Cutaneous muscle - archive.sau.edu.bd

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Cutaneous muscle: Thin muscular layer develop in the superficial fascia between the skin and deep fascia Very closely attached to the skin and responsible for skin movement. When a fly rests on the horse, the cutaneous muscle enable the horse to shake the skin Very little attachment to the skeleton. Doesn’t cover the entire body. Has 4 parts: 1. Facial part: the facial part of the cutaneous muscle is called M. cutaneous faciei 2. Cervical part: M. cutaneous colli 3. Omobrachial part (Omo means shoulder): cutaneous muscle of shoulder and arm is called M. cutaneous omobrachialis 4. Abdominal part: M. cutaneous trunci. Muscles of the lips and cheeks/facial expression: Fig. 3 Superficial muscles of the head and neck 1. orbicularis oris-closes the opening of the mouth 2. incisive muscles (mm. incisivi), 3. m. levator nasolabialis 4. m. levator labii superioris, 5. m. caninus 6. m. depressor labii superioris-pulls upper lip down 7. m. depressor labii inferioris-pulls upper lip down 8. m. mentalis 9. m. zygomaticus and 10. m. buccinator- forms the wall of the cheek Muscles of the eyelid: 1. Orbicularis oculi-sphincter muscle. Situated in and around the eyelid. It closes the eyelid 2. Corrugator supercilii 3. Malaris-to depress the lower eyelid 4. Levator palpebrae superioris- open the upper eyelid Muscles of the external ear: Auricular muscle 1. mm. auriculares caudales 2. mm. auriculares dorsales 3. mm. auriculares rostrales Fig. 2 Muscles of the Head Fig. 1 Cutaneous muscles

Transcript of Cutaneous muscle - archive.sau.edu.bd

Cutaneous muscle:

Thin muscular layer develop in the superficial fasciabetween the skin and deep fascia

Very closely attached to the skin and responsible forskin movement.

When a fly rests on the horse, the cutaneous muscleenable the horse to shake the skin

Very little attachment to the skeleton. Doesn’t cover the entire body. Has 4 parts:

1. Facial part: the facial part of the cutaneousmuscle is called M. cutaneous faciei

2. Cervical part: M. cutaneous colli

3. Omobrachial part (Omo means shoulder): cutaneous muscle of shoulder and arm is called M. cutaneousomobrachialis

4. Abdominal part: M. cutaneous trunci.

Muscles of the lips and cheeks/facial expression:

Fig. 3 Superficial muscles of the head and neck 1. orbicularis oris-closes the opening of

the mouth 2. incisive muscles (mm. incisivi),3. m. levator nasolabialis 4. m. levator labii superioris, 5. m. caninus 6. m. depressor labii superioris-pulls

upper lip down 7. m. depressor labii inferioris-pulls

upper lip down 8. m. mentalis 9. m. zygomaticus and 10. m. buccinator- forms the wall of the

cheek

Muscles of the eyelid: 1. Orbicularis oculi-sphincter muscle. Situated in and around the eyelid. It closes the eyelid2. Corrugator supercilii3. Malaris-to depress the lower eyelid4. Levator palpebrae superioris- open the upper eyelid

Muscles of the external ear: Auricular muscle 1. mm. auriculares caudales2. mm. auriculares dorsales3. mm. auriculares rostrales

Fig. 2 Muscles of the Head

Fig. 1 Cutaneous muscles

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Systematic Myology
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4. mm. auriculares profundi5. m. styloauricularis 6. m. scutularis 7. m. parotidoauricularis

Muscles of the eyeball Consists of 7 muscles. 4 recti/straight-Recrus dorsalis, Rectus ventralis, Rectus

medialis and Rectus lateralis. Dorsal rectus turns the eye upward, ventral rectus turns the

eye downward, medial rectus turns the eye inward andlateral rectus turns the eye outward.

