Permanent dentition teethCats are carnivores that have highly specialized teeth. There are four types of permanent dentition teeth that structure the mouth: twelve '' incisors, four
Deciduous dentition teethA 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.
TongueThe 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. A cats 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.
EarsSimilar to dogs, cats have sensitive ears that allow them to move each ear independently of one another. 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 ears pointing upward. Unlike with dogs, flap-eared breeds are extremely rare (''
NoseCats 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
LegsCats are digitigrades, which means that they walk on their toes, just like dogs. The advantage of this is that cats (and other digitigrades) are more agile than other animals. Most animals have ground reaction forces (GRFs) 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. The cat's
ClawsLike nearly all members of the family
Temperature and heart rateThe normal body temperature of a cat is between . A cat is considered ''
SkinCats 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
ScruffThe 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 pouchesSome cats share common traits due to heredity. One of those is the primordial pouch, sometimes referred to as "spay sway" by owners who notice it once the cat has been spayed or neutered. 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.
SkeletonCats have seven cervical vertebrae like almost all mammals, thirteen
SkullThe cat skull is unusual among mammals in having very large eye sockets and a powerful and specialized jaw. Compared to other felines, domestic cats have narrowly spaced canine teeth, adapted to their preferred prey of small rodents.
Internal abdominal obliqueThis muscle's origin is the lumbodorsal fascia and ribs. Its
Transversus abdominisThis muscle is the innermost abdominal muscle. Its origin is the second sheet of the lumbodorsal fascia and the pelvic girdle and its insertion is the linea alba. Its action is the compression of the abdomen.
Rectus abdominisThis muscle is under the extensive aponeurosis situated on the
DeltoidThe deltoid muscles lie just lateral to the trapezius muscles, originating from several fibers spanning the clavicle and scapula, converging to insert at the humerus. Anatomically, there are only two deltoids in the cat, the ''acromiodeltoid'' and the ''spinodeltoid''. However, to conform to human anatomy standards, the clavobrachialis is now also considered a deltoid and is commonly referred to as the ''clavodeltoid''.
AcromiodeltoidThe acromiodeltoid is the shortest of the deltoid muscles. It lies lateral to (to the side of) the clavodeltoid, and in a more husky cat it can only be seen by lifting or reflecting the clavodeltoid. It originates at the acromion process and inserts at the deltoid ridge. When contracted, it raises and rotates the humerus outward.
SpinodeltoidA stout and short muscle lying posterior to the acromiodeltoid. It lies along the lower border of the scapula, and it passes through the upper forelimb, across the upper end of muscles of the upper forelimb. It originates at the spine of the scapula and inserts at the deltoid ridge. Its action is to raise and rotate the humerus outward.
MasseterThe Masseter is a great, powerful, and very thick muscle covered by a tough, shining fascia lying
TemporalisThe temporalis is a great mass of mandibular muscle, and is also covered by a tough and shiny fascia. It lies
OcularCats have three eyelids. The cat's third eyelid is known as the nictitating membrane. It is located in the inner corner of the eye, which is also covered by conjunctiva. In healthy cats, the conjunctiva of the eyelids is not readily visible and has a pale, pink color.
IntegumentalThe two main integumental muscles of a cat are the '' platysma'' and the ''cutaneous maximus''. The ''cutaneous maximus'' covers the dorsal region of the cat and allows it to shake its skin. The ''platysma'' covers the neck and allows the cat to stretch the skin over the pectoralis major and deltoid muscles.
Neck and back
RhomboideusThe rhomboideus is a thick, large muscle below the trapezius muscles. It extends from the vertebral border of the scapula to the mid-dorsal line. Its origin is from the neural spines of the first four thoracic vertebrae, and its insertion is at the vertebral border of the scapula. Its action is to draw the scapula to the dorsal.
Rhomboideus capitisThe Rhomboideus capitis is the most cranial of the deeper muscles. It is underneath the clavotrapezius. Its origin is the superior nuchal line, and its insertion is at the scapula. Action draws scapula cranially.
SpleniusThe Splenius is the most superficial of all the deep muscles. It is a thin, broad sheet of muscle underneath the clavotrapezius and deflecting it. It is crossed also by the rhomboideus capitis. Its origin is the mid-dorsal line of the neck and fascia. The insertion is the superior nuchal line and atlas. It raises or turns the head.
Serratus ventralisThe serratus ventralis is exposed by cutting the wing-like
Serratus DorsalisThe serratus dorsalis is medial to both the scapula and the serratus ventralis. Its origin is via apoeurosis following the length of the mid-dorsal line, and its insertion is the dorsal portion of the last ribs. Its action is to depress and retracts the ribs during breathing.
IntercostalsThe intercostals are a set of muscles sandwiched among the ribs. They interconnect ribs, and are therefore the primary respiratory skeletal muscles. They are divided into the ''external'' and the ''internal subscapularis''. The origin and insertion are in the ribs. The intercostals pull the ribs backwards or forwards.
PectoantebrachialisPectoantebrachialis muscle is just one-half-inch wide and is the most superficial in the pectoral muscles. Its origin is the manubrium of the
Pectoralis majorThe pectoralis major, also called ''pectoralis superficialis'', is a broad triangular portion of the pectoralis muscle which is immediately below the pectoantebrachialis. It is smaller than the pectoralis minor muscle. Its origin is the
Pectoralis minorThe pectoralis minor muscle is larger than the pectoralis major. However, most of its anterior border is covered by the pectoralis major. Its origins are ribs three–five, and its insertion is the coracoid process of the scapula. Its actions are the tipping of the scapula and the elevation of ribs three–five.
