THORACIC & PELVIC - MUSCLE

Superficial pectoral muscle

flat-muscle, extending from the sternum to the cranial surface of the humerus

descending pectoral

(superficial) and transverse pectoral (deeper)

2 parts of Superficial pectoral muscle

Deep pectoral/ascending pectoral

a broad muscle extending from the sternum to the greater and lesser tubercles of the humerus; it draws the limb caudally and adduct it

pectoralis profundus

Deep pectoral/ascending pectoral is also known as

Subclavius

a pectoral muscle over the cranial border of supraspinatus muscle; absent in carnivores

Brachiocephalicus

wide muscle extending from the head and neck to the arm

Omotransversarius

is a narrow muscle that extends between the transverse processes of the atlas (and possibly also the succeeding vertebrae) and the acromion and adjacent part of the scapula. It assists in advancement of the limb

Trapezius

triangular muscle extending from the dorsomedial neck and thorax to the scapular spine; it elevates the scapula

cervical part (trapezius cervicis), and the thoracic part (trapezius thoracis)

Trapezius has two heads

Rhomboideus

extrinsic muscle lying deep to the trapezius; it extends from the median raphe of the neck, thoracic vertebral spine, and the skull to the dorsal border of the scapula and scapular cartilage; it elevates the forelimb

Serratus ventralis

serrated, fan-shaped muscle extending from the last five cervical vertebrae and first seven or eight ribs to the medial surface of the scapula. It supports the trunk

Subscapularis

large muscle originating from the subscapular fossa; it crosses the shoulder joint and inserts on the lesser tubercle of humerus

medial collateral ligament

Subscapularis serves as shoulder’s ——

Teres major

arises from the caudal border of the scapula and inserts with the latissimus dorsi muscle on the medial side of the humerus (teres major tuberosity)

Tensor fasciae antebrachii

thin, strap muscle that extends from the latissimus dorsi to the medial fascia of the antebrachium and olecranon.

triceps brachii muscle

Tensor fasciae antebrachii lies on the long head of the ——

Triceps brachii

large, powerful muscle composed of four head; its long head crosses the shoulder, and all heads cross the elbow joint to insert on the olecranon. It extends the elbow and flexes the shoulder (long head of triceps)

Anconeus

small muscle that arises from the distal part of the humerus to insert on the lateral part of the olecranon

Biceps brachii

long, fusiform muscle that arises from the supraglenoid tubercle of the scapula and runs through the intertubercular groove of humerus and inserts on the medial tuberosity of the proximal end of radius and on the adjacent part of ulna.

Brachialis

long, thin muscle that arises from the proximocaudal part of the humerus and winds laterally in the brachialis groove of humerus

Coracobrachialis

small muscle that extends between the medial aspect of the supraglenoid tubercle and the proximal part of the shaft of humerus

Extensor carpi radialis

the most medial member of the group; situated cranially into the subcutaneous border of the radius. It inserts on the proximal extremity of the 3rd metacarpal bone (sometimes in 2nd MC bone)

Common digital extensor

long muscle inserting on the extensor process of the distal phalanges of each functional digits

Lateral digital extensor

originates from the proximal end of the radius and inserting on the lateral digits

Ulnaris lateralis or Extensor carpi ulnaris

the most caudal extensor muscle; it inserts on the proximal part of metacarpal bone and accessory carpal bone

Supinator

small, fusiform muscle placed deep to the extensor muscles and passing obliquely over the flexor aspect of the elbow from the lateral epicondyle to the upper quarter of the medial border of the radius

Extensor carpi obliquus

also known as abductor pollicis longus,

originates from the cranial surface of the radius and by the oblique medio-distal course pursued by its tendon, which attaches to the most medial metacarpal bone present.

Brachioradialis

Also known as “long supinator” is a thin fleshy

ribbon that extends from the lateral epicondyle of

humerus to the distal medial part of the forearm

within the superficial fascia

Pronator teres

arises from the medial epicondyle of humerus and converges on the insertion of the supinator on the radius.

Flexor carpi radialis

most medial and runs directly caudal to the subcutaneous border of the radius. It ends on the upper end of 2nd MC bone

Superficial digital flexor (SDF)

arises from the medial epicondyle of the humerus and inserts on the middle phalanx.

Flexor carpi ulnaris

two-headed muscle inserting on the accessory carpal bone

Deep digital flexor (DDF)

three-headed muscle arising from the humerus , radius, and ulna. It inserts on the distal phalanx

Pronator quadratus

Found only in carnivores

- It passes from the shaft of the ulna to that of the radius , bridging the medial aspect of the interosseous space of the forearm

Median nerve

Pronator quadratus is supplied by

Interosseous

A muscle of the manus arising from the proximal palmar surface of the metacarpal bones.

- it extends distally and splits into two tendons

Interflexorius/ flexor digitorium brevis manus

this muscle originates from a fascial sheet from flexor digitorium profundus muscle (humeral, medial, and lateral head) in the distal one quarter of the antebrachium.

