The ventral musculature of the lower vertebrates stretches continuously along the ventral side of the body. In higher vertebrates, it differentiates into 4 areas: cervical, thoracic, abdominal and caudal.

In humans, in connection with upright posture, the abdominal part of the ventral muscles especially develops.

On the neck, it is represented by the muscles attaching to the hyoid bone, as well as the scalene and prevertebral muscles, in the thoracic region - by the intercostal and transverse muscles, as well as by the diaphragm, in the abdominal region - by the oblique, transverse and rectus abdominal muscles, as well as m.quadratus lumborum; in the caudal region, it is reduced due to the reduction of the tail.

The autochthonous musculature of the trunk, originating from the ventral processes of myotomes, despite the different differentiation in individual areas, in general, has one type of device. With the full development of the ventral muscles in it, first of all, one can distinguish the lateral part (broad muscles), usually consisting of those layers, and then the anterior (rectus muscles), located longitudinally from the pelvis to the head on the sides of the median connective tissue septum (white line). This type is most pronounced in the abdominal region, where there is a well-developed lateral musculature. (mm.obliquvi et transversus abdominis) and anterior rectus muscles (m.rectus abdominis); in the thoracic region, the anterior rectus muscles are absent due to the development of the sternum, while there are again on the neck (muscles that attach to the hyoid bone).

The lateral muscles in the abdominal region have no segmentation, but in the thoracic region, primary metamerism has been preserved in it in a pronounced form due to the presence of ribs located along myosepta myotomes (mm.intercostales). On the neck, the lateral muscles were transformed into three scalene muscles (mm.scaleni). As mentioned earlier, traces of metamerism (tendon bridges) remain in the rectus muscles. In addition, in some places areas of the ventral muscles are displaced posteriorly to the anterior, surface of the spine (prevertebral muscles) or to its lateral side ( square muscle lower back) or even go to the dorsal surface of the spine, being part of the dorsal muscles.

The prevertebral muscles are developed at the cranial end of the trunk (on the neck), similar muscles at the caudal end in humans have gone to the formation of the muscular pelvic floor (m. levator ani et m. coccygeus). The ventral group includes another peculiar muscle that exists only in mammals. It - diaphragm, a derivative of the cervical muscles, descending to the lower end chest, on the border with the abdominal cavity. Finally, on top of the autochthonous ventral muscles, in some places alien muscles are located - derivatives of the visceral arches and parts of the muscles of the limbs.

CHEST MUSCLES.

The muscles of the chest are divided into muscles that begin on the surface of the chest and go from it to the shoulder girdle and upper limb, and into their own (autochthonous) muscles of the chest, which are part of the walls of the chest cavity.

1. Muscles of the chest related to the upper limb:m.pectoralis major, m.pectoralis minor, m.subclavius, m.serratus anterior.

The first two muscles - truncated, the second two - truncofugal.

2.Autochthonous muscles of the chest: mm.intercostales externi, mm.intercostales interni, mm.subcostales, m.transversus thoracis.

The pectoralis major and minor muscles, in addition to their main function, also perform auxiliary ones. With a fixed upper limb, they raise the ribs, that is, they participate in the act of inhalation.

The external intercostal muscles fill the intercostal spaces, following from the spinal column to the costal cartilage, from top to bottom.

Internal intercostal muscles fill the intercostal spaces from the sternum to the corners of the ribs, and their bundles go up and forward. Thus, these muscles are antagonistic muscles. The first raise the ribs (inhale), the second lower the ribs (exhale).

Abdominal obstruction (diaphragma) , is a flat thin muscle, m.phrenicus, domed curved. Its muscle fibers, starting around the entire circumference of the lower opening of the chest, rise up and, turning inward, pass into a tendon extension that occupies the middle of the diaphragm and is called the tendon center.

The diaphragm is the largest and most important respiratory muscle. Straining, it flattens, negative pressure is created in the chest cavity and inhalation occurs. Relaxing, it takes on a domed shape again - exhalation. It should be noted that there are a number of holes in the diaphragm that can serve as hernial orifices with increased intra-abdominal pressure. Most often - this is the opening of the esophagus, where a hernia of the esophageal opening of the diaphragm occurs.

ABDOMINAL MUSCLES.

The abdominal muscles occupy the space between the lower chest circumference and the upper edge of the pelvis. They surround the abdominal cavity, forming its walls.

1. Lateral muscles: m.obliquus abdominis externus, m.obliquus abdomini internus, m.transversus abdominis.

2. Front muscles: m.rectus abdominis, m.pyramidalis.

3. Back muscles: m.quadratus lumborum.

The lateral muscles are three wide muscle layers lying on top of each other, tendon stretches, which, forming a sheath for the rectus muscles, are connected in front of the abdomen along the so-called white line, -----.

1. External oblique muscle of the abdomen, starting on the lateral surface of the chest, descends downward and medially, partly attaching to the iliac crest (outer lip), partly to the inguinal ligament, the rest of the fibers pass into a wide aponeurosis, which runs in front of the rectus abdominis muscle and connects along the midline with such the same aponeurosis.

The lower, free edge of the aponeurosis of the external oblique muscle of the abdomen is thrown between the anterior superior iliac spine and the pubic tubercle, tucking inward in the form of a groove. This edge, artificially allocated from the rest of the rest of the aponeurosis, is called inguinal, or pupar ligament (lig.inguinalis).

