MUSCLES OF THE NECK
The composition of the cervical muscles includes muscles of different origin.
1. Derivatives of visceral arches:
a) derivatives of the first visceral arch - m. mylohyoideus, venter anterior w. digastrici. (Inn. p. trigeminus);
b) derivatives of the second visceral arch - m. stylohyoideus, venter posterior t. digastrici, platysma. (Inn. p. facialis);
c) derivatives of gill arches - m. sternocleidomastoideus.
2. Autochthonous neck muscles:
a) front: m. sternohyoideus, m. sternothyreoidus, m. thyreohyoideus and m. omohyoideus, as well as m. geniohyoideus;
b) side: 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 remnants of the ventral musculature, the distribution of which was influenced by two important circumstances: the reduction of the ribs and the reduction of the body cavity. As a result, part of the autochthonous muscles of the neck disappeared in humans, 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 connected with the hyoid apparatus and are innervated from the ansa cervicalis.
Topographically, the muscles of the neck are divided into the following groups:
1. Superficial muscles (platysma, m. sternocleidomastoideus).
2. Middle muscles, or muscles of the hyoid bone:
a) muscles lying above it (mm. mylohyoideus, digastricus, stylohyoideus, geniohyoideus);
b) 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 - DERIVATES OF VISCERAL ARCHES
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 fascia pectoralis et deltoidea, and is attached to the edge of the lower jaw and to fascia parotidea et fascia masseterica, partly continuing into the muscles of the mouth.
Function. By pulling the skin of the neck, the muscle protects the saphenous veins from compression; in addition, she can pull down the corner of her mouth, which is important in facial expressions.
2. M. sternocleidomastoideus, sternocleidomastoid muscle, lies immediately under the previous one, separated from it by the cervical fascia. It starts from the handle of the sternum and from the sternal end of the clavicle and is attached to the mastoid process and to the linea nuchae superior of the occipital bone. By its origin, the muscle represents the separated part of m. trapezius and therefore has one innervation with this muscle.
Function. With unilateral contraction, the muscle tilts the cervical spine in its direction; at the same time, the head is raised with the rotation of the face in the opposite direction.
With bilateral contraction, the muscles hold the head in a vertical 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, forward flexion of the cervical spine can also occur with simultaneous lifting of the face. When fixing the head, it is possible to raise the chest during breathing (auxiliary inspiratory muscle).
MIDDLE MUSCLES, OR MUSCLES OF THE HYLOGULASS
Muscles 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 the tendon suture, raphe, stretching from the inside of the chin to the body of the hyoid bone along the midline along the border between both mm. mylohyoidei. The back of the muscle is attached to the body of the hyoid bone. Both mm. mylohyoidei, converging together, form the muscular floor of the mouth, diaphragma oris, which closes the oral cavity from below.
2. M. digastricus, digastric muscle, consists of two bellies connected by a round 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 belly, venter posterior, begins in the incisiira mastoidea of the temporal bone and goes to the tendon, through which it connects to the anterior belly. The intermediate tendon is attached to the body and the greater horn of the hyoid bone.
3. M. stylohyoideus, awl-hyoid 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 with two bundles.
Derivative of the anterior longitudinal muscle of the trunk:
4. M. geniohyoideus, geniohyoid muscle, lies above 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 raise the hyoid bone upward. When it is fixed, then three muscles (mm. mylohyoideus, geniohyoideus, digastricus) lower the lower jaw, thus being antagonists of the masticatory muscles. The fixation of the hyoid bone is carried out by the muscles located below it (mm. sternohyoideus, omohyoideus, etc.). Without this fixation, it is impossible to lower the lower jaw, otherwise the hyoid bone, which is lighter and more mobile than the jaw, will be raised. These same three muscles, especially m. mylohyoideus, during their contraction during the act of swallowing, they raise their tongue, pressing it against the palate, due to which the food bolus is pushed into the throat.
The muscles located above the hyoid bone are part of a complex apparatus, including the lower jaw, hyoid bone,
larynx and windpipe and plays an important 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 hand, with the appearance of articulatory movements. Therefore, when comparing the skulls of Neanderthal and modern humans, 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 belly of the same muscle - fossa digastrica - moves medially in modern man;
c) 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) place of attachment m. geniohyoideus - spina mentalis - is almost absent in Neanderthals and occurs only in modern man, who also has a chin protrusion. All these changes in the bones are due to the development of these muscles, which are involved in the act of articulate speech, characteristic only of a person.
Muscles below the hyoid bone, - derivatives of the anterior longitudinal muscle of the trunk - belong to the system of the 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 body to the shoulder girdle (truncofugal).
1. M. sternohyoideus, sternohyoid muscle, starts from the back surface of the handle of the sternum, sternoclavicular joint and sternal end of the clavicle, goes up and is attached to the lower edge of the hyoid bone. Between the medial edges of mm. sternohyoidei there is a narrow vertical gap closed by fascia - the so-called white line of the neck.
Function. Pulls down the hyoid bone.
2. M. sternothyreoideus, sternothyroid muscle, lies under the previous one. It originates from the posterior surface of the sternum handle and cartilage of the 1st rib and is attached to the lateral surface of the thyroid cartilage (to its linea obliqua).
Function. Lowers the throat.
3. M. thyreohyoideus. thyrohyoid 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 is pulled upward.
4. Momohyoideus. scapular-hyoid muscle, consists of two bellies. The lower abdomen, beginning medially incisiira scapulae, fits under the sternocleidomastoid muscle, where it continues through the intermediate tendon 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, contributing to the expansion of large venous trunks 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, scalenus anterior, starts from the anterior tubercles of the transverse processes of the III-VI cervical vertebrae and is attached 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 is attached to the 1st 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 is attached to the outer surface of the II rib.
