Cartilage : Structure, Function and its Types MCQ - Practice Questions with Answers

• It is the soft skeletal tissue found more abundantly in vertebrate embryos because the bones of the adult skeleton are cartilaginous during early stages. 
• Cartilage is also found in the body of adult vertebrates. 
• Cartilage is described as being avascular.
• Cartilage cells receive their nutrition through diffusion in the perichondrium of cartilage canals. 

Structure of cartilage: Cartilage consists of cartilage cells embedded in a ground substance.

Cartilage cells:  

• A cartilage cell is present in a fluid-filled space called cartilage lacuna
• Young cartilage cells are small, flattened and have small projections. These cells are called chondroblast.
• Mature cartilage cells are larger, rounded with a few projections. These cells are called chondrocytes. 

Ground substances: 

• It is made up of water, proteoglycans, lipids, collagen, non-collagenous proteins and collagen fibres. 
• The core protein is aggrecan while the carbohydrates are glycosaminoglycans.
• Chondroitin sulphate, keratin sulphate and hyaluronic acid are also present.

Cartilage is of three types i.e. hyaline cartilage, fibrous cartilage and calcified cartilage. 

Hyaline cartilage :

• It is made up of the clear, large amount of translucent slightly elastic matrix having fewer fibres. 
• It forms articular surface at the joints of long bones and is called articular cartilage. 
• It also forms rings of trachea and bronchi, sternal parts of ribs, hyoid apparatus, nasal septum and part of the larynx. 
• Hyaline cartilage forms most of the embryonic skeleton.

Fibrous cartilage :

• It is made up of well-developed fibres in the matrix. 
• Fibrous cartilage can be of two types based on the type of fibres:
• White fibrous cartilage: In this type, the matrix possesses white fibres. It is the strongest cartilage. It is found in the intervertebral discs and in the pubic symphysis. 
• Yellow elastic fibrous cartilage: The matrix consists of yellow fibres. Presence of yellow fibres makes this cartilage elastic. It is found in-ear pinna. 

Calcified cartilage :

• This cartilage is not found in the human body but presents in the skeleton of sharks, frogs, etc. 
• In calcified cartilage, the matrix of cartilage is laden with calcium.