XiphihumeralisThe most posterior, flat, thin, and long strip of pectoral muscle is the xiphihumeralis. It is a band of parallel fibers that is found in felines but not in humans. Its origin is the xiphoid process of the sternum. The insertion is the humerus.
TrapeziusIn the cat there are three thin flat muscles that cover the back, and to a lesser extent, the neck. They pull the scapula toward the mid-dorsal line, anteriorly, and posteriorly.
ClavotrapeziusThe most anterior of the trapezius muscles, it is also the largest. Its fibers run obliquely to the ventral surface. Its origin is the superior nuchal line and median dorsal line and its insertion is the clavicle. Its action is to draw the clavicle dorsally and towards the head.
AcromiotrapeziusAcromiotrapezius is the middle trapezius muscle. It covers the dorsal and lateral surfaces of the scapula. Its origin is the neural spines of the cervical vertebrae and its insertion is in the metacromion process and fascia of the clavotrapezius. Its action is to draw the scapula to the dorsal, and hold the two scapula together.
SpinotrapeziusSpinotrapezius, also called ''thoracic trapezius'', is the most posterior of the three. It is triangular shaped. Posterior to the acromiotrapezius and overlaps latissimus dorsi on the front. Its origin is the neural spines of the thoracic vertebrae and its insertion is the scapular fascia. Its action is to draw the scapula to the dorsal and caudal region.
Digestive systemThe digestion system of cats begins with their sharp teeth and abrasive tongue papillae, which help them tear meat, which is most, if not all, of their diet. Cats naturally do not have a diet high in carbohydrates, and therefore, their saliva doesn't contain the enzyme amylase. Food moves from the mouth through the esophagus and into the stomach. The gastrointestinal tract of domestic cats contains a small cecum and unsacculated colon. The cecum while similar to dogs, doesn't have a coiled cecum. The stomach of the cat can be divided into distinct regions of motor activity. The proximal end of the stomach relaxes when food is digested. While food is being digested this portion of the stomach either has rapid stationary contractions or a sustained tonic contraction of muscle. These different actions result in either the food being moved around or the food moving towards the distal portion of the stomach. The distal portion of the stomach undergoes rhythmic cycles of partial depolarization. This depolarization sensitizes muscle cells so they are more likely to contract. The stomach is not only a muscular structure, it also serves a chemical function by releasing hydrochloric acid and other digestive enzymes to break down food. Food moves from the stomach into the small intestine. The first part of the small intestine is the duodenum. As food moves through the duodenum, it mixes with bile, a fluid that neutralizes stomach acid and emulsifies fat. The pancreas releases enzymes that aid in digestion so that nutrients can be broken down and pass through the intestinal mucosa into the blood and travel to the rest of the body. The pancreas doesn't produce starch processing enzymes because cats don't eat a diet high in carbohydrates. Since the cat digests low amounts of glucose, the pancreas uses amino acids to trigger insulin release instead. Food then moves on to the jejunum. This is the most nutrient absorptive section of the small intestine. The liver regulates the level of nutrients absorbed into the blood system from the small intestine. From the jejunum, whatever food that has not been absorbed is sent to the ileum which connects to the large intestine. The first part of the large intestine is the cecum and the second portion is the colon. The large intestine reabsorbs water and forms fecal matter. There are some things that the cats are not able to digest. For example, cats clean themselves by licking their fur with their tongue, which causes them to swallow a lot of fur. This causes a build-up of fur in a cat's stomach and creates a mass of fur. This is often thrown up and is better known as a
Female genitaliaIn the female cat, the genitalia includes the uterus, the vagina, the genital passages and teats. Together with the vulva, the
Male genitaliaIn the male cat, the genitalia includes two testicles and the penis, which is covered with small spines.
PhysiologyCats are familiar and easily kept animals, and their physiology has been particularly well studied; it generally resembles those of other carnivorous mammals, but displays several unusual features probably attributable to cats' descent from desert-dwelling species.
Heat toleranceCats are able to tolerate quite high temperatures: Humans generally start to feel uncomfortable when their skin temperature passes about , but cats show no discomfort until their skin reaches around , and can tolerate temperatures of up to if they have access to water.
Temperature regulationCats conserve heat by reducing the flow of blood to their skin and lose heat by evaporation through their mouths. Cats have minimal ability to sweat, with glands located primarily in their paw pads, and pant for heat relief only at very high temperatures (but may also pant when stressed). A cat's body temperature does not vary throughout the day; this is part of cats' general lack of circadian rhythms and may reflect their tendency to be active both during the day and at night.
Water conservationCats' feces are comparatively dry and their urine is highly concentrated, both of which are adaptations to allow cats to retain as much water as possible. Their kidneys are so efficient, they can survive on a diet consisting only of meat, with no additional water. They can tolerate high levels of salt only in combination with freshwater to prevent dehydration.Merck Veterinary Manual
Ability to swimWhile domestic cats are able to swim, they are generally reluctant to enter water as it quickly leads to exhaustion.
See also* Cat senses *