Anatomy of a guinea pig. Anatomical and physiological characteristics of guinea pigs Description of the guinea pig species according to morphological criteria

Guinea pigs have only 258 bones in their body. The spine has 34 bones and consists of 7 cervical, 12 thoracic, 6 lumbar, 4 sacral and 7 caudal vertebrae. However, despite the presence of caudal vertebrae, they do not have a tail itself. Also, these rodents almost completely lack collarbones. The front legs have 43 bones each, the hind legs have 36, and the remaining bones are in the skull, ribs and sternum. Guinea pigs have very short legs, with the front legs being much shorter than the back ones. The number of fingers with which the animal’s limbs are equipped varies. There are 4 toes on each front paw of a guinea pig, and 3 on each hind paw. In appearance, they resemble hooves. Guinea pigs, having many bones in their paws, are not able to jump well and land softly; any fall can lead to a broken leg, so they must be under your supervision.

Guinea pigs have 20 teeth, but without special tools you can only see 4 incisors in the front of the mouth, 2 at the top and 2 at the bottom. These incisors are used for grasping and biting pieces of food. The remaining teeth at the back of the mouth are molars and are used for chewing food. Guinea pigs chew in a side-to-side motion and can make 200 of these movements per minute. For a guinea pig, mealtime is the happiest time! A guinea pig's teeth are constantly growing and in order to avoid overgrowing them, the animal must constantly chew, because. Grinding of teeth occurs exclusively during grinding of hard food.

ORGANS OF THE ORAL CAVITY
1. Hard palate
2. Middle tubercle (tubercle) of the palate
3. Soft palate
4. Palatoglossus arch
5. Throat
6. Epiglottis
7. Root of tongue
8. Body of the tongue
9. Top of the tongue
10. Lower incisors
11. Upper incisors
12. Intraoral fat layer of the upper lip
13. Incisive palatal ridge
14. Condylar process of the lower jaw
15. Upper premolar
16. Upper molars
17. Lower premolar
18. Lower molars

Internal structure:

1- incisors
2 - lymph glands
3 - larynx
4 - salivary glands
5 - esophagus
6 - heart
7 - lungs (they are not visible in the figure)
8 - diaphragm
9 - stomach
10 - liver (4 lobes)
11 - gallbladder
12 - duodenum
13 - small intestine
14 - cecum
15 - large intestine
16 - bladder
17 - ureter

18 - anus

The eyes are large and set on the sides of the head. They have a wide field of vision to spot predators from any angle on earth. However, they are not able to see what is happening in front of their noses! Their vision has not yet been fully studied, although it is known that pigs can distinguish colors and distinguish moving objects well.

Due to the position of their eyes, guinea pigs are able to look both forward and to the sides without turning their heads. Thus, they have a relatively wide field of vision, which is especially important for protection from their natural enemies in the wild. Guinea pigs can at least distinguish between the colors red, yellow, green and blue. This also plays a role when eating. But it should be noted that pigs are myopic, and therefore they trust their eyes least of all.

Nose.
Guinea pigs have a very well-developed sense of smell and they also have whiskers around their nose, eyes and mouth that are very sensitive to the touch. The senses of smell and touch are very important in selecting food (their favorite pastime is eating), as due to the structure of their eyes they are unable to see what they eat.

Guinea pigs' sense of smell is focused primarily on contact with each other and on sexual behavioral norms. For example, their urine plays an important role in marking. Thus, males who are ready for mating inject urine, females who are not in heat, along with hostile behavior, use scent to demonstrate to the male that they are not ready for mating.

Guinea pigs rely primarily on their sense of smell.

Guinea pigs in a social community recognize each other by smell. This applies not least to the loss after re-identification of young animals.

It was noted that this group-specific identification, after repetition for several days, disappears in adult animals. Marking territory with secretions, as well as urine, explains why guinea pigs feel at ease in their familiar environment and are very restless and insecure in an unfamiliar one. This later manifests itself in their timid behavior.

