmcytoplasm

Multi-cellular animals body planMulti-cellular animals body plan two-layered sac ... e.g. coelenterates / cnideriatwo-layered sac ... e.g. coelenterates / cnideria flat-shaped body ... max. surface area exposed flat-shaped body ... max. surface area exposed

to water (e.g. the flat worms)to water (e.g. the flat worms) most complex animals have a small SA : most complex animals have a small SA :

volume and lack adequate exchange area on volume and lack adequate exchange area on the the outerouter surface but….. surface but….. Highly folded, moist, Highly folded, moist, internalinternal surfaces for surfaces for

material exchange.material exchange. Circulatory system shuttles materials between the Circulatory system shuttles materials between the

inner & outer surfaces inner & outer surfaces

Regulating the internal Regulating the internal environmentenvironment

MechanismsMechanisms interstitial fluidinterstitial fluid Regulators: Regulators:

Internal controls used to maintain homeostasis Internal controls used to maintain homeostasis if external environment changesif external environment changes

Conformers:Conformers: internal conditions vary with external internal conditions vary with external

environmental changesenvironmental changes**animal may be regulate according to 1 variable **animal may be regulate according to 1 variable

& conform to another& conform to another Homeostasis depends on feedback circuits Homeostasis depends on feedback circuits

(i.e. nervous system)(i.e. nervous system) receptorsreceptors - detects internal change - detects internal change control centercontrol center - processes information from - processes information from

receptors & directs the effectors to respondreceptors & directs the effectors to respond effector effector provides a responseprovides a response

feedbackfeedback (common method of regulation (common method of regulation in animals) in animals)

positive feedbackpositive feedback enhancement of a responseenhancement of a response RareRare Ex. Blood clotting, childbirth contractionsEx. Blood clotting, childbirth contractions

negative feedbacknegative feedback reduced responsereduced response examples: insulin regulation in mammal, body examples: insulin regulation in mammal, body

temp. regulationtemp. regulation hypothalamus ... detects high blood hypothalamus ... detects high blood

temperature temperature impulse to sweat gland impulse to sweat gland sweat gland increases output sweat gland increases output evaporative evaporative cooling cooling normal temperature obtainednormal temperature obtained stops sending impulsestops sending impulse

Thermo-regulatorsThermo-regulators Animal maintains internal temperature Animal maintains internal temperature

within a tolerable rangewithin a tolerable range Can be ectotherm or endothermCan be ectotherm or endotherm

PoikilothermPoikilotherm Internal temps vary widely Internal temps vary widely

HomeothermHomeotherm Relatively stable internal tempsRelatively stable internal temps

Modes of heat exchange between Modes of heat exchange between organism & the environment:organism & the environment: ConductionConduction ConvectionConvection RadiationRadiation EvaporationEvaporation

Adaptations for thermo-Adaptations for thermo-regulationregulation

InsulationInsulation Hair, feathers, & fat layersHair, feathers, & fat layers Reduce flow of heat between organism & the Reduce flow of heat between organism & the

environmentenvironment Circulatory adaptationsCirculatory adaptations

Vaso-dilationVaso-dilation Increase diameter of surface blood vesselsIncrease diameter of surface blood vessels Warms skin & transfers heat to environment by Warms skin & transfers heat to environment by

radiation, convection, & conductionradiation, convection, & conduction VasoconstrictionVasoconstriction

Decreases diameter of surface blood cellsDecreases diameter of surface blood cells Reduces blood flow to the surfaceReduces blood flow to the surface Retain heatRetain heat

Countercurrent heat exchangeCountercurrent heat exchange Arrangement of blood vessels to help trap heat in Arrangement of blood vessels to help trap heat in

body core body core Reduces heat lossReduces heat loss

Cooling by evaporative heat lossCooling by evaporative heat loss SweatingSweating BreathingBreathing PantingPanting Increase mucus productionIncrease mucus production Spread of saliva on body surfaceSpread of saliva on body surface

Behavioral responsesBehavioral responses Move between shaded & sunny locales Move between shaded & sunny locales HuddlingHuddling ShiveringShivering TorporTorpor

Hibernation- long term (cold)Hibernation- long term (cold) Estivation/summer torpor- slow in summer Estivation/summer torpor- slow in summer

to survive high temps & low water levelsto survive high temps & low water levels Daily torpor- based on feeding timesDaily torpor- based on feeding times

AcclimatizationAcclimatization Physiological response occurring over Physiological response occurring over

days or weeks to environmental days or weeks to environmental temperature changetemperature change

Occurs by:Occurs by: Increasing or decreasing insulation (fur or Increasing or decreasing insulation (fur or

fat)fat) Changing functional enzymesChanging functional enzymes Changing proportions of unsaturated fats & Changing proportions of unsaturated fats &

cholesterol in the cell membranecholesterol in the cell membrane Rapid adjustments to temperature change Rapid adjustments to temperature change

involve stress-induced proteinsinvolve stress-induced proteins i.e. heat shock proteins- protect other proteins i.e. heat shock proteins- protect other proteins

from denaturization at high temperaturesfrom denaturization at high temperatures