Function. mm. scaleni raise the upper ribs, acting as inspiratory muscles. With fixed ribs, contracting on both sides, they bend 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, long neck muscle, has the form of a triangle lying on the front surface of the spine on both sides throughout all the cervical and three thoracic vertebrae.
2. M. longus capitis, longus capitis, covers the upper part of the previous muscle. It originates from the transverse processes of the III-VI cervical vertebrae and is attached to the pars basilaris of the occipital bone.
3 and 4. M. m. recti capitis anterior et lateralis, anterior and lateral rectus capitis, 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 forward. M. longus colli, contracting with all fibers on both sides, flexes the cervical part of the spine, when acting on one side, the spine tilts to one side; oblique beams are involved in turning, in tilting the head to one side; m helps him. rectus capitis lateralis.
TOPOGRAPHY OF THE NECK
Neck, collum, are divided into four regions: posterior, lateral, region of the sternocleidomastoid muscle and anterior (Fig. 79).
Posterior region, regio colli posterior, located behind the outer edge 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, from below by the clavicle and behind by m. trapezius.
Regio sternocleidomastoidea corresponds to the projection of this muscle.
The anterior region, regio colli anterior, lies anterior to m. sternocleidomastoideus and is limited behind by the named muscle, in front - by the middle line of the neck and from above - by the edge of the lower jaw. A small area behind the angle of the mandible and in front of the mastoid process is called the fossa retromandibularis. It contains the posterior part of the parotid gland, nerves and blood vessels.
The anterior and lateral regions are divided into a series of triangles by means of 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 clavicle (bottom).
Two triangles are distinguished in regio colli anterior: 1) trigonum caroticum (a. carotis passes through it) is formed by m. sternocleidomastoideus (behind), the posterior belly of t. digastricus (front and top) and the upper belly of m. omohyoideus (front and bottom); and 2) trigonum submandibular (it contains the submandibular gland) is formed by the lower edge of the mandibulae (above) and two bellies m. digastricus.
Between the scalene muscles there are triangular gaps 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 1st rib, where the subclavian artery and the brachial nerve plexus pass.
2. Ahead m. scatenus anterior -spatium antescalenum, covered in front mm. sterno-thyreoideus and sternohyoideus (the subclavian vein, a. suprascapularis and m. omohyoideus pass through it).
With fractures of the lower jaw, the function of each of the masticatory muscles is realized differently than normal, and depends on how the fracture line passes. So, if the fracture line passes through the neck of the lower jaw, then the superficial part of the masticatory muscle and the medial pterygoid muscle displace the lower jaw (without condylar processes) anteriorly and upwards.
Table 10 Muscles involved in the movements of the lower jaw
Continuation of the table. 10
The end of the table. 10
Typical features of masticatory muscles
The surface layer of the masticatory muscle in brachycephaly and chameprosopic face shape is usually wide and low, muscle fibers diverge downward (Fig. 85); with dolichocephaly and leptoprosopic face shape, it is long and narrow, muscle fibers run parallel. The intermediate layer of this muscle in dolichocephaly and leptoprosopia protrudes more from under the posterior edge of the superficial layer than in brachycephaly and chameprosopia.
The temporal muscle with a dolichocephalic form of the skull is low and long, and with a brachycephalic it is high and short (see Fig. 85).
Both heads of the lateral pterygoid muscle with a brachycephalic skull shape are short and wide, with a narrow gap between them, with a dolichocephalic one they are long and narrow, with a wide gap between them (Fig. 86).
The medial pterygoid muscle with a dolichocephalic shape of the skull and a leptoprosopic face shape is long and narrow, and with brachycephaly and chameprosopia it is low and wide (Fig. 87).
The shape of the pterygoid and chewing muscles is determined by the shape of the mandibular branch and the infratemporal fossa, but at the same time it corresponds to the structure of the bone components of the temporomandibular joint. This relationship is especially clearly reflected in the external structure of the lateral pterygoid muscle. When opening the mouth (lowering the lower jaw) and moving the lower jaw forward in people with a brachycephalic skull, the head of the joint is shifted to the top of the flat articular tubercle, i.e. the articular path slightly deviates from the horizontal plane. This movement of the head of the jaw is provided by the lower head of the lateral pterygoid muscle, which lies almost horizontally. In the dolichocephalic form of the skull, the articular head slides down the steep and high slope of the articular tubercle rather than horizontally. This movement is provided by the lower head of the lateral pterygoid muscle, the beginning of which is lower on the high lateral plate of the pterygoid process, and the muscle pulls the head of the jaw down rather than forward.
Ventral muscles of the neck
1. Sternohyoid muscle(m.sterno-hyoideus). It starts on the body of the sternum, ends on the body of the hyoid bone.
Function:
2. Scapulohyoid muscle(m. omo-hyoideus). It starts on the subscapular fascia (in ruminants - on the deep cervical fascia). It ends on the body of the hyoid bone. The dog is missing.
Function: pulls the hyoid bone back.
3. Sternothyroid muscle(m. sterno-thyreoideus). It starts on the handle of the sternum, ends on the thyroid cartilage of the larynx.
Function: pulls the larynx back when swallowing.
4. Sternomaxillary muscle(m. sterno-mandibularis). Begins at the handle of the sternum. Ends on the branch of the lower jaw. Available in cattle and horses.