Compared to humans, guinea pigs have a heightened sense of smell. It is about a thousand times more developed than in humans. Thus, they perceive a variety of odors that are not noticed by people at all, and therefore can be excited for various reasons.

Guinea pigs are accustomed to living and playing in small groups.

Likewise, when eating, guinea pigs’ sense of smell plays a very important role in distinguishing between healthy and unhealthy food. The same applies to identifying different individuals.

Ears.
The cochlea of the inner ear in a guinea pig has four turns, but in mice and rats, even in humans there are only two and a half. Thus, guinea pigs have relatively more space for auditory cells, resulting in particularly good hearing. If a person can perceive sounds from 20,000 Hz (child) to 15,000 Hz (adult), then guinea pigs perceive sounds with a frequency of up to 33,000 Hz.
Guinea pigs have very sensitive hearing, and hear sound frequencies that are inaudible to the human ear. They can hear you open the refrigerator door from a very long distance away!
The guinea pig has nothing to do with the sea or pigs. The very name “pig” probably appeared due to the structure of the animals’ heads. Maybe that's why they called her piggy. These animals are characterized by an elongated cylindrical body, a short neck, and relatively short legs; The forelimbs have four and the hind limbs have three fingers, which are armed with ribbed claws. Tailless pig. This also explains the name of the animal. In a calm state, a guinea pig's voice resembles the gurgling of water, but in a state of fright it turns into a squeal. So the sound made by this rodent is very similar to the grunting of pigs, which is probably why it was called “pig”.

A female guinea pig has one pair of mammary glands located at the back of the abdomen.

The guinea pig belongs to the order of rodents, the pig family. The animal has two false molars, six molars and two incisors in each jaw. A characteristic feature of all rodents is that their incisors grow throughout their lives.

The incisors of rodents are covered with enamel - the hardest substance - only on the outer side, so the back of the incisor wears off much faster and thanks to this, a sharp, outer cutting surface is always preserved.

Incisors are used for gnawing various roughage (plant stems, root crops, hay, etc.). There are many known species of wild cavy. All of them are similar in appearance to domestic animals, they are tailless, but the color of the fur is the same color, most often gray, brown or brownish. Although the female has only two teats, there are often 3-4 babies in one litter. Pregnancy lasts about 2 months. The cubs are well developed, sighted, grow quickly and after 2-3 months they are already capable of giving birth to offspring. In nature there are usually 2 litters per year, but in captivity there are more.

The guinea pig is born with the most developed brain compared to other rodents. By the time of birth, the morphological development of the structures of the cerebral cortex ends. The nervous system of newborns is capable of providing adaptation to independent life.

Typically, the weight of an adult pig is approximately 1 kg, length is about 25 cm. However, the weight of individual specimens approaches 2 kg. The life expectancy for a rodent is relatively long - 8-10 years.

The heart of adult guinea pigs weighs 2.0-2.5 g. The average heart rate is 250-355 per minute. The heartbeat is weak and diffuse.

The lungs of guinea pigs are sensitive to mechanical stress and the actions of infectious agents (viruses, bacteria). The normal respiratory rate is 80-130 times per minute.

The gastrointestinal tract is well developed and, like other herbivores, relatively large. The volume of the stomach is 20 - 30 cm3. It is always filled with food. The intestine reaches a length of 2.3 m and is 10-12 times the length of the body.

Guinea pigs have good hearing and sense of smell. When kept indoors, guinea pigs behave calmly, are easy to train, quickly get used to it and recognize their owner. You can pick them up. Having good hearing, guinea pigs get used to the owner's voice, so you need to talk to them more often. However, when exposed to external stimuli unfamiliar to the animal, they are easily excited and shy.

If it is necessary to thoroughly examine the guinea pig, take it with your left hand behind the back and under the chest so that the thumb and forefinger cover the neck, and the other fingers immobilize the forelimbs and limit head movements. The right hand holds the back of the body.

The normal body temperature of guinea pigs is in the range of 37.5-39.5°C. An increase in temperature above 39.5°C indicates that your pet is sick.

With good care and maintenance, a guinea pig can live up to eight to ten years.

