[Zoo301] Muscles Oia

Abdominal Muscles

Muscle External Oblique This is the large muscle constituting the outermost layer of the abdominal wall. Internal Oblique It is a short muscle lying beneath the more dorsal portion of the external oblique. Its fibers are directed obliquely downward and forward, and are continued by a very broad aponeurosis. Transverse Abdominis Its fibers are directed ventrally and slightly posteriorly. Rectus Abdominis

Chest Muscles

This is a long slender muscle on each side of the linea alba, extending from the pubic symphysis to the anterior part of the thorax. It is found inside of and between the aponeuroses of the preceding muscles. Pectoantibrachialis Anterior and most superficial of the chest muscles. Pectoralis Major Posterior to the pectoantibrachialis and extending anteriorly dorsal to the pectoantibrachialis, which should be cut across. Pectoralis Minor Posterior to the pectoralis major and covered in large part by the pectoralis major. Xiphihumeralis

Muscles of the Neck and Throat

A thin, flat, long muscle, passing from the xiphoid process of the sternum, its anterior part passing dorsal to the posterior part of the pectoralis minor. Sternomastoid This is the superficial muscle of the ventral side of the neck. A large vein, the external jugular vein, crosses its surface at an angle to the direction of its fibers. Sternohyoid The anterior ends of these muscles are visible between the two sternomastoids, as the cleidomastoid diverge from the median raphe. They extend in the median ventral line from the first costal cartilage to the body of the hyoid bone, the two being closely united in the median line. Cleidomastoid Long muscle passing from the head to the upper arm lateral to the sternomastoid. Extends from the clavicle, which will be found as a slender bone on the internal surface of the long muscle just mentioned at the level of the shoulder, to the mastoid process. Clavotrapezius and clavobrachial The long muscle on the side of the neck and passing over the ventral surface of the shoulder to the forearm is sometimes considered as one muscle, the cephalobrachial, or as two. In the latter case, it is known as the clavotrapezius and extends from the skull to the clavicle. The lower part from the clavicle to the forearm is the calvobrachialis. Masseter The great thick muscle covering the angle of the jaws situated in front of the submaxillary and parotid glands. A very tough shining fascia covers it. Temporal A great mass of muscle covered by a strong shining fascia occupying the temporal fossa of the skull, dorsal to the ear. Digastric The muscle lying along the medial surface of each

Origin Lumbodorsal fascia and posterior ribs by separate slips

Insertion Extensive neurosis which passes to the linea alba and also in the pubis Linea alba by the extensive aponeurosis

Action Constrictor of the abdomen

Second sheet of the lumbodorsal fascia and border of the pelvic girdle Anterior end of pubic symphysis

Linea alba by the extensive aponeurosis

Compressor of the abdomen

Sternum and costal cartilages

Retracts ribs and sternum and compresses abdomen

Manumbrium

Flat tendon on the fascia of the forearm

Draws the arm toward the chest

Sternum and median ventral raphe

Humerus

Draws the arm toward the chest

Sternum

Humerus

Draws the arm toward the chest

Xiphoid process of the sternum

Humerus

Draws the arm toward the chest

Median raphe and the manubrium of the sternum

On the skull from the lambdoidal ridge onto the mastoid process

Singly turn the head, together depresses head on neck

Second sheet of the lumbodorsal fascia and border of the pelvic girdle

Compressor of the abdomen

Draw the hyoid posteriorly

Clavicle

Sternomastoid

Pulls clavicle craniad or turns head, acting singly, or lowers head on neck

Clavicle and fibers of the clavotrapezius

Ulna

Flexor of the forearm

Zygomatic Arch

Posterior half of the lateral surface of the mandible

Elevator of the lower jaw

Side of the skull from the superior nuchal line to the zygomatic process of the frontal bone, and from part of the zygomatic arch Jugular and mastoid processes of the skull

Coronoid process of the mandible

Elevator of the jaw

Mandible

Depressor of the lower jaw

half of the mandible. It extends posteriorly internal to the submaxillary gland. Mylohyoid

