Nervous + eye

• What is homeostasis?

  Homeostasis is the maintenance of constant internal conditions in the body
• What are the components of an automatic control system?

  A stimulus, a receptor, a coordination center, an effector, and a response
• What does the central nervous system consist of?

  The brain and the spinal cord
• What is the role of receptors in the nervous system?

  Receptors detect stimuli and send electrical impulses to the CNS
• What is another term for nerve cells?

  Neurons
• What do effectors do in the nervous system?

  Effectors bring about a response
• What are the two types of effectors mentioned?

  Muscles and glands
• Why is the nervous system important for humans?

  It enables humans to react to their surroundings and coordinate behavior
• What is the reflex arc?

  • A pathway that controls reflex actions
  • Involves sensory neurons, relay neurons, and motor neurons
  • Allows for rapid responses without conscious thought
• What happens when you touch a hot object?

  The stimulus (heat) is detected by a receptor in the skin
• What is the role of sensory neurons in the reflex arc?

  Sensory neurons carry impulses from receptors to the CNS
• What occurs at the synapse between the sensory neuron and the relay neuron?

  A chemical is released that triggers an electrical impulse in the relay neuron
• What happens after the electrical impulse passes through the relay neuron?

  It reaches another synapse and triggers an impulse in a motor neuron
• What is the final step in the reflex arc when touching a hot object?

  The motor neuron sends an impulse to a muscle, causing it to contract
• What is the response when you pull your hand away from heat?

  Pulling the hand away is called the response
• How is the ruler positioned before it is dropped?

  The zero mark should be between Person 1's thumb and first finger
• How do reflexes differ from other actions in terms of brain involvement?

  Reflexes do not involve decision-making by the conscience part of the brain
• What should Person 1 do when the ruler is dropped?

  Catch the ruler with their thumb and first finger as quickly as possible
• Why are reflexes important?

  They help to protect us from danger by enabling rapid responses
• What does Person 2 do after Person 1 catches the ruler?

  Records the measurement on the ruler at the level of Person 1's thumb
• What are the control variables in the reaction time experiment?

  • Distance between thumb and first finger should be constant
  • Ruler should always be measured at the top of the thumb
  • Conditions in the room (lighting, background noise) should be the same
• Why is it important to keep control variables constant in the reaction time experiment?

  To ensure that changes do not affect the dependent variable, which is reaction time
• What are some other independent variables that could be investigated in the reaction time experiment?

  • Effect of practice on reaction time
  • Effect of dominant vs. non-dominant hand
  • Effect of chemicals like caffeine on reaction time
• What is the expected outcome when testing reaction time with the dominant hand compared to the non-dominant hand?

  The reaction time is expected to be shorter with the dominant hand
• What is the function of the cornea?How?

  • What: Starts the focusing of light rays
  • How: Transparent
• What is the colored part of the eye called?

  Iris
• What is the role of the lens in the eye?

  To focus light rays onto the retina of the eye
• What is accommodation in the context of the eye?

  It is the ability of the lens to change shape to focus on distant or near objects
• What is the retina responsible for?

  • Contains receptor cells for light
  • Detects light intensity and color
  • Sends electrical impulses to the brain
• What is the white part of the eye called?

  Sclera
• What do the ciliary muscles and suspensory ligaments do?

  They work with the lens to allow focusing on distant or near objects
• What is the pupil?

  The space in the center of the iris through which light passes
• How does the iris control the size of the pupil?

  By contracting or relaxing muscles in response to light intensity
• What happens to the pupil when you enter a dark room?

  The pupil becomes larger to allow more light to enter the eye
• What is a reflex action in the context of pupil size adjustment?

  It is an automatic response that does not involve the conscious part of the brain
• What occurs when you walk into a bright room?

  The pupil becomes smaller to reduce the amount of light entering the eye
• What should you be able to describe by the end of the video on how the eye focuses?

  How the eye focuses on near or distant objects
• What is the role of the retina in the eye?

  The retina contains receptor cells sensitive to light intensity and color
• What part of the eye carries out most of the focusing?

  The cornea
• What is the function of the lens in the eye?

  The lens allows us to focus on near or distant objects by changing its shape