2 oblique-Obliquus dorsalis and obliquus ventralis; rotatethe eye

1 retractor-retractor bulbi; pull the eye deeper into the socket

Mandibular muscle/muscles of mastication: All originate from the maxilla and the cranium and inserted

into the mandible.1. Masseter muscle- closes the jaw. Originates fron the

zygomatic arch and insert on the masseteric fossa.2. Temporalis m.-largest and strongest muscle of the head. It

also closes the jaw.3. Pterygoideus- consists of 2 parts medialis & lateralis.

Muscles of the intermandibular region: 1. Digastricus -open the jaw. Originates from the jugular process and inserts on the angle of the mandible.2. Mylohyoideus-lies transversely between the rami of the mandible

Lingual muscles: Muscles of Tongue Classified into two groups.1. Intrinsic-orgin and insertion within the tongue. No bony attachment.2. Extrinsic-

Three pairs of extrinsic muscles have bony origin and Insertion into the tongue. They are as follows

1. m. styloglossus, 2. m. hyoglossus- arise from the hyoid 3. m. genioglossus- originates from the mandible

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Fig. Mandibular muscles
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Fig. Eyeball muscles
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Muscles of the hyoid:

Consists of 8 muscles. All are paired except hyoideus transversus1. Mylohyoideus2. Stylohyoideus3. Occipitohyoideus4. Ceratohyoideus5. Geniohyoideus6. Hyoideus transverses7. Sternothyrohyoideus8. Omohyoideus

Muscles of the thoracic limb

Muscles of the shoulder girdle 1. Trapezius:

Triangular flat muscle.

Fig. 4 Superficial muscles of ventral shoulder and neck

Fig. 5 Deep muscles of the neck

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Origin-ligaments of the dorsal midline, insertion-spine of scapula Consists of 2 parts: Pars cervicalis and Pars thoracica

2. Rhomboideus: heavier muscle lies just beneath to the trapezius. Consist of cervicis and thoracis Origin-ligaments of the dorsal midline Insertion-medial side of the scapular cartilage

3. Serratus ventralis- large, fan-shaped muscle Consists of 2 part-cervical and thoracic The name 'Serratus' derived from the serrated edge. Origin-transeverse processes of caudal cervical and

cranial thoracic vertebra (cervical part); first 8 or 9 ribs Insertion- medial surface of scapula and scapularcartilage

4. Latissimus dorsi- spinous proc. of thoracic and lumbar vertebraeto medial humerus

5. Brachiocephalicus-(Brachio-arm; cephalicus-head) Extends from head to neck. covering the point of shoulder Divided into- cleidobrachialis(clavicle to humerus)

and cleidocephalicus (clavicular tendon to head andneck).

Cleidocephalicus divided into 2 parts- mastoid part(cleidomastoideus) and occipital part(cleidooccipitalis)

6. Pectoralis-superficialis and deep (profundus)

** Pectoralis muscle: located in between the ventral part of the chest wall and shoulder & arm**

Muscles of the shoulder:

Lateral group 1. Deltoideus : has 3 part: clavicular part, scapular part, acromial part

Origin- scapular spine Insertion-deltoid tuberosity

2. Supraspinatus Origin- supraspinous fossa of scapula

Fig. 6 Deep muscles of the left forelimb: lateral view

Insertion-greater tubercleof humerus

3. Infraspinaus Origin- infraspinous fossa

of scapula Insertion-greater tubercle

of humerus4. Teres minor- origin: caudal border

of scapula insertion- proximal todeltoid tuberosity

Medial group 1. Subscapularis- Origin: subscapular

fossa; Insertion- medial to humerus

2. Teres major-Origin: caudal borderof scapula; Insertion- medial to humerus

3. Coraco-brachialis-Origin: coracoidprocess of scapula Insertion: medial to humerus

4. Capsularis/Articularis humeri

**Synsarcosis (Syn-Attachment; Sarco- Muscle): the Attachment by muscles instead of joint. The muscles of the forelimb attach the forelimb to the body trunk by synsarcosis.**

Muscles of synsarcosis 1. Trapezius2. Rhomboideus3. Latissimus dorsi4. Brachiocephalicus5. Pectoralis (superficialis and deep)6. Serratus ventralis

Muscles of the Arm (Brachium) Consists of five muscles Grouped around the humerus. Arise from the scapula and humerus, Inserted into the forearm (radius-ulna).

