Explained
How a cat anatomy works.
Built to hunt
Every part of a cat's body is shaped by its life as a small predator that stalks, pounces and climbs. This stylised model shows three layers you can switch on and off: the skin, the skeleton and four key organs, the brain, heart, lungs and stomach. It isn't a veterinary diagram, but the arrangement and the facts follow standard feline anatomy.
Start with the skeleton. A cat's spine is long and very flexible, which lets it arch its back, twist in mid-air and stretch its stride when sprinting. The tail continues the spine with a chain of small vertebrae and helps with balance on narrow perches. Cats walk on their toes rather than on the whole foot, a posture called digitigrade, which effectively lengthens the legs and keeps footsteps quiet. Unusually, a cat's collarbones float in muscle instead of joining the shoulder to the breastbone, so its front legs can move freely and its shoulders can fit through narrow gaps. The ribcage, usually 13 pairs of ribs, protects the heart and lungs.
Inside the chest and belly
The heart has four chambers, just like ours. The right side pumps blood to the lungs to collect oxygen; the left side sends it on around the body. The two lungs fill most of the chest, and air travels down branching tubes to tiny air sacs called alveoli, where gas exchange happens. Behind the diaphragm sits the stomach. Cats are obligate carnivores, which means they must eat animal tissue to get certain nutrients, such as the amino acid taurine. They also can't taste sweetness, because one of the genes needed for the sweet taste receptor doesn't work in cats.
Senses and the brain
The brain sits in a rounded skull with large eye sockets. Forward-facing eyes give overlapping fields of view, which helps a cat judge distance before it leaps. The cerebellum, at the back of the brain, coordinates the fine balance behind those leaps and landings. Whiskers are deeply rooted, nerve-rich hairs that pick up tiny air movements and help a cat feel its way in the dark. And the purr? It's produced by rapid twitching of the muscles of the larynx, the voice box, as the cat breathes in and out. Tap the cat in play mode to hear it, in spirit at least.
Parts glossary
- Skin and fur
- The skin and coat insulate and protect the body and are packed with touch receptors. Whiskers are thick, deeply rooted hairs that sense air movement and nearby objects.
- Skull
- The skull protects the brain and holds large, forward-facing eyes that help a cat judge distance before it pounces.
- Spine and tail
- A long, very flexible backbone lets a cat arch, twist and stretch its stride when running. The tail vertebrae continue the spine and help with balance.
- Ribcage
- Curved ribs protect the heart and lungs and move with the breathing muscles. Fun fact: Cats usually have 13 pairs of ribs.
- Leg bones
- Cats walk on their toes rather than flat-footed, which effectively lengthens the leg for speed and quiet stalking. Fun fact: A cat's collarbones aren't joined to the rest of the skeleton, which helps its shoulders squeeze through narrow gaps.
- Brain
- The brain processes signals from the senses and controls movement. The cerebellum at the back coordinates the precise balance behind a cat's jumps and landings.
- Heart
- A four-chambered heart, like ours, pumps blood through the lungs to pick up oxygen and then around the body.
- Lungs
- Two spongy lungs fill most of the chest. Air reaches tiny sacs called alveoli, where oxygen passes into the blood and carbon dioxide passes out.
- Stomach
- Cats are obligate carnivores: their digestive system is built for meat, and they need nutrients such as taurine that come from animal food. Fun fact: Cats can't taste sweetness, because one of the genes for the sweet taste receptor doesn't work in cats.
