Week 9 — Count the Skeleton, Read the Joints: A Skeleton Report

Assignment 8 of the term — add the skeleton up from its regions, read the limbs and joints from the anatomical position, and explain a joint's trade in plain words for someone new to anatomy and physiology.

This adaptive assignment uses a coaching dialogue to help you turn a first attempt into a clear, evidence-based report. You stay the author: the coach asks questions, checks the reasoning you show, and waits for you to revise before it writes its report. Week 1 gave you the anatomical position and the medial and lateral pair, and Week 7 showed you a single long bone; this week those ideas place every bone in the skeleton and every joint between them. This week's lecture tutorial, quiz, discussion, and A&P Lab & Inquiry work the same ideas from other angles; this assignment is where you put them together.

The task

This week's shared dataset is Dataset F, the skeleton counts: canonical counts, not measured data. An adult skeleton has 206 bones, 80 axial and 126 appendicular. The axial skeleton is the skull (22 bones), the associated bones (the hyoid and six ossicles, 7 bones), the vertebral column (26 bones), and the thoracic cage (25 bones). Each limb has 30 bones, and the girdles that attach the limbs count with the appendicular skeleton.

Work these four problems, showing your arithmetic:

1. The skull has 22 bones, the associated bones number 7, the vertebral column has 26 bones, and the thoracic cage has 25 bones. How many bones make up the axial skeleton?
2. The appendicular skeleton has 126 bones, and each of the 4 limbs has 30 bones. How many bones belong to the girdles?
3. The vertebral column has 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae above the sacrum. How many separate vertebrae sit above the sacrum?
4. The thoracic cage holds 12 pairs of ribs, with 2 ribs in each pair, and 1 sternum. How many bones make up the thoracic cage?

Beside each answer, add one brief interpretation:

• Problem 1: name the four axial regions in the sum, and explain why the six ossicles and the hyoid are counted apart from the skull's 22 while the scapula is not in this total at all.
• Problem 2: name the six girdle bones and explain why they count as appendicular even though they sit on the trunk, and then, reading from the anatomical position, name the forearm bone on the thumb side and the leg bone that bears the body's weight.
• Problem 3: give the three regions in order from the top down and tie the thoracic count to the rib pairs, and then classify the joint at an intervertebral disc and the joint at a skull suture by structure.
• Problem 4: name the rib groups and explain why the floating ribs are not a third group beside the true and false ribs, and then name the part of a synovial joint that secretes synovial fluid and the rule that links every synovial joint to its functional class.

Explain it to a non-expert

A friend who recently joined a climbing gym asks why a shoulder can slip out of place more easily than a hip, when both are ball joints. Write a 3–5 sentence message that explains what a ball-and-socket joint is, how the shoulder's socket differs from the hip's, and what each one trades for what. Name one limit, for example that this is a picture of how the joints are built and not advice about anyone's shoulder. Put any technical term in everyday words. More than one good message is possible.

For a different, ungraded example, imagine a friend who asks why an elbow only bends one way. Model answer: "Your elbow is a hinge joint, a joint built to bend and straighten in one direction, like a door on its hinges. When you bend it, the angle between your upper arm and forearm gets smaller, and that move is called flexion; straightening it again is extension. The shape of the bones where they meet lets them swing in one plane and not twist freely. That is why the elbow is steady for carrying a bag, but it cannot circle the way a shoulder can. This explains how the joint is built, not why any one elbow might hurt."

Use that pattern for the message to your friend, with your own wording and evidence.

Part 1 — Student instructions

1. Draft all four answers, the four brief interpretations, and your message to your friend before you open a chatbot.
2. Open any course-approved chatbot. Copy the entire Coach Prompt box, including its first and last marker lines, and paste it as one message. The coach asks for your draft and then works one question at a time.
3. Answer in your own words. Show calculations when asked. Use the coach's feedback to revise at least one calculation or explanation, even if your first attempt was correct.
4. Keep going until the prompt's exit condition is met.
5. Save the chat's share link and copy the final report exactly as the coach gives it.

The chatbot is a coach, not a ghostwriter. It draws out your reasoning; it does not write the report for you.

Coach Prompt

COPY EVERYTHING BELOW THIS LINE
ROLE: You are a careful learning coach for a first-semester anatomy and physiology course. Draw out and challenge MY thinking about the skeleton's divisions and its joints. Do not write my assignment for me and do not invent work I never did. Never invent a measurement, a study, a bone marking, or a percentage, and never offer medical advice or comment on anyone's health or care.

ASSIGNMENT: Work through these four problems in order, one at a time. Do not invent, replace, or reorder a problem. The data: Dataset F, the skeleton counts (canonical): 206 bones, 80 axial and 126 appendicular; the axial skeleton is the skull (22), the associated bones (7: the hyoid and six ossicles), the vertebral column (26), and the thoracic cage (25); each limb has 30 bones, and the girdles are appendicular.
PROBLEM P1: The skull has 22 bones, the associated bones number 7, the vertebral column has 26 bones, and the thoracic cage has 25 bones. How many bones make up the axial skeleton?
PROBLEM P2: The appendicular skeleton has 126 bones, and each of the 4 limbs has 30 bones. How many bones belong to the girdles?
PROBLEM P3: The vertebral column has 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae above the sacrum. How many separate vertebrae sit above the sacrum?
PROBLEM P4: The thoracic cage holds 12 pairs of ribs, with 2 ribs in each pair, and 1 sternum. How many bones make up the thoracic cage?
After the four answers, I must briefly interpret each one: for P1, name the four axial regions and explain why the six ossicles and the hyoid are counted apart from the skull's 22 while the scapula is not in the total; for P2, name the six girdle bones and why they count as appendicular, then name the forearm bone on the thumb side and the weight-bearing leg bone from the anatomical position; for P3, give the three regions in order and tie the thoracic count to the rib pairs, then classify the disc joint and the suture by structure; for P4, name the rib groups and why the floating ribs are not a third group, then name the part that secretes synovial fluid and the rule that links every synovial joint to its functional class. I must then write a 3-5 sentence message to a friend explaining what a ball-and-socket joint is, how the shoulder's socket differs from the hip's, what each one trades, and one limit. I must explain technical terms in everyday words.

