levels of organization life is built on successive levels of increasing complexity: chemical (or...
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Levels of Organization• Life is built on successive levels of
increasing complexity:• Chemical (or Molecular)• Cellular• Tissue• Organ• Organ System• Organism
OrganismLevel
Integumentary
SkeletalMuscular
NervousEndocrine
CardiovascularLymphatic
RespiratoryDigestive
Urinary
Reproductive
OrganLevel
Theheart
Cardiacmuscletissue
Tissue Level
Cellular Level
Heartmuscle
cell
Protein filaments
Complex proteinmolecule
Atoms incombination
Chemical orMolecular Level
OrganSystem Level
Overview of Organ Systems• The human body is arranged in 11
organ systems:• Integumentary• Skeletal• Muscular• Nervous• Endocrine
• Cardiovascular• Lymphatic• Respiratory• Digestive• Urinary• Reproductive
The Integumentary System
Figure 1-2(a)
The Skeletal System
Figure 1-2(b)
The Muscular System
Figure 1-2(c)
The Nervous System
Figure 1-2(d)
The Endocrine System
Figure 1-2(e)
The Cardiovascular System
Figure 1-2(f)
The Lymphatic System
Figure 1-2(g)
The Respiratory System
Figure 1-2(h)
The Digestive System
Figure 1-2(i)
The Urinary System
Figure 1-2(j)
Male Reproductive System
Figure 1-2(k)
Female Reproductive System
Figure 1-2(l)
Introduction to Organ Systems
• The body can be divided into 11 organ systems, but all work together and the boundaries between them aren’t absolute.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Homeostatic Regulation• Homeostasis• Maintains stable internal conditions
• Temperature• Ionic concentrations• Blood sugar levels, etc.
• Utilizes negative feedback mechanisms
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Homeostatic Regulation• Regulation depends on:
• Receptor sensitive to a particular stimulus• Effector that affects the same stimulus
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
RECEPTOR
Thermometer
STIMULUS:Room temperature
rises
Normalconditiondisturbed
HOMEOSTASISNormalroom
temperature
RESPONSE:Room temperature
dropsNormalconditionrestored
EFFECTOR
Air conditionerturns on
Sendscommands
to
Informationaffects
CONTROL CENTER(Thermostat)
20o 30o 40o
Homeostatic Regulation• Negative Feedback:
• Variation outside normal limits triggers automatic corrective response
• Response negates disturbance
RECEPTOR
Body’stemperature
sensorsSTIMULUS
Body temperaturerises above 37.2oC(99oF)
RESPONSE
Increased blood flowto skinIncreased sweatingStimulus removedHomeostasis restored
Controlmechanismwhen body
temperaturerises
EFFECTOR
Blood vesselsand sweat
glands in skin
Negativefeedback
Sendscommands
to
Informationaffects
Informationaffects
CONTROLCENTER
Thermoregulatorycenter in brain
Sendscommands
to
EFFECTOR
Blood vesselsand sweat glands
in skinSkeletal muscles
Negativefeedback
Controlmechanismwhen body
temperaturefalls
RECEPTOR
Body’stemperature
sensors STIMULUS
Body temperaturefalls below 37.2oC(99oF)
RESPONSE
Decreased blood flowto skinDecreased sweatingShiveringStimulus removedHomeostasis restored
Homeostatic Regulation•Positive Feedback:• Stimulus produces response that reinforces the
stimulus• Response rapidly completes critical process
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Homeostatic Regulation• Homeostasis and Disease • Failure of homeostatic regulation• Symptoms appear• Organ system malfunction
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
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