Week 11 — Quiz (auto-graded) · The Muscular System

Course: Anatomy & Physiology I (BIOL 2301 + BIOL 2101) · Silver Oak University (fictional sample) · Prof. Navarro
Objective tested: Objective 5 — origin/insertion; muscle teamwork (agonist/antagonist/synergist); muscle naming; the three lever classes & the force-vs-speed tradeoff; the major muscles and their actions.
Points: 10 (1 each) · Assignment group: Quizzes (10% of grade) · Due: end of Module 11.

This is the human-readable quiz with its vetted answer key and feedback. The import-ready Classic QTI is in F-quiz-week-11-qti.xml (generated by the shared validated script — parses with 10 items, every single-answer item exactly one correct). The reusable item-bank entries and the Canvas placement block are at the bottom of this file.

Blueprint

No trick questions; distractors target the Week 11 misconceptions named in the lecture outline.

Questions, key, and feedback

Q1 (MC). A skeletal muscle attaches to two bones across a joint. Which statement correctly describes the origin and the insertion?
- A. The origin is on the bone that moves the most; the insertion is on the stationary bone
- B. The origin is on the stationary (fixed) bone; the insertion is on the bone that moves ✅
- C. Both the origin and the insertion are on the same moving bone
- D. The origin and insertion are interchangeable terms for the muscle belly
Feedback: The origin is the fixed anchor; the insertion is on the bone that moves (it's pulled in toward the origin). A reverses the two — the most common Week 11 trap. The belly is the fleshy middle, not an attachment.

Q2 (Matching). Match each muscle to the action it produces.
| Muscle | Correct action |
|---|---|
| Biceps brachii | Flexes the forearm at the elbow |
| Triceps brachii | Extends the forearm at the elbow |
| Quadriceps femoris | Extends the leg at the knee |
| Hamstrings | Flexes the leg at the knee |
Feedback: The two classic antagonist pairs: biceps flexes / triceps extends the forearm, and quadriceps extends / hamstrings flex the knee. Learn each muscle with its action — "biceps bends, triceps straightens."

Q3 (MC). When the biceps brachii contracts to flex the forearm, it is acting as the agonist (prime mover). Which muscle is the antagonist for this movement?
- A. The deltoid, which abducts the arm
- B. The triceps brachii, which extends the forearm ✅
- C. The brachialis, which assists forearm flexion
- D. The pectoralis major, which flexes the arm
Feedback: The antagonist has the opposite action and relaxes/lengthens as the agonist contracts — for flexion at the elbow that's the triceps (it extends the forearm). The brachialis is a synergist (it assists, not opposes); the deltoid and pectoralis act at the shoulder, not the elbow.

Q4 (MC). Which class of lever is by far the most common in the human body, with the effort applied between the fulcrum (joint) and the load?
- A. First-class lever
- B. Second-class lever
- C. Third-class lever ✅
- D. Fourth-class lever
Feedback: Third-class levers (effort in the middle) dominate the body — the biceps curl is the model. (There is no fourth class.) First-class = fulcrum in the middle; second-class = load in the middle.

Q5 (MC). In a musculoskeletal lever system, the joint, the bone, and the contracting muscle correspond to which lever parts?
- A. The joint is the load, the bone is the effort, the muscle is the fulcrum
- B. The joint is the fulcrum, the bone is the lever, the muscle supplies the effort ✅
- C. The bone is the fulcrum, the joint is the lever, the muscle is the load
- D. The muscle is the fulcrum, the joint is the load, the bone is the effort
Feedback: The bone is the rigid lever, the joint is the fulcrum (pivot), the muscle supplies the effort, and the load is the weight moved. Anchoring these four parts is the key to classifying any body lever.

Q6 (Multiple answer — select all that apply). Which of the following statements about how skeletal muscles work in groups are TRUE?
- A. A muscle can never act as an agonist in one movement and an antagonist in another
- B. The agonist is the prime mover that produces a given movement ✅
- C. The antagonist opposes the prime mover and relaxes (or lengthens) as the agonist contracts ✅
- D. A synergist assists the prime mover or stabilizes a joint ✅
- E. Skeletal muscles push bones apart to create movement
Feedback: B, C, and D are the correct roles. A is false — the roles are relative to the movement (biceps is agonist in a curl, antagonist in extension). E is false — muscles only pull (shorten); the antagonist pulls the other way to reverse a movement.

