Maximiliano Solís

TOPIC: Swine Anatomy and Physiology

GENERAL OBJECTIVE: To technically describe the anatomy and physiology of the pig

INTRODUCTION
Anatomy studies the form and structure of organisms. Physiology, in turn, is concerned with...
for the study of the functions of the body. Both are in close correlation and from them
it depends on the proper understanding of the internal functioning and the problems, especially of type
pig health
Pig farming has evolved to such an extent that the concept of the pig from three...
decades as a carrier of diseases and having meat with an abundant amount of fat
harmful to human health, is now considered a safe food and
one of the main sources of proteins, minerals, and vitamins known.
advances in genetics and pig feeding have allowed for the production of animals with a
cholesterol content similar to that of white meats. The similarity of pork in
the cardiac physiology and anatomy of this species have allowed considering it as that of the human being
as one of the most widely used experimental models and its contributions
the scientific knowledge is immeasurable. This is why, and for other reasons especially of
sanitary nature, that the anatomy and physiology of the pig is starting to be considered with some
rigor in certain postgraduate studies, from different institutions and centers
university students.

Swine Anatomy and Physiology

The head is triangular in shape with its base located caudally at the level of the occipital and its
the vertex ends at the level of the anterior tip of the nasals. The zygomatic arches are
wide. The head generally has an elongated shape, especially in the nasal region. There is a
marked depression between the nasal and frontal regions. The facial tuberosity is connected to the arch
Zygomatic. The prenasal bone is located between the two nostrils.
The paramastoid apophyses are long and directed downward and backward, the condyles of
occipital are short, the ventral condylar fossa is shallow. The bony bullae are
prominent and directed downwards on the hard palate, the palatine processes of the maxilla
they are quite wide
The lacrimal bone is very constricted on its facial side and has two lacrimal openings.
that communicate with the tear duct.
The skull varies with race. The frontal region is sloped and the nasal region is long or flattened.
according to race

The ribs are 14 or 15 pairs that contribute to forming the rib cage.
The skeleton comprises: the axial skeleton which is formed by the skull, the spine
vertebrae, the sternum and the ribs. The appendicular skeleton that is formed by the bones
of the members.
Bones are classified according to their function and shape into long, short, and flat bones.
made up of hard bone tissue and a surrounding membrane called periosteum.
The pig is born with all its canines; its temporary dental formula is 2 (1 3/3 + C 1/1 + P
4/4) = 32. After eight months the definitive dental formula is: 2 (I 3/3 + 1/1 + P 4/4 +
M 3/3)=44
Pigs use their snouts to dig in the ground and with their jaws, they bring food to their mouths.
interior of the mouth. The pig has a snout or rostrum, this is a cartilaginous structure that
the nasal septum continues and is called rostrum, the larynx is relatively large.
The pig is an even-toed ungulate, meaning they have an even number of hooves, hence they are called
cloven or split hoof
The heart of the pig has a number of beats of 60-80 per minute.
His stomach is monogastric, large in size, has a fundus and pyloric portion. The fundus is
it is located to the left of the midplane and presents a blind sac, the gastric diverticulum. The
The pyloric portion is to the right of the midline. When full, it rests on the floor of the
abdomen.
The urinary system of the pig is formed by the kidneys, which are located beneath the
the first four lumbar vertebrae weigh between 200 to 300 grams. Their function is to filter
the blood. The ureters are long and flexible tubes responsible for carrying urine from the
kidney to the bladder, is located in the pelvic cavity, it is an elastic sack that accumulates the
urine coming from the kidneys.
The reproductive system of the pig, the testicles have an external position, they are covered
through the bags or scrotum, located a short distance from the anus, they are large with a longer axis
directed upwards and backwards. They are wrapped in a layer, the epididymis intimately attached to
testicle, the spermatic cord is long and flexible. Inside the testicle is the
winding deferent duct and where the seminal vesicles converge, which is where
they form spermatozoa. The most important glands are the prostate, the glands of
Cowper and the seminal vesicles.
The reproductive system of the sow has its ovaries hidden in the ovarian pouch very close.
the kidneys, have a lobulated appearance, the fallopian tubes measure 15 cm and are not very
flexuous, the uterine body is muscular and has long, flexuous, and mobile horns,
measures 1.20m, the vagina measures 10 to 12 cm and the vulva measures 7.5 cm. The sexual cycle of the sow
it occurs every 21 days, the normal range is considered to be 18-24 days in tropical countries
its reproductive efficiency is similar throughout the year. The estrus after proestrus, in the
the next 2 or 3 days which is the duration of estrus pass the tertiary follicles which
after halfway through the estrus, they will ovulate. Hormonal changes at this stage show a drop in
the estrogens, progesterone begins to rise slowly and the luteinizing hormone (LH)
presents its peak.
In this phase, it has been observed that young animals have a shorter estrous duration.
than the adult sows. Similarly, sows that come into contact with the boar show
a reflex of lordosis greater than those who do not have it. The lordosis reflex is the
immobility of the sow to the boar when the sow is in heat.
The mammary glands exist in the sow as two rows of mammary glands that
they extend from the pectoral region to the inguinal area, generally there are 6 pairs. This number can
vary, each gland contains a milk cistern with a large number of glomeruli and ducts
that lead to two ducts, one anterior and the other posterior, which end in the nipple.
The main function is the production of milk through the action of hormones and external stimuli.
The circulatory system of the pig consists of a small heart in proportion to the
The body size occupies a large space in the mediastinum, and is enveloped by a fibrous serous layer.
pericardial call that fixes and lubricates.
It is divided into 4 chambers: 2 atria and 2 ventricles, right and left. The atria
more serous receive the blood and the ventricles expel the blood to the whole body and towards the
lungs to be oxygenated.
The nervous system of the pig functions to connect the external environment with the
animal and regulate organic activity. The nervous system consists of the brain that
It consists of the cerebrum, cerebellum, and medulla oblongata, located in the cranial cavity, the medulla
spinal, the peripheral nervous system that consists of a series of nerves and the sympathetic system
which consists of two chains of ganglia along the spine and in connection with
the different organs.
The endocrine system is responsible for producing hormones, these hormones are
produced by glands that release their secretion product into the bloodstream or to others
Organs, the most important glands are the thyroid located in the animal's neck.
parathyroids located riding on the thyroid and the thymus placed behind the sternum,
it disappears when the animal is adult, the pituitary gland located in the cranial cavity.

REFERENCES
Aragon, H. (1987). COMPARATIVE ANATOMY AND PHYSIOLOGY OF PIG AND CHICKEN
AND RABBIT
Ortiz, J. (1996). COMPARATIVE ANATOMY
Interactive Anatomy of the Pig
NATIONAL TECHNOLOGICAL INSTITUTE GENERAL DIRECTORATE OF TRAINING
PROFESSIONAL
Pérez, M. (2007). PIG FARMING MANUAL