At the place of medial attachment of the pupar ligament, its fibrous fibers are wrapped downward, to the crest of the pubic bone, forming the so-called lacunar (zhimbernatova) ligament (lig.lacunare).

2. Internal oblique muscle of the abdomen, lies under the previous one. It originates from the thoracolumbar fascia, the intermediate line of the iliac crest and from the lateral 2/3 of the inguinal ligament. The direction of the fibers is generally ascending, or rather fan-shaped. The posterior muscle bundles, going upwards, are attached to the lower edge of the 12, 11 and 10 ribs. Its continuation between the ribs is the internal intercostal muscle. The fibers extending from the anterior part of the iliac crest run more or less transversely, and the lower fibers, starting at the pupar ligament, even have a descending direction. The muscle, like the previous one, passes into a wide aponeurosis.

3. Transverse abdominal muscle, the deepest and thinnest of all the abdominal muscles. It starts from the inner surface of the six lower ribs with six teeth, alternating with the teeth of the diaphragm. Above, its continuation is transverse muscle chest. Below, closer to the pelvis, its fibers go transversely and pass along an arcuate, convex to the lateral side of the line, linea semilunaris , into a wide aponeurosis, which in the upper section runs behind the rectus muscle, and below in front of it. In many mammals, this muscle is very well developed and can pull the testes into the body cavity from the scrotum. In humans, only small bundles depart from the internal oblique muscle of the abdomen and transverse to the testicle, forming a rudimentary muscle lifting the testicle, m.cremaster.

The anterior muscles lie on the sides of the median plane and are represented in humans by two muscles.

1. The rectus abdominis muscle, consists of longitudinal muscle bundles running in the vertical direction. It begins in the form of a rather wide muscle ribbon with three teeth from the anterior surface of the 5th, 6th and 7th costal cartilage and from the xiphoid process of the sternum, then, gradually narrowing, goes down and is attached with a strong tendon to the pubic bone in the space between the symphysis and the pubic tubercle. The low onset of the muscle in comparison with animals, as already mentioned, is due to the expansion of the chest in anthropomorphic monkeys and humans, which has become a support for the developed muscles of the upper limb in connection with brachyation (in monkeys) and labor (in humans). Along the entire length, the muscle is interrupted by transverse tendon bridges, which, however, do not penetrate through the entire thickness of the muscle. The bridges grow together with the anterior wall of the vagina, in which the muscle is located. Tendon bridges represent traces of segmental development of the ventral muscles. They also have a functional significance: dividing the muscle into separate segments, they enable each of them to contract independently, which, however, requires special training.

Ventral muscles of the neck

1. Sternohyoid muscle(m.sterno-hyoideus). It begins on the body of the sternum, ends on the body of the hyoid bone.

Function:

2. Scapular-hyoid muscle(m. omo-hyoideus). It begins on the subscapularis fascia (in ruminants, on the deep cervical fascia). Ends on the body of the hyoid bone. The dog is absent.

Function: pulls the hyoid bone back.

3. Sterno-thyroid muscle(m. sterno-thyreoideus). It starts at the handle of the sternum, ends at the thyroid cartilage of the larynx.

Function: pulls the larynx back when swallowing.

4. Sterno-jaw muscle(m. sterno-mandibularis). It starts at the sternum hilt. Ends on the branch of the lower jaw. Available in cattle and horses.

Function: lowers the lower jaw, and when the jaws are closed, lowers the head and bends the neck.

5.G rude-mastoid muscle(m. sterno-mastoideus). It begins at the handle of the sternum, ends with the pump-shaped process of the temporal bone. The horse is missing.

Function: lowers his head and bends his neck.

On the lateral side of the neck, it stands out raging gutter(sulcus jugularis). It is limited: from above by the brachiocephalic muscle, from below by the sterno-jaw (in herbivores) or sterno-mastoid (in a dog and a pig). The external jugular vein passes through it.

Muscles of the head form several groups: mimic, chewing, muscles of the auricle, hyoid bone, eyeball, pharynx, larynx.

Mimic muscles

1.Circular muscle of the mouth(m. orbicularis oris) - annular , lies at the base of the lips.

Function: sphincter of the oral gap.

2.Nasolabial lifter(m. levator naso-labialis). Begins on the frontal and nasal bones. Ends by weaving into circular muscle mouth.

Function: mouth dilator.

3. Upper lip lifter(m. levator labii superioris). Begins on the maxillary bone, ends, woven into the circular muscle of the mouth.

Function: mouth dilator.

4. Canine muscle(m. caninus). It begins on the maxillary bone, ends, weaving into the circular muscle of the mouth.

Function: mouth dilator.

5. Upper lip dropper(m. depressor labii superioris). It starts on the facial tubercle, ends, weaving into the circular muscle of the mouth. Available only in cattle.

Function: mouth dilator.

6. Zygomatic muscle(m. zygomaticus). It begins on the zygomatic bone, ends, weaving into the circular muscle of the mouth.

Function: dilatator oral fissure.

7. Lower lip dropper(m. depressor labii inferioris). Begins on the mandibular bone, ends, woven into the circular muscle of the mouth. The dog is absent.

Function: mouth dilator.

8. Buccal muscle(m. buccinator). Connects the upper and lower jaw.
Consists of two layers: outer and inner, outer has a feathery structure.

