1 / 12

Structural Levels, continued…

Learn about the six essential characteristics of life, including organization, metabolism, growth, cells, reproduction, and the importance of maintaining homeostasis. Discover how organisms interact with their environment and the concept of positive and negative feedback mechanisms.

smithjuan
Download Presentation

Structural Levels, continued…

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Structural Levels, continued… • Organism – any living thing considered as a whole • Unicellular, multicellular • Human organism is a complex of organ systems that are mutually dependent on one another

  2. Characteristics of Life • Six Essential Characteristics of Life • Organization – an organism’s parts are interrelated • All living things are composed of cells • Metabolism (Energy) – ability to use energy to perform vital functions such as growth, movement, and reproduction • Energy from sun (plants) or food (animals)

  3. Six Essential Characteristics of Life, continued… • Homeostasis – ability of an organism to sense changes in the environment and make the adjustment that help maintain its life • Growth – ability of an organism to increase in size (partially or totally) • Either by increasing cell number or cell size

  4. Six Essential Characteristics of Life, continued… • Cells – all organisms are made of one more cells • Reproduction – the formation of new cells or organisms a. Sexual or asexual reproduction

  5. Environmental Requirements of Organisms Organisms require certain factors in their environment or surroundings: • Water • Foods • Oxygen • Heat – energy from metabolic reactions • Pressure • Atmospheric  breathing • Hydrostatic  blood pressure

  6. Homeostasis – Maintenance of Life • The existence and maintenance of a relatively constant environment within the body • Narrow range of conditions (variables) • Temperature, volume, chemical content • Set point = ideal normal value • Normal range = range of values in which an organism can operate normally

  7. Examples: Cold = shiver Hot = sweat

  8. Negative Feedback • Maintains homeostasis by resisting deviation from the set point • Three components: • Receptor – monitors the value of a variable • Control center – establishes the set point around which the variable is maintained • Effector – can change the variable

  9. Hole’s Essentials of Human Anatomy and Physiology, 8th ed., Shier, et al, 2003, McGraw-Hill Higher Education Negative Feedback, continued… • Example: • Stimulus/Response: exercise increases HR and blood pressure increases • Receptor: blood vessels near heart • Control center: brain receives message and sends message to decrease HR • Effector: heart decreases HR • Response: blood pressure decreases

  10. Negative Feedback, continued…

  11. Positive Feedback • Mechanism by which any deviation from an ideal normal value or set point is made greater • Does not maintain homeostasis

  12. Positive Feedback, continued… Example

More Related