1. Biceps brachii-This is a strong fusiform muscle, which lies on the cranial surface of the humerus.Origin-Supraglenoid tubercleInsertion-Cranial aspect of radius-ulna.

2. Brachialis-This muscle occupies the musculo-spiral groove of the humerus.Origin-Caudal surface of the humerus.

Fig. 7 Muscles of the left medial forelimb

Insertion-The medial surface of the neck of the radius.

3. Tensor fasciae antebrachii-This is athin muscle which lies on the medial surface of the triceps. Origin-caudal border of the scapula. Insertion-olecranon process

4. Triceps brachii-It is clearly divisibleinto four heads except in horse (3 head).

(a) Long head -Largest and longest of the three heads.

(b) Lateral (c) Medial head (d) Accessory head- absent in

horse

Origin- The long head) originated from the caudal border of the scapula and others (lateral, medial and accessory) from the proximal end of the humerus Insertion-Olecranon process

5. Anconeus-small muscleOrigin-caudolateral of the humerus. Insertion-olecranon process.

MUSCLES OF THE FOREARM AND MANUS

Extensor Division

Fig. 8 Muscles of the left antebrachium and manus

1. Extensor carpi radialis-This is the largest muscle of the extensor division and lies on the dorsal surface of theradius. Origin-lateral humeral epicondyle; Insertion-Mc III 2. M. Extensor digitalis communis- Longest extensor muscle of the forelimb.Origin-lateral epicondyle of humerus ; Insertion- third phalanx 3. Lateral digital extensor: Origin-Proximal on radius and ulna; Insertion- dorsal aspect of digit4. Extensor carpi obliquus -This is a small muscle which curves obliquely over the distal half of the radius and thecarpus. Origin-The craniolateral surface of the radius. Insertion-The head of the medial (second) metacarpal bone.

Flexor division 1. Flexor carpi radialis- lies on the medial surface of the forearm.

Origin- medial epicondyle of humerus; Insertion- proximal end of second metacarpal bone. 2. Flexor carpi ulanaris (Ulnaris lateralis)

Origin- medial epicondyle of humerus just behind the flexor carpi radialis. Insertion-proximal edge of the accessory carpal bone.

3. Superficial digital flexorOrigin-medial epicondyle; Insertion-2nd phalanx

4. Deep digital flexor: Origin- medial epicondyle of humerus, medial surface of olecranon.Insertion-third phalanx

Lateral muscles of the hip and thigh 1. Tensor fasciae latae-originated from tuber coxe and inserted on the patella.2. Gluteals-Gluteus superficialis, Gluteus medius, Gluteus accessories, Gluteus profundus

G. Superficialis-origin: Gluteal fascia; Insertion: third trochanter of femurG. Medius-Origin:gluteal surface of ilium; Insertion: greater trochanter of femurG. Profundus- Origin:body of ilium; Insertion:greater trochanter of femur

3. Biceps femoris(gluteobiceps)-Origin: sacrum; Insertion:patella

4. Semitendinosus- Origin: ischial tuber; Insertion: tibia and calcanean tendon5. Semimembranosus- Origin: ischial tuber; Insertion: femur and tibia.