SCORING CRITERIA: Score only evidence I supply: correct computations (40 points), skeleton and joint reasoning (32 points), clarity for a non-expert reader (16 points), and showing work so it can be checked (12 points). For each of P1-P4, give 2, 1, or 0 evidence units per criterion; one unit is worth 5 computation points, 4 reasoning points, 2 clarity points, or 1.5 showing-work points. Sum the four problems within each criterion. Count my message to my friend only with P1, and only for clarity.
COMPUTATION UNITS: A correct result in any equivalent notation = 2; the right values and operations with one arithmetic slip = 1; a missing result or a wrong operation, such as adding the limbs where the girdle count subtracts = 0.
REASONING UNITS: For each problem, an interpretation that covers both named parts = 2; one accurate part = 1; none = 0. Calling a girdle bone axial, putting the ulna on the thumb side, naming the fibula as the weight-bearer, counting the floating ribs as a third group, calling a suture synovial, or crediting the cartilage with making the synovial fluid is not accurate. An arithmetic slip alone is not a reasoning error.
CLARITY UNITS: For each problem, labeled evidence a newcomer can follow, with terms in everyday words = 2; evidence that needs a reread because of an unclear label or unexplained term = 1; no readable evidence = 0. Include my message to my friend with P1. Missing reasoning alone does not lower clarity for otherwise clear work.
SHOWING-WORK UNITS: For each problem, values and steps that let a reader rebuild the result = 2; one relevant but incomplete value or step = 1; a bare result or no method = 0. A visible method stays checkable despite an arithmetic slip.

Do NOT invent grading rules.

DIALOGUE RULES: Ask exactly one question per message and wait for my answer. Start by asking for my complete first attempt. Build each next question from my exact words. Probe an unsupported claim and ask me what supports it. Keep the conversation on questions, not on finished work.

ENGAGEMENT GUARDS: A greeting, a copied prompt, a yes/no reply, or a one-word answer is not a substantive exchange. Do not flatter or treat agreement as evidence. Praise only a concrete move I made. If evidence is missing, say what is missing and ask for it. Require a real revision plus a short reflection on why the revision is better. Never score evidence I did not supply, and do not issue the report early.

EXIT CONDITION: Continue until at least five substantive exchanges have occurred AND I have supplied all four answers and their brief interpretations AND written my message to my friend AND revised at least one calculation or explanation AND reflected on the revision. Stop only after whichever requirement happens last.

REPORT: After the exit condition is satisfied, output exactly these labelled lines in this order. Replace X with the exact earned score; it may end in .5 and must not be rounded. Base every line only on evidence in this chat; write "Not supplied" for missing evidence and never raise the score for polished chatbot prose.
STUDENT'S SCORE: X/100
EVIDENCE FOR THE SCORE: [specific evidence from my calculations and reasoning]
REVISION MADE: [what I changed and why]
STRENGTH: [one earned strength]
NEXT STEP: [one concrete improvement]
Then tell me to submit this report, my revised skeleton report, and the share link.
COPY EVERYTHING ABOVE THIS LINE

Deliverables

Submit these three items in the assignment entry:

• your revised skeleton report with all four answers, their brief interpretations, and your message to your friend — written, or recorded as audio or video with a transcript, or as a labeled sketch of the skeleton sorted into its regions with a short note; every form is graded by the same scoring criteria;
• the coach's five-line report; and
• the conversation share link.

Submit in any accessible file type or as a link; a recorded response may be submitted as audio or video with a transcript, or as text.

Equivalent route (no AI required)

This route assesses the same Week 9 skills — adding the skeleton up from its regions, sorting the girdle bones into the appendicular skeleton, reading the radius and the tibia from the anatomical position, and classifying joints by structure, function, and type — for comparable time and effort, about 60 to 90 minutes, the same as the coached route. Complete the same four problems, the four brief interpretations, and the message to your friend. Then audit your own first draft against the attached scoring criteria, one criterion at a time, and write a second draft. Add a 150–200 word revision memo that names one calculation or explanation you changed, the evidence that prompted the change, and one question you still have. Submit the revised report, your completed criteria checklist, and the revision memo in the assignment entry; together they replace the share link and the coach's report. This route uses the same scoring criteria and the same points, with no penalty for choosing it.

How you'll be graded

The full analytic rubric is attached to this assignment in Canvas.

Academic integrity and AI use

The calculations, reasoning, revision, and final report must be your own. Do not ask the chatbot to create the assignment or to add evidence you did not produce. Submit an honest share link from your own dialogue. The equivalent route keeps the same workload and evidence and needs no AI account.

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