Function: lowers the lower jaw, and with closed jaws - lowers the head and bends the neck.
5. G sternomastoideus muscle(m. sterno-mastoideus). It starts at the manubrium of the sternum and ends at the papillary process of the temporal bone. The horse is missing.
Function: lowers head and flexes neck.
On the lateral side of the neck stands out jugular groove(sulcus jugularis). It is limited: from above - by the brachiocephalic muscle, from below - by the sternomaxillary (in herbivores) or sternomastoid (in dogs and pigs). It contains the external jugular vein.
Muscles of the head form several groups: mimic, chewing, muscles of the auricle, hyoid bone, eyeball, pharynx, larynx.
Mimic muscles
1.Orbicular muscle of the mouth(m. orbicularis oris) - annular , lies at the base of the lips.
Function: sphincter of the mouth.
2.Nasolabial lift(m. Levator naso-labialis). Begins on the frontal and nasal bones. It ends, weaving into the circular muscle of the mouth.
Function: mouth dilator.
3. Upper lip lifter(m. levator labii superioris). It starts on the maxillary bone, ends, weaving into the circular muscle of the mouth.
Function: mouth dilator.
4. canine muscle(m. caninus). It starts on the maxillary bone, ends, weaving into the circular muscle of the mouth.
Function: mouth dilator.
5. upper lip lowerer(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 starts on the zygomatic bone, ends, weaving into the circular muscle of the mouth.
Function: dilator of the oral fissure.
7. lower lip lowerer(m. depressor labii inferioris). It starts on the mandibular bone, ends, weaving into the circular muscle of the mouth. The dog is missing.
Function: mouth dilator.
8. buccal muscle(m. buccinator). Connects the upper and lower jaws.
It consists of two layers: outer and inner, the outer one has a pinnate structure.
Function: movement of food in the oral cavity during chewing.
Chewing muscles
1. Large chewing muscle(m. masseter). It starts from the facial crest (mound) and from the zygomatic arch. It ends in the fossa of the large chewing muscle.
Function: closes jaws.
2. temporalis muscle(m. temporalis). It starts in the temporal fossa and ends on the coronoid process of the mandibular bone.
Function: closes jaws.
3. Winged we shtsa (m. pterygoideus). It starts around the choanae on the pterygoid, sphenoid and palatine bones, ends in the alar fossa.
Function: closes jaws.
4. Digastric(m. digastricus). It starts on the jugular process and ends on the mandibular body.
Function: lowers the lower jaw.
5. Jugular jaw muscle(m. jugulo-mandibularis). It starts on the jugular process and ends on the lower jaw. There is only horsepower.
Function: lowers the lower jaw.
Lesson 5. Muscles of the chest limb
Shoulder muscles
Extensors
1. Prespinous muscle(M. supraspinatus). It starts in the supraspinous fossa, ends on the tubercles of the humerus (in the dog - only on the large tubercle).
Flexors
1. Deltoid(m. deltoideus). It starts on the spine of the scapula and on the infraspinatus muscle, ends on the deltoid roughness of the humerus.
Additional feature; shoulder joint supinator.
2. teres major muscle(m. teres major). It starts on the caudal edge of the scapula and ends on the round roughness of the humerus.
Additional function: pronator of the shoulder joint.
3.teres minor muscle(m. teres minor). It starts at the caudal edge of the lower third of the scapula and ends at the neck of the humerus.
Abductor
1. infraspinalis muscle(m. infraspinatus). It starts in the posterior fossa and ends on the greater tubercle of the humerus.
Adductors
1. Subscapularis(m. subscapularis). It starts in the subscapular fossa and ends in the small tubercle of the humerus.
2. Coracobrachial 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.
Elbow muscles
Extensors
1. Triceps brachii(m. triceps brachii). It has three heads: long, lateral and medial (and in dogs and pigs - and additional). The long head begins at the caudal edge of the scapula, the rest - on the humerus. The muscle ends on the ulnar tubercle.
Additional function: shoulder flexor.
2. Fascia tensor.forearm(m. tensor fasciae antebrachii). It starts on the caudal edge of the scapula and on the latissimus dorsi muscle. It ends on the ulnar tubercle and fascia of the forearm.
Additional function: shoulder flexor.
3. Elbow muscle(m. anconeus). It starts in the cubital fossa, ends on the cubital tubercle.
Flexors
1.Biceps brachii(m. bicepsbrachii). Begins on the supraarticular tubercle of the scapula , ends on the radial roughness and on the ulna.
Additional function: shoulder extensor.
2. shoulder muscle(m. brachialis). It starts on the neck of the humerus, ends on the radial roughness and on the ulna.
pronator
1. Round pronator(m. pronatog teres). It starts on the medial epicondyle of the humerus and ends on the medial surface of the radius. Available only in dogs.
Muscles of the wrist
Extensors
1. extensor carpi radialis(m. extensor carpi radialis). It starts on the lateral epicondyle of the humerus and ends on the proximal epiphysis of the III metacarpal bone.
Additional function: elbow flexor.
2. Long thumb abductor(m. abductor pollicis longus). It starts on the lower part of the radius, ends on the I - II metacarpal bones.
Flexors
1. flexor carpi radialis(m. flexorcarpi radialis). Begins on the medial epicondyle of the humerus, ends at the proximal ends of the II - III metacarpal bones .
Additional function: elbow extensor.
2. Flexor carpi ulnaris(m. flexor carpi ulnaris). It begins with two heads: on the medial epicondyle of the humerus and on the ulnar tubercle. It ends on the accessory bone of the wrist.
