Types of Cartilage

The speaker begins by explaining the skeletal system, comprising cartilage and bone as two types of connective tissue. They elaborate on the different types of connective tissues, emphasizing the supporting connective tissue, particularly cartilage, which lacks blood vessels and nerves. The speaker discusses the structure of connective tissue, including cells, matrix, collagen, elastic fibres, and chemical substances, with a focus on cartilage.

Cartilage is described as having chondroblasts and chondrocytes, where chondroblasts can divide and lay down matrix until they become chondrocytes, losing the ability to divide. The matrix contains collagen and elastic fibres, and the ground substance includes chondroitin sulphate. The speaker notes the avascular nature of cartilage, emphasizing its presence in areas like the trachea, nose, and joints, providing smooth surfaces to reduce friction and endure stress.

Three types of cartilage are introduced: hyaline cartilage, fibrocartilage, and elastic cartilage. Hyaline cartilage, the most abundant type, is described as glassy under a microscope and is crucial in the embryonic and foetal skeleton. It is present in locations such as the trachea, nose, and articular surfaces of joints. The speaker highlights its avascular nature, leading to issues like osteoarthritis with age. Fibrocartilage, the second type, is characterized by a dense arrangement of collagen fibres and is found in intervertebral discs and certain joints.

It provides strength and rigidity due to the thick bundles of collagen fibres. The third type, elastic cartilage, contains an elastic fibre network, seen in structures like the ear and epiglottis. The epiglottis, shaped like a leaf, plays a crucial role in swallowing, preventing food and drink from entering the respiratory passages.

In summary, the speaker provides a detailed explanation of the skeletal system's connective tissues, focusing on cartilage and its various types. They emphasize the structural components, locations, and functions of each cartilage type, shedding light on their importance in the body's mechanical support and functionality.