Mrs. Valdes AP Biology Chapter 40: Basic Principles of Form and Function - PowerPoint Presentation

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Mrs. Valdes

AP Biology

Chapter 40: Basic Principles of Form and Function

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Overview: Diverse Forms, Common Challenges

Anatomy

:

study of biological form

of

organism

Physiology: study of biological functions organism performs Comparative study of animals reveals form and function closely correlated… you know this!

Slide3

Concept 40.1: Animal form and function

correlated

at

ALL levels

of organization

B

ody plans evolved

and determined by genomePhysical Constraint: ability to perform certain actions depends on animal’s

shape, size, and environmentEvolutionary convergence reflects different species’ adaptations to similar environmental challengePhysical laws impose constraints on animal size and

shapeEnvironment Exchange:

animal

’

s

size and shape directly affect how it exchanges energy and materials with its surroundings

occurs as substances dissolved in aqueous medium diffuse and are transported across cells’ plasma membranesSingle-celled: protist living in water has sufficient surface area of plasma membrane to service its entire volume of cytoplasmMulticellular organisms: some have sac body plan; body walls only two cells thick, facilitating diffusion of materialsMore complex organisms: highly folded internal surfaces for exchanging materialsVertebrates: space between cells filled with interstitial fluidallows for movement of material into and out of cellsA complex body plan helps animal in variable environment to maintain stable internal environment

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Cells > Tissues > Organs > Organ System

Tissues classified

into four main categories: epithelial, connective, muscle, and nervous

Hierarchical Organization of Body Plans

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Epithelial Tissue

Epithelial

tissue:

covers

outside

of body

and lines organs and cavities within bodycontains cells closely joinedshape of epithelial cells:

cuboidal (like dice) columnar (like bricks on end)squamous

(like floor tiles)arrangement of epithelial

cells:

simple

(single cell layer

) stratified (multiple tiers of cells) pseudostratified (a single layer of cells of varying length)

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Connective Tissue

mainly

binds and supports

other

tissues

contains

sparsely packed cells scattered through

extracellular matrixmatrix consists of fibers in liquid, jellylike, or solid foundation Types of connective tissue

fiber:Collagenous fibers provide strength and flexibilityElastic fibers stretch and snap back to original lengthReticular fibers join connective tissue to adjacent tissues

Connective cells:

Fibroblasts

:

secrete the protein of extracellular fibers

Macrophages: involved in immune systemFibers and foundation combine to form six major types of connective tissue: Loose connective tissue: binds epithelia to underlying tissues; holds organs in placeCartilage: strong and flexible support materialFibrous connective tissue: found in tendons (attach muscles to bones) and ligaments (connect bones at joints)Adipose tissue: stores fat for insulation and fuelBlood: composed of blood cells and cell fragments in blood plasmaBone: mineralized and forms skeleton

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Fig. 40-5c

Connective Tissue

Collagenous fiber

Loose

connective

tissue

Elastic fiber

120 µm

Cartilage

Chondrocytes

100 µm

Chondroitin

sulfate

Adipose

tissue

Fat droplets

150 µm

White blood cells

55 µm

Plasma

Red blood

cells

Blood

Nuclei

Fibrous

connective

tissue

30 µm

Osteon

Bone

Central canal

700 µm

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Fig. 40-5d

Collagenous fiber

120 µm

Elastic fiber

Loose connective tissue

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Fig. 40-5e

Nuclei

Fibrous connective tissue

30 µm

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Fig. 40-5f

Osteon

Central canal

Bone

700 µm

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Fig. 40-5g

Chondrocytes

Chondroitin

sulfate

Cartilage

100 µm

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Fig. 40-5h

Fat droplets

Adipose tissue

150 µm

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Fig. 40-5i

White blood cells

Plasma

Red blood

cells

55 µm

Blood

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Muscle Tissue

consists

of long cells called

muscle fibers, which contract in response to nerve signals

Types:

