Question

How does cartilage receive nutrients?

Answer 1

The type of connective tissue that is softer and firmer than bone is called cartilage. It is often considered a precursor to the bone. It forms an important structural component of the body.

Complete answer:
The tissue that connects, supports, and separates various tissues in our body is called the connective tissue. It is mesodermal in origin and is the most abundant and widely distributed tissue in our body. It is made up of extracellular matrix and cells. It serves various functions like- storage of reserve fuels, protection of various tissues and organs, transportation of substances within the body, support to the body and its organs, binding of various tissues in our bodies, providing insulation to various organs and tissues, etc.
Based on the structure of the extracellular matrix and cells present, connective tissue can be classified as

Connective tissue proper- They are found throughout the body. They are further subdivided
into two categories- Loose connective tissue and Dense connective tissue.

Special connective tissue- They have specific cells and are present in specific places- and have specific functions. They consist of reticular connective tissue, adipose tissue, cartilage, bone, blood, and embryonic connective tissue.

Cartilage is a type of special connective tissue and is flexible in its structure. They are thin and avascular and cannot be easily compressed by the- external forces due to the presence of flexibility in their structure. The cartilage is composed of an extracellular matrix and cells like- chondrocytes and chondroblasts. They do not contain any blood vessels or nerves (avascular and aneural). There are three types of cartilages found in our bodies. They are- Hyaline cartilage, Fibrous cartilage, and elastic cartilage. Fibrous cartilage is the toughest cartilage present in our body- and hyaline cartilage is the most abundant cartilage of our body.

The cartilage is not supplied with nutrients due to the lack of blood vessels in their structures. The cartilage receives nutrition through the process of diffusion. Diffusion is the movement of liquids and gases from a region of higher concentration to a region of lower concentration. The nutrients diffuse from a high nutrient-rich area of dense connective tissues to these tissues. These high nutrient-rich areas are- perichondrium and synovial fluid.

The perichondrium is a dense irregular connective tissue layer. It is present around various cartilages in our body- like elastic cartilages. It has blood capillaries that diffuse nutrients to the core of the cartilage. The oxygen and nutrients can pass through these tissues without any obstruction. Hence, they strengthen and nourish our cartilage.

The synovial fluid is a viscous fluid found in the cavities of the synovial joints. It reduces the friction between the articular cartilage. It is present between the joints and helps in the- cushioning of the bones. The synovial fluid is rich in nutrients and diffuses these nutrients to the cells of the cartilage called- Chondrocytes. It transports water and other important solutes like glucose through it. It even removes the waste products from the cartilage. It is an important source of nutrients for articular cartilage present in the cavity of synovial joints.
The chondrocytes are scattered throughout the cartilage and receive nutrients from the nearby gel-like matrix or structures.

Note: The hyaline cartilage is found- in the nose, trachea, larynx, and bronchi. They are also found- at the ending of the joints and ribs. The fibrous cartilage is present in the intervertebral discs at the ligaments and tendons. The elastic cartilage is mainly found in the ear.