Skeletal and Muscular System

The stapes is one of the three ossicles (tiny bones) in the middle ear and measures approximately 2-3mm in length. It is the smallest and lightest bone in the entire human body, transmitting sound vibrations from the incus to the inner ear.

It is the smallest bone found in our body and is present in the ear.

The femur, or thigh bone, is the largest and longest bone in the human body. It extends from the hip to the knee and can withstand tremendous forces during walking and running. The stapes is the smallest bone, while 'forearm bone' and 'knee bone' are not specific enough: there are two forearm bones (radius and ulna) and the knee primarily contains the patella.

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Chronic recurrent multifocal osteomyelitis is a rare condition in which the bones have lesions, inflammation, and pain. Its definition is evolving. It is an autoimmune disease that has symptoms similar to osteomyelitis, but without the infection.

Cartilage is a type of connective tissues composed of special cells known as chondrocytes along with collagen or yellow elastic fibres. The fibres and the cells are embedded in a firm gel like matrix rich in mucopolysaccharides. Cartilage is not as hard and rigid as bone. It is much more flexible and elastic.

A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signalling. Chemical signalling occurs via synapses, specialized connections with other cells/

Chondrocytes are the only cells found in cartilage. They produce and maintain the cartilaginous matrix, which consists mainly of collagen and proteoglycans.

Bone marrow is the flexible tissue found in the interior of bones. In humans, marrow in large bones produces new blood cells. It constitutes 4% of the total body mass of humans, i.e. , approximately 2.6 kg (5.7 lbs.) in adults weighing 65 kg or 143 lbs. Bone marrow also prevents the backflow of lymph, working as a vital part of the lymphatic system.

Cartilage has no blood vessels or lymphatics and the nutrition of the cells diffuses through the matrix. This explains the slow  healing  in cartilages.

The perichondrium is a layer of dense irregular connective tissues which surrounds the cartilage of developing bones. It consists of two separate layers: an outer fibrous layer and inner chondrogenic layer. The fibrous layer contains fibroblasts, which produce collagenous fibres.

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