Function: moving food in the mouth when chewing.

Chewing muscles

1. Large masseter muscle(m. masseter). It starts from the facial crest (tubercle) and from the zygomatic arch. Ends in the fossa of the masseter muscle.

Function: closes the jaw.

2. Temporalis muscle(m. temporalis). It begins in the temporal fossa, ends on the coronoid process of the mandibular bone.

Function: closes the jaw.

3. Krylovaya we shtsa (m. pterygoideus). It begins around the choanas on the pterygoid, sphenoid and palatine bones, and ends in the pterygoid fossa.

Function: closes the jaw.

4. Digastric(m. digastricus). It begins on the articular process, ends on the lower jaw.

Function: lowers the lower jaw.

5. Jaw-jaw muscle(m. jugulo-mandibularis). It begins on the jugular process, ends on the corner of the lower jaw. There are only horses.

Function: lowers the lower jaw.

Lesson 5. Muscles of the pectoral limb

Muscle shoulder joint

Extensors

1. The supraspinatus muscle(m. supraspinatus). It starts in the anterior fossa, ends on the tubercles humerus(in a dog - only on a large bump).

Flexors

1. Deltoid (m. deltoideus). It begins on the spine of the scapula and on the extraspinatus muscle, ends on the deltoid roughness of the humerus.

Additional function; instep support of the shoulder joint.

2. Large round muscle(m. teres major). It begins at the caudal edge of the scapula, ends at the round roughness of the humerus.
Additional function: pronator of the shoulder joint.

3.Small round muscle(m. teres minor). It begins at the caudal edge of the lower third of the scapula and ends at the neck of the humerus.

Abductor

1. Posterior muscle(m. infraspinatus). It begins in the extraostamke, ends on the large tubercle of the humerus.

Adductors

1. Subscapularis muscle(m. subscapularis). It begins in the subscapular fossa, ends on the humerus tubercle.

2. Coracohumeral muscle(m. coraco-brachialis). It starts on the coracoid process of the scapula, ends on the cranio-medial surface of the upper part of the humerus.

Additional function : pronator of the shoulder joint.

Muscle elbow joint

Extensors

1. Triceps shoulder(m. triceps brachii). It has trig-heads: long, lateral and medial (and in a dog and a pig - and an additional one). Long head begins at the caudal edge of the scapula, the rest on the humerus. The muscle ends at the ulnar bulge.

Additional function: shoulder flexor.

2. Fascia Strainer Forearm(m. tensor fasciae antеbrachii). It begins at the caudal edge of the scapula and the latissimus dorsi. Ends at the elbow tuberosity and the fascia of the forearm.

Additional function: shoulder flexor.

3. Elbow myische(m. anconeus). It starts in the ulnar fossa, ends at the ulnar tubercle.

Flexors

1.Biceps brachii(m. bicepsbrachii). It begins on the nasal tubercle of the scapula , ends on the radial roughness and on the ulna.

Additional function: shoulder joint extensor.

2. Shoulder muscle (m. brachialis). It starts at the neck of the humerus, ends at the radial roughness and at the ulna.

Pronator

1. Round pronator(m. pronatog teres). It begins on the medial epicondyle of the humerus, ends on the medial surface of the radius. Only available in a dog.

Muscles of the carpal joint

Extensors

1. Radial extensor wrist(m. extensor carpi radialis). It begins at the lateral epicondyle of the humerus, ends at the proximal epiphysis of the third metacarpal bone.

Additional function: flexor of the elbow joint.

2. Long abductor thumb (m. abductor pollicislongus). It begins on the lower part of the radius, ends on the I-II metacarpals.

Flexors

1. Radial flexor of the wrist(m. flexorcarpi radialis). It begins at the medial epicondyle of the humerus, ends at the proximal ends of the II-III metacarpals .

Additional function: an extensor of the elbow joint.

2. Elbow wrist flexor(m. flexor carpi ulnaris). It begins with two heads: on the medial epicondyle of the humerus and on the ulnar tubercle. Ends at the accessory bone of the wrist.

Additional function: an extensor of the elbow joint.

3. Elbow wrist extensor(m. extensor carpi ulnaris). It begins on the lateral epicondyle of the humerus, ends on the accessory bone of the wrist and on the IV-V bones of the metacarpus. In a dog, it is a wrist extensor.

Muscles of the finger joints

Extensors

1. Common finger extensor(m. extensor digitorum communis). Begins on the lateral epicondyle of the humerus. Ends on the extensor processes of the bones of the distal phalanges.

Additional function: elbow flexor and wrist extensor.

2. Lateral extensor of the fingers(m. extensor digitorum lateralis). It begins at the proximal ends of the forearm bones. Ends on the extensor processes of the bones of the distal phalanges.

Additional function: wrist extensor.

Flexors

1. Superficial finger flexor(m. flexor digitorumsuperficialis). It begins on the medial epicondyle of the humerus. Ends on the bones of the middle phalanges.

Main function: flexor of fetlock and coronary joints.

Additional function:

2. Deep finger flexor(m. flexor digitorum profundus). It begins with three heads: the humerus - on the medial epicondyle of the humerus, ulnar - on the ulnar tubercle, radius - on the lateral surface of the radius. Ends on the bones of the distal phalanges.

Main function: flexor of all finger joints.