Mandible

Median raphe

Raises floor of the mouth and brings hyoid forward

Mandible near the symphysis

Body of the hyoid

Draws the hyoid forward

A pair of long, slender muscles lying in the median line. Sternothyroid

Sternum

Thyroid cartilage of the larynx

Pulls the larynx posteriorly

Located on each side of the trachea, dorsal to the sternohyoids. Thyrohyoid

Thyroid cartilage

Posterior horn of the hyoid

Raises the larynx

From the neural spines of the last thoracic and most of the lumbar vertebrae and from the lumbodorsal fascia Spines of the thoracic vertebrae and passes forward obliquely forward Neural spines of the cervical and first thoracic vertebrae

Tendon on the medial surface of the humerus

Pulls the forelimb dorsally and caudally

Fascia of the scapula

Draws the scapula dorsad and caudad

Metacromion process and spine of the scapula and fascia of the preceding muscle Clavicle

Draws the scapula dorsad and holds the two scapula together

Metacromion process and neighboring fascia

Draws the scapula craniad

Neural spines of the vertebrae and adjacent ligaments

Ventral border of the scapula

Draws scapula dorsad

Superior nuchal line

Scapula

Draws the scapula craniad and rotates it

Middorsal line and fascia

Superior nuchal line

Raises or turns the head

Whole surface of the supraspinatus fossa

Greater tuberosity of the humerus

Extends the humerus

Acromion process

Surface of other muscles of the shoulder

Raise and rotate the humerus

Spine of the scapula

Ridge (Deltoid ridge) of the humerus

Raise and rotate he humerus

Infraspinous fossa of the scapula

Greater tuberosity of the humerus

Rotates the humerus

Axillary border of the scapula and fascia of neighboring muscles

Common with latissimus dorsi on the medial surface of the humerus

Rotates the humerus and lowers it

Axillary border of the scapula

Greater tuberosity

Assists the infraspinatus

Subscapular fossa

Lesser tuberosity of the humerus

Pulls the humerus medially

Slips from the first nine or ten ribs and the

Scapula near the vertebral border

Draws the scapula craniad, ventrad, and

Thin transverse sheet passing across between the two digastrics from one half of the mandible to the other. Geniohyoid

Muscles of the Upper Back and Shoulder and Back of the Neck

Short, narrow muscle on each side of the thyroid cartilage Latissimus Dorsi The large flat muscle extending obliquely forward from the middle of the back to the upper arm. Spinotrapezius Posterior trapezius Acromiotrapezius Middle trapezius Clavotrapezius Anterior trapezius Levator Scapulae Ventralis Flat, bandlike muscle which passes anteriorly, diverging from the acromiotrapezius and passing internal to the clavotrapezius Rhomboideus Thick muscle beneath the spinotrapezius and acromiotrapezius extending from the vertebral border of the scapula to the middorsal line Rhomboideus Capitis Extends as a slender band forward Splenius Large sheet of muscle covering the back of the neck in front of the rhomboideus, internal to the trapezii and crossed by the rhomboideus capitis Supraspinatus stout muscle occupying the supraspinous fossa of the scapula Acromiodeltoid Short, thick muscle passing ventrally from the acromion process Spinodeltoid Muscle which passes to the upper arm, across the upper ends of the muscles of the upper arm Infraspinatus Two large muscles that are posterior to the scapula Teres Major The stout muscle immediately behind the Infraspinatus, its fibers running in the same direction. Teres Minor On the posterior border of the infraspinatus and somewhat covered by it Subscapularis Occupies the subscapular fossa and covers the inner or medial surface of the surface Serratus Ventralis

Superior nuchal line and median dorsal line of neck Transverse process of the atlas and occipital bone

Draws the clavicle dorsad and craniad

A large, fan-shaped muscle extending from the ventral border of the scapula to the sides of the thorax and neck. Serratus Dorsalis

Upper Arm Muscles

against the thoracic wall

Last ribs

Draw the ribs forward

Draws the ribs forward and bend the neck

Draw the ribs back again

The anterior part of this muscle arises by a number of fleshy slips from the ribs near the angles. The posterior part of this muscle consists of a few slips lying under the latissimus dorsi. Scalenes

