D313 Anatomy and Physiology II with Lab, catalog number SCIE 1012, is the four-CU continuation that covers the cardiovascular, respiratory, digestive, urinary, reproductive and lymphatic systems across six sections with laboratory activity attached. It is the harder half of the pair, and not because the vocabulary grows. It is harder because these systems are all transport and exchange systems, so every one of them is a set of pressures, gradients and flows rather than a set of parts. Students who passed the first course by memorising structures often find the second one asks a different question entirely.
Why SCIE 1012 punishes memorisation
Look at what the six systems in D313 have in common. Blood moves down a pressure gradient. Air moves down a pressure gradient. Filtrate moves across a membrane because of hydrostatic and osmotic forces in competition. Nutrients cross an epithelium. Lymph returns fluid the capillaries lost. Almost the whole course is one idea repeated in six settings: something is moved from where there is more of it to where there is less, and the body spends energy and builds structures to control the rate.
That is good news, because it means the course has a spine. A student who genuinely holds pressure, gradient, resistance and surface area can reason a way to most answers rather than retrieving them. A student who does not will meet the renal section, which is where physiology courses traditionally break people, with no tools at all. The nephron is not hard because it has many parts. It is hard because each segment does something different to the same fluid and you have to hold the running state of that fluid in your head while you move along it.
The second thing D313 tests is integration across systems. Acid-base balance is respiratory and renal at once. Blood pressure is cardiac, vascular, renal and endocrine at once. Questions that look unfair are usually questions that expect you to cross a system boundary, and they are foreseeable if you have noticed that the body does not organise itself by chapter.
Reading the rubric into a plan you can hold
Scored detail lives in your Course of Study rather than the public catalog, so start with your own assessment materials. WGU scores every aspect independently against a three-point scale and a score of 2 in each aspect passes a task. There is no averaging, which in a course this broad means one neglected system can hold up everything else.
If any part of D313 is assessed by submitted work, build the document from the rubric's headings rather than from the body's anatomy. The failure this prevents is specific: physiology writing tends to become a narrated journey along a tube, and a narrated journey answers the aspects in an order nobody asked for.
The word budget, worked. Take a rubric with six scored aspects and directions asking for roughly 2,000 words. Set aside 150 for an opening that names the system, the variable being regulated and the question, and 120 for a close, leaving 1,730 for the scored body. Six into 1,730 is about 288 words per aspect. Weight any aspect that asks for a multi-step mechanism, a pressure calculation or a compensation pathway up to about 400, and take the difference from whichever aspect is a straight description of structure. Description saturates; a traced mechanism keeps earning credit for every correct step.
Where your version of the course is exam-facing, run the same discipline against the calendar. Six sections, hard dates, and the renal section gets the longest block. Give it a full extra study day for every day you would have given the digestive section, because the digestive system rewards reading and the kidney does not.
A structure for writing about transport and exchange
Where the directions specify their own arrangement, that arrangement wins. Where they leave it open, this shape suits every system in this course, because every system in this course moves something.
| Section | What to put in it | Why it earns credit |
|---|---|---|
| The variable being controlled | Name the quantity the system holds steady: pressure, pH, volume, osmolality, gas partial pressure | Frames everything after it and prevents an answer that describes without explaining |
| The route | The path the substance takes, in order, with each structure it crosses | Sequence errors are the most detectable mistake in physiology writing |
| The driving force | What makes movement happen at each step, and whether energy is spent | Separates passive from active transport, which students conflate constantly |
| The control loop | Sensor, control centre, effector, and the direction of the correction | Regulation aspects are where thin submissions lose their second point |
| Compensation | What another system does when this one cannot keep up | Shows cross-system integration, which single-system answers never demonstrate |
| Failure and its signs | Where the mechanism breaks and what a clinician would observe or measure | Ties physiology to assessment findings and lab values |
| Sources | Course materials, atlas figures and outside references in the required style | Uncited physiology reads as copied even when it is not |
Compensation is the row that turns an adequate answer into a strong one. Respiratory acidosis with no mention of renal compensation is half an answer, and it is the half that any aspect asking for analysis is looking for.
Evidence craft when the evidence is a value in range
The second course leans more on numbers than the first. Cardiac output, tidal volume, glomerular filtration rate, pH, partial pressures. Using those numbers well is its own skill, and it is more often the difference between scores than the underlying understanding is.