Additional function: elbow extensor and wrist flexor.

3. Third interosseous muscle(m. interosseus tertius). It begins at the proximal end of the third metacarpal bone. It ends on the sesame bones of the proximal phalanx, and also gives off branches to the dorsal surface of the fingers. In all ungulates it has become a bundle.

Function: u dogs - flexor of the joint of the proximal phalanx, in ungulates it fixes this joint.

NECK MUSCLES

Muscles of different origins are part of the cervical muscles.

1. Derivatives of the visceral arches:

a) derivatives of the first visceral arch - m. mylohyoideus, venter anterior sh. digastrici. (Inn. P. Trigeminus);

b) derivatives of the second visceral arch - m. stylohyoideus, venter posterior T. digastrici, platysma. (Inn. P. Facialis);

c) derivatives of the branchial arches - m. sternocleidomastoideus.

2. Autochthonous muscles of the neck:

a) front: m. sternohyoideus, m. sternothyreoideus, m. thyreohyoideus and m. omohyoideus as well as m. geniohyoideus;

b) lateral: mm. scaleni anterior, medius et posterior;

c) prevertebrates: m. longus colli, m. longus capitis and m. rectus capitis anterior.

The autochthonous muscles of the neck represent the remains of the ventral muscles, the distribution of which was influenced by two important factors: reduction of the ribs and reduction of the body cavity. As a result, in humans, part of the autochthonous muscles of the neck disappeared and only the scalene, prevertebral, and m. geniohyoideus. According to development, they are innervated by the anterior branches of the cervical spinal nerves.

As for the muscles located below the hyoid bone, they are associated with the hyoid apparatus and are innervated from the ansa cervicalis.

Topographically, the neck muscles are divided into the following groups:

1. Superficial muscles(platysma, m. sternocleidomastoideus).

2. Middle muscles, or muscles of the hyoid bone:

a) the muscles lying above it (mm. mylohyoideus, digastricus, stylohyoideus, geniohyoideus);

b) the muscles lying below it (mm.sternohyoideus, sternothyreoideus, thyreohyoideus, omohyoideus).

3. Deep muscles:

a) lateral, attached to the ribs (mm. scaleni ant., med. et post.);

b) prevertebrates (m. longus colli, m. longus capitis, m. rectus capit. ant. et lat.)

SURFACE MUSCLES - VISCERAL ARCS DERIVATIVES

1.M. Platysma, subcutaneous muscle of the neck(Fig. 76), lies directly under the skin on the fascia in the form of a thin plate. It starts at the level of the II rib from the fascia pectoralis et deltoidea, and attaches to the edge of the lower jaw and to the fascia parotidea et fascia masseterica, partly continuing into the muscles of the mouth.

Function. Pulling the skin of the neck, the muscle protects the saphenous veins from compression; in addition, she can pull down the corner of the mouth, which is important in facial expressions.

2.M. Sternocleidomastoideus, sternocleidomastoid muscle, lies immediately under the previous one, separating from it by the cervical fascia. It starts from the handle of the sternum and from the sternal end of the clavicle and attaches to the mastoid process and to the linea nuchae superior of the occipital bone. By its origin, the muscle is the detached part of m. trapezius and therefore has one innervation with this muscle.

Function. With a unilateral contraction, the muscle tilts the cervical spine towards its side; at the same time, the head is raised with a rotation of the face in the opposite direction.

With bilateral contraction, the muscles hold the head in an upright position (head holder): therefore, the muscle itself and the place of its attachment (processus mastoideus) are most developed in humans due to their upright posture. With bilateral contraction, flexion of the cervical spine forward with simultaneous lifting of the face can also occur. When fixing the head, it is possible to lift the chest during breathing (inspiratory accessory muscle).

MEDIUM, OR HYGLUS MUSCLES

Muscles lying above the hyoid bone, - derivatives of the visceral arches (Fig. 77) lie between the lower jaw and the hyoid bone.

1.M. mylohyoideus, maxillofacial muscle, starting from the linea myiohyoidea of the lower jaw, ends at a tendon suture, raphe, extending from inside chin to the body of the hyoid bone along the midline along the border between both mm. mylohyoidei. Rear part the muscle attaches to the body of the hyoid bone. Both mm. mylohyoidei, coming together, form the muscular floor of the mouth, diaph-ragma oris, closing the bottom of the oral cavity.

2.M. Digastricus, digastric muscle, consists of two abdomens connected by a circular intermediate tendon. The anterior abdomen, venter anterior, originates in the fossa digastrica of the lower jaw and goes back to the hyoid bone. The posterior abdomen, venter posterior, begins in the incisiira mastoidea of the temporal bone and goes to the tendon, through which it connects to the anterior abdomen. The intermediate tendon attaches to the body and horn of the hyoid bone.

3.M stylohyoideus, stylohyoid muscle, descends from the processus styloideus of the temporal bone to the body of the hyoid bone, covering the intermediate tendon of the digastric muscle in two bundles.

Derivative of the anterior longitudinal muscle of the trunk:

4. M. geniohyoideus, sublingual muscle, lies over m. mylohyoideus on the side of the raphe, extending from the spina mentalis of the lower jaw to the body of the hyoid bone.

