Biology ch:5 - homeostasis and response

• What is homeostasis?

  Maintaining a stable internal environment
• Why is homeostasis important for cells?

  Cells need right conditions for proper function
• What does homeostasis regulate in the body?

  Internal and external conditions
• What are the two types of communication systems in homeostasis?

  Nervous and hormonal communication systems
• What are the three main components of automatic control systems?

  Receptors, coordination centres, and effectors
• What is the process of negative feedback in homeostasis?

  • Receptor detects a stimulus
  • Coordination centre processes information
  • Effector produces a response to restore balance
• What happens when a level is too high in negative feedback?

  Receptor detects stimulus and responds
• What happens when a level is too low in negative feedback?

  Receptor detects stimulus and responds
• How does the body know to stop producing responses in negative feedback?

  Receptor detects if the level becomes too different
• What is a stimulus?

  A change in the environment
• Why do multicellular organisms need a nervous system?

  To communicate and respond to stimuli
• What does the Central Nervous System (CNS) consist of?

  The brain and spinal cord
• What are sensory neurones responsible for?

  Carrying information to the CNS
• What do motor neurones do?

  Carry impulses from the CNS to effectors
• What are effectors?

  Muscles and glands responding to impulses
• What are the functions of different brain regions?

  • Cerebral cortex: consciousness, intelligence, memory, language
  • Medulla: controls unconscious activities like breathing
  • Cerebellum: responsible for muscle coordination
• How do scientists study the brain?

  Using methods like damage observation and MRI
• What does electrical stimulation of the brain do?

  Causes muscle contraction and movement
• What is an MRI scanner used for?

  To produce detailed pictures of brain structures
• What are the risks of messing with the brain?

  Physical damage and increased function problems
• What are the steps in a reflex arc?

  1. Stimulus detected by receptors
  2. Impulses sent along sensory neurone
  3. Relay neurone processes information
  4. Impulses sent along motor neurone
  5. Effector responds (e.g., muscle contracts)
• What is a reflex?

  A rapid, automatic response to stimuli
• How do reflexes help prevent injury?

  They provide quick responses without thinking
• What is the role of synapses?

  Connect two neurones and transfer signals
• What happens at a synapse?

  Chemicals diffuse and trigger new signals
• What is the effect of caffeine on reaction time?

  Caffeine can speed up reaction time
• What is the procedure to measure reaction time using a ruler?

  1. Rest arm on table
  2. Hold ruler vertically
  3. Let go without warning
  4. Catch ruler as quickly as possible
  5. Measure the distance caught
  6. Repeat and calculate mean
• Why is it important to control variables in a reaction time test?

  To ensure a fair and accurate test
• How can computers improve reaction time measurement?

  They provide precise measurements in milliseconds
• What is the consequence of predicting a response in a reaction time test?

  It can lead to inaccurate measurements
• What is the role of the brain in complex behaviors?

  Controls and coordinates all actions
• What happens if a part of the brain is damaged?

  Effects can indicate the function of that part
• What is the function of the cerebral cortex?

  Responsible for consciousness and memory
• What does the medulla control?

  Unconscious activities like heartbeat
• What is the function of the cerebellum?

  Responsible for muscle coordination
• What is the purpose of studying brain damage effects?

  To learn about the functions of brain areas
• How does electrical stimulation help in brain studies?

  It shows what different brain parts control
• What does an MRI scanner do?

  Produces detailed images of brain structures
• What are the risks of brain treatments?

  Physical damage and functional problems