- Give every value a unit and a reference range. A pH of 7.31 is only meaningful next to the normal band, and a reader should not have to supply it.
- Say whether a change is a cause or a compensation. The same numeric shift means opposite things depending on which it is, and stating your reading of it is part of the analysis.
- Cite the source of any range you quote. Reference intervals differ between references, and naming yours prevents an accuracy dispute.
- Report lab observations before interpreting them. What the simulated activity showed and what you conclude from it are separate sentences with separate standards.
- Use flow diagrams while drafting. If you cannot draw the loop with arrows, the prose version will be missing a step you have not noticed.
- Keep direct quotation almost to zero. Physiological definitions are heavily reproduced text and a similarity check will surface them.
Strong submissions state the assumption their reasoning rests on. Assuming a healthy heart while explaining renal compensation is reasonable, and saying so in one clause shows the evaluator that the simplification is deliberate rather than accidental.
What separates Competent from a return
Because each aspect is scored on its own, D313 returns are usually one specific gap rather than a weak paper. The most frequent gap is an aspect that asked how a system responds to a change and received a description of how it works when nothing changes.
- Every scored aspect has a heading in the rubric's own language, and nothing is buried inside a neighbour.
- Every mechanism has a direction. Substances move somewhere, and the answer says which way and why.
- Every number carries units and a reference point, inside sentences as well as in tables.
- Every claim about disease is built on the normal physiology already established in the submission.
- At least one cross-system connection appears wherever an aspect asks for analysis rather than description.
Revising and resubmitting a performance assessment carries no grade penalty at WGU, which makes a return a delay and not a mark. The cost is the term. Six months at a flat rate makes courses closed the only number that matters, and a four-CU science course that takes three attempts has eaten the room you were keeping for the next one.
Where D313 is assessed by a proctored objective assessment, the boundary is fixed and we state it plainly. Proctored exams are yours to sit. We prepare only: section calendars, mechanism drills, value interpretation practice, retrieval sets and an honest readiness read. We neither sit nor assist during an assessment, and portal credentials are never requested.
Six mistakes that cost time in D313
- Approaching the kidney as a list of segments. Follow one hypothetical drop of filtrate the whole way through and describe what happens to it at each point. The list becomes a story and the story sticks.
- Learning cardiac anatomy without the pressure story. Valves open and close because of pressure differences. A student who knows the valve names and not the pressures cannot explain a single murmur or a single phase of the cycle.
- Treating acid-base as a chemistry aside. It is the most integrative topic in the course and the one most likely to appear where two systems meet.
- Skipping the lymphatic system because it looks small. It carries fluid balance and immune content that later coursework assumes you already own.
- Assuming D312 material is finished. Nervous and endocrine control run through every system here, and a shaky membrane potential from the first course resurfaces immediately in cardiac conduction.
- Rereading instead of retrieving. Physiology rewards closed-book explanation out loud more than any other pre-nursing subject, and it exposes gaps that highlighting hides.
How support works on this course
Send your Course of Study materials and the details of what your assessment asks for. Written work comes back aspect-mapped, with mechanisms traced in order, values reported against ranges, and cross-system connections drawn where an aspect asks for analysis. The walkthrough that comes with it explains the method, because the same six-part structure works for all six systems and is worth owning before the next science course.
On the exam side, help means a section calendar weighted toward the renal and acid-base material, drilled retrieval on mechanisms rather than names, practice reading values in context, and a candid read on whether you are ready rather than an encouraging one.
Questions students ask about D313
Is D313 the same course as SCIE 1012?
Do I have to finish D312 before starting D313?
Which part of D313 do students find hardest?
Renal section not going in?
Send over the Course of Study materials and the assessment particulars. You get aspect-mapped work, traced mechanisms and a six-section calendar weighted where the difficulty actually is.
Where D313 sits in WGU's programs
The July 2026 catalog places this code in 6 current WGU programs. Open a program page for the complete standard path and term positions. The live Degree Plan remains authoritative after transfer credit, substitutions, and mentor planning.
The assessments, one by one
The public catalog does not publish this course's PA/OA identity or task count. WGU Tutors publishes at most one PA manual per course and only from a WGU-controlled public rubric. Until that source exists, PA help begins from the student's real Course of Study and OA support remains preparation only.