1. Chapter 1 The Human Body: An Orientation
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 1 The Human Body: An Orientation
Slides 1.9 – 1.20
Lecture Slides in PowerPoint by Jerry L. Cook
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

2. Organ System Overview Cardiovascular
Transports materials in body via blood pumped by heart
Oxygen
Carbon dioxide
Nutrients
Wastes
Figure 1.2f
Slide 1.9
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3. Organ System Overview Lymphatic Returns fluids to blood vessels
Disposes of debris
Involved in immunity
Figure 1.2g
Slide 1.10
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4. Organ System Overview Respiratory Keeps blood supplied with oxygen
Removes carbon dioxide
Figure 1.2h
Slide 1.11
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5. Organ System Overview Digestive Breaks down food
Allows for nutrient absorption into blood
Eliminates indigestible material
Figure 1.2i
Slide 1.12
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6. Organ System Overview Urinary Eliminates nitrogenous wastes
Maintains acid – base balance
Regulation of materials
Water
Electrolytes
Figure 1.2j
Slide 1.13
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7. Organ System Overview Reproductive Production of offspring Figure 1.2k
Slide 1.14
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8. Necessary Life Functions (Physiology)
Maintain Boundaries
cell membranes & integumentary system accomplish this
keep cells or organs from drying out, keep bacteria & chemical substances out and protect tissues from damaging effects of heat & sunlight
Movement
Locomotion – all of the activities that propel us from one place to another
Movement of substances – blood, food, etc
Slide 1.15
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9. Necessary Life Functions (Physiology)
Responsiveness (or irritability)
Ability to sense changes in environment & react, ie: pulling hand away after touching something hot
Carried out primarily by nervous sys.
Digestion
Break-down and delivery of nutrients
Carried out by digestive system
Slide 1.15
Slide 1.15
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

10. Necessary Life Functions
Metabolism – all chemical reactions within the body cells
Production of energy
Making body structures
Carried out by digestive, respiratory, circulatory & endocrine systems
Excretion
Elimination of waste from metabolic reactions
Involves digestive, urinary & respiratory sys.
Slide 1.16a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

11. Necessary Life Functions
Reproduction
On a cellular level, new cells are used for growth & repair
On an organismal level, leads to production of future generation
Growth
Increasing of cell size and number
Cell-constructing activities must occur faster than cell-destroying ones
Slide 1.16b
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12. Survival Needs Nutrients Oxygen Chemicals for energy and cell building
Includes carbohydrates, proteins, lipids (fats), vitamins, and minerals
Oxygen
Required for chemical reactions
Slide 1.17a
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13. Survival Needs
Water
60–80% of body weight (most abundant chemical in our bodies)
Obtained from food & drink; lost through evaporation in lungs & skin and excretions
Provides for metabolic reaction
Slide 1.17b
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14. Survival Needs Slide 1.17b Stable body temperature
Too low and metabolism becomes too slow to keep cells alive
Too high and metabolism is too fast; proteins break down
Either extreme can cause death
Slide 1.17b
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15. Survival Needs Slide 1.17b Atmospheric pressure must be appropriate
High altitude causes low gas exchange & makes metabolism difficult
High pressure (under water) allows gases to dissolve in blood
Slide 1.17b
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16. Homeostasis
Maintenance of a stable internal environment, regardless of what’s happening outside of the body
A dynamic state of equilibrium
Homeostasis must be maintained for normal body functioning and to sustain life
Homeostatic imbalance – a disturbance in homeostasis resulting in disease
Slide 1.18
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17. Maintaining Homeostasis
The body communicates through neural and hormonal control systems
Endocrine & nervous systems
Receptor
Responds to changes in the environment (stimuli)
Sends information to control center
Slide 1.19a
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18. Maintaining Homeostasis
Control center
Determines set point (normal level)
Analyzes information
Determines appropriate response
Effector
Provides a means for response to the stimulus
Either a positive or negative feedback
Slide 1.19b
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19. Feedback Mechanisms Negative feedback
Includes most homeostatic control mechanisms
Shuts off the original stimulus, or decreases its intensity
Works like a household thermostat
Stopping a fever, decreasing breathing rate or blood pressure
Slide 1.20a
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20. Feedback Mechanisms Positive feedback
Increases the original stimulus so the reaction occurs at an even faster rate
In the body this only occurs in blood clotting and birth of a baby
Slide 1.20b
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21. Homeostatic Imbalance
Most disease is considered an imbalance in our homeostasis
Many aspects of aging are the result of our bodies being less able to maintain homeostasis because organs become less efficient and our bodies respond more slowly to change, etc
Slide 1.20b
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