北醫，舞台，聽選翻思

what is the osmolarity of interstitial fluid?

what is the osmotic pressure contributed by sodium ions at the capillary?

2013年到了喔!

大家可以把書本拿出來曬了，把問題和大家一起討論，練習用英文進行

⋯⋯ 第一階段的筆試有165題MCQ也就是多選題難度不低

第二階段的口試搶答還得把習慣的中文轉成英文

簡單的例如List down the following cell counts in increasing order in blood plasma: leukocytes erythrocytes and platelets

也有大家都認為理所當然的觀念要你解釋例如Explain why Blood plasma in a hypertonic bath is considered hypotonic ?

畢竟我們不是英文授課，聽說方面沒有練習過就會很吃虧

至少要練習能夠給出complete explanations for every answer

大家可以上網找找看有關生理的Question and Answer Bank

現在想想，生理學好一點，對臨床的幫助比組織解剖還重要

主辦人還為辦這個活動寫了一篇paper，裡面有開頭那兩題的參考回答，網址如下

http://advan.physiology.org/content/34/1/20.full

新年快樂啦

容易讓你回答"false!"的true敘述(敘述後面數字是錯誤率)如果你也錯的話，趕快去找答案來討論吧......

1. The glomerular filtrate concentration of inulin is always less than the urine concentration of inulin. 69%

2. Dilation of the preglomerular afferent arteriole does not affect the filtration fraction. 68%

3. Partial pressure of oxygen in expired air is greater than that in alveolar air. 55%

4. At an inhibitory synapse, increased frequency of action potentials produce summation of the postsynaptic potential. 45%

5. The partial pressure of CO2 in alveolar air is greater than in expired air. 44%

6. In chronic diabetes mellitus with reduced GFR, the renal plasma threshold for glucose is increased. 44%

7. A 0.3 M urea solution will cause erythrocytes to expand when placed in it. 41%

8. In emphysema, both the airway resistance and the functional residual capacity are increased. 40%

9. Blockage of the lymphatic drainage will increase both the interstitial hydrostatic and interstitial oncotic pressure. 40%

小心>在他們的出題方式，有"always"不一定錯，不像我們考試中有"總是"的選項總是錯的

像3. 如果沒讀書會以為expired air是吐出的廢氣，但在guyton裡面的定義是Expired air is a combination of dead space air and alveolar air

類似的還有elastic會以為是有彈性，但在生理學的elastic blood vessel指的卻是a greater resistance to stretch or less compliance (artery) compared with a less-elastic, high-capacitance vein

例如6 “plasma threshold”在課本裡指的是濃度的threshold，單位mg/ml，而不是maximum limit of proximal tubular reabsorption，稱為reabsorption threshold” (是速率的threshold，單位 mg/min)

在1，要清楚filtered load(單位mg/min)、concentration(單位mg/ml)。單位時間下，腎絲球過濾液的inulin在正常的腎小管作用下根本就跟排出的inulin一樣多(mg)，但因為水分再吸收的關係，尿中的濃度一定比一開始過濾液的濃度高

像2，這題我個人覺得陷阱挖很大喇，因為我一看題目就會想起以前畫的圖，入球小動脈變粗，會使的GFR上升。但這題的意思是考afferent arteriole和glomerulus的上下游關係，當afferent arteriole中液體變多，管壁感到resistance上升，就會給下游訊息，造成vasoconstriction→renal blood/plasma flow減少，也會使glomerular hydrostatic pressure減少，所以淨filtration pressure和GFR都會下降，而問題所問的filtration fraction則是維持不變的。

在5，語言會影響心裡所想的，看了題目會以為在肺泡裡面當然比交換完吐出來CO2分壓低，但Expired air仔細想想指的是alveolar air+ unaltered inspired air (幾乎0% CO2) in the anatomic dead space，空氣吸進肺中交換出的CO2主要是代謝廢物，dead space裡面沒有交換，所以alveolar air的CO2分壓當然比alveolar air和dead space都算進去的分壓來的大。好玩吧~

在7，滲透壓的先決條件是溶質不會穿過細胞膜，對吧!?大家一定都忘記考慮urea是會穿過細胞膜到濃度比較低的胞內，所以儘管0.3M urea一開始是等張300mOsm，細胞外液也會漸漸變低張而使水進到細胞內

容易讓你回答"True!"的false敘述(敘述後面數字是錯誤率)你能對幾題呢，趕快去找答案來討論吧......

1. The one-directional peristalsis is produced by autonomic neural control of the enteric nervous system. 71%

2. The excreted load of a solute is calculated from multiplying the urine volume and the urine concentration of the solute. 65%

3. During a fatty meal, the greater rate of enterohepatic circulation increases the synthesis of bile salts in the liver. 58%

4. Vasoconstrictor agents reduce GFR by decreasing the net filtration pressure, but the filtration coefficient is unchanged. 58%

5. Absorption of peptides from the intestinal lumen into the enterocytes requires sodium cotransport mechanism. 52%

6. One factor that determines the glomerular filtration rate is the charge of the filtered solute. 51%

7. Planning and initiation of voluntary movement involved the primary motor cortex. 49%

8. Intestinal epithelial cells secrete disaccharides into the lumen to digest maltose and lactose. 45%

9. Decreased extracellular calcium will reduce the strength of skeletal muscle contraction. 43%

10. During exercise, the increased in pulmonary blood flow is due mainly to metabolic vasodilators. 42%

11. After gastrectomy, the protein digestion will be significantly affected. 42%

12. The transmission of action potential from atria to the ventricles is via gap junctions. 40%

在2 “load”在renal physiology是(不論過濾或排出的)process rate的專有名詞，單位mass/min，而不是指absolute amount，所以excrete load應該要用GFR(volume/min)x尿中濃度(mass/volume)

同樣的 “clearance” 指的是尿中該物質的排出率(mass/time)而非多少plasma中的該物質排出率(volume/time).

在8 [(題目好像誤植disaccharidases成disaccharides，但就算打對還是false)]“secretion”嚴格的定義是 “from the cytosol into the lumen” 或 “transepithelial secretion from a capillary into the lumen” 而所謂雙糖脢disaccharidases只是enterocyte membrane enzyme components然後在細胞表面進行hydrolysis把雙糖變成monosaccharides。同樣的不要說kidneys “secrete urine”，她一天的GFR就有180L/day並不需要去分泌尿液。

在9，鈣離子在兩種情況扮演的腳色不一樣，作為muscle contraction trigger的是intracellular的鈣離子而不是extracellular，extracellular影響的是神經、肌肉細胞膜上的激活反應，hypocalcemia大家都知道會造成細胞膜反應性增加，在臨床上看到的是tetany

在10，肺部的血管很特別，它的vascular resistance是由mechanical factor而不是metabolic factor決定：hypoxia的時候他會vasoconstriction來維持最佳的ventilation-perfusion balance，而在cardiac output增加、pulmonary arterial pressure增加時，會變的順應性較大，擴張血管以收集更多血