Question

Where would you expect to find spongy bone in a long bone? What are its functions? (page 230 )

Short answer

Spongy bone is primarily found in the epiphyses (ends) of long bones, where it provides structural support, shock absorption, and houses bone marrow for blood cell production. Additionally, spongy bone stores crucial minerals such as calcium and phosphorus, which are essential for the body's functions.

Step-by-step solution

1. Understanding the components of a long bone

A long bone has three main parts: (i) diaphysis - the central shaft, (ii) epiphyses - the rounded ends, and (iii) metaphysis - the region between the shaft and the ends, which contains the epiphyseal growth plate.

2. Location of spongy bone in a long bone

Spongy bone is found primarily in the epiphyses (ends) of the long bones. This type of bone is also known as cancellous, or trabecular bone, and it has a lattice-like structure with many open spaces filled with bone marrow.

3. Functions of spongy bone

An analysis of spongy bone reveals the following functions: (i) Support: Spongy bone provides structural support to the long bone by evenly distributing the weight it bears. (ii) Shock absorption: The open, lattice-like structure of spongy bone allows it to absorb stresses applied to the bone, thus reducing the risk of fractures. (iii) Bone marrow production: The spaces within the spongy bone contain bone marrow, which is responsible for producing blood cells and is essential for overall health. (iv) Mineral storage: Like compact bone, spongy bone also stores minerals such as calcium and phosphorus, which can be released into the bloodstream as needed for the body's functions. In conclusion, spongy bone is an essential component of long bones because of its many functions in providing support, shock absorption, bone marrow production, and mineral storage.