Question

b) Explain the structure of bone and cartilage tissues, how this relates to their functions and explain the differences between them.

c) Explain the key conditions for adequate bone development and maintenance

Answer 1

b) Bone and cartilage are types of connective tissues in the body. In simple terms, a bone is hard tissue that forms the skeletal structure of the body while cartilage is not as hard and rigid as bone and present in ear, nose, and joints. Cartilage covers the ends of the bones and acts as a shock absorber to prevent bones from rubbing against each other.

The structure of bone and their functions: The skeletal system forms the mechanical framework of the body. The bones themselves are formed from several different connective tissues including bone tissue, periosteum, red bone marrow, yellow bone marrow, and Endosteum. Bone tissue is of two types -- compact bone and spongy bone. The function of bone is to provide skeleton and to provide the framework to body. It also provides mechanical protection for internal organs and reduces the risk of injury. It also helps in motion using associated muscles contraction. Bone tissues stores minerals like calcium and phosphorus. Bones release minerals into the blood to maintain the minerals in the body. It also produce blood cells. This process takes place in the red bone marrow inside larger bones.

The structure of cartilage tissues and their functions: Cartilage is connective tissue. It consists of a collagen and elastic fibres embedded in a rubbery ground substance. The surface of most of the cartilage in the body is surrounded by a membrane of dense irregular connective tissue called perichondrium. This is important to remember especially because, unlike other connective tissues, cartilage contains no blood vessels or nerves except in the perichondrium. There are three different structures of cartilage -- hyaline cartilage, fibrocartilage, and elastic cartilage.

Hyaline cartilage is the most abundant of the three types of cartilage. It consists of a bluish-white, shiny ground elastic material. These tissues provide smooth surfaces. It enables tissues to move/slide easily over each other. It also provides flexibility and support.

Fibrocartilage is a tough form of cartilage that consists of chondrocytes. It provides support and rigidity to attached/surrounding structures. It is found in Calli, Intevertebral discs, Pubic symphysis.

Elastic cartilage is yellowish in colour. These are located in a threadlike network of elastic fibres. These provide support to surrounding structures and helps to maintain the shape of the area in which it is present.

Difference between bone and cartilage tissues

	Bone	Cartilage
Types	Bones are either compact or spongy. It is classified into long, short, flat, irregular, sesamoid and sutural bones.	Three types: Hyaline cartilage, fibrocartilage and elastic cartilage.
Structure	Bones are made up mostly of osteoblasts, osteocytes, and osteoclasts. A bone is highly vascularized.	Cartilages comprise chondroblasts, precursor cells, chondrocytes, and a dense matrix of collagen and elastic fibers. Cartilage is avascular.
Function	Bones protect the internal organs against mechanical damage, assist in the movement, provide a framework and shape for the body. It stores minerals, and produce red blood & white blood cells.	It reduces friction at joints, supports the respiratory tract, acts as shock absorbers between weight-bearing bones. It maintains the shape and flexibility of fleshy appendages.
Location	Bones make up the majority of the axial and appendicular skeleton.	Cartilage is a much softer, more pliable component that is mostly found in between joints of bones.

C) The growth and development of the human skeleton requires an adequate supply of many different nutritional factors. Balanced nutritional requirement is the main requirement for the development and maintenance of a healthy skeleton. Physical activities and exercise are also major factor which effects the development of bones. Maintenance of adequate bone strength is linked to maintain the adequate muscle mass and function.