Basic Principles of Animal Form & Function

Chapter 40

Anatomy & Physiology

• Anatomy– Biological form

• Physiology– Biological function

• Why do animals have such various appearances when they have such similar demands placed on them?

Physical constraints

• Water– Shapes of animals that are swimmers– Why streamlined?

• Size– Size of skeleton– Size of muscles– Relation to speed of organism

Exchange with the environment

Rate of exchange proportional to surface area

Amount of materials that must be exchanged is proportional to volume

Differences in unicellular vs. multicellular organisms

Interstitial fluid

Fig. 40-4

0.5 cmNutrients

Digestivesystem

Lining of small intestine

MouthFood

External environment

Animalbody

CO2 O2

Circulatorysystem

Heart

Respiratorysystem

Cells

Interstitialfluid

Excretorysystem

Anus

Unabsorbedmatter (feces)

Metabolic waste products(nitrogenous waste)

Kidney tubules

10 µm

50 µ

m

Lung tissue

Hierarchical Organization

Cells Tissues Organs Organ System

Digestive Circulatory Respiratory Immune Excretory Endocrine Reproductive Nervous Skeletal Muscular Integumentary

Organism

Epithelial Tissue Sheets of tightly packed cells Cells joined tightly together with little material

between them Functions

Protection Absorption or secretion of chemicals Lining of organs

Free surface Exposed to air or fluid

Basement membrane Extracellular matrix that cells at base of barrier are

attached

Classification of Epithelial tissue

Number of cell layers Simple epithelial

Single layer of cells Stratified epithelial

Multiple tiers of cells Pseudostratified epithelial

Single-layered but appears stratified Shape of cells

Cuboidal Columnar Squamous

Epithelial Tissue

Epithelial Tissue

Cuboidalepithelium

Simplecolumnarepithelium

Pseudostratifiedciliated

columnarepithelium

Stratifiedsquamousepithelium

Simplesquamousepithelium

Connective Tissue• Cells spread out scattered through extracellular matrix

– Substances secreted by connective tissue cells– Web of fibers embedded in foundation

• Structure– Protein

• Function– Bind and support other cells

• Fibroblasts– Secrete protein of extracellular fibers

• Macrophages– Engulf bacteria & dead cells– Defense

Classification of connective tissue Collagenous fibers

Made of collagen Nonelastic fibers Do not tear easily

Elastic fibers Long threads Made of elastin Rubbery

Reticular fibers Very thin and branched Collagen Tightly woven fibers Joins connective tissue to adjacent tissues

Types of Connective Tissue

• Loose Connective Tissue– Most widespread– All 3 fibers– Bind epithelium & hold organs in place

• Fibrous Connective Tissue– Mostly collagenous fibers– Parallel fibers– Nonelastic strength– Tendons and ligaments

Types of Connective Tissue• Bone

– Mineralized connective tissue– Osteoblasts– Hard mineral and flexible collagen– Osteons

• Concentric layers of mineralized matrix

• Cartilage– Mainly collagenous fibers in rubbery matrix– Chondrocytes – Abundant in embryo skeletons

Types of Connective Tissue

Adipose Fat Loose connective tissue Cushions, insulates, stores fuel

Blood Liquid extracellular matrix (plasma) Erythrocytes Leukocytes Platelets

Connective Tissue

Fig. 40-5c

Connective Tissue

Collagenous fiber

Looseconnective

tissue

Elastic fiber12

0 µ

m

Cartilage

Chondrocytes

10

0 µ

m

Chondroitinsulfate

Adiposetissue

Fat droplets

15

0 µ

m

White blood cells

55

µm

Plasma Red bloodcells

Blood

Nuclei

Fibrousconnective

tissue

30

µm

Osteon

Bone

Central canal

70

0 µ

m

Muscle Tissue Contract when stimulated Contractile proteins

Actin & myosin Skeletal muscle

Voluntary muscle Striated

Cardiac muscle Heart Striated, intercalated discs Involuntary

Smooth muscle No striations Lines walls of organs Involuntary

Fig. 40-5j

Muscle Tissue

50 µmSkeletalmuscle

Multiplenuclei

Muscle fiber

Sarcomere

100 µm

Smoothmuscle

Cardiac muscle

Nucleus

Musclefibers

25 µm

Nucleus Intercalateddisk

Nervous Tissue

Receives stimulus and transmits signals Glial cells

Nourish, insulate, replenish neurons Neuron

Nerve cell Cell body with 2 or more extensions

Axons Transmit signals

Dendrites Receive signals

Fig. 40-5n

Glial cells

Nervous Tissue

15 µm

Dendrites

Cell body

Axon

Neuron

Axons

Blood vessel

40 µm

Coordination and Control in Animals

• Endocrine System– Signaling molecules in bloodstream– Coordinates gradual changes

