lecture 3 homeostatis
TRANSCRIPT
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Organ system inter-relationship
Necessary Life Functions
Survival NeedsHomeostasis
Homeostasis control Mechanism
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OrganOrganSystemsSystemsInterrelationshipsInterrelationships
The integumentary system protects the bodyfrom the external environment
Digestive and respiratory systems, in contact
with the external environment, take innutrients and oxygen.
Nutrients and oxygen are distributed by the
blood
Metabolic wastes are eliminated by the
urinary and respiratory systems
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Necessary Life FunctionsNecessary Life Functions
Maintain Boundaries The internal environment remains distinct from
the external environment, eg
Cellular Level plasma membranes Organism Level skin
Movement
Locomotion
Movement of substances
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Necessary Life FunctionsNecessary Life Functions
Responsiveness
Ability to sense changes in theenvironment and respond to them.
DigestionBreak-down and delivery of nutrients
Metabolism all the chemical reactionsthat occur within the body
Production of energy
Making body structures
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Necessary Life FunctionsNecessary Life Functions
Excretion Elimination of waste from metabolic
reactions
Reproduction Production of future generation
Growth
Increasing of cell size and number
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Survival NeedsSurvival Needs
Nutrients
Chemicals for energy and cell building
Includes carbohydrates, proteins, lipids,vitamins, and minerals
Oxygen
Required for metabolic reactions
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Survival NeedsSurvival Needs Water
6080% of body weight
Provides necessary environment formetabolic reactions
Stable body temperature
Necessary for metabolic reactions to occur
at life sustaining rate Atmospheric pressure
Required for normal breathing and gas
exchange in lungs
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HomeostasisHomeostasis
Maintenance of a stable internal environmentin an ever changing out side world
The internal environment of the body is in a
dynamic state of equilibrium Homeostasis must be maintained for normal
body functioning and to sustain life
Homeostatic imbalance a disturbance inhomeostasis resulting in disease
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Maintaining HomeostasisMaintaining Homeostasis
The body communicates through neuraland hormonal control systems to maintainhomeostasis.
The three interdependent components ofcontrol mechanism include:
1. Receptor
2. Control Center
3. Effector
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Maintaining HomeostasisMaintaining Homeostasis
1- Receptor Monitors the environment and
responds to changes (stimuli)
2- Control centerDetermines set point at which variable is
maintained.
Analyzes information
Determines appropriate response
3- Effector
Provides a means for response to the stimulus
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Maintaining HomeostasisMaintaining Homeostasis
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Feedback MechanismsFeedback Mechanisms
Negative feedback Positive feedback
Negative feedback
Includes most homeostatic controlmechanisms
Shuts off the original stimulus, or reducesits intensity
Works like a household thermostat
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Negative feedback
Most body systems
regulate Via this
mechanism, eg
Regulation of BloodPressure
Removal of CO2 from
body
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Feedback MechanismsFeedback Mechanisms
Positive feedback
Increases the original stimulus to push thevariable farther
In the body this only occurs in blood clotting
and birth of a baby
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Positive feedback
Blood Clotting Cascade