D312 Section 3 Lab Questions on Skeletal Anatomy and Structure

Grace J.
November 9, 2025November 9, 2025
BSN, D312, Western Governors University

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Western Governors University

D312 Anatomy and Physiology I with Lab

Prof. Name

Date

D312: Anatomy and Physiology I with Lab

Lab Questions Section 3 – Skeletal Anatomy and Structure of Bones and Bones of the Head and Neck

This section addresses key questions related to bone anatomy and physiology based on lab materials. Each question is followed by a detailed explanation of why each answer choice is correct or incorrect, enhancing understanding and retention of the skeletal system’s structure and function.

1. Which bone cells are entrapped in the bone matrix?

Answer Choices:

Choice	Explanation
a. Osteoclast cells	Incorrect. Osteoclasts are large, multinucleated cells responsible for bone resorption; they are not entrapped in the matrix but act on its surface.
b. Osteogenic cells	Incorrect. These are undifferentiated precursor cells located in the periosteum and endosteum, responsible for producing osteoblasts, not entrapped.
c. Osteoblast cells	Incorrect. Osteoblasts synthesize and deposit bone matrix but are not trapped within it; once trapped, they become osteocytes.
d. Osteocyte cells	Correct. Osteocytes are mature bone cells that originate from osteoblasts trapped in the bone matrix; they maintain the bone tissue.

Explanation:
Osteocytes are the only bone cells permanently encased within the mineralized bone matrix. They originate from osteoblasts that secrete the matrix and subsequently become embedded, differentiating into osteocytes, which maintain bone tissue and communicate with other bone cells through canaliculi.

2-5. Label the components of the bone matrix.

Question 2: What is the name of the tissue labeled A?
Answer: Spongy Bone
Question 3: What is the name of the tissue labeled B?
Answer: Bone Marrow
Question 4: What is the name of the tissue labeled C?
Answer: Compact Bone
Question 5: What is the name of the tissue labeled D?
Answer: Periosteum

No further explanation is needed for these labeling questions.

6. Which statement is true about the diaphysis labeled D in the long bone diagram?

Choice	Explanation
a. The diaphysis is comprised of compact bone and cartilage.	Correct. The diaphysis mainly consists of compact bone for strength, while cartilage is found at growth plates near the epiphysis.
b. The diaphysis is comprised mostly of compact bone.	Partially correct but incomplete. It overlooks the presence of cartilage in growth plates adjacent to the diaphysis.
c. The diaphysis is comprised of spongy bone and cartilage.	Incorrect. Spongy bone is mainly found in the epiphyses, not in the diaphysis.
d. The diaphysis is comprised mostly of spongy bone.	Incorrect. Spongy bone is located in the ends of long bones, not the diaphysis.

Explanation:
The diaphysis, or shaft of a long bone, is primarily made of dense compact bone providing structural support and strength. Cartilage is present only in the epiphyseal (growth) plates at the ends where the diaphysis meets the epiphysis.

7. Which image is classified as an irregular-shaped bone?

Choice	Explanation
a. A – Long bones	Incorrect. Long bones are elongated and cylindrical, such as the femur or humerus.
b. B – Sesamoid bone	Incorrect. Sesamoid bones are small, embedded in tendons near joints, like the patella.
c. C – Flat bones	Incorrect. Flat bones are thin, with two layers of compact bone enclosing spongy bone, like the sternum.
d. D – Irregular bones	Correct. Irregular bones have complex shapes, such as vertebrae, sphenoid, and ethmoid bones.

8. Which type of bone is labeled A?

Choice	Explanation
a. Irregular bones	Incorrect. These bones have complex, varied shapes, unlike the bone labeled A.
b. Short bones	Incorrect. Short bones are roughly cube-shaped, like carpals and tarsals.
c. Long bones	Correct. Long bones have a long shaft and expanded ends, composed mainly of compact bone with spongy bone inside.
d. Flat bones	Incorrect. Flat bones are thin and flat, like the ribs and skull bones.

9. Bones that surround the spinal cord are classified as ________ bones.

Choice	Explanation
a. Flat	Incorrect. Flat bones include ribs and skull bones, not the spinal cord surround.
b. Irregular	Correct. Vertebrae are irregular bones due to their complex shapes tailored to protect the spinal cord.
c. Short	Incorrect. Short bones are found in wrists and ankles, not in the vertebral column.
d. Sesamoid	Incorrect. Sesamoid bones are small and embedded in tendons, not related to spinal protection.

10. What is the classification of bones labeled A and B in the human skeleton image?

Choice	Explanation
a. Long bone	Correct. Bones such as the humerus, radius, femur, and phalanges fall under this category.
b. Flat bone	Incorrect. Flat bones include the sternum and skull bones.
c. Irregular bone	Incorrect. Irregular bones include the vertebrae and sphenoid.
d. Short bone	Incorrect. Short bones are carpals and tarsals.

11. What is part of the axial skeleton?

Choice	Explanation
a. Thigh bones	Incorrect. Thigh bones are part of the appendicular skeleton (limbs).
b. Vertebral column	Correct. The axial skeleton consists of bones forming the head, neck, and trunk, including the vertebral column.
c. Foot bones	Incorrect. Foot bones are part of the appendicular skeleton.
d. Shoulder bones	Incorrect. Shoulder bones belong to the appendicular skeleton.

12. The appendicular skeleton ________.

Choice	Explanation
a. forms the vertical axis of the body	Incorrect. The axial skeleton forms the vertical axis.
b. includes all bones of the body trunk and limbs	Incorrect. The axial skeleton includes the trunk, not the appendicular.
c. consists of 126 bones	Correct. The appendicular skeleton includes 126 bones of the upper and lower limbs.
d. is comprised of the bones of the lower and upper limbs	Correct. The appendicular skeleton comprises the limbs’ bones and their girdles.

Summary Table of Bone Classifications

Bone Type	Description	Examples
Long Bones	Longer than wide, cylindrical shafts, mostly compact bone	Femur, humerus, radius
Short Bones	Cube-shaped, mostly spongy bone surrounded by thin compact bone	Carpals, tarsals
Flat Bones	Thin, flat, two layers of compact bone with spongy bone between	Sternum, ribs, skull bones
Irregular Bones	Complex shapes tailored for specific functions	Vertebrae, sphenoid, ethmoid
Sesamoid Bones	Small, embedded within tendons, protect tendons	Patella

References

Martini, F. H., Nath, J. L., & Bartholomew, E. F. (2017). Fundamentals of Anatomy & Physiology (11th ed.). Pearson.