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