raajat

Raajat (Finnish for limbs) are appendages of the vertebrate body that enable movement, manipulation, and interaction with the environment. In humans, raajat are divided into two pairs: the upper limbs (arms, forearms, hands) and the lower limbs (thighs, legs, feet). In other animals, raajat may take the form of wings, fins, flippers, or legs, reflecting adaptations to different modes of locomotion.

Anatomically, the upper limb includes the humerus in the arm, the radius and ulna in the forearm, and the carpal, metacarpal, and phalangeal bones of the hand. The lower limb comprises the femur, patella, tibia, and fibula, with tarsal, metatarsal, and phalangeal bones in the foot. Joints such as the shoulder, elbow, wrist, hip, knee, and ankle provide a range of movements. Muscles, tendons, ligaments, nerves, and blood vessels support movement and sensation; motor nerves from the brachial plexus serve the upper limb, while the lumbosacral plexus serves the lower limb.

Developmentally, limb formation begins with limb buds in the embryo and is guided by genetic and molecular signals, including HOX genes. Variations in limb formation can lead to conditions such as polydactyly (extra digits), syndactyly (fused digits), or limb reduction.

Functionally, raajat enable locomotion, balance, and precise manipulation of objects, contributing to daily tasks and complex activities. Clinically relevant topics include injuries such as fractures, sprains, and dislocations, as well as nerve or vascular injuries and degenerative conditions like arthritis. Rehabilitation may involve physical therapy, surgery, and, in cases of amputation, the use of prosthetics or orthotics.