血管：圧力と物質交換への適応構造
導入済み| English | 意味 |
|---|---|
| artery/ˈɑːtəri/ | 動脈 |
| capillary/kəˈpɪləri/ | 毛細血管 |
What would explain this observation?
- A vessel supplying tissue under high pressure has a different structure from a vessel where exchange with cells occurs.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Arteries carry blood away from the heart and have thick muscular, elastic walls suited to higher pressure. Veins return blood toward the heart at lower pressure; they generally have a larger lumen and valves helping prevent backflow. Capillaries have very thin walls, allowing a short diffusion path between blood and tissues.
- artery 动脉: A blood vessel carrying blood away from the heart; capillary 毛细血管: A very small vessel with a thin wall supporting exchange.
毛細血管での交換を直接的に支える特徴はどれか？
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交換には短い拡散距離が必要であり、毛細血管壁は単一細胞層である。厚い筋肉層は交換を妨げ、ラベル付けでは物理的変化は生じない。
各専門用語を正確な意味と対応させよ。
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関連する物理量やプロセスを区別するために定義を使用せよ。
Choose evidence that can test it
- Use structure → effect → function. A capillary wall only one cell thick reduces diffusion distance. Arterial muscle and elastic tissue cope with and modify blood flow under pressure. Venous valves aid one-way flow, particularly when pressure is low. Direction defines artery versus vein, while exchange defines the key capillary role.
- Compare provided transverse vessel diagrams using their own scale information. Identify wall thickness and lumen, and distinguish a section image from the direction of flow. A collapsed specimen or schematic drawing should not be treated as a precise pressure measurement.
この場合、調査やモデルをより妥当にする2つの習慣は何か。
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条件や仮定を明記することで他者が正確に再現でき、根拠となる証拠を記録することで結論を検証できます。相反する結果を隠すと、誤った結論を疑う証拠を失いますし、単一の測定でより広い主張を成立させることはできません。
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: in a fictional diagram an artery lumen radius is 1 mm and a vein lumen radius is 2 mm. Circular areas are π and 4π mm², giving area ratio 4. Doubling radius gives four times the area; it does not alone specify actual flow or pressure because those depend on further conditions.
Two model circular lumens have radii 1 and 3 units. Calculate larger/smaller area ratio. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
2つのモデル円形管腔の半径が 1 と 3 単位である。大きい方の断面積と小さい方の断面積の比を計算せよ。
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結果は 9 である。既知：管腔半径 1 および 3 単位。面積は r^2 に比例するため、比 = (pi x 3^2)/(pi x 1^2) = 9 。幅の広い管腔は断面積が9倍であり、血流は圧力や抵抗にも依存する。
Check the conclusion and its limits
- A vein does not necessarily carry oxygen-poor blood: the pulmonary vein returns oxygen-rich blood. Large lumen area is not by itself evidence that a vessel’s flow rate is greater. Capillaries are small exchange vessels, not tiny versions with all arterial wall layers.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
A vessel’s oxygen content alone defines whether it is an artery. This claim is false: Arteries are defined by direction - away from the heart. The pulmonary artery carries oxygen-poor blood and the pulmonary vein oxygen-rich blood, so oxygen content cannot define the vessel type.
Blood vessels: structure fits pressure and exchange: Use structure → effect → function. A capillary wall only one cell thick reduces diffusion distance. Arterial muscle and elastic tissue cope with and modify blood flow under pressure. Venous valves aid one-way flow, particularly when pressure is low. Direction defines artery versus vein, while exchange defines the key capillary role.
血管の酸素含有量だけでそれが動脈かどうかを定義できるわけではない。
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動脈は心臓から離れる方向で定義される。肺動脈は酸素欠乏血を、肺静脈は酸素豊富血を運ぶため、酸素含有量で血管種を定義することはできない。
心臓から血液を運搬する血管：技術用語を記せ。
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動脈とは、心臓から血液を運搬する血管を指す。