Ch. 35.1

  All the body cells work together  Cells are both INDEPENDENT an INTERDEPENDENT of each other.  LEVELS OF ORGANIZATION: cells, tissues, organs, and organ systems  Tissues are groups of similar cells that perform a single function.  Organ is a group of tissues that work together to perform a COMPLEX function  Organ systems is a group of organs that perform closely related functions Organization of the Body

  MUSCLE TISSUE: most abundant tissue in most animals.  Controls internal movement of blood and food  Controls external movements of body parts  EPITHELIAL TISSUE: covers the surface of the body and line internal organs  Lines the chambers of the heart; prevents leakage of blood  Glands are made from epithelial tissue too Types of Tissues

  CONNECTIVE TISSUE: holds organs in place and binds to different parts of the body  Tendons (bones to muscle); Ligaments (bone to bone)  Provides support for the body  Keeps walls of heart flexible

  NERVOUS TISSUE: receives messages from external and internal envrionments  Analyzes data, directs a response  Controls heart rate

  Controlled, stable environment (HOMEOSTASIS)  Temperature controls, energy control, food intake, digestive waste output  Think of it like a house’s furnace. Once the heat is too cold, then the furnace knows to turn on and warm up  FEEDBACK INHIBITION: a process will limit operation Maintaining Homeostasis

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  Our body uses feedback inhibition  Stable temperature = BALANCE between heat production and heat loss  HYPOTHALAMUS has nerve cells that monitor temperature and core temperature  Shivering to warm up and sweating to cool down