Cat anatomy
Cat anatomy comprises the anatomical studies of the visible parts of the body of a domestic cat, which are similar to those of other members of the genus Felis.
Mouth
Permanent teeth
Cats are carnivores that have highly specialized teeth. There are four types of permanent teeth that structure the mouth: twelve incisors, four canines, ten premolars and four molars. The premolar and first molar are located on each side of the mouth that together are called the carnassial pair. The carnassial pair specialize in cutting food and are parallel to the jaw. The incisors located in the front section of the lower and upper mouth are small, narrow, and have a single root. They are used for grasping and biting food.Deciduous teeth
A cat also has a deciduous dentition prior to the formation of the permanent one. This dentition emerges seven days after birth and it is composed of 26 teeth with slight differences. The mouth will have smaller incisors, slender and strongly curved upper canines, vertical lower canines, and even smaller upper and lower molars. Although the upper and lower molars are smaller than the ones that arise during permanent dentition, the similarities are striking.Tongue
The cat's tongue is covered in a mucous membrane and the dorsal aspect has 5 types of sharp spines, or papillae. The 5 papillae are filiform, fungiform, foliate, vallate, and conical. Papillae allow a cat to groom itself. A cat's sense of smell and taste work closely together, having a vomeronasal organ that allows them to use their tongue as scent tasters, while its longitudinal, transverse, and vertical intrinsic muscles aid in movement.Ears
Like dogs, cats have sensitive ears that can move independently of each other. Because of this mobility, a cat can move its body in one direction and point its ears in another direction. The rostral, caudal, dorsal, and ventral auricular muscle groups of each ear comprise fifteen muscles that are responsible for this ability. Most cats have straight, triangular ears that point upward. Unlike with dogs, flap-eared breeds are extremely rare. When angry or frightened, a cat will lay back its ears to accompany the growling or hissing sounds it makes. Cats also turn their ears back when they are playing or to listen to a sound coming from behind them. The fold of skin forming a pouch on the lower posterior part of the ear, known as Henry's pocket, is usually prominent in a cat's ear. Its function is unknown, though it may assist in filtering sounds.Nose
Cats are highly territorial, and secretion of odors plays a major role in cat communication. The nose helps cats to identify territories, other cats and mates, to locate food, and has various other uses. A cat's sense of smell is believed to be about fourteen times more sensitive than that of humans. The rhinarium – the visible leathery part of the nose – is quite tough, to allow it to absorb rather rough treatment sometimes. The color varies according to the genotype of the cat. A cat's skin has the same color as the fur, but the color of the nose leather is probably dictated by a dedicated gene. Cats with white fur have skin susceptible to damage by ultraviolet light, which may cause cancer. Extra care is required when outside in the hot sun.Legs
Cats are digitigrades, which means that they walk on their toes, just like dogs. The advantage of this is that cats are more agile than other animals. Most animals have ground reaction forces at around two to three times their body weight per limb. But digitigrades have a higher GRF than other animals due to the increased weight on a smaller surface area, which would be about six times their body weight per limb.Toe tufts are commonly found on cats with medium to long coats. Clumps of fur that stick out at least beyond the paw pad can be considered tufts. In addition to soft paw pads, toe tufts help a cat to silently stalk its prey by muffling excess noise. However, outdoor cats tend to lose their toe tufts due to excessive abrasion on the rougher outdoor surfaces. This is in distinct contrast to indoor cats, who spend most of their time walking on carpet or smooth floors.
Cats are also able to walk very precisely. Adult cats walk with a "four-beat gait", meaning that each foot does not step on the same spot as any other. Whether they walk fast or slowly, a cat's walk is considered symmetric because the right limbs imitate the position of the left limbs as they walk. This type of locomotion provides a sense of touch on all four paws that is necessary for precise coordination.
Cats are also able to jump from greater heights without serious injury, due to the efficient performance of their limbs and ability to control impact forces. In this case, hindlimbs are able to absorb more shock and energy in comparison to the forelimbs, when jumping from surface to surface, as well as steer the cat for weight-bearing and breaking.