Fig. 9 Muscles of the hindlimb (Lateral view)

Medial muscles of the thigh

1. Sartorius-ilium to medial fascia of stifle 2. Gracilis-pelvic symphysis to tibial crest 3. Pectineus-pubis to proximal tibia 4. Adductor-ventral pubis to medial femur 5. Semimembranosus 6. Quadratus femoris-ventral sacrum to femur 7. Obturator externus-ventral pelvis to trochanteric fossaof femur

Fig. 10 Deep muscles of the left lateral forelimb

8. Obturator internus-absent in ox9. Gamellus-ischium to trochanteric fossa

Cranial muscles of the thigh 1. Sartorius2. Quadriceps femoris

Fig. 11 Superficial muscles of the left hindlimb: Medial view

Rectus femoris Vastus lateralis Vastus medialis Vastus intermedius

Muscles of the leg and foot

Fig. 12 Deep muscles of the left medial hindlimb

Dorso-lateral group

Fig. 13 Muscles of the left leg and Pes; caudal view

1. Long digital extensor 2. Lateral digital

extensor 3. Peroneus tertius 4. Tibialis cranialis

Planter group

1. Gastrocnemius 2. Soleus 3. Superficial digital

flexor 4. Deep digital flexor 5. Popliteus

Muscles of the trunk The muscles of the trunk can

be grouped based on their topography as follows:

1. Muscles of the neck (mm. colli),

2. Muscles of the back (mm. dorsi),

3. Muscles of the thoracic wall (mm. thoracis),

4. Muscles of the abdominal wall (mm. abdominis) and

5. Muscles of the tail (mm. caudae)

Ventral cervical Muscles

1. Cutaneous colli 2. Brachiocephalicus muscle 3. Sterno-cephalicus: extends

from the sternum to the jaw. It forms ventral boundary of the jugular furrow.

Fig. 14 Muscles of left leg and Pes; lateral view

4. Sternothyroideus-manubrium sterni to thyroid cartilage 5. Sternohyoideus-manubrium sterni to basihyoid 6. Omohyoideus-cervical fascia to basihyoid bone

7. Scalenus- consists 3 parts: dorsalis, medius and ventralis. Originated from cranial border of the first rib and inserted to transverse processes of C4-C7

8. Iliocostalis- consist of 3 parts- cervicis, thoracis and lumborum

9. Rectus capitis ventralis 10. Rectus capitis lateralis 11. Longus colli- consists of 2

parts: thoracic(tranverse process of C6-C7 to atlas) and cervical

12. Intertranversarii colli

Lateral cervical muscle

1. Trapezius 2. Rhomboideus 3. Serratus ventralis- large,

fan-shaped muscle 4. Splenius- flat, triangular

muscle Consists of 2 parts:

capitis and cervicis Origin: Spinous

process of T1-T3 and thoracolumbar fascia

Insertion: capitis: occipital bone; cervicis: wing of atlas and transverse process of axis

5. Longissimus muscle: this is the longest and largest muscle in the body.

It extends from the sacrum to neck

Consists of 4 parts:

atlantis et capitis, cervicis, thoracis, lumborum

Origin: atlantis: articular proc. of C3-T2; cervicis: transverse proc. of first 6-7 thoracic vertebrae; thoracis: spinous proc. of the last thoracic vertebra; lumborum: lumbar & sacral vertebrae; iliac crest and tuber coxae.

Fig. 15 Muscles of the left leg and pes; caudal view

Insertion: mastoid process of temporal bone; transverse process of the last 4 cervical vertebrae; transverseprocess of C7; ventral ends of ribs and transverse proc. of thoracic and lumbar vertebrae.

6. Semispinalis capitis: lies on the ligamentum nuchae under spenius7. Multifidus: consists of 2 parts: cervicis, thoracis and lumborum8. Interspinales9. Rectus capitis dorsalis major10. Rectus capitis dorsalis minor11. Obliquus capitis cranialis12. Obliquus capitis caudalis

Muscles of back and loins: 9 pairs of muscles 1. Trapezius2. Latissimus dorsi- spinous proc. of thoracic and lumbar vertebrae to medial humerus3. Rhomboideus thoracis4. serratus dorsalis cranialis- from supraspinous ligament to cranial border of ribs 5-95. serratus dorsalis caudalis-thoracolubar fascia to caudal border of ribs 10-136. iliocostalis7. longissimus8. multifidus9. intertransversales lumborum

Muscles of the tail (mm. caudae)

