Anatomy

Diagram of the general anatomy of a male cat

Domestic cats are similar in size to the other members of the genusFelis, typically weighing between 4 kilograms (8 lb 13 oz) and 5 kilograms (11 lb 0 oz).^[20] However, some breeds, such as theMaine Coon, can exceed 11 kilograms (25 lb). Conversely, very small cats (less than 1.8 kilograms (3 lb 15 oz)) have been reported.^[32] The world record for the largest cat is 21.297 kilograms (46 lb 15.2 oz).^[33] The smallest adult cat ever officially recorded weighed around 1.36 kilograms (3 lb).^[34] Cats average about 23–25 centimeters (9–10 in) in height and 46 centimeters (18.1 in) in head/body length (males being larger than females), with tails averaging 30 centimeters (11.8 in) in length.^[35]

Cats have 7 cervical vertebrae like almost all mammals, 13thoracic vertebrae (humans have 12), 7 lumbar vertebrae(humans have 5), 3 sacral vertebrae like most mammals (humans have 5 because of their bipedal posture), and a variable number ofcaudal vertebrae in the tail (humans retain 3 to 5 caudal vertebrae, fused into an internal coccyx).^[36] The extra lumbar and thoracic vertebrae account for the cat's spinal mobility and flexibility. Attached to the spine are 13 ribs, the shoulder, and the pelvis.^[37] Unlike human arms, cat forelimbs are attached to the shoulder by free-floating clavicle bones, which allows them to pass their body through any space into which they can fit their heads.^[38]