Ribs

Long muscles seen in the chest wall ventral to the origin of the serratus ventralis and in front of the anterior boundary of the external oblique External Intercostals

Ribs

Transverse processes of the cervical vertebrae, uniting anteriorly into one band Ribs

Their fibers run obliquely backward and downward. Internal Intercostals

Ribs

Ribs

The fibers run obliquely forward and downward. Longissimus dorsi

Serratus Ventralis

Median part Iliocostalis

Transverse processes of the vertebrae

Ribs

Prominent tendons

Distal end of the humerus

Lateral surface of the ulna

Strengthens the elbow joint

Latissimus dorsi

Olecranon

Tending to rotate the ulna

Glenoid fossa

Radius

Flexor of the forearm

Lateral surface of the humerus

Ulna

Flexor of the forearm

Lateral epicondyle of the humerus, and semilunar notch of the ulna Lateral surface of humerus above the lateral epicondyle

Proximal end of fifth metacarpal Tendon passes internal to wrist ligaments

Extends fifth digit and ulnar side of wrist Extends three or four digits

Lateral surface of humerus above the lateral epicondyle Middle of humerus

Tendon passes internal to wrist ligaments

Extends three or four digits

Lower end of radius and adjacent ligaments

Rotates hand to supine position

Humerus near other extensors

Second and third metacarpals

Extends hand

Medial epicondyle of the humerus

Radius

Rotates radius to prone position

Medial epicondyle of humerus

Second and third metacarpals

Flexes these metacarpals

Medial epicondyle of humerus

Flexor of digits

Ulna and humerus

Flat tendon passes through wrist ligaments and divides into four or five tendons Basal phalanges

Olecranon process of the ulna

Pisiform bone of the wrist

Flexes ulnar side of wrist

Ventral part Triceps brachii (aconeus) In the cat, there is also a small fourth part of the triceps, a small triangular muscle at the elbow joint, covered by the distal end of the lateral head. Epitrochlearis (Extensor antibrachii) A thin sheet located on the medial side of the long head Biceps brachii Visible only after cutting the insertions of the pectoral muscles. Brachialis

Forearm Muscles

anterior part (sometimes called levator scapulae) from the tranverse processes of the last five cervical vertebrae Aponeurosis from the median dorsal line

Lateral to the biceps, in contact with the lateral head of the triceps. Extensor Carpi Ulnaris The first muscle preaxial to the ulna Extensor Digitorum Lateralis Next to the extensor carpi ulnaris, going toward the preaxial side Extensor Digitorum Communis Next to the extensor digitorum lateralis Brachioradialis (Supinator Longus) Next to the extensor digitorum communis on the preaxial border of the forearm, but loose and standing away from the underlying extensor Extensor Carpi Radialis Underlies the brachioradialis and extends onto the inner or medial surface of the arm. Pronator Teres Next to the extensor carpi radialis longus and somewhat under it Flexor Carpi Radialis Lies next to, and mostly under pronator teres Palmaris Longus Flat muscle forming outer surface of forearm next to flexor carpi radialis Flexor Profundus Digitorum This is the complex muscle which lies under the palmaris longus and projects to he radial side of it. Flexor Carpi Ulnaris

Bring the ribs forward

General flexor of the fingers

Thigh Muscles

This consists of two nearly separate muscles which form the ulnar border of the forearm from the medial view. Tensor Fasciae Latae

Ilium and neighboring fascia

Fascia Lata

Tightens the fascia lata

Tuberosity of the ischium

Patella and tibia by a tendon, and the fascia of the shank

Abductor of the thigh and flexor of the shank

Transverse processes of the second and third caudal vertebrae

Muscle passes ventrally, concealed by the anterior margin of the biceps femoris

Abductor of the thigh, extensor of the shank

Fascia and transverse processes of the last sacral and first caudal vertebrae

Fascia lata and to a slight extent on the greater trochanter

Abductor of the thigh

Adjacent fascia, crest of the ilium, and lateral surface of the ilium, and transverse processes of the last sacral and first caudal vertebrae Crest and ventral border of the ilium