However, like any living creature, a guinea pig is susceptible to infectious and invasive diseases.

It is necessary to create good sanitary and hygienic living conditions, adequate nutrition, and prevent overcrowding of animals. It must be remembered that the guinea pig is afraid of dampness and drafts.

Having discovered unusual behavior of the animal - reduced motor activity, the absence of characteristic sounds usually made by healthy animals, you should take a closer look at the guinea pig. If the animal is lethargic, trembling, its fur is disheveled, or it has rapid breathing, decreased appetite, or loose stools, then it must be shown to a veterinarian.

As a laboratory animal, the guinea pig is irreplaceable due to its high sensitivity to pathogens of many infectious diseases of humans and farm animals. This ability of guinea pigs determined their use for the diagnosis of many infectious diseases of humans and animals (for example, diphtheria, typhus, tuberculosis, glanders, etc.).

In the works of domestic and foreign bacteriologists and virologists I.I. Mechnikova, N.F. Gamaleya, R. Koch, P. Ru and others, the guinea pig has always occupied and occupies one of the first places among laboratory animals.

Consequently, the guinea pig was and is of great importance as a laboratory animal for medical and veterinary bacteriology, virology, pathology, physiology, etc.

In our country, guinea pig is widely used in all areas of medicine, as well as in studying issues of human nutrition and especially in studying the effect of vitamin C.
Among its relatives are the well-known rabbit, squirrel, beaver, and the huge capybara, familiar only from the zoo.

The guinea pig is a typical representative of the rodent order. However, it differs in many ways from many of its counterparts. Pigs are smart, they know their owner, they can even be trained. In a word, this is an almost ideal pet. However, pigs have some specific anatomical features, and therefore require additional care and attention from the owners.

That is why it is important to find out all its physiological data before buying a guinea pig. Undoubtedly, such knowledge will help the owner to surround the pet with care and attention and provide decent living conditions.

Features in the structure

So, physiologically, the guinea pig has some differences from other related animals from the order of rodents. Firstly, its body has a cylindrical shape, 25 cm long. The fur is smooth and grows very quickly, up to 1 mm per day. Males are much larger than females and can sometimes reach a weight of one and a half kg, while the weight of females usually does not exceed a kilogram.

Guinea pig teeth

The rodent has sharp and well-developed incisors, which grow throughout the life of the animal. Sometimes the incisors reach such sizes that they can cause discomfort to the animal and even injure the tongue or lips. The pig has no fangs, and the molars have characteristic folds and tubercles.

The lower jaw is equipped with only ten teeth:

2 false roots,
6 indigenous
2 incisors.

The lower jaw is characterized by high mobility, which is expressed in the ability to move in different directions (and not just forward and backward). On the upper jaw there are:

2 false roots;
6 indigenous;
2 incisors.

Moreover, the incisors are shorter than those on the lower jaw. The front teeth have very strong enamel, but on the back teeth it is soft and therefore wears off quickly.

Skeleton

The guinea pig skeleton consists of 258 bones:

tail – 7 pcs.;
ribs – 13 pairs;
vertebrates – 34;
scull;
rib cage;
hind legs - 72.

However, a large number of bones does not mean their strength. The fragile bones of the animal’s limbs are especially prone to damage and fractures. Every owner should remember this.

Does a guinea pig have a tail?

The guinea pig has a tail, but it is small and almost invisible.

The caudal spine is made up of seven bones. These bones are too small and are located near the pelvis. This gives the impression that the guinea pig has no tail at all.

How many fingers does a guinea pig have?

The pig's limbs are very short; it is noteworthy that the front legs are shorter and the hind legs are longer. Outwardly, they resemble small hooves and are equipped with three fingers on the back and four on the front.

Basic rodent systems and their features

The hematopoietic and blood supply system is exactly the same as that of other rodents. The heart weighs about 2 grams. and beats at a frequency of 350 beats per minute.

The respiratory system is distinguished by excessive sensitivity to bacteria and infections of various kinds; animals often suffer from respiratory diseases.