Skeletal muscle

: or striated muscle, responsible for voluntary movementSmooth muscle: responsible for involuntary body activities

Cardiac muscle: responsible for contraction of the heart

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Fig. 40-5j

Muscle Tissue

50 µm

Skeletal

muscle

Multiple

nuclei

Muscle fiber

Sarcomere

100 µm

Smooth

muscle

Cardiac muscle

Nucleus

Muscle

fibers

25 µm

Nucleus

Intercalated

disk

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Fig. 40-5k

Skeletal muscle

Multiple

nuclei

Muscle fiber

Sarcomere

100 µm

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Fig. 40-5l

Smooth muscle

Nucleus

Muscle

fibers

25 µm

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Fig. 40-5m

Nucleus

Intercalated

disk

Cardiac muscle

50 µm

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Nervous Tissue

senses

stimuli and transmits signals throughout the animal

Contains

:

Neurons

: nerve cells, that transmit nerve impulsesGlial cells, or glia: help nourish, insulate, and replenish neurons

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Coordination and Control

D

epend

on

endocrine

system and

nervous systemEndocrine system: transmits hormones to receptive cells throughout

body via bloodhormone may affect one or more regions throughout bodyHormones relatively slow acting, but can have long-lasting effectsN

ervous system: transmits information between specific locationsinformation conveyed depends on a signal’s pathway

NOT type of signalNerve signal transmission is FAST

Nerve impulses

received

by neurons, muscle cells, and endocrine

cells

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Concept 40.2: Feedback control loops maintain

internal environment in many animals

Animals manage

internal environment by regulating or conforming to

external

environment

Regulator: uses internal control mechanisms to moderate internal

change in face of external, environmental fluctuationConformer

: allows internal condition to vary with certain external

changes

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Homeostasis

Maintain “steady state

”

or internal balance regardless of external environment

Humans:

body temperature, blood pH, and glucose concentrationMechanisms: moderate changes in internal environmentFor

given variable, fluctuations above/below set point serve as stimulus that are detected by sensor

and trigger responseresponse returns the variable to the set pointFeedback Loops:Negative feedback

Helps return variable to either normal

range

or

a set point

Most homeostatic control systems function by negative feedback, where buildup of the end product shuts the system offPositive feedback occur in animals, but do not usually contribute to homeostasisSet points and normal ranges change with age or show cyclic variationAcclimatization: homeostasis can adjust to changes in external environment

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Concept 40.3: Homeostatic processes for thermoregulation involve form, function,

& behavior

Thermoregulation

:

process by which animals maintain

internal

temperature within tolerable rangeEndotherm: animal generates heat by metabolism;

Ex: birds and mammalsactive at a greater range of external temperaturesmore energetically expensive Homeotherm: body temperature relatively constant

Ectotherm: animal gains heat from external sources; include most invertebrates, fishes, amphibians, and non-avian reptiles

tolerate greater variation in internal temperature, while endotherms are

Poikilotherm

:

body temperature varies

with its environment,

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Balancing Heat Loss

& Gain

Organisms exchange heat by

:

conduction

convection

radiationevaporationHeat regulation in mammals involves integumentary system

: skin hair nails General adaptations:

InsulationCirculatory adaptationsCooling by evaporative heat lossBehavioral responsesAdjusting metabolic heat production

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Insulation

M

ajor

thermoregulatory adaptation in mammals and birds

Ex: Skin

, feathers, fur, and blubber

Reduce heat flow between an animal and its environment

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Regulation of blood flow near

body

surface significantly affects thermoregulation

Many endotherms and some

ectotherms

alter amount of blood flowing between body core and skinVasodilation: blood flow in skin increases

increase heat lossVasoconstriction: blood flow in skin decreases decrease heat lossCountercurrent exchange:

important mechanism for reducing heat loss; transfer heat between fluids flowing in opposite directionsarrangement of blood vessels in marine

mammals and birdsSome bony fishes and sharks

Many

endothermic insects

use to maintain high

temperature in

thoraxCirculatory Adaptations

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Cooling by Evaporative Heat Loss