Function. All four described muscles lift the hyoid bone upward. When it is fixed, then three muscles (mm.mylohyoideus, geniohyoideus, digastricus) lower the lower jaw, thus being antagonists chewing muscles... The muscles located below it (mm.sternohyoideus, omohyoideus, etc.) carry out the fixation of the hyoid bone. Without this fixation, lowering of the lower jaw is impossible, since otherwise the hyoid bone, which is lighter and more mobile than the jaw, will rise. The same three muscles, especially m. mylohyoideus, when they contract during the act of swallowing, they raise the tongue, pressing it to the palate, so that the food lump is pushed into the pharynx.

The muscles located above the hyoid bone are part of a complex apparatus, including the lower jaw, the hyoid bone,

larynx and windpipe and plays a large role in the act of articulate speech. In the process of human evolution, morphological changes occurred in these muscles, associated, on the one hand, with a decrease in the grasping function of the jaws, which the hands acquired, and on the other, with the appearance of articulatory movements. Therefore, when comparing the skulls of a Neanderthal and a modern man, one can see the following changes in the places of attachment of the corresponding muscles:

a) the place of attachment of the posterior abdomen m. digastricus - incisura mastoidea, flat in Neanderthal, becomes deep in modern man;

b) the place of attachment of the anterior abdomen of the same muscle - fossa digastrica - moves medially in a modern person;

c) the place of attachment m. mylohyoideus - linea mylohyoidea - becomes more pronounced and falls lower, as a result of which the diaphragm of the mouth in a modern person is lower;

d) the place of attachment m. geniohyoideus - spina mentalis - is almost absent in Neanderthals and occurs only in modern humans, who also have a chin protrusion. All these changes in the bones are due to the development of the named muscles involved in the act of articulate speech peculiar only to humans.

Muscles below the hyoid bone, - derivatives of the anterior longitudinal muscle of the trunk - refer to the system of ventral rectus muscles of the neck and are located on the sides of the midline immediately under the skin in front of the larynx, windpipe and thyroid gland, stretching between the hyoid bone and the sternum, with the exception of m. omohyoideus, which goes to the scapula and by its origin is a muscle that has shifted from the trunk to shoulder girdle(truncofugal).

1.M. Sternohyoideus, sternohyoid muscle, starts from the posterior surface of the sternum handle, the sternoclavicular joint and the sternal end of the clavicle, goes up and attaches to the lower edge of the hyoid bone. Between the medial edges mm. sternohyoidei is a narrow vertical gap closed by the fascia - the so-called white line of the neck.

Function. Pulls down the hyoid bone.

2.M. Sternothyreoideus, sterno-thyroid muscle, lies under the previous one. It originates from the posterior surface of the sternum handle and the cartilage of the 1st rib and is attached to the lateral surface of the thyroid cartilage (to its linea obliqua).

Function. Lowers the larynx.

3. M. thyreohyoideus. thyroid hypoglossal muscle, is, as it were, a continuation of the previous muscle, stretches from the linea obliqua of the thyroid cartilage to the body and the large horn of the hyoid bone.

Function. With a fixed hyoid bone, the larynx pulls up.

4. Momohyoideus. scapular-hyoid muscle, consists of two abdomens. The lower abdomen, starting medial to the incisiira scapulae, fits under the sternocleidomastoid muscle, where, through the intermediate tendon, it continues into the upper abdomen, which goes to the body of the hyoid bone.

Function. M. omohyoideus lies in the thickness of the cervical fascia, which it stretches during its contraction, promoting the expansion of the large venous trunks located under the fascia. In addition, the muscle pulls down the hyoid bone.

DEEP MUSCLES

Lateral, attached to the ribs - ladder (Mm. Scateni)- represent modified intercostal muscles; this explains their attachment to the ribs (Fig. 78).

1.M. Scalenus anterior, scalene anterior muscle, starts from the anterior tubercles of the transverse processes of the III-VI cervical vertebrae and attaches to the tuberculum m. scaleni anterioris I ribs in front of sulcus a. subclaviae.

2.M. Scalenus medius, middle scalene muscle, originates from the anterior tubercles of the transverse processes of all cervical vertebrae and attaches to the I rib, posterior to sulcus a. subclaviae.

3.M. Scalenus posterior, posterior scalene muscle, starts from the posterior tubercles of the three lower cervical vertebrae and attaches to the outer surface of the II rib.

Function. Mm. scaleni lifts the upper ribs, acting as an inspiratory muscle. With fixed ribs, contracting on both sides, they flex the cervical part of the spine anteriorly, and with a unilateral contraction, they bend and turn it in their direction.

Prevertebral muscles(see fig. 78).

1.M. longus colli, longus muscle of the neck, has the form of a triangle lying on the front surface of the spine on both sides along all the cervical and three thoracic vertebrae.

2.M. Longus capitis, longus muscle of the head, closes itself upper part previous muscle. It originates from the transverse processes of the III-VI cervical vertebrae and attaches to the pars basilaris of the occipital bone.

3 and 4. M. m. recti capitis anterior et lateralis, anterior and lateral rectus muscles of the head, extend from the lateral mass of the atlas (anterior) and the transverse process (lateral) to the occipital bone.

Function. M. rectus capitis anterior and m. longus capitis bend the head anteriorly. M. longus colli, contracting with all fibers on both sides, bends the cervical part of the spine; when acting on one side, it tilts the spine to one side; oblique beams are involved in turning, in tilting the head to one side; he is helped by m. rectus capitis lateralis.