The digestive system is well developed, the stomach reaches a volume of 30 cm, the intestines are extended and have a size 12 times the length of the body. It is for this reason that pigs take a very long time to digest food, about a week.

An interesting feature of the pig’s body structure is the fecal pocket located below, under the anus. The glands of the fecal pouch produce a specific thick secretion. This is another important point in caring for a guinea pig - the pocket needs to be cleaned periodically.

The owner should pay special attention to the health of the lymph nodes located near the ears on the neck. Unusual or too lethargic behavior, poor appetite - a reason to consult a veterinarian. Inflammation of the lymph nodes can lead to an abscess, which is very rare in pigs.

Peculiarities of vision, hearing and smell of a guinea pig

Cute fluffies have a remarkable ability to observe the entire space around them. This is achieved thanks to the lateral position of the eyes. However, this feature leads to certain problems: the frontal vision of pigs is weakened.

Since pigs are nearsighted, nature compensated by giving them a powerful sense of smell. This is the main landmark in the life of a rodent. The power of smell is hundreds, or even thousands of times stronger than that of humans. Thanks to such a powerful tool, males determine the possibility of females to mate; they are able to sense odors that humans are not even aware of.

The animal navigates the area using tactile hairs on its face. Even in pitch darkness, the animal is able to assess the size of the hole and the ability to penetrate it.

The guinea pig compares favorably with mice and rats in its sensitive hearing. The bulk of mammals have a standard ear structure, where the inner cochlea consists of 2.5 turns. But a guinea pig has 4 such turns. This allows the pig to perceive sound in the range of up to 3000 Hz, while a person hears only 1500 Hz.

General physiological data of a rodent

Let's now talk about the basic physiological parameters of rodents. A standard pig lives for 8 years, weighs about two kg, and grows up to 30 cm in length. Among these cute rodents there are also long-livers, some animals live up to 10 years. The body temperature of an adult pig is 39 °C. Sexual maturity occurs in females at 40 days, in males at 60. After a 70-day pregnancy, each female brings a litter of up to 5 cubs.

Guinea pig, unlike other representatives of the rodent order, has some features. So, there are only 20 teeth, which are already present in newborns. Of these, there are four incisors - two on the upper and two on the lower jaw. There are no fangs. Four premolars and twelve molars. The chewing surface of molars and premolars is covered with tubercles.

The body of guinea pigs is cylindrical. The front legs are shorter than the hind legs and have four toes, while the hind legs have only three.

A female guinea pig has one pair of mammary glands located at the back of the abdomen.

The heart of an adult guinea pig weighs 2.0 - 2.5 g. The average heart rate is 250-355 per minute. The heartbeat is weak and diffuse. The morphological composition of blood is as follows: 5 million red blood cells per 1 mm 3, hemoglobin - 2%, 8 - 10 thousand leukocytes per 1 mm 3.

The lungs of guinea pigs are sensitive to mechanical stress and the actions of infectious agents (viruses, bacteria). The normal respiratory rate is 80 - 130 times per minute.

Guinea pigs have a well-developed excretory system. An adult animal excretes 50 ml of urine containing 3.5% uric acid.

However, like any living creature, a guinea pig is susceptible to infectious and invasive diseases.

Guinea pigs are less likely to be affected by helminths than other animals.

Club "Schukin Rat"

The guinea pig is one of the representatives of a large order of rodents, but differs in many ways from its closest relatives. They are smart, able to recognize their owner, are easy to train and are favorite pets. However, due to their anatomical features, guinea pigs require additional care and special attention from their owners.

Description of the guinea pig

The second and official name of the guinea pig is cavy or cavy. The first animals were domesticated many centuries ago by the Incas and were used to produce very tasty and valuable meat, and only then as ornamental animals.

Despite their name, the animals have nothing in common with either the sea or pigs.

They probably began to be called pigs because of the sounds they made, similar to grunting, as well as the proportions of their body. According to one version, they began to be called sea animals due to the fact that the animals often accompanied humans during sea voyages. They take up little space, are omnivores, and their meat is very nutritious and rich in vitamins.

