Protein serves as the basic structural molecule of all tissues in your body. Approximately one quarter of all the protein in your body is collagen 1.

Collagen is the main protein found in connective tissue 1. Cartilage is one type of connective tissue comprised of cells called chondrocytes and a strong, flexible matrix of collagen, protein and sugar 1. Collagen and cartilage perform different roles, but your body depends on both to function normally 1.

What Collagen and Cartilage Have in Common

Strength and the ability to bend under tension are two characteristics of collagen, which is the main component in ligaments and tendons 1. Ligaments bind bones to bones while tendons bind muscles to bones. The strength and flexibility of collagen allow you to move with ease 1.

Strength and flexibility are two characteristics of cartilage, which cover the ends of your bones at a joint. Cartilage allows one bone to glide over another as it protects and prevents bones from rubbing against each other.

How Collagen and Cartilage Differ

Apart from their complimentary roles in the skeletomuscular system, collagen and cartilage have different and distinct functions in your body 1. There are three types of cartilage -- hyaline, elastic and fibrocartilage. Hyaline is the most abundant type of cartilage in your body. It is the supportive tissue in your ears, nose, trachea, larynx and smaller respiratory tubes.

In addition to cushioning your bones at a joint, hyaline cartilage is found where the ribs attach to the sternum. Elastic cartilage is found in your earlobes, eusatachian tubes and epiglottis. Fibrocartilage has a spongy appearance and cushions both the intervertebral disks and the pubic symphysis, which is in your pelvic area. Collagen is a primary component in the inner layer of your skin called the dermis 1. It provides strength, support and elasticity to your mucous membranes, nerves and blood vessels. Collagen can be found in the connective tissue that surrounds and protects delicate organs such as the kidneys and spleen 1.

Consequences of Collagen Degradation

Exposure to the sun’s ultraviolet rays, smoking and normal aging are factors that contribute to collagen degradation or loss 1. Wrinkles and sagging skin are the most obvious signs.

Scurvy, which is a disease caused by a vitamin C deficiency, affects the synthesis of collagen within the body’s cells 1. Less collagen is formed and whatever collagen is synthesized is of inferior quality 1. As a result, bones become brittle, new bones cannot form and old scars or wounds can rupture. Scleroderma, lupus and rheumatoid arthritis are examples of connective tissue diseases. Connective tissue disease collectively refers to conditions in which a person’s immune system mistakenly attacks collagen in connective tissue 1.

Consequences of Cartilage Degradation and Loss

Cartilage degradation refers to the breakdown and loss of cartilage caused by wear and tear. Osteoporosis is the most common joint disorder resulting from cartilage loss.

Without the protective cushion of cartilage, bones rub together and cause pain, inflammation and joint stiffness. It is not uncommon for bone spurs to develop around the unprotected joints. Ligaments and muscles at the hip joint become weak and stiff. Cartilage loss can also result from a tear in the meniscus, or the cartilage disk that cushions the knee joint.