B3.10 Homeostasis

• What is homeostasis?

  Maintaining a stable internal environment despite changing conditions 
• Why do cells need homeostasis?

  To function properly under certain conditions
• What conditions must be regulated for cells to function?

  Temperature, acidity, glucose, and water levels
• How does the body regulate internal conditions?

  By keeping levels around the right bounds
• What is the definition of homeostasis?

  Regulation of internal conditions to maintain stability
• How does the body respond to external changes?

  By maintaining internal conditions despite changes
• What temperature do human cells typically maintain?

  37 degrees Celsius
• What are the three main components of automatic control systems?

  Receptors, coordination centers, and effectors
• What do receptors do in the control system?

  Detect changes in conditions
• What role do coordination centers play?

  Interpret changes and decide actions
• What are effectors in the control system?

  Muscles or glands that carry out changes
• How do the nervous and endocrine systems communicate?

  Nervous system uses electrical impulses; endocrine uses hormones
• What is the speed of response for the nervous system?

  Fast and precise
• How does the endocrine system operate?

  Releases hormones into the bloodstream
• What is the nature of the endocrine system's effects?

  Slower, longer-lasting, and more generalized
• What mechanism is used for maintaining homeostasis?

  Negative feedback
• How does negative feedback function?

  Decreases high levels and increases low levels
• What happens when glucose levels rise too high?

  Negative feedback decreases glucose levels
• What occurs if body temperature drops too low?

  Receptors detect cold and signal muscles to shiver
• What happens if body temperature rises too high?

  Receptors detect heat and signal sweating
• What is the overall process of homeostasis?

  • Maintaining a stable internal environment
  • Involves receptors, coordination centers, and effectors
  • Uses negative feedback to regulate conditions
• How do the nervous and endocrine systems differ in their functions?

  Nervous System:

  • Fast response
  • Uses electrical impulses
  • Precise and localized effects

  
  

  Endocrine System:

  • Slower response
  • Uses hormones in the bloodstream
  • Generalized and longer-lasting effects
• Describe the negative feedback mechanism in homeostasis.

  • Detects changes in internal conditions
  • Reverses changes to maintain stability
  • Increases low levels and decreases high levels
• What are the steps involved when body temperature changes?

  1. Receptors detect temperature change
  2. Coordination centers interpret the information
  3. Effectors carry out responses (e.g., shivering or sweating)
  4. Body temperature returns to normal
• Why does the body need to maintain optimal conditions?


  For optimal enzyme action and cell function
• Which of these are considered 'internal conditions'?


  Blood glucose concentration

  Blood Ph levels
• Which of these are considered 'external conditions'?


  Room temperature 

  The amount of fluids you drink
• Homeostasis relies on automatic control systems.  In what order are signals passed along the control system? 


  receptor ➔ coordination centre ➔ effector
• What is the role of a receptor? 


  Detects changes in the internal or external environment
• What is the role of a coordination centre? 


  Interprets changes and organises a response.
• Where are the coordination center's located in the body?


  Spinal cord

  Brain
• Name the two types of effectors and state what they do.


  Muscle's contract

  Glands release hormones
• The nervous system is much faster acting as it relies on electrical impulses that can travel very quickly. 
• The endocrine system acts more generally as it involves releasing hormones into the blood stream which means they spread throughout the entire body. 
• Homeostasis relies on a system of negative feedback, meaning whenever the levels of something get too high they're brought back down, and whenever the levels of something get too low, they're brought back up.
• Negative feedback always involves reversing a change. So if the body temperature gets too high, negative feedback will bring it back down towards optimum. 
• How does negative feedback work?


  Any change in a system causes an action that reverses the change
• What is negative feedback?

  Negative feedback is when a change in a system causes an action that reverses the change.
• Name 3 internal conditions that homeostasis regulates.


  1. Blood glucose concentration.
  2. Body temperature.
  3. Water Levels.