5A · Exam 1 at a Glance

Exam 1 covers Modules 1 through 4 and is administered during Module 5. It is open in Canvas from day 3 to day 7 of that module, runs 2 hours, and combines objective questions, multiple choice and true/false, with problem-solving and short answer. No outside help.

What the assignment keys actually reward¶

Reading all four solution keys side by side, the same patterns govern every question.

• One point per discrete claim. Every sub-part is scored separately: the “how do you know”, the “why”, the “what happens to X”. Each needs its own explicit sentence, or it scores zero.

• Lecture wording wins. The key for Module 1 Question 1 expects “concentration of extracellular fluid” because that is how the narration phrases it. “Plasma osmolality” is accepted, but earns nothing extra.

• Depth stops at the lectures. The keys say repeatedly that nothing beyond the notes is expected. Outside detail costs time and earns no points.

• Cite the slide. Nearly every answer in the key carries a slide number. Doing the same matches what the grader is checking against.

• Mechanisms need the full chain. A leads to B leads to C, every link written out. The endpoint alone gets partial credit at best.

• Rationale earns points on its own. On the hypokalemia and hyperkalemia questions, the key awards the rationale points even when the prediction is wrong, as long as the logic holds.

• Comparisons must cover both sides. “Own words” questions are graded generously, but describing only excitable membranes and not non-excitable ones loses half.

• True/false asks for a reason. Assignments 3 and 4 use “true or false, and if false explain why”: 1 point for the verdict, 1 for the reason. A true statement scores both points by saying it is true as written.

• “Pick the correct statement, then explain the rest.” Assignment 4 does this twice. Every wrong statement needs its specific error named.

• Calculations are at least half work. Chord conductance in Module 2 is 7 points: 2 for showing work, 1 for each ionic term, 1 for V_m, 1 for the gap.

Two answer templates¶

For a calculation, write in this order:

1. State the equation, with its source slide.

2. State every assumption: 1 kg water = 1 L, body temperature 310 K, which ion charge, which values are held constant.

3. Substitute numbers, units attached.

4. Show every intermediate term. For chord conductance, each ion’s weighted term on its own line.

5. Box or bold the final answer, with units and sensible precision.

6. One sentence interpreting what the number means physiologically.

For a mechanism, write the causal chain as arrows, one link per line, then answer each sub-part the question names in its own sentence. If the question says “why”, the word “because” must appear.