The body of the animal is shaped like a cylinder and on average is about twenty to twenty-five centimeters in length. The weight of an adult male is about 1500 grams, females - up to 1100 grams. The animals' fur is smooth and silky, growing very quickly - up to 1 mm per day. However, there are also animals without hair. Keeping hairless guinea pigs is becoming increasingly popular in many countries. The color depends on the type and breed of the animal.

The most common:

white and gold color,
golden agouti,
gray agouti,
silver agouti,
carrot agouti,
piebald agouti,
plain color,
albino,
Himalayan color,
piebald color,
Dutch color,
rosette color,
tortoiseshell color,
Peruvian color,
angora color.

Guinea pig physiology

Guinea pigs, like any rodents, have sharp and highly developed incisors that continue to grow throughout their lives. If the incisors grow too long, unpleasant and dangerous consequences for health can occur. Sharp teeth can injure the lips, tongue and palate of an animal. In order to avoid trouble, guinea pigs should eat solid food (special pellets, carrots, sugar beets, hay) and chew tree branches. The guinea pig's mouth is structured differently than that of rats or rabbits. The mammal has no fangs, and the surface of the molars has peculiar folds or tubercles. The lower jaw consists of two incisors, six molars and two false molars. The lower jaw is very mobile: capable of moving not only back or forward, but also to the sides. The upper teeth of a guinea pig are six molars and a pair of false molars, a pair of sharp and shorter incisors than the lower ones.

Guinea pigs' front teeth are covered with strong enamel only at the front - the back is softer and wears off faster, allowing for natural wear and sharpness.

The skeleton of a guinea pig consists of:

thirty-four bones of the spine,
eighty-six bones of the forelimbs,
seventy-two bones of the hind legs,
seven tail bones,
thirteen pairs of ribs,
chest bones and skull.

In total - two hundred and fifty-eight seeds. Despite the fact that the limbs consist of so many bones, they cannot be called strong. An animal's paws are a very vulnerable place. A fall or an unsuccessful jump often leads to fractures. Another feature is its inconspicuous tail.

Guinea pigs have seven bones in the caudal vertebrae, but they are quite small and located close to the mammal's pelvis. This is why many people think that pigs do not have a tail.

Organs of touch, sight, smell and hearing

The animal's eyes are large and located on the sides of a small and neat head, which gives them a wider field of vision. The blind area is in front of the nose. The features of the animal’s vision have not yet been studied much, but it is known for sure that they can distinguish colors and moving objects. Most animals are myopic and rely less on vision in their daily lives.

The sense of smell in pigs, like the sense of touch, is very developed. The sense of smell plays an important role not only when choosing food, but also in communicating with each other. By smell they determine the sex and age of the animal, and its readiness to reproduce. Their hearing is also more developed when compared with mice and rats. The cochlea of the inner ear has four turns - many mammals have only two and a half. A person is capable of perceiving sounds with a frequency of up to fifteen thousand Hertz, and guinea pigs - up to thirty-three thousand Hertz.

Taste perception

If the mammal is not able to identify the offered food by color or smell, then it tastes a piece of the treat. Guinea pigs have a very good memory and a highly developed instinct, which helps them recognize edible and inedible, tasty and not tasty objects. When it comes to food, guinea pigs are individualists. What one may like may not always be to the taste of another. However, most prefer sweet and juicy foods and rarely eat salty or spicy foods.

Communication between guinea pigs

Pigs also differ from most of their distant relatives in the rather wide variety of sounds they make. If the animal is happy and calm, it makes a sound similar to muttering, and clicking its teeth indicates irritability or aggression. Animals can also make sounds reminiscent of cooing if they want to contact another individual.

Features of the digestive system

Guinea pigs have very weak intestines. Before entering the stomach and further, food is thoroughly chewed in the oral cavity and abundantly moistened with saliva. The animal's stomach consists of one chamber and very thin walls. It takes food on average about five hours to move from the stomach to the intestines. The animal’s intestines are of the “fillable” type. This means that food moves through the stomach not by peristalsis, but by the arrival of new food. This is why fasting is contraindicated for animals (lack of food can lead to serious digestive problems and even death).