NECK TOPOGRAPHY

Neck, collum, are divided into four areas: the posterior, lateral, the area of the sternum-clavicular-mastoid muscle and the anterior (Fig. 79).

Back area, regio colli posterior, located behind the outer edge of m. trapezius and represents the back of the head, or neck, nucha.

Lateral region, regio colli lateralis, lies behind m. sternocleidomastoideus and is limited in front by the named muscle, below the clavicle and behind m. trapezius.

Regio sternocleidomastoidea corresponds to the projection of this muscle.

The anterior region, regio colli anterior, lies anterior to m. sternocleidomastoideus and is bounded behind by the named muscle, in front by the midline of the neck and from above by the edge of the lower jaw. A small area behind the corner of the mandible and in front of the mastoid process is called the fossa retromandibularis. It houses the posterior parotid gland, nerves and blood vessels.

The anterior and lateral regions are subdivided into a series of triangles by m. omohyoideus, passing obliquely, from top to bottom and back, and crossing m. sternocleidomastoideus.

In regio colli lateralis, trigonum omoclaviculare is isolated, which is limited to m. sternocleidomastoideus (front), lower abdomen m. omohyoideus (top) and collarbone (bottom).

In regio colli anterior, two triangles are distinguished: 1) trigonum caroticum (a. Carotis passes in it) m. sternocleidomastoideus (behind), the back abdomen of the t. digastricus (in front and above) and the upper abdomen of m. omohyoideus (front and bottom); and 2) trigonum submandibular (the submandibular gland lies in it) is formed by the lower edge of the mandibulae (top) and two abdomens of m. digastricus.

Between scalene muscles there are triangular slits or spaces through which the nerves and vessels of the upper limb pass.

1. Between mm. scaleni anterior et medius - spatium interscalenum, limited from below by the I rib, where the subclavian artery and brachial plexus pass.

2. Ahead of m. scatenus anterior -spatium antescalenum, covered in front mm. sterno-thyreoideus and sternohyoideus (the subclavian vein passes through it, a. suprascapularis and m. omohyoideus).

Ventral muscles of the spine

This musculature lies under the vertebral bodies (Fig. 78). Flexes the spine or parts of it. When combined with the dorsal muscles, they promote lateral rotation or rotation of the head, neck, tail, as well as fixation of the spine (with bilateral joint action). The ventral musculature is less developed than the dorsal one and is located mainly in the neck and lumbar region.

Long neck muscle- m. longus colli is a multifidus muscle that lies along the ventral surface of the bodies of all cervical and first thoracic vertebrae. Along the median line, it is adjacent to the same muscle of the other side. In the cervical and thoracic parts, the muscle bundles go in different directions. It starts from the bodies of the thoracic vertebrae - from the 5th-6th and goes cranially. The muscle bundles lie obliquely and are attached through 2-3 segments to the transverse costal processes of the anterior vertebrae. The muscle ends on the ventral tubercle of the atlas. The muscle has a complex structure and belongs to the semi-static (pig, cattle) or static-dynamic (sheep) type. It is innervated by the cervical and thoracic spinal nerves. It is vascularized by the vertebral and intercostal arteries. Function - bends the neck.

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Rice. 78. Ventral muscles of the spinal column in the lumbar region:

1- internal intercostal mm .; 2 - small and 3 - large lumbar mm .; 4

Square lumbar m; 5 - iliac and.

Long muscle of the head - m. 1оngus capitis is a complex muscle, lies on the ventral surface of the bodies of the middle cervical vertebrae, on the side of the long neck muscle. It starts from the transverse costal processes of the middle cervical vertebrae. It ends on the muscular tubercles of the occipital bone.

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Vrakin V.F., Sidorova M.V.	MORPHOLOGY OF AGRICULTURAL ANIMALS

It is innervated by the cervical spinal nerves. It is vascularized by the vertebral and common carotid arteries. Function - bends the head and neck.

Square muscle of the lower back- m. quadratus lumborum (see Fig. 78-4) -

lies with separate muscle teeth on the ventral surface of the transverse costal processes of the lumbar vertebrae. Covered by a large lumbar muscle... It starts from the vertebral ends of the last two ribs and from the transverse costal processes of the lumbar vertebrae. The bundles are directed backward, fixing on the subsequent vertebrae along the way. The muscle ends on the ventral surface of the wings of the sacral bone. It is abundantly penetrated by tendon layers and belongs to the static-dynamic type. It is innervated by the lumbar spinal nerves. It is vascularized by the lumbar arteries. Function - lumbar flexion.

Psoas minor muscle- m. psoas minor (2) -not large muscle,

lies on the ventral side of the lumbar region, medially from the psoas major muscle. It starts from the bodies of the last thoracic and first lumbar vertebrae. It ends at the lumbar tubercle of the ilium. It belongs to the semi-static-dynamic type. It is innervated by the lumbar spinal nerves. It is vascularized by the lumbar arteries. Function - tightens the pelvis and flexes the lower back.

