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

Organ System Overview Cardiovascular Transports materials in body via blood pumped by heart Oxygen Carbon dioxide Nutrients Wastes Figure 1.2f Slide 1.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Organ System Overview Lymphatic Returns fluids to blood vessels Disposes of debris Involved in immunity Figure 1.2g Slide 1.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Organ System Overview Respiratory Keeps blood supplied with oxygen Removes carbon dioxide Figure 1.2h Slide 1.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Organ System Overview Digestive Breaks down food Allows for nutrient absorption into blood Eliminates indigestible material Figure 1.2i Slide 1.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Organ System Overview Urinary Eliminates nitrogenous wastes Maintains acid – base balance Regulation of materials Water Electrolytes Figure 1.2j Slide 1.13 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Organ System Overview Reproductive Production of offspring Figure 1.2k Slide 1.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

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

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings