Homeostasis and Response

Cards (320)

  • Why is homeostasis important for cells?
    It maintains the right conditions for enzyme action
  • What does homeostasis regulate?
    Conditions inside the body and cells
  • What types of systems regulate the internal environment?
    Nervous and hormonal systems
  • Name one control system that maintains body temperature.
    Thermoregulation system
  • What are the main components of automatic control systems?
    Receptors, coordination centres, and effectors
  • How does negative feedback work in homeostasis?
    It counteracts changes to restore optimum levels
  • What are the steps of negative feedback in homeostasis?
    1. Receptor detects a stimulus (too high or too low)
    2. Coordination centre processes information and organizes a response
    3. Effector produces a response to restore optimum level
  • What happens if the level changes too much during negative feedback?
    Receptors and negative feedback activate automatically
  • What is the role of effectors in homeostasis?
    They produce responses to counteract changes
  • What is an example of a stimulus that receptors might detect?
    Water level or temperature
  • What does the coordination centre do in the feedback process?
    It receives and processes information
  • What happens when the level of a substance is too high?
    Receptor detects the stimulus
  • What happens when the level of a substance is too low?
    Receptor detects the stimulus
  • How long do effectors produce responses?
    As long as needed by the coordination centre
  • What is the consequence of effectors producing too much response?
    It may cause levels to change too much
  • What is the primary function of the nervous system?
    To monitor and respond to environmental changes
  • How does the nervous system help organisms survive?
    By organizing successful responses to stimuli
  • What are the main components of the Central Nervous System (CNS)?
    • Brain
    • Spinal cord
  • What connects the CNS to the body in mammals?
    Sensory neurones and motor neurones
  • What do sensory neurones do?
    Carry information to the CNS
  • What is the role of motor neurones?
    Carry impulses from the CNS to effectors
  • What are effectors in the nervous system?
    Muscles and glands responding to impulses
  • What is the process involving receptors and effectors?
    1. Receptors detect stimuli.
    2. Various types exist (tongue, nose, skin, eyes).
    3. Receptors can be part of complex organs (e.g., retina).
    4. Effectors respond to impulses and bring changes.
    5. Muscles contract; glands secrete hormones.
  • What is the role of the CNS in coordinating responses?
    It receives information and decides on responses
  • Describe the response of a bird when it spots a cat.
    1. Bird spots cat (stimulus).
    2. Receptors in the eye are stimulated.
    3. Sensory neurones send information to the CNS.
    4. CNS decides on a response.
    5. CNS sends information to wing muscles (effectors).
    6. Muscles contract, bird flies away.
  • What do nerve impulses do in the body?
    Travel rapidly to and from the brain
  • What is the connection between neurones called?
    A synapse
  • How is the nerve signal transferred across a synapse?
    By chemicals that diffuse across the gap
  • What happens after chemicals diffuse across the synapse?
    They set off an electrical signal in the next neurone
  • What are reflexes?
    Rapid automatic responses to stimuli
  • How do reflexes help prevent injury?
    They reduce the chances of being injured
  • What happens to your pupils when bright light shines in your eyes?
    They automatically get smaller
  • What hormone is released when you get a shock?
    Adrenaline
  • What is the passage of information in a reflex called?
    A reflex arc
  • Where do neurones in reflex arcs go through?
    The spinal cord or unconscious brain
  • What happens when a painful bee sting is detected?
    Impulses are sent along a sensory neurone
  • What triggers the release of chemicals at a synapse?
    Impulses reaching the synapse
  • What happens when impulses reach the synapse between the relay neurone and motor neurone?
    Chemicals are released, causing impulses
  • What does the motor neurone do in a reflex arc?
    It sends impulses to the effector
  • What is usually the effector in a reflex action?
    A muscle