homeostatic regulation homeostasis maintains stable internal conditions temperature ionic...

Homeostatic Regulation

Homeostasis

• Maintains stable internal conditions

• Temperature

• Ionic concentrations

• Blood sugar levels, etc.

Utilizes negative feedback mechanisms

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Homeostatic Regulation

Regulation depends on:• Receptor - sensitive to a particular

stimulus• Control Center - receives and

processes information from the receptor

• Effector - that responds to the commands of the control center which have been affected by the same stimulus

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

HOMEOSTASISNormalroom

temperature

Figure 1-3

2 of 6

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RECEPTOR

Thermometer

STIMULUS:Room temperature

rises

Normalconditiondisturbed

HOMEOSTASISNormalroom

temperature

Figure 1-3

3 of 6

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RECEPTOR

Thermometer

STIMULUS:Room temperature

rises

Normalconditiondisturbed

HOMEOSTASISNormalroom

temperature

Informationaffects

CONTROL CENTER(Thermostat)

20o 30o 40o

Figure 1-3

4 of 6

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RECEPTOR

Thermometer

STIMULUS:Room temperature

rises

Normalconditiondisturbed

HOMEOSTASISNormalroom

temperature

EFFECTOR

Air conditionerturns on

Sendscommands

to

Informationaffects

CONTROL CENTER(Thermostat)

20o 30o 40o

Figure 1-3

5 of 6

RECEPTOR

Thermometer

STIMULUS:Room temperature

rises

Normalconditiondisturbed

HOMEOSTASISNormalroom

temperature

RESPONSE:Room temperature

dropsNormal

conditionrestored

EFFECTOR

Air conditionerturns on

Sendscommands

to

Informationaffects

CONTROL CENTER(Thermostat)

20o 30o 40o

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Figure 1-3

6 of 6

Homeostatic Regulation

Negative Feedback:• Variation outside normal limits

triggers automatic corrective response• Response negates disturbance

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Homeostatic Regulation

Negative Feedback Example - thermoregulation• Altering the relationship between

heat loss and heat production

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

STIMULUS

Body temperaturerises above 37.2oC(99oF)

Controlmechanismwhen bodytemperature

rises

CONTROLCENTER

Thermoregulatorycenter in brain

Figure 1-4

2 of 10

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RECEPTOR

Body’stemperature

sensorsSTIMULUS

Body temperaturerises above 37.2oC(99oF)

Controlmechanismwhen bodytemperature

rises

CONTROLCENTER

Thermoregulatorycenter in brain

Informationaffects

Figure 1-4

3 of 10

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RECEPTOR

Body’stemperature

sensorsSTIMULUS

Body temperaturerises above 37.2oC(99oF)

Controlmechanismwhen bodytemperature

rises

EFFECTOR

Blood vesselsand sweat

glands in skin

Sendscommands

to

CONTROLCENTER

Thermoregulatorycenter in brain

Informationaffects

Figure 1-4

4 of 10

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

RECEPTOR

Body’stemperature

sensorsSTIMULUS

Body temperaturerises above 37.2oC(99oF)

RESPONSEIncreased blood flowto skinIncreased sweatingStimulus removedHomeostasis restored

Controlmechanismwhen bodytemperature

rises

EFFECTOR

Blood vesselsand sweat

glands in skin

Negativefeedback

Sendscommands

to

CONTROLCENTER

Thermoregulatorycenter in brain

Informationaffects

Figure 1-4

5 of 10

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STIMULUSBody temperaturefalls below 37.2oC(99oF)

Controlmechanismwhen bodytemperature

falls

CONTROLCENTER

Thermoregulatorycenter in brain

Figure 1-4

6 of 10

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RECEPTOR

Body’stemperature

sensors STIMULUSBody temperaturefalls below 37.2oC(99oF)

Controlmechanismwhen bodytemperature

falls

CONTROLCENTER

Thermoregulatorycenter in brain

Informationaffects

Figure 1-4

7 of 10

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RECEPTOR

Body’stemperature

sensors STIMULUSBody temperaturefalls below 37.2oC(99oF)

Controlmechanismwhen bodytemperature

falls

EFFECTOR

Blood vesselsand sweat glands

in skinSkeletal muscles

Sendscommands

to

CONTROLCENTER

Thermoregulatorycenter in brain

Informationaffects

Figure 1-4

8 of 10

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RECEPTOR

Body’stemperature

sensors STIMULUSBody temperaturefalls below 37.2oC(99oF)

RESPONSEDecreased blood flowto skinDecreased sweatingShiveringStimulus removedHomeostasis restored

Controlmechanismwhen bodytemperature

falls

EFFECTOR

Blood vesselsand sweat glands

in skinSkeletal muscles

Negativefeedback

Sendscommands

to

CONTROLCENTER

Thermoregulatorycenter in brain

Informationaffects

Figure 1-4

9 of 10

Figure 1-4

10 of 10Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

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

Figure 1-5

Homeostatic Regulation

Remember:• Negative feedback: negates the

disturbance – opposes the limit from normal limits• Positive feedback: reinforces

the stimulus

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Homeostatic Regulation

Homeostasis and Disease • Failure of homeostatic regulation

causes• Symptoms to appear• Organ system to malfunction

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Homeostatic Regulation

Key Note

Physiological systems work together to maintain a stable internal environment. They monitor and adjust internal conditions.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

The Language of Anatomy

Surface Anatomy• Anatomical Position

• Hands at side• Palms forward• Feet together

• Supine: Face up

• Prone: Face down

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The Language of Anatomy

Figure 1-6(a)

The Language of Anatomy

Figure 1-6(b)

The Language of Anatomy

Anatomical Regions• Two methods to map abdominal and

pelvic regions

• Four abdominopelvic quadrants

• Nine abdominopelvic regions

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The Language of Anatomy

Figure 1-7(a)

The Language of Anatomy

Figure 1-7(b)

The Language of Anatomy

Figure 1-7(c)

The Language of Anatomy

A few anatomical directions:• Anterior (= ventral)• Posterior (= dorsal)• Superior• Inferior• Lateral• Medial• Proximal• Distal

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The Language of Anatomy

Figure 1-8

The Language of Anatomy

Sectional Anatomy: Planes and Sections

• Transverse plane• Transverse section

• Frontal plane• Frontal section

• Sagittal plane• Sagittal section

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The Language of Anatomy

Figure 1-9

The Language of Anatomy

Ventral body cavity

• Protects delicate organs

• Permits organ growth and movement

• Surrounds:

• Respiratory

• Cardiovascular

• Digestive

• Urinary

• Reproductive organsCopyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

The Language of Anatomy

Diaphragm subdivides ventral cavity:

• Thoracic cavity

• Pleural cavities (R and L)• Pericardial cavity

• Abdominopelvic cavity

• Abdominal cavity

• Pelvic cavity

• Peritoneal membrane

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

The Language of Anatomy

Key Note

Anatomical descriptions refer to an

individual in the anatomical position:

standing, with the hands at the sides,

palms facing forward, and feet together.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

The Language of Anatomy

Figure 1-10(a)

The Language of Anatomy

Radiological Procedures

• X-rays

• CT Scans

• MRIs

• Ultrasound

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X-Rays

Figure 1-11(a)

X-Rays

Figure 1-11(b)

Common Scanning Techniques

Figure 1-12(a)

Common Scanning Techniques

Figure 1-12(b)

Common Scanning Techniques

Figure 1-12(c)

Common Scanning Techniques

Figure 1-12(d)