The complete process of digesting food can take up to seven days, and the total length of the intestines exceeds the length of the animal’s body ten times!

Interesting facts about the anatomy of the animal

The animal's heart weighs no more than two and a half grams, and the frequency of contractions of the heart muscle is up to 350 per minute. A guinea pig takes approximately one hundred to one hundred twenty breaths per minute. The animal's lungs are very susceptible to various viruses and bacteria, and the most common diseases are respiratory in nature. The excretory system of the guinea pig is well developed and the animal produces about 55 - 60 ml of urine per day. The anatomy of a guinea pig has other features.

Males and females have a caudal gland. In males it is more pronounced; in females it can sometimes be completely absent. The gland is located a centimeter above the anus. The main function is the release of odorous aromatic substances.

The second feature is the fecal pocket. It is located under the anus. In the male's fecal pouch there are glands that are responsible for secreting a thick and odorous liquid. The fecal pocket should be cleaned regularly, as particles of feces, hairs, shavings or sawdust, and hay can accumulate in it. The third feature is one pair of mammary glands (mice have five pairs, rats have six pairs, and rabbits have four pairs). The animal's lungs are also different. The left lung is divided into three parts, and the right lung into four. The right lung is also heavier than the left.

The stomach of a guinea pig has the shape of a deformed horn and an almost transverse position to the left of the midline, the same sections as in humans - the fundus, body, cardiac and pyloric parts.

topography

guinea pig

1. Kovalevsky K.L. Guinea pig / ed. Metelkina A.I. – M.: publishing house TsNIIOI named after P.A. Herzen, MKT “Rabbitoptitsa”, 1948. – 99 p.

2. Kulagina K.A. Guinea pigs. – M.: publishing house “Veche”, 2008. – 240 p.

3. Petrenko V.M. Shape and topography of the stomach in a white rat // Advances in modern science. – 2012. – No. 4. – P. 27-29.

4. Rebinger G. Guinea pig / trans. with him. Ed. Bronshteina O.I. – M.-L.: State. publishing house, 1929. – 154 p.

5. Romer A., Parsons T. Anatomy of vertebrates. Per. from English – M.: publishing house “Mir”, 1992. – T. 2. – 406 p.

6. Surgical anatomy of the abdomen / ed. A.N. Maksimenkova. – L.: publishing house “Medicine”, 1972. – 688 p.

7. Shevkunenko V.N., Geselevich A.M. Typical human anatomy. – L.-M..: State. publishing house biol. and honey Literary, 1935. – 232 p.

The shape and topography of the guinea pig stomach has not been described in the literature. Mainly attention is paid to the significant volume of the stomach (20-30 cubic cm), which in a guinea pig is constantly filled with food.

The human stomach is divided into cardiac and pyloric parts and the body between them; the fornix or fundus is distinguished, the degree of its severity varies. In humans, the stomach is located mainly to the left of the midline, with the exception of the pylorus, and has a variable shape and position, which depend on the degree of filling of the organ. Normally, it has three main radiological forms - horns (20-55% of people, usually brachymorphic physique), hook (36-90% of people, with dolichomorphic or mesomorphic physique, more often in women) and stocking (0-9% of people, dolichomorphic body type) . The size of the human stomach varies within very wide limits: capacity - 1-1.5 liters (20-30 ml - on the 2-3rd day after birth); length (from cardia to pylorus) - 14-30 cm, (maximum) width - 10-16 cm, i.e. The width to length ratio (h/l) most often fluctuates around 0.6. The widest stomach is in the shape of a horn, the narrowest is in the shape of a stocking. In addition, there are 3 types of stomach: 1) oblique position, which corresponds to the shape of a bull’s horn, equally common in both men and women; 2) vertical position, hook shape; 3) horizontal position with low placement of the cardiac part.

The purpose of the study was to describe the shape and topography of the stomach in the guinea pig.

Materials and research methods

The work was performed on 10 guinea pigs for 2-3 months, fixed in a 10% solution of neutral formaldehyde, by layer-by-layer dissection and photographing the abdominal organs.

Research results and discussion

The stomach of a guinea pig (Fig. 1-5) has: 1) the shape of a deformed horn or horseshoe (somewhat reminiscent of an early embryo), with the duodenal bulb forming a “false hook”; 2) 4 parts - cardiac, fundus (head of the “embryo”), body (cardiac and hepatic protrusions of the “embryo”), pyloric (tail of the “embryo”); 3) 3 circular constrictions - proximal (subcardial - on the lesser curvature of the body, incomplete), intermediate (between the body and the pyloric part) and distal (pylorus, largest). The stomach of a guinea pig has an unequal width throughout, it gradually decreases in the distal direction, h/l ≈ 0.5, if we take into account the full length of the organ, but if the length is measured from the cardia to the pylorus, then h/l ≈ 0.6, which is characteristic of the human stomach in the form of a horn and a hook. The fundus of the guinea pig's stomach is relatively small (1/6 of the total length of the organ, while the body accounts for half of it).

Rice. 1. Guinea pig 2 months (structural option I): 1 - liver (right medial lobe); 2 - stomach; 3 - duodenum; 4 - loops of the small intestine; 5 - cecum; 6-8 - first, second and third loops of the ascending colon

Rice. 2. Guinea pig 2 months (I version of the structure): 1 - esophagus, abdominal part; 2-5 - cardiac part, fundus, body and pyloric part of the stomach; 6,8,10,9 - bulb, cranial and descending parts, cranial flexure of the duodenum; 7 - portal vein of the liver and hepatoduodenal ligament; 11 - cranial spur of the head of the pancreas; 12 - first loop of the ascending colon. Liver removed

Rice. 3. Guinea pig 2 months (2nd variant of structure): 1 - liver; 2 - gallbladder; 3 - duodenum; 4 - loops of the small intestine, immured in a loop of the ascending colon; 5,6 - cranial and caudal ventral loops of the transverse colon; 7 - first loop of the ascending colon; 8 - cecum

Rice. 4. Guinea pig 2 months (2nd variant of structure): 1 - esophagus; 2-5 - fundus, cardiac part, body and pylorus of the stomach; 6 - duodenal bulb and hepatoduodenal ligament; 7 - descending part of the duodenum; 8 - right kidney; 9 - distal loop of the ascending colon; 10 - loops of the small intestine; 11 - cecum; 12 - first loop of the ascending colon. Liver removed

Rice. 5. Guinea pig 2 months, organ complex: P - esophagus, abdominal part; CC, T, D, PR, MK, BC - the stomach, its cardiac part, body, fundus, pyloric part, lesser and greater curvature; LDK - duodenal bulb. The arrow shows the pylorus. Stomach in a collapsed (empty) state

The pyloric part of the guinea pig's stomach is located ventrally and slightly caudal to the fundus, the most dorsal part of the stomach. Its greater curvature faces left and caudally, and its lesser curvature faces right and cranially, located slightly cranial to the greater curvature. Therefore, the stomach of a guinea pig occupies an oblique position (between the sagittal and transverse planes), closer to the transverse one, in addition, it is located to the left of the midline, which approximately corresponds to the entrance and exit of the organ, in the cranial half of the abdominal cavity. A pronounced narrowing of the pylorus separates the stomach from the duodenum. Between its bulb (on the right), the pyloric part (ventrally) and the body of the stomach (on the left), a small caudate lobe of the ovoid liver protrudes. The pyloric part of the stomach and the duodenal bulb meet at an acute angle, which is located approximately in the midline and opens ventrocaudally. The pyloric part of the stomach forms most of the left branch of the gastroduodenal angle, the rest falls on the curved duodenal bulb. At an angle (caudal) there is a sharp bend of the colon - the transition of the ascending section into the transverse one, inconsistently - the cranial ventral loop of the transverse colon. On the ventral side, the stomach is covered by the left lobe of the liver; the dorsocranial part of the greater curvature of the stomach always protrudes from under the left edge of its lateral lobe, but to varying degrees. Its ventrocaudal, pyloric part does not always protrude from under the caudal edge of the left lateral lobe of the liver, which correlates with the individually different longitudinal size of this lobe of the liver. Dorsal to the stomach is a small, oblique-transverse, coffee-bean-shaped spleen. It is located obliquely, between the fundus of the stomach (cranial edge) and the left kidney (caudal edge), on the ventral side, and the costal part of the diaphragm, on the dorsal side. The right pole of the oblique transverse spleen faces the left lumbar pedicle of the diaphragm and the esophagus, and its left pole faces the base of the left cranial branch of the tail of the pancreas. On the left, the tail of the pancreas is adjacent to the greater curvature of the stomach. Its long cranial branch rises to the fundus of the stomach, can turn to the right to varying degrees and reach the pyloric part of the stomach. The left dorsal branch of the tail of the pancreas wraps dorsally from the stomach and to the right, towards the right end and the hilum of the spleen. The right dorsal branch of the tail of the pancreas goes dorsally, to the left lumbar leg of the diaphragm, near the right end of the spleen turns to its gate. Adjoining the greater curvature of the stomach on the caudal side are: on the left - the first loop of the ascending colon and (lateral or/and caudal) the left fold of the cecum, on the right - the transverse colon and loops of the ileum.

The shape and position of the stomach in a guinea pig is not constant, which depends not only and not so much on the degree of filling of the organ. Individual variants of its structure and topography differ in: 1) the degree of severity of circular constrictions. Option I - deeper, Option II - smoother; 2) the degree of curvature of the pyloric part. Option I - the most curved so that the stomach forms a “horseshoe” and vaguely resembles a hook; Option II - the least curved, the stomach resembles a horn; 3) features of holotopy. Option I: the longitudinal axis is almost sagittal, the plane of organ placement is between the sagittal and transverse (the greater curvature is caudal to the lesser, the pyloric part is slightly caudal to the bottom); Option II: the longitudinal axis is almost sagittal, the plane of organ placement is almost transverse (the pyloric part is slightly caudal to the bottom); Option III: the longitudinal axis is oblique-agital, the plane of placement is almost transverse (the pyloric part is to the right and slightly caudal to the bottom); 4) features of syntopy. Option I: adjacent to the greater curvature is a wide loop of the transverse colon and loops of the ileum (on the right) and the first loop of the ascending colon, bent under the pressure of the stomach (on the left); Option II: adjacent to the greater curvature are the right loops of the transverse colon, separated by loops of the ileum (right), dorsal loops of the transverse colon and the first loop of the ascending colon (left).

Conclusion

The guinea pig's stomach, compared to the human stomach, has less variability in shape, which can be regarded as a deformed horn. The position of the stomach in a guinea pig is close to transverse, with a low placement of the cardiac part, which is typical for a white rat, and in humans it occurs when the stomach prolapses. The stomach of a guinea pig: 1) is closer in shape and structure to a human than to a rat, in which the esophagus ends in the middle of the lesser curvature of the stomach; 2) less curved than that of a rat, whose stomach is hook-shaped (in a guinea pig - only together with the duodenal bulb); 3) has a much smaller bottom and a shorter, less curved pyloric part than that of the rat; 4) is distinguished by a large body (half the total length of the organ; in the rat it is always shorter and narrower than the bottom), therefore the relative width of the organ as a whole is larger, and without a bottom it is smaller than in the rat; 3) has an additional, compared to the rat, subcardial circular constriction, which may be associated with greater stretching of the organ (herbivorous animal).

Bibliographic link

Petrenko V.M. SHAPE AND TOPOGRAPHY OF THE STOMACH IN A GUINEA PIG // Advances in modern natural science. – 2013. – No. 11. – P. 69-72;
URL: http://natural-sciences.ru/ru/article/view?id=33122 (access date: 06/26/2019). We bring to your attention magazines published by the publishing house "Academy of Natural Sciences"