Strong tendon on the greater trochanter of the femur

Abductor of the thigh

Greater trochanter and surface of the femur

Proximal end of the tibia and the patella and the fascia and ligaments between Patella and adjacent ligaments

Adductor and rotator of the thigh and extensor of the shank Extensor of the shank

Ilium near the acetabulum

Patella and adjacent ligaments

Extensor of the shank

Femur

Patella and adjacent ligaments

Extensor of the shank

Surface of the femur

Patella and adjacent ligaments

Extensor of the shank

Ichial and pubic symphysis

Aponeurosis which passes to the tibia

Adductor of the leg

Pubis

Femur

Adductor of the thigh

It consists of three muscles passing from the median ventral line to the femur. Adductor Femoris

Pubis

Femur

Adductor of the thigh

Middle muscular mass Semimembranosus

Ischium

Extensor of the thigh

The large posterior part of mass, covered by the gracilis. Semitendinosus

Ischial tuberosity

Medial Epicondyle of the femur and proximal end of the tibia Tibia

Thick triangular muscle located in dorsal part of tough fascia. Biceps Femoris This is the large muscle on the lateral surface of the thigh posterior to the fascia lata and covering more than half of the surface of the thigh. Caudofemoralis A narrow flat muscle passing from the side of the root of the tail toward the dorsal end of the biceps femoris Gluteus Maximus A thin, flat muscle immediately anterior to the caudofemoralis that is imbedded in the fascia and is continuous with the tensor fasciae latae anteriorly Gluteus Medius The very large, triangular muscle immediately in front of the gluteus maximus and partly covered by it Sartorius This muscle forms the anterior margin from the lateral view of the thigh. Vastus Lateralis The large stout muscle which was covered by the fascia lata Rectus Femoris Stout muscle lying on its medial side and covered externally by the sartorius Vastus Medialis On the medial side of the thigh posterior to the rectus femoris Vastus Intermedius A muscle seen deep down, next to the shaft of the femur Gracilis This is the large, flat muscle forming the posterior half of the medial surface of the thigh. Adductor Longus

The most posterior muscle of the thigh, posterior to the semimembranosus. Tenuissimus A narrow, long muscle beneath the biceps femoris Shank Muscles

Tibialis Anterior

Transverse processes of the second caudal vertebrae Proximal parts of tibia and fibula

Most ventral muscle, whose ventral border is in contact with the tibia

Extensor Digitorum Longus This is the muscle next dorsal to the tibialis anterior

Lateral epicondyle of the femur

On the same fascia as the insertion of the biceps (fascia of the shank) Strong tendon, which should be traced into the foot, where it will be found to pass obliquely to the medial side of the foot to be inserted on the first metatarsal Stout tendon, which if followed into the foot is found to diverge into

Flexor of the shank

Flexor of the foot

Extensors and flexors of the foot

on the lateral surface of the shank. Peroneus These are next dorsal to the extensor digitorum longus. Gastrocnemius This is the large muscle forming the posterior or caudal surface of the shank. It has two large portions, one on the medial surface, and the other on the lateral surface of the shank. The lateral head is divisible into four heads. Soleus A flat muscle in contact with the peroneus muscles ventrally. It tapers abruptly to a tendon, which joins the gastrocnemius. Plantaris

Fibula

Immediately dorsal to the bone which consists of two parts, somewhat separated. Tibialis Posterior It is the long tendon between the two parts of the flexor digitorum longus.

Extensors and flexors of the foot

Surface fascia, the femur and the tendon and fascia of the plantaris muscle

Strong tendon, which passes to the heel bone (calcaneus)

Extensor of the foot

Fibula

Calcaneus

Extensor of the foot

Patella and femur

Thick tendon which passes in the middle of a sort of tube formed by the tendon of the gastrocnemius and soleus onto the ventral surface of the calcaneus Digits

Flexor of the digits

Scaphoid and medial cuneiform of the ankle

Extensor of the foot

Large muscle lying between the two heads of the gastrocnemius, which practically enclose it.

Flexor Digitorum Longus

four tendons, one of which is inserted on each digit Metatarsals and digits

Tibia, fibula, and adjacent fascia Fibula, tibia, and fascia

Flexor of the digits