Skip to main content
Human A&P BIO 304 · American River College ← Course home (Week 3)

BIO 304 . WEEK 3 . TUESDAY . LAB WORKBOOK

Axial Skeleton

Skull, vertebral column, ribs, and sternum: the body's central pillar.

Print this page. You will draw your own diagrams from the directions below, then hand-label the structures listed. Drawing by hand is the integrity mechanism for this course.

← Back to syllabus hub

Part 1 of 2

Anatomy Lab

1A. What you will draw

The axial skeleton supports the head and trunk and protects the brain, spinal cord, and thoracic organs. Today you'll draw the vertebral column with its regions, then the rib cage with the sternum.

Box A. Vertebral column (lateral view)

Directions

  1. Draw the vertebral column from the side. Show it curving (the natural S-curve of the spine).
  2. Label the four regions from top to bottom: Cervical (7 vertebrae), Thoracic (12), Lumbar (5), Sacral (5 fused), Coccygeal (3 to 4 fused).
  3. Mark each region with its vertebra count.
  4. Add the primary curves (thoracic, sacral, concave anteriorly) and secondary curves (cervical, lumbar, convex anteriorly).
  5. Below the drawing, label C1 (atlas, supports head, allows yes nod) and C2 (axis, with the odontoid process, allows no rotation).

Box B. Thoracic cage

Directions

  1. Draw the thoracic cage in anterior view: the sternum down the middle, 12 pairs of ribs curving around to the back.
  2. Label the sternum and its three parts: manubrium (top), body, xiphoid process (bottom).
  3. Label the costal cartilages connecting ribs to the sternum.
  4. Identify rib categories with color or labels: True ribs (1 to 7, attach directly via own costal cartilage), False ribs (8 to 10, attach indirectly to costal cartilage of rib 7), Floating ribs (11 to 12, no anterior attachment).

1C. Structures to label (15)

After you finish each drawing, label every structure below directly on your sketch.

  1. Cervical vertebrae (7)
  2. Thoracic vertebrae (12)
  3. Lumbar vertebrae (5)
  4. Sacrum
  5. Coccyx
  6. Atlas (C1)
  7. Axis (C2)
  8. Odontoid process (dens)
  9. Manubrium
  10. Sternal body
  11. Xiphoid process
  12. Costal cartilage
  13. True ribs
  14. False ribs
  15. Floating ribs

Part 2 of 2

Physiology Lab

2A. Structure-function reasoning

For each axial-skeleton feature below, name what it allows the body to do, and explain why the structure suits that function.

1. The foramen magnum at the base of the skull.
2. The vertebral foramen running the length of every vertebra.
3. The intervertebral discs between adjacent vertebrae.
4. The articulation between the atlas (C1) and the occipital bone.
5. The articulation between the atlas (C1) and the axis (C2).
6. The flexibility of the costal cartilages connecting ribs to sternum.

2B. Synthesis questions

Answer each in 2 to 4 sentences. Use the language from this week's lecture and your drawings as evidence.

1. A car accident causes a hyperextension injury (head snaps backward). Which axial structure is at highest risk, and what neurological consequence is most dangerous if that structure is damaged?
2. A patient has a herniated lumbar disc pressing on a spinal nerve root. Predict the symptoms (motor, sensory, reflexes) and explain why disc herniation is more common in the lumbar region than the thoracic region.
3. Breathing involves the rib cage expanding and contracting. Explain how the costal cartilages and the rib articulations work together to make this possible, and predict what would happen if the costal cartilages ossified (turned to bone).

3. What to submit

Complete both the Anatomy Lab (your own drawings, hand-labeled, plus the structures list) and the Physiology Lab (activity and synthesis questions). Photograph or scan every page and upload to Canvas before the deadline listed on the schedule. Hand-drawn, hand-labeled work is the integrity mechanism for this course. Typed or AI-generated diagrams are not accepted.