Q7 (Matching). Match each muscle to the body region where it is found.
| Muscle | Correct region |
|---|---|
| Masseter | Jaw / head (chewing) |
| Gastrocnemius | Posterior lower leg (calf) |
| Rectus abdominis | Anterior abdominal wall |
| Gluteus maximus | Buttock / hip |
Feedback: Many muscle names announce their location: the masseter works the jaw, the gastrocnemius is the calf, the rectus abdominis is the straight muscle of the abdomen, and the gluteus maximus is the largest buttock muscle. Reading the name often gives you the region.

Q8 (True / False). "The origin is the muscle attachment that moves the most during a contraction."
- True
- False ✅
Feedback: False. The insertion is the attachment that moves (it's pulled in toward the origin); the origin is the fixed/stationary anchor. Students reverse these constantly — remember the Insertion is pulled In, so it moves.

Q9 (MC). Following the structure-to-function idea, the deltoid is a thick triangular muscle capping the shoulder. Its main action is to —
- A. flex the forearm at the elbow
- B. abduct the arm (raise it away from the body's midline) at the shoulder ✅
- C. extend the leg at the knee
- D. plantarflex the foot at the ankle
Feedback: The deltoid caps the shoulder and abducts the arm — raises it out to the side, away from the midline. (Forearm flexion = biceps; knee extension = quadriceps; plantarflexion = gastrocnemius.) Its triangular shape over the shoulder joint predicts the action.

Q10 (MC). A forearm acts as a lever. A 60 N load in the hand sits 36 cm from the elbow (the fulcrum), and the biceps inserts 4 cm from the elbow. Using effort × effort-arm = load × load-arm, how much effort must the biceps generate to hold the load?
- A. 6.7 N
- B. 60 N
- C. 270 N
- D. 540 N ✅
Feedback: effort × 4 = 60 × 36 = 2160, so effort = 2160 ÷ 4 = 540 N. The biceps must pull with nine times the load because its effort arm (4 cm) is one-ninth the load arm (36 cm) — the force "cost" of a third-class lever, paid back in speed and range of motion.

Answer key (quick reference)

Quality gate (self-checked): each single-answer item has exactly one correct option; the multiple-answer item (Q6) requires B, C, D selected and A, E left unselected; the two matching items (Q2, Q7) pair four entries to four distinct targets; every muscle action is verified against standard anatomy (OpenStax A&P §11.1–11.2; InnerBody muscular) — origin = fixed bone, insertion = moving bone; biceps flexes / triceps extends the forearm; quadriceps extends / hamstrings flex the knee; deltoid abducts the arm; gastrocnemius plantarflexes; third-class levers are the most common in the body. Anatomy-accuracy gate: PASS. The lever calculation in Q10 (and the practice/assignment lever items) was pre-computed and independently re-verified with a Python check (60 × 36 ÷ 4 = 540 N; cross-checks 50 × 40 ÷ 5 = 400 N, 200 × 15 ÷ 5 = 600 N — all clean integers). Quantitative gate: PASS.

Item-bank entries (for variants + the midterm/final)

All ten items are tagged course=BIOL2301 · week=11 · objective=5 · topic=muscular-system-organization-levers-actions and deposited in Item Bank: Week 11 — The Muscular System. The final (Week 16) and the per-term variant updates draw fresh items from this bank. (Tags: q1 origin-vs-insertion, q2 muscle-action-match, q3 agonist-antagonist, q4 third-class-lever, q5 lever-components, q6 muscle-teamwork-true, q7 muscle-region-match, q8 origin-moves-misconception, q9 deltoid-action, q10 lever-calculation.)

Canvas placement block

canvas_object   = Quizzes::Quiz
title           = "Week 11 Quiz — The Muscular System"
assignment_group = "Quizzes"
points_possible = 10
grading_type    = points
due_offset_days = 5        # 5 days after module start (Sunday, before the Tue/Thu lecture week)
published       = true
shuffle_answers = true
provenance      = "~ Prof. Navarro's edition · Fall 2026 · built with thecoursemaker.com"