Psoas major muscle(3), see mm. pelvic limb. Short ventral muscles of the spine- located

laid in the area of the junction of the head with the neck and on the tail. Participate in the opus

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Chest muscles

V the muscles of the chest can distinguish four muscle layers

with different direction of muscle bundles, although not developed everywhere (see Fig. 76, 77 and 79). Muscles with a caudoventral and longitudinal direction of the bundles are inhalers - inspirators, since when they contract, the ribs turn in such a way that the chest expands. The diaphragm is considered an inspirator that increases the length of the chest. Muscles with cranioventral and transverse direction of the bundles

Exhalers are expirators. When they contract, the ribs rotate in such a way that the ribcage narrows. With shallow breathing, short muscles act: intercostal, rib lifters. With deep breathing, the long muscles of the chest wall are also included: the dorsal dentate, lumbar-costal, scalene, and straight chest. If the abdominal muscles take an active part in the breathing space, breathing is called abdominal.

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Vrakin V.F., Sidorova M.V.	MORPHOLOGY OF AGRICULTURAL ANIMALS

Rice. 79. Deep trunk musculature:

1 - plaster-like m; 2 - serrated dorsal inhaler; 3 - ileal-costal m; 4 - serrated dorsal expirator; 5 - lumbar-rib m; 6 - iliac m.: 7 - ladder m.; 8 - straight m. Chest; 9 - external intercostal mm .; 10 - internal intercostal mm .; 11 - straight m. Abdomen; 12 - internal oblique m. Abdomen.

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sebaceous serratus(serrated dorsal inhaler) -m. serratus dorsalis cranialis (2) -complex, lamellar. Lies on the dorsal muscles and vertebral ends of the ribs, covered by the latissimus dorsi muscle. It begins with a wide lamellar tendon from the spinous processes of the thoracic vertebrae of the withers. It turns into a flat muscular abdomen, composed of 4-6 teeth in cattle, 3 teeth in a sheep, 4-5 teeth in a pig, 7-8 teeth in a horse. The direction of the muscle bundles is caudoventral. It ends at the cranial edges from the 4-5th to the 8-9th rib in cattle, from the 4th to the 6th rib in the sheep, from the 4-5th to the 8th rib in the pig, from 5 -6th to 11-12th rib in a horse. It belongs to the dynamic type. Innervated by intercostal nerves Vascularized by intercostal arteries.

Rib lifters- mm. levatores costarum - short muscles of tre-

coal-shaped, covered with the longest muscle of the back and the iliocostal muscle. They start from the transverse processes of the vertebrae. Terminate at the vertebral ends behind the lying ribs. The direction of the muscle bundles is caudoventral. They are of the dynamic type. Innervated by intercostal nerves. Vascularized by the intercostal arteries.

Intercostal external muscles- mm. intercostales externi (9) - jav-

They are a direct continuation of the rib lifters to the lateral walls of the chest, forming its soft walls. Lie on the intercostal inner

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Vrakin V.F., Sidorova M.V.	MORPHOLOGY OF AGRICULTURAL ANIMALS

muscles, covered with the dentate ventral and latissimus dorsi. They are located between adjacent ribs so that the muscle bundles run caudoventrally from the caudal edge of the previous rib to the cranial edge of the next rib. They are of the dynamic type. Innervated by intercostal nerves. Vascularized by the intercostal arteries.

Ladder muscle- m. scalenus (7) - lamellar, in the form of 2-3

comparatively narrow strips, lying in steps. It is a continuation of the intercostal external muscles in the neck area. It starts from the transverse costal processes of the last 4-5 cervical vertebrae. Muscle bundles go caudoventrally and are fixed in cattle and pigs in two portions: on the first and 2-4 ribs. The horse only has a portion of the muscle that ends on the first rib. It belongs to the dynamic type.

It is innervated by the cervical and intercostal nerves. It is vascularized by the common carotid artery. The function - in addition to inspiration with bilateral contraction, lowers the neck, with unilateral contraction - bends it to the side.

Rectus chest muscle - m. rectus thoracis (8) is lamellar, in the form of a small tape. Lies on the intercostal muscles below the dentate ventral, covered with a deep pectoral muscle... It begins at the sternal end of the first rib, the muscle bundles are directed caudally. Along the way, in separate portions, it ends on 2-4 costal cartilages and passes into the tendon of the rectus abdominis muscle. It belongs to the dynamic type. It is innervated by intercostal nerves. It is vascularized by the external thoracic artery.

Changed with the DEMO Diaphragm VERSION of (abdominal CAD-KAS PDF-Editor obstruction (http: // www) -diaphragma .cadkas.com) -. lamellar the muscle is domed. Lies across the body cavity, covering the wide exit from the chest (caudal chest opening), and separates the chest and abdominal cavities. The top of the convextendon centerdirected into the chest cavity. The peripheral part of the diaphragm consists of muscle bundles directed towards the center, and, depending on the place of attachment, is divided into lumbar, costal and sternal parts. The lumbar part begins under the bodies of the lumbar and last thoracic vertebrae, forminglegs of the diaphragm.The right leg is longer than the left. The costal part starts from the medial surface of the ribs, and the sternum part - from the xiphoid process of the sternum. All three parts converge at the tendon center. The diaphragm has three openings for the vessels and the esophagus: between the legs of the diaphragmaortic opening,below it, on the border with the tendon center -esophageal opening,in the tendon center -opening of the caudal vena cava.In terms of its internal structure, the diaphragm is of the static-dynamic type. It is innervated by the phrenic nerve. It is vascularized by the diaphragmatic and intercostal arteries. Function

It is an inspirator, while simultaneously exerting a pressor effect on the aorta and vena cava. Working together with abdominal muscles, promotes bowel movements, urination, childbirth. With the contraction of the diaphragm, the chest cavity increases in length.

