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Animal Physiology:. How Do Organisms Respond to Change?. What Are The Underlying Principles of Physiology?. Cells of multicellular organisms are hierarchically arranged Multicellular organisms are more than the sum of their parts
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Animal Physiology: How Do Organisms Respond to Change?
What Are The Underlying Principles of Physiology? • Cells of multicellular organisms are hierarchically arranged • Multicellular organisms are more than the sum of their parts • Multicellular organisms function best within stable internal environments • Feedback systems control many physiological processes
Cells of Multicellular Organisms are Hierarchically Organized • Multicellular organisms have cells that are organized into tissues • Groups of similar cells performing a similar function
Four Types of Tissues • Epithelial • Covers surfaces throughout the body ( inside and out) and protect what they cover. • Three types based on cell shape: Columnar, Cuboidial, Squamous.
Four Types of Tissues • Connective • Usually composed of living cells surrounded by nonliving matrices. • Found throughout the body. • Various Functions
Four Types of Tissues • Muscle • Highly contractile • Major function: move internal parts, or along with bones to move body as a whole. • Three types: • Striated • Smooth • Cardiac
Four Types of Tissues • Nerve tissue • Abundant throughout the body • Primary function is to relay information from the external and internal environments to the brain. • Process that other information , and relay messages from the brain to all internal body parts.
Organs • Complex systems of tissue that work together to perform common functions. • Examples: • Stomach • Skin • Forearm
Organs are Organized into Organ Systems • Organ Systems: A group of organs that work together to perform a specific function.
Multicellular Organisms are More Than The Sum of Their Parts • They are synergisms • An instance of the combined effect of several actions being greater than the sum of the individual actions.
Multicellular Organisms Function Best Within Stable Environments • Homeostasis • Maintaining a constant internal environment • Multicellular organisms function best under nearly steady-state internal conditions.
Feedback Systems Control Many Physiological Processes • Feedback • Regulation of a process by which a component from a later stage in the process controls its own production by influencing an earlier stage in the process. • 2 types • Positive and Negative
Additional Points to Remember: • All physiological processes are a cellular phenomena • Example: Digestion of nutrients in intestine and their movement through the blood • There is a relationship between form and function • Example: structure of cell is related to its function
Additional Points to Remember: • Tolerable ranges of internal and external conditions often vary from one organism to the next. • Example: algae living in near boiling hot springs
Additional Points to Remember: • Evolution often results in increasing complexity, but not always. • Example: the digestive systems of various animals • Plants are structurally and physiologically less complex than plants. • Example: most advanced plants produce flowers which consists of only three organ systems.
How Do Organisms Obtain Information From Their Environment? • Organisms need to assess: • What is the current state of the environment? • What changes are taking place? • What adjustments need to be made to adapt to these changes? • Two systems devoted to answering these questions: • Endocrine and Nervous systems
Endocrine Systems • Most primitive environmental monitoring system • Based on the presence of absence of chemicals • These systems produce hormones • Chemical messages
Endocrine Systems • Hormones are respond to long-term changes in an organism’s environments. • Key in such processes as growth, maturity, preproduction and metabolism.
Nervous Systems • Allows for quick adjustment to environmental conditions that may be necessary for survival. • Found only in animals • Basic cellular unit in vertebrates is neurons. • Allows the brain to be connected with all parts of the body. • This system evolved from rather simple networks into highly complex systems . • composed of numerous lateral nerves that feed information into and out of highly complex, centralized nerve cords and brains.
How Do Organisms Acquire and Process Nutrients and Wastes? • We are all dependent on our surroundings. • Ultimately dependent on the sun • Each of these systems depend on diffusion and osmosis to move nutrients and water between cells, tissues, and organs systems.
Primitive Organisms Process Nutrients and Wastes • Bacteria and fungi digest their food outside the cells • They obtain nutrients by excreting enzymes onto their food. • The enzymes break down complex compounds into simpler ones.
Multicellular Organisms Have Digestive Systems • Among animals, digestive systems (absent in sponges) evolved from those with • Single openings • Example: jellyfish and flatworms • Into simple, undifferentiated tubes with two openings • Example: Roundworms • To complex, convoluted tubes with accessory organs • Example: other animals such as humans
Animals Use Respiration to Obtain the Gases They Need • Three basic types of systems: • Skin- • the outer body covering • Gills • Outpockets of tissue that work best in water • Lungs • Inpockets of tissue that work best in air • Share two characteristics: • Extensive surface area and thin, moist cell layers to facilitate diffusion
Animals Use Respiration to Obtain the Gases They Need • Simple organisms such as hydra and flatworms exchange gases via their skin.
Animals Use Respiration to Obtain the Gases They Need • Insects have a system of internal tubes that open to the outside thought spiracles and connect to internal air sacs.
Animals Use Respiration to Obtain the Gases They Need • Bony fish bring water with oxygen into mouth and it passes over gills where gaseous exchange occurs.
Animals Use Respiration to Obtain the Gases They Need • Mammals use muscles to pump air containing oxygen into the lungs where gaseous exchange occurs. • Structure of lungs increases the surface area.