Epiphysis and diaphysis of bone isA. End and shaft of long bone respectivelyB. Shaft and end of long bone respectivelyC. Head and neck of long boneD. Spongy bone only

The correct answer is A. End and shaft of long bone respectively.
1. Epiphysis: The epiphysis refers to the end of a long bone. It is typically wider than the shaft and consists of spongy bone surrounded by a layer of compact bone. The epiphysis plays a crucial role in joint movement and is involved in the formation of the articular surface (the surface that forms joints with other bones).
2. Diaphysis: The diaphysis refers to the shaft of a long bone. It is the long, central portion of the bone and is composed mainly of compact bone, providing strength for weight-bearing. The diaphysis surrounds the medullary cavity, which contains bone marrow.
To clarify the terms:
• Epiphysis is the end of the bone, involved in joint formation.
• Diaphysis is the shaft of the bone, providing structural support.
Why the other options are incorrect:
• B) Shaft and end of long bone respectively: This would be correct if reversed. The epiphysis is at the end of the bone, and the diaphysis is the shaft.
• C) Head and neck of long bone: This is not the correct terminology for the main parts of a long bone. The head and neck refer to other structures, like the head of the femur, but they are not general terms for the epiphysis and diaphysis.
• D) Spongy bone only: The epiphysis contains spongy bone, but the diaphysis is primarily made of compact bone, not spongy bone.
Thus, the epiphysis and diaphysis refer to the end and shaft of a long bone, respectively, making the correct answer A. End and shaft of long bone respectively.