animal bodieschapter 39

organization• constraints on form

• surface area-to-volume ratio• levels of organization

• cells -- tissues -- organs -- organ systems• Tissue organization

• eumetazoa• sponges?

• general tissue types:• epithelial• connective• nervous• muscle

5

1

1

6 150 750

125 1251

6 61.2

Total surface area[Sum of the surface areas(height × width) of all boxessides × number of boxes]

Total volume[height × width × length ×number of boxes]

Surface-to-volume(S-to-V) ratio[surface area ÷ volume]

Surface area increases whiletotal volume remains constant

epithelial tissue• epithelia

• simple• stratified• cell shapes

• cuboidal • columnar • squamous

• joined by tight junctions • basement membrane

connective tissue• connective tissue

• types of fibers• collagenous fibers • elastic fibers• reticular fibers

connective tissue• loose

• packing material of the body• ex. basement

membrane • contains

macrophages and fibroblasts

• adipose —• fat storage

connective tissue• fibrous

• dense• many parallel

collagenous fibers • non-elastic strength...

connective tissue• bone --

• lacunae • osteoblasts

• cartilage • chondrocytes secrete chondroitin. • strong, but flexible support• pads many joints• no blood supply

connective tissue• blood —

• erythrocytes, leukocytes, platelets. • liquid matrix called plasma

nervous tissue• nerves --

• neurons • axons• dendrites

Neuron

AxonSignal

Signal travelsalong axon to

a specificlocation.

Signal

Axons

Response

muscle tissue• skeletal muscle

(striated)• voluntary• multinucleate

• cardiac muscle • involuntary • intercalated discs

• obliquely striated muscle• voluntary • some invertebrates

• smooth muscle • usually involuntary..• tapered cells

homeostasis• homeostatic mechanisms

• modes of dealing with stochastic (random) environment• regulators• conformers

• osmoregulation • excretion • thermoregulation

• homeostatic control mechanisms• negative feedback loops• positive feedback

heat• types of thermoregulation

• poikilothermy -- • homeothermy -- • ectothermy - “cold-blooded?”• endothermy - “warm - blooded?”

• examples of endotherms• mammals • birds• sharks and tuna• insects• dinosaurs? (at

least the therapods)

• examples of ectotherms

• reptiles • insects• fish • spiders • molluscs• annelids

• heat exchange -- gain or loss• effect on metabolic reactions (Q10 effect)• conduction • convection • radiation• evaporation [e.g. sweating, panting, gaping])

Radiation Evaporation

Convection

Conduction

ectothermy• ectotherms

• behavioral control of temperature (allostatic mechanisms) • movement between shade and sun• body orientation

• physiological control of temperature -- • localized vasodilation• color change --

• melanophore cells

endothermy• endotherms

• metabolic heat production --

• methods of metabolic heat production• heat of basal metabolic rate• specific dynamic action of food ration • actions of skeletal muscle• NST

• raising and lowering of hair or feathers• goose bumps• ruffled feathers• traps air

• extreme temperature problems• lower lethal temperature

• positive feedback loop• Q10 effect

• upper lethal temperature • hyperthermia...

• (heat exhaustion, heat stroke -- body stops sweating.)

• Adaptation to “out of range” conditions• torpor • hibernation

• rodents, bears?, etc • aestivation • daily torpor