Additional function: elbow extensor.
3. Elbow extensor of the wrist(m. extensor carpi ulnaris). It starts 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 the dog, it is an extensor of the carpal joint.
Muscles of the fingers
Extensors
1. Common finger extensor(m. extensor digitorum communis). Begins on the lateral epicondyle of the humerus. It ends on the extensor processes of the bones of the distal phalanges.
Additional function: flexor of the elbow and extensor of the carpal joints.
2. Lateral extensor of fingers(m. extensor digitorum lateralis). Begins at the proximal ends of the bones of the forearm. It ends on the extensor processes of the bones of the distal phalanges.
Additional function: carpal joint extensor.
Flexors
1. Superficial finger flexor(m. flexor digitorum superficialis). It begins on the medial epicondyle of the humerus. It ends on the bones of the middle phalanges.
Main function: flexor of the 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, the ulna - on the ulnar tubercle, the radius - on the lateral surface of the radius. It ends on the bones of the distal phalanges.
Main function: flexor of all finger joints.
Additional function: extensor of the elbow and flexor of the carpal joints.
3. Third interosseous muscle(m. interosseus tertius). Begins at the proximal end of the III metacarpal bone. It ends on the sesame bones of the proximal phalanx, and also gives branches to the dorsal surface of the fingers. In all ungulates it has turned into a bunch.
Function: u dogs - flexor of the joint of the proximal phalanx, in ungulates it fixes this joint.
long neck muscle(see Fig. 3.73) lies on the ventral surface of the cervical and thoracic spine. The thoracic part starts from the bodies of the first six thoracic vertebrae and ends on the transverse process of the seventh cervical vertebra. The cervical part originates from the transverse costal processes and the bodies of the last five cervical vertebrae, and ends at the crest of the cervical vertebrae and the ventral tubercle of the atlas. Action: flexes the neck.
long head muscle(see Fig. 3.73) follows from the transverse processes of the fifth - second cervical vertebrae to the muscular tubercle of the occipital bone. Action: flexes the neck and head.
Peculiarities. In pigs, horses and dogs, it is located, as in cows.
Rectus ventral capitis goes from the muscular tubercle of the occipital bone to the ventral tubercle of the atlas. Action: lowers head.
Rectus lateralis muscle of the head from the jugular process goes to the ventral arch of the atlas. Action: lowers head.
Peculiarities. In pigs, horses and dogs, the muscle lies in the same way as in cows.
sternocephalic muscle(see Fig. 3.67 - 3.72) consists of two parts: the sternomastoideus and sternomaxillary muscles. sternomastoideus muscle stretches from the handle of the sternum to the mastoid process. sternomaxillary muscle goes from the handle of the sternum to the lower jaw. Action: Lowers the head and neck.
Peculiarities. In pigs and dogs, the muscle is represented only by the sternomastoideus muscle. Horses are built like cows.
humerohyoid muscle(see Fig. 3.67 - 3.72) starts from the transverse processes of the third, fourth (fifth) cervical vertebrae, ends on the hyoid bone. Action: pulls back the hyoid bone.
Peculiarities. In pigs and horses, the humerohyoid muscle is arranged like in cows. It is absent in dogs.
Sternothyroid muscle(see Fig. 3.67 - 3.72) extends from the handle of the sternum to the thyroid cartilage. Action: pulls the larynx back.
Peculiarities. In pigs, the sternothyroid muscle originates from the first rib. In horses, it is built like in cows. In dogs, the sternothyroid muscle begins with the sternohyoid muscle at the manubrium of the sternum.
Sternohyoid muscle(see Fig. 3.67 - 3.72) starts from the handle of the sternum, ends on the body of the hyoid bone. Action: pulls the hyoid bone back.
Peculiarities. In pigs, the sternohyoid muscle starts from the first rib. In horses and dogs, it is located like in cows.
Square psoas lies under the transverse processes of the lumbar vertebrae. It extends from the last ribs to the wing of the sacrum. Action: flexes the lower back.
Peculiarities. In pigs, horses and dogs, the muscle is arranged like in cows.
Psoas minor muscle goes from the ventral surface of the bodies of the lumbar and last thoracic vertebrae to the lumbar tubercle of the pelvis. Action: flexes the lower back.
Peculiarities. In pigs, horses and dogs, the muscle is attached like in cows.
Iliopsoas muscle(see Fig. 3.67, 3.69, 3.72, 3.73) consists of two independent muscles: the psoas major and iliacus. psoas major goes from the bodies of the lumbar and last thoracic vertebrae to the lesser trochanter. Iliac muscle consists of two heads: the lateral head starts from the tubercle of the ilium, and the medial from the sacrum and the body of the ilium. Both heads terminate at the lesser trochanter of the femur. Action: flexes the lower back and hip joint.
Peculiarities. In pigs, horses and dogs, the muscle is arranged like in cows.
Long tail drop begins on the ventral surface of the sacrum and transverse processes of the first caudal vertebrae and ends on the ventral surface of the transverse processes and vertebral bodies. Action: lowers the tail.
Peculiarities. In pigs, the tail dipper is poorly developed. In horses and dogs, it is located, as in cows.
Short tail drop originates from the ventral surface of the sacrum and the first seven (eight) caudal vertebrae and ends in tendons on the vertebral bodies. Action: lowers the tail.
Peculiarities. In pigs, the tail dipper is poorly developed. In horses and dogs it attaches like in cows.
tail muscle starts from the ischial spine of the pelvis, ends on the transverse processes of the first three (four) caudal vertebrae. Action: lowers the tail.
