Lesson 1 - OOB

• Tissue


  A group of similar cells that work together to perform a specific function
• Main tissue types in humans

  • Muscular
  • Epithelial
  • Nervous
  • Connective
• Organ


  An identifiable structure of the body composed of two or more tissues types
• Organ example


  • The stomach contains muscular tissue, epithelial tissue, nervous tissue and connective tissue
• Organ function


  Organs often perform a specific physiological function
• Organ system


  A group of organs that work together to perform a specific function
• Organ system example


  • The stomach, small and large intestines are all organs of the digestive system
• Human organism


  The most complex level of organization, composed of many organ systems that work together to perform the functions of an independent individual
• Body cavity


  A fluid-filled space inside the body that holds and protects internal organs
• Main body cavities


  • Ventral cavity
  • Dorsal cavity
• Serous membrane


  Membranes lining closed internal body cavities, secreting a slight amount of lubricating fluid
• Serous membranes


  • Pleura
  • Pericardium
  • Peritoneum
• Homeostasis


  A self-regulating process by which a living organism can maintain internal stability while adjusting to changing external conditions
• Homeostasis


  • It is a dynamic process that can change internal conditions as required to survive external challenges
  • It maintains a stable internal environment despite changes in the external environment
  • It controls variables like body temperature, blood pH, blood glucose, fluid balance, sodium, potassium and calcium ion concentrations
• Regulation of homeostasis


  Depends on effectors, receptors and a control center
• Receptor


  The sensing component responsible for monitoring and responding to changes in the external or internal environment
• Control center


  Also known as the integration center, it receives and processes information from the receptor
• Effector


  Responds to the commands of the control center, can oppose or enhance the stimulus