Homeostasis: detect a change and respond
הוצג| English | משמעות |
|---|---|
| homeostasis/ˌhəʊmiːəˈstɑːsiz/ | בית-צורה |
| effector/ɪˈfektə/ | אפקטור |
What would explain this observation?
- The temperature outside can change while the body maintains a much narrower internal range. Control systems respond to change rather than keeping the outside environment constant.
Build the model
- Homeostasis 稳态 regulates internal conditions of a cell or organism to maintain optimum conditions for function.
- It supports enzyme action and other cell functions.
- In humans the course examples are blood glucose concentration, body temperature and water levels.
- Control can involve nervous responses or chemical responses.
- homeostasis: Regulation of internal conditions to maintain optimum conditions for function.
- effector 效应器: A muscle or gland that produces a response in a control system.
Which component directly brings about a corrective response?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
The effector - a muscle or gland - carries out the corrective response. A receptor detects the change and a coordination centre processes it, but neither can itself restore the level.
Match each technical term to its precise meaning.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Receptors detect stimuli, or changes.
- A coordination centre such as the brain, spinal cord or pancreas receives and processes information.
- Effectors are muscles or glands that produce a response restoring suitable levels.
- A receptor detects a change; it is not necessarily the structure producing the corrective action.
In the lab: Use a paper control model with separate receptor, centre and effector cards. Present a stated change and follow the information and response arrows. Identify what the system measures and which internal condition it changes. The model must not claim that internal levels never fluctuate or that one organ alone performs every control function.
Which two habits make the investigation or model in this case more defensible?
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Stating the conditions and assumptions lets others repeat the work exactly, and recording the supporting evidence lets them check the conclusion. Hiding disagreeing results removes the evidence that could challenge a wrong conclusion, and one measurement can never establish a wider claim.
Work from known quantities
- Known: a fictional temperature-control record has a reference of 37.0 °C and readings of 36.8, 37.2 and 37.0 °C.
- Deviations are −0.2, +0.2 and 0.0 °C.
- The range is 0.4 °C.
- Small variation can coexist with regulation; these model values are not diagnostic thresholds or a request to measure students’ health.
Your turn: A fictional record spans 36.7 to 37.3 °C. Calculate its range.
A fictional record spans 36.7 to 37.3 °C. Calculate its range.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 0.6 °C. Known: record spans 36.7 to 37.3 degrees C. Range = maximum - minimum = 37.3 - 36.7 = 0.6 degrees C. Small variation is normal in a regulated system.
Check the conclusion and its limits
- Homeostasis maintains suitable internal conditions rather than a perfectly constant outside world.
- Receptor, coordination centre and effector describe roles, not interchangeable labels.
- Nervous and chemical systems can both contribute; detailed hormone-specific feedback is taught in its own section.
Not true: Homeostasis means the outside environment cannot change. Homeostasis keeps INTERNAL conditions suitable despite a changing outside world. It regulates the body's internal environment; it cannot and does not stop the external environment changing.
- Homeostasis regulates internal conditions of a cell or organism to maintain optimum conditions for function.
- Receptors detect stimuli, or changes.
- Watch for: homeostasis maintains suitable internal conditions rather than a perfectly constant outside world.
Homeostasis keeps INTERNAL conditions suitable despite a changing outside world.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
True. Homeostasis keeps INTERNAL conditions suitable despite a changing outside world. It regulates the body's internal environment; it cannot and does not stop the external environment changing.
Regulation of internal conditions to maintain optimum conditions for function: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
homeostasis means Regulation of internal conditions to maintain optimum conditions for function.