Peculiarities. In pigs, horses and dogs, the tail muscle is located like in cows.
Muscles of the abdominal wall
The muscles of the abdominal wall support the internal organs and perform a number of other functions.
Oblique external abdominal muscle(Fig. 3.74; see Fig. 3.67 - 3.69, 3.72 - 3.73) starts from the ribs from the fifth to the thirteenth, its muscle bundles go obliquely from top to bottom and back and end with a wide aponeurosis that forms the abdominal, pelvic and femoral plates.
The ventral plate is the widest, fused with the plate of the same name on the other side along the white line of the abdomen. pelvic plate ends at the inguinal ligament. femoral plate ends on the medial surface of the wide femoral fascia. Between the abdominal and pelvic plates in males is formed external inguinal ring rather large, elongated spindle-shaped. Starts from the outer inguinal ring inguinal canal cone-shaped, in which the spermatic cord is located. The inguinal canal is located between the external and internal oblique muscles of the abdomen. Outside, he
covered with yellow abdominal fascia. Channel ends internal inguinal ring small size (pencil-thick), which is limited by the posterior edge of the internal oblique muscle of the abdomen and the inguinal ligament.
Peculiarities. In pigs, horses, the muscle is arranged like in bulls. In dogs, the external inguinal ring is well expressed not only in males, but also in females.
Oblique internal abdominal muscle(see Fig. 3.72-3.74) starts from the maklok and from the transverse processes of the lumbar vertebrae and ends at the last ribs and the white line of the abdomen. Muscle bundles go from top to bottom and forward.
Peculiarities. In pigs, horses and dogs, it is located like in cows.
transverse abdominis muscle(see Fig. 3.73, 3.74) originates from the transverse processes of the lumbar vertebrae and from the last costal cartilages and follows to the white line of the abdomen. Muscle bundles are directed from top to bottom. Medially, this muscle is covered by the intra-abdominal transverse fascia and peritoneum.
Peculiarities. In pigs, horses and dogs, the transversus abdominis is attached like in cows.
rectus abdominis(see Fig. 3.72, 3.74) starts from the lower ends of the fourth-ninth costal cartilage and sternum and ends at the pubic crest. The muscle bundles run from front to back on the right and left along the white line of the abdomen and have five tendon bridges. The muscle is enclosed in a tendon sheath formed by aponeuroses of the external and internal oblique muscles of the abdomen (outer plate), transverse muscle and intra-abdominal fascia (inner plate). In the area of the second or third tendon bridge in cows, there is a milk well for passing the saphenous abdominal vein.
Action: all abdominal muscles not only support the viscera, but take part in the act of exhalation and help empty the abdominal organs during defecation, urination, and in females they participate in childbirth.
Muscles of the chest wall
The muscles of the chest wall, contracting, either expand the chest cavity, or, conversely, narrow it. The expansion of the chest cavity is accompanied by inhalation, and the narrowing by exhalation. The muscles that provide inspiration are called inspirators (inhalers), and those that cause exhalation are called expirators (exhalers).
Dorsal serratus cranial muscle(see Fig. 3.72) is poorly developed in cows. It starts from the spinous processes of the first - fifth thoracic vertebrae, goes from top to bottom and back to the fifth - eighth ribs. Action: participates in the act of inhalation.
Peculiarities. In pigs and dogs, the cranial serratus dorsalis muscle is developed, as in cows. In horses, it ends on the ribs from the fifth to the twelfth.
Rib lifters(see Fig. 3.72, 3.73) in the amount of 10-11 extend from the mastoid processes of the thoracic vertebrae to the tubercles of the ribs. Action: participate in the act of inspiration.
Peculiarities. In pigs, horses and dogs, the rib lifters are arranged like in cows.
Intercostal external muscles(see Fig. 3.72, 3.73) start from the rear edge of the rib, the fibers go from top to bottom and back to the front edge of the next rib. Action: participate in the act of inspiration.
Peculiarities. Pigs, horses and dogs have muscles attached like cows.
Scalene supracostal muscle(see Fig. 3.72) is well developed in cows. It starts from the fifth-second (first) ribs and ends on the transverse processes of the sixth-third cervical vertebrae.
Scalene ventral muscle(see Fig. 3.72) goes from the first rib to the transverse processes of the third - seventh cervical vertebrae. Action: participates in the act of breathing.
Peculiarities. In pigs, the muscle is arranged like in cows. In horses, it starts from the transverse processes of the fourth - seventh cervical vertebrae and ends on the first rib, between the muscle bundles is the brachial plexus. In dogs, muscle bundles from the transverse processes of the cervical vertebrae stretch: the upper tooth to the third or fourth rib, the middle tooth to the eighth rib, and the lower tooth to the first rib.
rectus pectoralis muscle(see Fig. 3.72) extends from the first rib to the fourth - sixth costal cartilage. Action: participates in the act of inhalation.
Peculiarities. In pigs and horses, the rectus pectoralis muscle terminates at the second or fourth costal cartilage; in dogs, the muscle extends to the third costal cartilage.
Diaphragm, or abdominal obstruction, separates the chest cavity from the abdominal (Fig. 3.75). On the diaphragm distinguish muscle peripheral part And tendon center. The peripheral part is divided into lumbar, costal and sternal.
Lumbar(see Fig. 3.75) consists of right And left leg, which are attached to the lumbar and last thoracic vertebrae. Between the crura of the diaphragm is aortic opening. Fits in the right leg esophageal opening. Muscle fibers stretch from top to bottom and forward to the tendon center.