Claws
Like nearly all members of the family Felidae, cats have protractable claws. In their normal, relaxed position, the claws are sheathed with the skin and fur around the toe pads. This keeps the claws sharp by preventing wear from contact with the ground and allows the silent stalking of prey. The claws on the forefeet are typically sharper than those on the hind feet. Cats can voluntarily extend their claws on one or more paws. They may extend their claws in hunting or self-defense, climbing, "kneading", or for extra traction on soft surfaces. It is also possible to make a cooperative cat extend its claws by carefully pressing both the top and bottom of the paw. The curved claws can become entangled in carpet or thick fabric, which can cause injury if the cat is unable to free itself.Most cats have a total of 18 digits and claws: 5 on each forefoot, and 4 on each hind foot. The dewclaw is located high on the foreleg, is not in contact with the ground and is non-weight bearing.
Some cats can have more than 18 digits, due to a common mutation called polydactyly or polydactylism, which can result in five to seven toes per paw.
Temperature and heart rate
The normal body temperature of a cat is between. A cat is considered febrile if it has a temperature of or greater, or hypothermic if less than. For comparison, humans have an average body temperature of about. A domestic cat's normal heart rate ranges from 140 to 220 beats per minute, and is largely dependent on how excited the cat is. For a cat at rest, the average heart rate usually is between 150 and 180 bpm, more than twice that of a human, which averages 70 bpm. However, it has been monitored in the wild that cats are often running at higher daily temperatures in order to properly operate and when night falls we see a larger decrease in their body temperature when compared to other cats that might inhabit indoors. The reading on a group of stray cats that was observed in Australia showed a more robust circadian rhythm than a regular house cat.Skin
Cats possess rather loose skin, which allows them to turn and confront a predator or another cat in a fight, even when it has a grip on them. This is also an advantage for veterinary purposes, as it simplifies injections. In fact, the lives of cats with chronic kidney disease can sometimes be extended for years by the regular injection of large volumes of fluid subcutaneously.Scruff
The particularly loose skin at the back of the neck is known as the scruff, and is the area by which a mother cat grips her kittens to carry them. As a result, cats tend to become quiet and passive when gripped there. This behavior also extends into adulthood, when a male will grab the female by the scruff to immobilize her while he mounts, and to prevent her from running away as the mating process takes place.This technique can be useful when attempting to treat or move an uncooperative cat; however, since an adult cat is heavier than a kitten, a pet cat should never be carried by the scruff, but should instead have its weight supported at the rump and hind legs, and at the chest and front paws.
Primordial pouch
The primordial pouch, sometimes referred to as "spay sway" by owners who notice it once the cat has been spayed or neutered, is hereditary in some cats. It is located on a cat's belly. Its appearance is similar to a loose flap of skin that might occur if the cat had been overweight and had then lost weight. It provides a little extra protection against kicks, which are common during cat fights as a cat will try to rake with its rear claws. In wild cats, the ancestors of domesticated felines, this pouch appears to be present to provide extra room in case the animal has the opportunity to eat a large meal and the stomach needs to expand. This stomach pouch also allows the cat to bend and expand, allowing for faster running and higher jumping.Skeleton
Cats have seven cervical vertebrae like almost all mammals, thirteen thoracic vertebrae, seven lumbar vertebrae, three sacral vertebrae, and, except for Manx cats and other shorter tailed cats, twenty-two or twenty-three caudal vertebrae. The extra lumbar and thoracic vertebrae account for the cat's enhanced spinal mobility and flexibility, compared to humans. The caudal vertebrae form the tail, used by the cat as a counterbalance to the body during quick movements. Between their vertebrae, they have elastic discs, useful for cushioning the jump landings.The cat's vertebrae are held by muscles rather than by ligaments as in humans. This contributes to the cat's elasticity and ability to elongate and contract their back by curving it upwards or oscillating it along their vertebral line.
Unlike human arms, a cat's forelimbs are attached to the shoulders by free-floating clavicle bones, which allow them to pass their body through any space into which they can fit their heads.