Dialysis and transplant: compare evidence and burdens
| English | 中文 | Pinyin |
|---|---|---|
| dialysis/daɪˈæləsɪs/ | 透析 | tòu xī |
| transplant/trænˈsplænt/ | 移植 | yí zhí |
What would explain this observation?
- A failed kidney cannot simply be replaced by a filter that removes every dissolved substance. A dialysis 透析 system must remove wastes while avoiding loss of needed materials.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- In dialysis, blood and dialysis fluid are separated by a partially permeable membrane. Small dissolved substances can diffuse across; cells and large proteins remain in blood. Dialysis fluid is prepared with suitable glucose and ion concentrations so that needed amounts are not unnecessarily lost, while urea diffuses from its higher concentration in blood into the fluid.
- dialysis: Removal of selected dissolved substances from blood across a membrane; transplant 移植: Replacement of a failed organ with a donor organ.
What drives net urea movement into dialysis fluid in the stated model?
Dialysis needs repeated treatment and imposes time and practical burdens. A successful kidney transplant can restore continuing kidney function, but needs a suitable donor, surgery and management of rejection. Compare risks, availability, lifestyle effects and evidence of benefit. Neither route should be presented as suitable for every individual or as a guaranteed cure.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Dialysis needs repeated treatment and imposes time and practical burdens. A successful kidney transplant can restore continuing kidney function, but needs a suitable donor, surgery and management of rejection. Compare risks, availability, lifestyle effects and evidence of benefit. Neither route should be presented as suitable for every individual or as a guaranteed cure.
- Analyse fictional treatment summaries and membrane models with stated particle sizes and concentrations. Draw the expected net diffusion directions for urea and a named useful solute. This school task does not involve blood handling, human dialysis equipment or personal treatment recommendations.
Which two habits make the investigation or model in this case more defensible?
Analyse fictional treatment summaries and membrane models with stated particle sizes and concentrations. Draw the expected net diffusion directions for urea and a named useful solute. This school task does not involve blood handling, human dialysis equipment or personal treatment recommendations.
Work from known quantities
- State the known values and their units. Choose the relation because its assumptions fit this case, then rearrange before substitution.
- Known: a fictional model has 24 waste units before dialysis and 9 after the stated interval. Removed amount = 15 units; proportion removed = 15/24×100 = 62.5%. This is an amount comparison. It does not establish a real treatment schedule, and fluid volumes would be needed to compare concentrations correctly.
A fictional waste amount falls from 40 to 10 units. Calculate percentage removed. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
A fictional waste amount falls from 40 to 10 units. Calculate percentage removed.
The result is 75 %. Known: a fictional model has 24 waste units before dialysis and 9 after the stated interval. Removed amount = 15 units; proportion removed = 15/24×100 = 62.5%. This is an amount comparison. It does not establish a real treatment schedule, and fluid volumes would be needed to compare concentrations correctly.
Check the conclusion and its limits
- Dialysis is not selective because it recognizes the name of a waste; membrane permeability and concentration differences matter. Cells and large proteins should not cross the stated membrane. A transplant decision includes ethical and practical considerations beyond a single removal percentage.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Dialysis must remove all glucose from blood to work. This claim is false: Dialysis is not selective because it recognizes the name of a waste; membrane permeability and concentration differences matter. Cells and large proteins should not cross the stated membrane. A transplant decision includes ethical and practical considerations beyond a single removal percentage.
Dialysis and transplant: compare evidence and burdens: Dialysis needs repeated treatment and imposes time and practical burdens. A successful kidney transplant can restore continuing kidney function, but needs a suitable donor, surgery and management of rejection. Compare risks, availability, lifestyle effects and evidence of benefit. Neither route should be presented as suitable for every individual or as a guaranteed cure.
Dialysis must remove all glucose from blood to work.
Dialysis is not selective because it recognizes the name of a waste; membrane permeability and concentration differences matter. Cells and large proteins should not cross the stated membrane. A transplant decision includes ethical and practical considerations beyond a single removal percentage.
Removal of selected dissolved substances from blood across a membrane: write the technical term.
dialysis means Removal of selected dissolved substances from blood across a membrane.