Costal part(see Fig. 3.75) steam room, begins at the lower ends of the 8-12th ribs. Muscle fibers go forward and medially to the tendon center. Between costal and lumbar
Rice. 3.75. Dog diaphragm (thoracic surface):
/ - dorsal muscles of the spinal column; 2 - left sympathetic trunk; 3 - dorsal esophageal trunk of the vagus nerve; 4 - left leg 5- ventral esophageal trunk of the vagus nerve; 6 - left phrenic nerve; 7 - costal part of the diaphragm; 8 - tendinous center of the diaphragm; 9 - the sternal part of the diaphragm; 10 - sterno-pericardial ligament; 11 - spinal cord; 12 - right unpaired vein and right sympathetic trunk; 13 - aorta; 14 - esophagus; 15 - mediastinal space; 16 - caudal vena cava; 17 - right phrenic nerve; 18 - mesentery of the caudal vena cava
parts are located lumbocostal triangles. Here, the diaphragm consists of only two sheets of serous membranes fused together - the pleura and peritoneum. In this place, ruptures of the diaphragm (diaphragmatic hernia) are possible.
sternal part(see Fig. 3.75) starts from the dorsal surface of the xiphoid cartilage. Muscle fibers are blown forward and up to the tendon center.
tendon center - a place of fusion of the tendons of all parts of the diaphragm. It has an opening for the caudal vena cava. The ventral concave surface of the diaphragm is covered abdominal. The thoracic convex surface is covered pleura. Action: when the diaphragm contracts, inhalation occurs; when the abdominal muscles contract, exhalation occurs.
Peculiarities. In pigs, the diaphragm is arranged in the same way as in cows. In horses, the right leg of the diaphragm starts from the bodies of the first four lumbar vertebrae, and the left leg from the first two lumbar vertebrae. The opening for the aorta lies between the peduncles, and the opening for the esophagus lies in the left pedicle.
Serratus caudalis dorsalis muscle (Fig. rice. 3.67, 3.68, 3.72) starts from the spinous processes of the lumbar vertebrae and ends at the I-XVIII ribs. Action: participates in exhalation.
Peculiarities. In pigs, a serrated dorsal expiratory extends from the lumbar spinous processes to the last five to six ribs. In horses, this muscle extends from the lumbar spinous processes to the eleventh to eighteenth ribs. In dogs, the muscle is located, like in cows.
Intercostal internal muscles(see Fig. 3.72, 3.73) start from the rear edge of the ribs, the muscle bundles go obliquely from below, back and up to the anterior edge of the next rib. They are also located between the costal cartilages. Action: exhalers.
Peculiarities. In pigs, horses and dogs, the intercostal muscles are located, as in cows.
lumbocostal muscle(see Fig. 3.72, 3.73) extends from the transverse processes of the first-third lumbar vertebrae to the last rib. Action: exhaler.
Peculiarities. In pigs and horses, the muscle is attached like in cows. It is absent in dogs.
transverse pectoralis muscle originates from the dorsal surface of the sternum and ends on the inner surface of the second - eighth costal cartilage. Action: exhaler.
Peculiarities. In pigs, horses and dogs, the transverse pectoral muscle is located, as in cows.
Direction of training 36.05.01 Veterinary
Compiled by: Candidate of Veterinary Sciences, Associate Professor Mustafin R.Kh.
Reviewer: candidate of veterinary sciences, associate professor Fayrushin R.N.
Responsible for the release: head. department, associate professor Bazekin G.V.
Ufa, BSAU Department of Morphology, Pathology,
pharmacy and non-communicable diseases
Plan.
1. Operations in the ventral region of the neck.
1.1. Anatomical and topographic data.
1.2 Tracheotomy
1.3 Esophagectomy
1.4. Surgical treatment of esophageal diverticulum.
1.5. Ligation and resection of the jugular vein.
1.6. Ligation of the common carotid artery.
1.7. Blockade of the stellate node.
Purpose of the lesson: to study the anatomical and topographical features of the ventral neck area of animals, to work out the technique of anesthesia of certain areas of the neck, to study the main types of surgical operations in the neck area.
Material support. Machine and operating table for large animals. Tool table. Belts, ropes. Safety razor, soap, towels, alcohol balls for hand disinfection. Yawners, Bayer's wedge, surgical saw, Farabef's straight rasp, spins for horses. A set of surgical instruments, suture and dressing material. Solutions: 5% alcohol solution of iodine, 0.5% and 2% solutions of novocaine, 2.5% solution of chlorpromazine, 2% solution of rompun, solution of ethacridine lactate (rivanol) 1:1000, potassium permanganate solution 1:1000. Antibiotics and sulfa drugs. Animals. Models and posters.
Control tasks:
1) fix the animals in accordance with the operation;
2) prepare the operation field;
3) perform anesthesia of the nerves of the neck in cows and horses;
4) perform an operation to open the esophagus.
5) to carry out a tracheotomy.
6) ligate the jugular vein.
Anatomical and tonographic data. The ventral region of the neck extends down from the cervical vertebrae, having its borders: from above - the long muscle of the neck (m. longus cosh), located on the ventral side of the cervical vertebrae; in front - the posterior edges of the lower jaw; behind - the handle of the sternum and below - the free edge of the neck.
Tissues and organs of this area. The skin is thin and mobile; mild subcutaneous tissue, in which the branches of the cervical nerves, skin blood and lymphatic vessels pass.