• Growth, development, reproduction, digestion– Hormones

• Only picked up by cells with the correct receptors• Slow acting but long lasting

• Nervous System– Impulse travels along target cell only– Transmission is very fast and short lasting– Immediate response

• Locomotion, behavior

Homeostasis• Negative feedback

– Change in environment triggers control mechanism to turn off stimulus

– Prevent small changes to become big problems– Most body processes

• Sweating

• Positive feedback– Change in environment triggers control

mechanism to increase stimulus– Childbirth

Fig. 40-UN1

Homeostasis

Stimulus:Perturbation/stress

Response/effector

Control center

Sensor/receptor

Thermoregulation

• Five general adaptations help animals thermoregulate:– Insulation– Circulatory adaptations– Cooling by evaporative heat loss– Behavioral responses– Adjusting metabolic heat production

Fig. 40-12

Canada goose Bottlenosedolphin

Artery

Artery

Vein Vein

Blood flow

33º35ºC

27º30º

18º20º

10º 9º

Metabolic Rate Amount of energy an animal uses in a unit of time Measured in calories or Joules Calculated – heat loss, O2 consumed, CO2 produced, food

consumption Endothermic

Warm-blooded Heat generated by metabolism Requires lots of energy

Exothermic Cold-blooded Requires less energy Incapable of intense activity for long period of time

Fig. 40-17

Organic moleculesin foodExternal

environment

Animalbody Digestion and

absorption

Nutrient moleculesin body cells

Carbonskeletons

Cellularrespiration

ATP

Heat

Energy lostin feces

Energy lost innitrogenous

waste

Heat

Biosynthesis

Heat

Heat

Cellularwork

Fig. 40-20

An

nu

al e

ner

gy

exp

end

itu

re (

kcal

/hr)

60-kg female humanfrom temperate climate

800,000Basal

(standard)metabolism

ReproductionThermoregulation

Growth

Activity

340,000

4-kg male Adélie penguinfrom Antarctica (brooding)

4,000

0.025-kg female deer mousefrom temperateNorth America

8,000

4-kg female easternindigo snake

Endotherms Ectotherm

Metabolic rate (cont)

Metabolic rate is inversely proportional to body size

Basal metabolic rate Metabolic rate of nongrowing endotherm at

rest, empty stomach, no stress Human average = 1600 – 1800 kCal per day

for males; 1300-1500 kCal per day for females Standard metabolic rate

Metabolic rate of resting, fasting, non-stressed ectotherm

Alligator = 60 kCal per day

Metabolic Rate (cont)

• Maximum metabolic rate = peak activity times

• Maximum rate = inversely proportional to duration of activity

• Sustained activity depends on ATP supply and respiration rate

• Age, sex, size, temperature, quality & quantity of food, activity level, oxygen availability, hormonal balance, time of day all affect metabolic rate

Fig. 40-19

Elephant

Horse

HumanSheep

DogCat

RatGround squirrel

MouseHarvest mouse

Shrew

Body mass (kg) (log scale)B

MR

(L

O2/h

r) (

Iog

sca

le)

10–3 10–210–2

10–1

10–1

10

10

1

1 102

102

103

103

(a) Relationship of BMR to body size

Shrew

Mouse

Harvest mouse

Sheep

Rat CatDog

Human

Horse

Elephant

BM

R (

L O

2/h

r) (

per

kg

)

Ground squirrel

Body mass (kg) (log scale)10–3 10–2 10–1 1 10 102 103

0

1

2

3

4

5

6

8

7

(b) Relationship of BMR per kilogram of body mass to body size