A

nimals lose heat through evaporation of water in sweat

Panting increases cooling effect in birds and many mammals

Sweating/bathing moistens skin, helping cool animal down

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E

ndotherms

and

ectotherms

use behavioral responses to control body temperature

T

errestrial invertebrates have postures to minimize

or maximize absorption of solar heatEx: Dragonfly obelisk to minimize sun exposure Behavioral Responses

Slide29

Adjusting Metabolic Heat Production

Some animals

regulate

body temperature by adjusting

rate

of metabolic heat production

Heat production increased by muscle activity like moving or shiveringSome ectotherms

shiver to increase body temperature

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Birds and mammals

vary insulation

to acclimatize to seasonal temperature changes

Temps subzero:

some

ectotherms produce “antifreeze” compounds to prevent ice formation in their cellsThermoregulation

: controlled by hypothalamusHypothalamus: triggers heat loss or heat generating mechanismsFever: result of change

to set point for biological thermostatAcclimatization in Thermoregulation

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Concept 40.4: Energy requirements

related

to animal size, activity, and environment

Bioenergetics

:

overall flow and transformation of energy in an animaldetermines how much food

animal needsrelates to animal’s size, activity, and environmentEnergy Allocation and Use

Animals harvest chemical energy from food Food  ATP  Cellular WorkAfter needs of staying alive met, remaining food molecules

used in biosynthesisBiosynthesis:

includes

body

growth and

repair synthesis of storage material such as fatproduction of gametes

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Metabolic

rate:

amount of energy

animal uses in unit

of time

One way to

measure: determine amount of oxygen consumed OR carbon dioxide producedaffected by many factors besides whether an animal is an endotherm or ectothermsize

activityBasal metabolic rate (BMR): metabolic rate of endotherm at rest at “comfortable”

temperatureStandard metabolic rate (SMR): metabolic rate of ectotherm

at rest at specific temperature

Both rates assume

nongrowing

, fasting, and

nonstressed

animalEctotherms have lower metabolic rates than endotherms of comparable sizeQuantifying Energy Use

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Size and Metabolic Rate

Metabolic rate per gram

inversely

related to body size among similar animals

H

igher metabolic rate of smaller animals higher oxygen delivery rate, breathing rate, heart rate, and greater (relative) blood volume, compared with a larger animal

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M

aximum

metabolic rate animal can sustain

inversely related to

duration

of the activity

Activity and Metabolic Rate

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Different species use energy and materials

in

different ways depending on

environment

Use of energy is partitioned to BMR (or SMR), activity, thermoregulation, growth, and reproduction

Energy Budgets

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Torpor and Energy Conservation

Torpor

:

physiological state in which activity is low and metabolism decreases

enables

animals to save energy while avoiding difficult and dangerous conditionsHibernation: long-term torpor; adaptation to winter cold and food

scarcityEstivation: summer torpor; enables animals to survive long periods of high temperatures and scarce water suppliesDaily torpor:

exhibited by many small mammals and birds; seems adapted to feeding patterns

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You should now be able to:

Distinguish among the following sets of terms: collagenous, elastic, and reticular fibers; regulator and conformer; positive and negative feedback; basal and standard metabolic rates; torpor, hibernation, estivation, and daily torpor

Relate structure with function and identify diagrams of the following animal tissues: epithelial, connective tissue (six types), muscle tissue (three types), and nervous

tissue

Compare and contrast the nervous and endocrine systems

Define thermoregulation and explain how endotherms and

ectotherms manage their heat budgets

Describe how a countercurrent heat exchanger may function to retain heat within an animal bodyDefine bioenergetics and biosynthesisDefine metabolic rate and explain how it can be determined for

animals