Superficial two-layered fascia. Relatively loosely connected to the underlying layer, and in the midline fused with the outer leaf of the deep fascia. In the posterior and middle third of the neck there is a subcutaneous muscle of the neck, merging with the upper edge of the brachiocephalic muscle, and below covering the jugular groove.
Sternobrachiocephalic muscle (i.e. sternobrachiocepha/icus). At
the horse is wide and consists of two merged muscles - the sternum
head and brachiocephalic. The first begins on the handle of the sternum and is covered by the subcutaneous muscle, and the second originates
from the shoulder crest, passes through the region of the shoulder joint to
neck and together with the previous muscle forms the upper edge of the jugular groove. Both muscles end in a lamellar tendon on the cervical angle of the ventral jaw, mastoid process of the temporal bone and transverse crest of the occipital bone, and teeth on the transverse costal processes of the 2nd-4th cervical vertebrae.
The muscle is covered with thin outer and inner sheets of deep fascia.
Ventral to the sternobrachiocephalic muscle, the jugular vein lies in the jugular vein. From the outside and inside it
covered with fascia passing from the sternocleidomastoid muscle. Under the fascia is loose tissue. In addition, the vein is enclosed in a thin fascia of its own. The diameter of the vein with good filling reaches 2-2.5 cm.
Below the vein follows the sternomaxillary muscle, dressed in sheets of fascia, continuing from the jugular vein. The upper edge of this muscle forms the lower wall of the jugular groove. In the posterior third of the neck, both muscles are located on the ventral side of the trachea, tightly adjacent to each other, and then diverge laterally and are fixed by tendons on the posterior edge of the lower jaw. As a result, in the middle and anterior thirds of the neck, a ventral
cervical triangle, facilitating access to the trachea.
The bottom of the jugular groove in its anterior half is the humerohyoid muscle up to 1-1.5 cm thick, and in the posterior half is the deep fascia of the neck. In the anterior part of the neck, both humerohyoid muscles converge at the lower edges, and in the larynx area they are tightly connected, being separated by a fascial plate along the midline, which protrudes as a white stripe.
On the ventral side of the neck on the tracheal fascia lie paired narrow and thin sternothyroid and sternohyoid muscles. They are dressed in a thin fascia, which forms a white line of the neck between them along the median line.
At the level of its lower outer edge, a plate is separated from the fascia - the prevertebral fascia (jascia praevertebralis), covering from the outside the long muscle of the neck. 2-3 cm below the place of separation of the prevertebral fascia, the deep fascia is divided into two more plates: the dorsal fascia (jascia retrotrachealis), running parallel to the prevertebral fascia, and the ventral plate (jascia praetrachealis). The latter serves as a continuation of the deep fascia of the neck, goes ventrally and is divided into two terminal sheets - the fascia of the trachea and the fascia of the sternothyroid and sternohyoid muscles. In addition to these main sheets, the deep fascia of the neck forms a sheath for the esophagus and the neurovascular bundle located on the trachea.
Between the plates of the deep fascia, as well as between them and the organs that they dress, especially below and above the trachea, there is a lot of loose connective tissue. Its presence creates anatomical prerequisites for the spread of purulent processes both in the neck area itself and outside it - into the chest cavity, and, conversely, from the chest cavity to the neck.
The ventral region of the neck contains the vital organs.
The trachea lies ventral to the longus neck muscle. The cervical part of it stretches from the larynx to the entrance to the chest cavity. The basis of the trachea is not completely closed cartilage rings. On the dorsal side, the ends of the cartilaginous rings become thinner and are connected to each other by a transverse connective tissue ligament. The width of each ring of the cervical part of the trachea in horses and cattle reaches an average of 1-1.5 cm, and the thickness on the ventral side is 0.4-0.5 cm. The mucous membrane is directly adjacent to the lower and lateral walls of the trachea and is loosely connected with them. The fasciae of the trachea, esophagus and neurovascular bundle are interconnected.
The cervical part of the trachea is very mobile, especially to the sides, which should be taken into account during surgical interventions on it.
The trachea is supplied with blood from the short tracheal branches of the common carotid artery, which anastomose with each other on the lateral surfaces of the organ, forming longitudinal arcs. Segmental interannular upper and lower vessels are separated from the latter on both sides, the branches of which are connected in the midline with the same-named branches of the other side.
The innervation of the trachea is carried out by branches of the vagus (recurrent) and sympathetic nerves.
The esophagus begins at the pharyngeal opening and first follows the dorsal wall of the larynx and trachea. At the level of the fourth cervical vertebra, it deviates to the left and goes along the left upper lateral edge of the trachea before entering the chest cavity. At the level of the seventh cervical vertebra, it returns to the dorsal surface of the trachea and in this position penetrates into the chest cavity.
Outside, the cervical part of the esophagus is covered with a connective tissue membrane (adventitia), closely soldered to the muscle layer of longitudinal and annular fibers. The mucous membrane of the esophagus is gray-white, dense and easily extensible. It is connected to the muscle layer by abundant loose fiber. At rest, the esophagus mucosa is collected in longitudinal folds.
The cervical part of the esophagus is enclosed in its own fascia (plate of the deep fascia of the neck). The left carotid artery and the vagosympathetic trunk adjoin the esophagus.