Levators of the tail are: 1. m. sacrococcygeus dorsalis medialis 2. m. sacrococcygeus dorsalis lateralis

Depressors of the tail are: 3. m. sacrococcygeus ventralis medialis 4. m. sacrococcygeus ventralis lateralis

Lateral flexors of the tail are: 5. mm. intertransversarii caudae6. m. coccygeus

In addition in carnivores, m. iliocaudalis and m. pubocaudalis

Sublumbar muscle: 1. psoas major2. psoas minor3. iliacus4. Quadratus lumborum5. Intertransversarii lumborum

Muscles of the thorax: Consists of following muscle:

1. Levatores costarum2. Intercostales externi3. Intercostales interni4. Retractor costae5. Rectus thoracis6. Transversus thoracis7. Diaphragm

Fig. 16 Muscles of the left lateral neck and thorax

Muscles of Respiration

The muscles which play important role in respiration are known as respiratory muscle or muscles of respiration. Consists of- Expiratory-compress thorax Inspiratory-expand thorax

Expiratory muscles: 1. Serratus dorsalis caudalis-thoracolumbar fascia to caudal border of ribs 10-132. Intercostales interni- Origin: intercostal space (cranial border of the ribs) Insertion: caudal border of the preceding

ribs

Fig. 17 Muscles of the left lateral thoracic cage

3. Retractor costae- Origin: Transverse process of L1-L3 insertion: caudal border of the last rib4. Transversus thoracis- origin: costal cartilage 2-7 insertion: sternebrae

Plus all abdominal musclesInspiratory muscles:

1. Serratus dorsalis cranialis- origin: supraspinous ligament insetion: cranial border of ribs 5-92. Levatores costarum- tranverse proc. of T1-T12 insetion- upper ends of the ribs3. Intercostales externi-caudal border of ribs to cranial border of the succeeding ribs4. Rectus thoracis- origin: first rib insertion: costal cartilages5. Diaphragm

Diaphragm

This is a broad, unpaired muscle which forms a partition between the thoracic and abdominal cavities. It is presentin all mammals.

In outline it has some resemblance to a palm-leaf fan. It is dome-shaped, compressed laterally. The thoracic surface is strongly convex and covered by the pleura. The abdominal surface is deeply concave and covered by the peritoneum. It consists of a central tendon and a muscular periphery.

Openings of the diaphragm- Pierced by three foramina.

Aortic hiatus- opening between the twocrura. This transmits the aorta, vena azygos,and thoracic duct.

Esophageal hiatus-Perforates the right crusnear its junction with the tendinous center. Itis situated a little to the left of the medianplane. It transmits the esophagus, the vagusnerves, and the oesophageal branch of thegastric artery.

Caval foramen-lies within the central tendonand transmit caudal venacava.

Attachments of diaphragm: There are three attachments of diaphragm. Costal attachment: attached to costal

cartilages Sternal attachment: attached to upper

surface of the xiphoid cartilage. Lumbar attachment: lumbar portions of the muscles consists of thickened muscular bundles called crura.

(right and left crus)

Muscles of the abdominal wall The muscles of the abdominal wall are large Relatively thin muscular sheets. Muscle fibres run in all directions They are arranged in layers like as plywood. They have broad flat sheet (aponeurotic insertions) that meet at the midventral line (linea alba). Support abdominal viscera.

There are four abdominal muscles, which derive their names from their position and structure. 1. m. obliquus abdominis externus, 2. m. obliquus abdominis internus, 3. m. transversus abdominis and 4. m. rectus abdominis

Fig. 18 Muscles of the ventral trunk

obliquus abdominis externus muscle- Most superficial muscle. The fibres lie obliquely ventrocaudally. Origin- from the lateral surface of the ribs and thoracolumbar fascia. Insertion- linea alba and inguinal ligament.

Obliquus abdominis internus muscle- Situated immediately beneath the external oblique muscle. Intermediate muscle of the lateral abdominal wall. Its fibres run obliquely ventrocranially. Origin and insertion same as internal oblique muscle. This muscles form

the deep wall of the inguinal canal.