Muscles - breathers - expirators. Caudal dorsal tooth

chattered muscle (dentate dorsal expiratory) - m. serratus dorsalis cau-

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Akaevsky A.I., Yudichev Yu.F., Mikhailov N.V., Khrustaleva I.V. Pet anatomy. Edited by A.I. Akaevsky - M .: Kolos, 1984 .-- 543 p.
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TO short muscles neck, providing head lifting, its lateral and rotational movements, include: a) the rectus dorsal major muscle of the head - m. rectus capitis dorsalis major (Fig. 74-39) - goes from the caudal edge of the spinous process of the axial vertebra to the scales of the occipital bone; b) rectus dorsal small muscle of the head m. rectus dorsalis minor - lies directly on the dorsal occipital membrane, originates at the dorsal tubercle of the atlas and ends at

occipital bone; c) the cranial oblique muscle of the head - m. obliguus capitis cranialis (33) - begins at the anterior edge of the wing of the atlas and ends at the base of the jugular process; d) caudal oblique muscle of the head - m. obliquus capitis caudalis (33 ") - begins on the spinous process of the axial vertebra and ends on the laterocaudal edge of the wing of the atlas.

In the tail section, the following tail lifters are distinguished:

a) Medial dorsal sacrotail muscle - m. sacrocau-dalis dorsalis medialis, or short tail lifter (Fig. 76-1), is located medially, adjacent to the spinous processes and the syminal muscle, has the form of a fusiform cord formed by individual muscle segments. It starts from the dorsal ridge of the sacrum and spinous processes of the caudal vertebrae, and ends on the articular processes and their rudiments of the caudally located vertebrae, passing one segment under them.

b) Lateral dorsal sacrotail muscle - m. sacrocau-dalis dorsalis lateralis, or long tail lifter (2), lies laterally from the previous one, originates from the intermediate crest of the sacrum and articular processes of the caudal vertebrae (in a pig and a dog, the beginning extends to the last two lumbar vertebrae), and ends It is located on the articular processes of the caudal vertebrae, starting from the 5th and on all subsequent ones, each muscle tooth passes up to five segments under it.

Function - lifts the tail and its lateral abductions. ...

The lateral muscles of the tail are represented by the short transverse muscles of the tail - mm. intertransversarii dorsales et ventrales caudae (6), which, located between the lateral dorsal and ventral muscles of the tail, are attached to the transverse processes. Towards the end of the tail, these muscles gradually decrease. In a pig, they are poorly expressed.

Function - carry out lateral movements of the tail, and in combination with the efforts of other muscles - its rotation.

Ventral muscles of the spine

The ventral muscle group of the spinal column is developed only in its mobile parts - the cervical, lumbar and caudal.

Long neck muscle - m. longus colli (Fig. 74-43) - in the form of short, and partially long and obliquely directed muscle bundles, lies on the ventral surface of the vertebral bodies ranging from the 1st cervical to the 5th (6th) thoracic. Part of the muscle bundles extends caudoventrally from the ventral crests of the first five cervical vertebrae and ends on the ventral surface of the bodies of subsequent vertebrae (2-6). The last tooth ends on the costal process 6¦J-O of the cervical vertebra. Another part of the muscle bundles begins on the ventral crests of the first 5 (6) thoracic vertebrae and goes to the craniolateral, ending on the ventral surface of the bodies of the anterior vertebrae. The last two muscle teeth are fixed on the transverse process of the 7th and costal processes of the 6th cervical vertebra. Thus, the apexes of the cranial muscle teeth are directed cranially, and the caudal ones - vice versa.

Long muscle of the head - m. longus capitis (Fig. 71, 74-29) - located on the ventral surface of the cervical vertebral bodies laterally from the long neck muscle. It starts from the costal processes of the 2nd-6th cervical vertebrae and ends at the muscular tubercle of the base, the skull.

"Function - promotes flexion and lateral movements of the neck. Innervation - nn. Cervicales. 4

Rice. 75- Ventral muscles of the spinal column of the lumbar region of the dog: 41 - Ch. psoas major; 42 "- m. Iliacus; 45 - tn. Transversus abdominis; 46 - m. Quadratus lumbo-rum; 47 - m. Psoas minor.

Rectus lateral muscle of the head -

m. rectus capitis lateralis (Fig. 74-40) - starts "from the ventral arch and in the pterygoid fossa of the atlas, and ends on the jugular process.

The rectus ventral muscle of the head - m. rectus capitis, ventralis (Fig. 74-32) - lies on the ventral surface of the occipital joint next to the muscle of the other side. The muscle begins at the ventral tubercle of the atlas and ends at the body of the occipital bone.

The quadratus lumbar muscle - t. Quadratus lumborum (Fig. 75-B-46) - is located on the ventral surface of the transverse processes of the lumbar vertebrae, covered with a large lumbar muscle. Consists of short muscle bundles starting on the medial surface of the vertebral ends of the last two ribs and on the transverse processes of the lobular, lumbar vertebrae, and, is fixed on the transverse processes of the last lumbar and on the ventral surface of the wings of the sacral bone.

Function - participates in the flexion of the spine, its strengthening and in lateral bends. Innervation - pp. lumbales.