Cole Trickle has bad acne. This affects the oil glands attached to his hair follicles, which are ______ glands and are examples of which type of gland?

A. in the medullary cavity of a long bone
In adults, the medullary cavity contains yellow marrow, not red marrow.

B. in the epiphysis of a flat bone
Flat bones (e.g., skull) don’t have epiphyses. This answer is anatomically inaccurate.

C. in the medullary cavity of a flat bone
Flat bones don’t have a true medullary cavity. Red marrow is found in their spongy bone, not in a central cavity.

D. in the epiphysis of a long bone
Red marrow in adults is found in the spongy bone of the epiphyses of long bones and in flat bones like the sternum and pelvis.

E. in the epiphyseal plate of a long bone
The epiphyseal plate is made of cartilage, not marrow. It is involved in growth, not hematopoiesis.

A. it is composed of osteons
Compact bone is made up of osteons (Haversian systems), each with a central canal and concentric lamellae.

B. it contains concentric and circumferential lamellae
Concentric lamellae are within osteons; circumferential lamellae line the outer and inner surfaces of compact bone.

C. it has very little air space compared to cancellous
Compact bone is dense with few spaces, unlike spongy (cancellous) bone, which has many air spaces.

D. the matrix is composed of trabeculae
Trabeculae are found in spongy (cancellous) bone, not compact bone. Compact bone has a solid matrix organized into osteons, not trabecular structures.