The thickness of the wall of the esophagus and the diameter of its lumen in different departments are not the same. In a horse in the anterior third of the neck, the diameter is 6.5 cm, and the wall thickness is 4 mm; on the border between the anterior and middle thirds, it narrows to 5.5 cm, and the wall thickens to 5 mm. In the abdominal cavity, the esophagus has a second narrowing, and the wall thickens to 1-1.2 cm. In cattle, the decrease in diameter and thickening of the wall occur in the middle and partly in the anterior third of the esophagus. In dogs, areas of narrowing of the esophagus are located in the middle and in the back third of the neck. In chickens, the esophagus extends unilaterally into the goiter before entering the chest cavity, while in ducks and geese it expands spindle-shaped.
Blood supply. The cervical esophagus receives blood from short branches of the common carotid artery and the cranial thyroid artery. common carotid artery (A. carotis cotunis) is placed on the upper side of the trachea in its own fascial case, surrounded by loose connective tissue. Very mobile and easily shifted up and down.
1 
Fig. 1 Muscles, vessels and nerves of the neck of cattle,
middle layer, selectively:
1,2 - rhomboid m., 3.4 - patch-shaped m., 5 - cervical part of the ventral cervical m., 10.25 - external jugular vein, 16 - common carotid artery and vagosympathicus, 17 - esophagus, 18 - trachea, 19 - internal jugular vein, 30 - superficial cervical lymph node, 34 - parotid gland, 37-40 cervical nerves,
Innervation. The esophagus is innervated by branches of the vagus (recurrent), sympathetic, and glossopharyngeal nerves. Vagus and sympathetic nerves (n. p. vagus sytpathicus) in the neck represent a common trunk (truncus vago-sytpathicus), which is located on the trachea along the dorsal edge of the common carotid artery. The sympathetic nerve is thinner and is located dorsal to the vagus. Upon entering the chest cavity, it separates from the trunk and enters the caudal cervical node. (ganglion cervicale caudale). Recurrent branch of the vagus nerve (n.recurrences) in the neck
passes on the outer side of the trachea, below the common carotid artery. On its way, it gives off esophageal and tracheal branches. Both recurrent nerves terminate in the larynx as caudal laryngeal nerves.
On the lateral side of the trachea, medial to the common carotid artery, the lymphatic duct is located. (ductus lymphaticus trachealis).
The dorsal (nuchal) and vertebral regions of the neck are of lesser practical importance, since here surgical interventions are very rare and are usually associated with gunshot and accidental wounds.
TRACHEOTOMY.
Indications - shortness of breath, asphyxia, swelling of the larynx. Cattle and small cattle are fixed in the lateral position, small animals - in the dorsal position. Horses are operated on in a standing position. Anesthesia - local infiltration l% solution of novocaine.
Operation technique. The incision of the skin, subcutaneous tissue, superficial fascia and the sheet of pretracheal fascia is carried out strictly along the midline of the ventral region of the neck on the border between its middle and anterior thirds. The length of the incision in large animals is 5-8 cm, in small animals 2-3 cm. Next, the sternohyoid muscles are pushed apart in a blunt way and the own fascia of the trachea is cut.
Then, depending on whether a permanent or temporary tracheotomy is performed, the procedure is different. For permanent wearing of the tracheotube in the lower wall of the trachea, an oval window is cut out from two adjacent rings, occupying half of each ring, or the ventral part of one ring is excised. With temporary tracheotomy, a linear incision is made in the ventral wall of the trachea, involving 2-3 rings. When opening the trachea, make sure that the mucous membrane, which is very loosely attached to the inner surface of the trachea, is also cut at the same time. A sterile tracheotube is inserted into the trachea and strengthened with gauze strips around the neck. A tracheotomy animal must be under constant veterinary supervision.
ESOPHAGOTOMY.
Produced with blockage of the esophagus in cases where it is impossible to remove the blocking object in a non-operative way. Small animals are strengthened for surgery in the dorsal or lateral position on the table, large animals can be operated on in a standing position (with reliable tranquilization). Anesthesia - local infiltration with a 1% solution of novocaine.
Operation technique. The place of operation depends on the localization of the foreign body that clogged the esophagus. In large animals, operative access to the esophagus is carried out through the jugular groove. The skin incision is made in the left jugular groove directly above or below the jugular vein, its length is 8-15 cm. In order to avoid damage to the vein, the skin is cut, forming a fold from it. Then the subcutaneous tissue and superficial fascia with the subcutaneous muscle are dissected, periodically squeezing the central end of the vein for orientation in the location of the tissues and to avoid damage to the vein. The jugular vein, together with its fascial sheath, is pushed up or down with a blunt lamellar hook and penetrates to the lateral wall of the trachea. Here, the esophagus is found attached to the trachea by a special fascia. It is necessary to first try to advance the foreign body that clogged the esophagus without opening it. If this fails, the esophagus is opened along its longitudinal axis as far as possible and the foreign body is removed. The wound of the esophagus is sutured with a two-tiered suture - a knotted catgut suture on the mucous membrane and a silk suture on the muscular and connective tissue wall of the esophagus, similar to the intestinal suture. If the walls of the esophagus are severely damaged or necrotic, wounds of the esophagus and skin, or only the skin, are left open.
In small animals, operative access to the esophagus is carried out through a median incision of the skin and superficial fascia of the neck. Then the sternohyoid muscles are moved apart, the left sternothyroid muscle is lifted and the esophagus is found on the left surface of the trachea. If operated in the anterior third of the neck, the esophagus is found on the dorsal wall of the trachea. It should be remembered that the recurrent nerve passes through the esophagus or near it, damage to which can cause asphyxiation of the animal.
Fig.2 Operative access to the esophagus.
1-esophagus, 2-common carotid artery, 3-vagosympathetic trunk,
4-recurrent nerve, 5-jugular vein, 6-trachea.