Transversus abdominis muscle- It is the deepest of the

abdominal muscle. Fibres run perpendicular

to the long axis of thebody.

Origin-Thoracolumbarfascia

Insertion-linea alba.

Rectus abdominis forms floor of the

abdomen. This is a broad band of

muscle on each side ofthe linea alba.

Origin-from thecartilages of the ribs and sternum.

Insertion-on the pubis by prepubic tendon

Muscles of abdominal Press: the contraction of the abdominal muscle and diaphragm on the viscera is known as abdominal press.

Function-muscles of abdomen perform multitude of function.

Compress the abdominal viscera during defecation, urination, parturition. . Help in regurgitation and vomiting. Serve as strong muscles for expiration of air from the lungs during coughing and sneezing. Helps in locomotion- arching back

Linea alba It is a median fibrous raphae which extends from the xiphoid cartilage to the prepubic tendon. It is formed by the

junction of the aponeurosis of the oblique and transverse abdominal muscles. A little behind to its middle, there is a cicatrix, the umbilicus, which indicates the umbilical opening of the fetus.

Prepubic tendon

It is the tendon of the insertion of the two straight abdominal muscles. It also furnishes the attachment to the oblique, gracilis and pectinei. It is attached to the cranial border of the pubic bones. It has clinical importance in regard to manipulation of the fetus in obstetrical cases.

Abdominal tunic It is the deep fascia of abdomen. This is a sheet of elastic tissue which assists the muscles in supporting the great

weight of the abdominal viscera. The linea alba reinforces the ventral abdominal wall together with the abdominal tunic in the midline. In large animals the ventral part of the abdominal tunic is yellow in colour due to elastic fibre. Due to the yellow color it is also called the yellow abdominal tunic (tunica flava abdominis).

Inguinal ligament: The inguinal ligament runs from the iliopubic eminence to the coxal tuberosity. It strengthens the iliac fascia on

either side of the prepubic tendon. This layer forms the superficial wall of the inguinal canal.

Flank It is the part of the lateral abdominal wall which is formed only of soft tissue and free of osseous structure.

Paralumbar fossa: A large triangular depression in the upper part of the flank is known as paralumbar fossa.

Inguinal region: It is the ventral surface of the caudal part of the abdominal wall in between the limbs and in front of the inguinal

ligament.

Femoral canal: It is bounded cranially by the sartorius, caudally by the pectineus and laterally by the ilio-psoas and vastus

medialis. Its medial wall is formed by the femoral fascia and the gracilis. It contains deep inguinal lymphnode, femoral artery and the saphenous nerve.

Calcanean tendon/Tendo Achilles/Achilles tendon: It comprises the tendon of the triceps surae (medial and lateral head of the gastrocnemius and soleus)

Common calcanean tendon/Hamstring tendon: It is a convenient designation for the aggregated tendons which are attached to the calaneus (point of the hock). It

includes calcanean tendon and the tendons of the flexor digitorum superficialis, biceps femoris and semitendinosus muscle.

Supraspinous ligament: It is a band of white fibrous tissue extending from the occipital bone to the base of the sacrum. It is attached to the

summits of the ventral spines.

Ligamentum nuchae/Nuchal ligament It is the modification of the supraspinous ligament into a cord like structure composed of mainly strong flattened

sheet of fibrous and elastic tisssues which extends from the occipital bone the withers. The function of this structure is to assist the extensor muscles of the head and neck in supporting of the weight of the head. It consists of 2 part – funicular part and lamellar part.

The funicalar part begins in the region of 2nd thoracic spinous process to the occipital bone and The lamellar part is confined to the cervical region.

Function- To assist the extensor muscles of the head and neck

Fig. Nuchal ligament of the horse. Red, funicular part; blue, laminar part.

Fig. Superficial muscles of the cow. m, muscle; n, nerve; v, vein.