Anatomy of a Long Bone MCQ - Practice Questions with Answers

Periosteum: 

• It is the sheath around a bone which is thick and tough by nature.
• It contains osteoblasts which are the bone-forming cells and blood vessels.
• Periosteum possesses collagen fibres which penetrate the matrix and thus a connection is established between periosteum and matrix.  

Endosteum:

• Endosteum occurs outer to the yellow bone marrow cavity
• It is composed of fibrous tissues which are present inner to osteoblasts. 

Bone marrow:

• Bone marrow refers to the soft and semi-solid fatty neurovascular tissue found inside the bone marrow cavity of long bones of limbs. 
• Bone marrow tissue is also called as myeloid tissue.
• There are two types of bone marrow i.e. red bone marrow and yellow bone marrow.

1. Redbone marrow: 

• This bone marrow is so named because it consists of a number of blood vessels.
• Redbone marrow is found in the spongy part of bone such as epiphysis.
• Redbone marrow gives rise to RBCs, monocytes, neutrophils, eosinophils, basophils and platelets.  
• Redbone marrow is abundant in the skeleton during foetal life and at the birth. However, it degenerates with age. 

      2. Yellow bone marrow:

• This type of bone marrow is found to be present in the shaft of long bones.
• As the name suggests, the colour of this bone marrow is yellow and it has fatty tissue.
• Yellow bone marrow takes over the function of red bone marrow and produces blood corpuscles in case of emergency (loss of blood).