Lumbricales

three-thin muscles originate from the tendon of flexor digitorium profundus muscle

Abductor digit I (pollicis) brevis

short, cylindrical muscle originates from the flexor retinaculum

Flexor digiti I brevis

short, thick muscle with muscle fibers traveling parallel to the metacarpals

Adductor digiti I /adductor pollicis

short, fan shaped muscle that is wide at origin and tapers at its insertion

Adductor digiti V

flat, fan-shaped muscle with slight aponeurosis on the proximal two-thirds of its palmar surface

Abductor digiti V

small, flat muscle that arises from the distal aspect of the pisiform

Flexor digiti V

small muscle that lies distal to the origin of abductor digiti V muscle and travels laterally over the flexor digitorium brevis digiti IV muscle

Adductor digiti II

relatively thick band of muscle lying on the palmar side of carpometacarpal joint

Interosseous ligament of forearm

The ————- connects the radius and ulna in the proximal half of interosseous space in carnivores, lateral to interosseous membrane of forearm

Quadratus lumborum

arises from the last ribs and from the transverse processes of the lumbar vertebrae; it inserts on the wings of the sacrum; it stabilizes the lumbar portion of the vertebral column.

Psoas minor

arises from the bodies of the thoracolumbar vertebrae and inserts on the psoas minor tubercle on the ilium;

it may also rotate the pelvis at the sacro-iliac joint.

Iliopsoas

fused psoas major and iliacus muscles which act as the chief flexors of the hip joint

Psoas major

strongest flexor of the hip, extending from the lumbar vertebrae caudoventrally with the iliacus muscle to the lesser trochanter of the femur

Iliacus

short muscle arising from the ilium, it joins the psoas major to insert on the lesser trochanter of the femur

Ilipsoas

is a flexor of the hip and an outward rotator of the thigh

Tensor fasciae latae

triangular muscle, originating from the tuber coxae and inserting on the lateral femoral fascia and in the patella.

Its action is to tense the fascia lata, flex the hip, and extend the stifle

Caudal crural abductor

strap-like “fire hydrant” muscle located deep to the biceps femoris in carnivores

Superficial gluteal muscle

caudally located gluteal muscle arising above the hip joint and inserting on the third trochanter. It acts to abduct the limb.

Middle gluteal muscle

the largest gluteal muscle arising from the wing of the ilium;

it runs over the deep gluteal muscle and hip joint to insert on the greater trochanter. It extends the hip joint and abducts the limb

Deep gluteal muscle

muscle extending from the shaft of the ilium over the hip joint to the greater trochanter. It extends the hip joint and abducts the limb

Piriformis

only in carnivores; deep and caudal to the middle gluteal muscle

Gluteobiceps muscle

fusion of superficial gluteal and biceps femoris in ruminants

Accessory gluteal muscle

part of the middle gluteal in ungulates

WHIRLBONE DISEASE

Also known as trochanteric bursitis or lameness/soreness

• Inflammation of the bursa between the middle gluteal muscle and greater trochanter of the femur in horses

Internal obturator muscle

fan–shaped muscle arising medially from the pelvic floor and covering the obturator foramen.

Its tendon travels over the lesser ischiatic notch to insert in the trochanteric fossa

External obturator muscle

fan-shaped muscle arising from the ventral surface of the os coxae, covering the obturator foramen externally.

It inserts in the trochanteric fossa and causes outward rotation of the femur

Gemelli

two-small twin bundles that passes from the ischial spine to the trochanteric fossa.

External rotators

Gemelli are also

Quadratus femoris

passes from the ventral aspect of the ischium to end on the femoral shaft close to the trochanteric fossa.

It is described as an extensor but can be of no significance in this role

Sartorius

strap-like muscle arising from the ilium and inserting on the medial side of the stifle. It flexes the hip and the stifle joint

Gracilis

broad, superficial muscular sheet extending from the pelvic symphysis down the medial thigh to insert medially on the tibia

Pectineus

long-spindle shaped muscle extending from the pubis to the medial side of the femur

Adductor

arises over an extensive area of the ventral aspect of the pelvic floor and inserts along the distal 2/3 of the medial rough line of the femur and to the fascia and ligaments of the medial aspect of the stifle

FEMORAL TRIANGLE

Shallow triangular space through which

the femoral vessels run to and from the

pelvic limb.

Cranially ; Caudally

The triangle lies between; ——- by the caudal belly of the Sartorius; ——- by the adductor and pectineus

Quadriceps femoris

large muscle and principal extensor of the stifle covering the lateral, medial, and cranial surfaces of the femur.

Composed of 4 heads joining in a common tendon that contains the patella.

All heads extends the stifle.

Articularis coxae

small-spindle shaped muscle lying on the craniolateral aspect of the hip joint capsule.

Articularis genus

small flat muscle composed of two parts, only a medial part was present in some dogs and was entirely absent in one specimen

Biceps femoris

largest and most lateral of the caudal thigh muscle.

It arises from ischiatic tuberosity extending distally on the lateral side of the thigh and inserts on patella, tibia, and calcanean tuber thus crossing the hip, stifle, and tarsal joints.

Semitendinosus

the long hamstring muscle forming the caudal border of the thigh.

It extends from the ischiatic tuberosity to the tibia and on the calcanean tuber by the calcanean tendon.

Semimembranosus

most medial hamstring muscle;

it splits into two bellies which arch medially to insert on the stifle

Caudal crural abductor

ribbon-like muscle in dogs, lies on the deep

face of the biceps femoris

Cranial tibial

tarsal joint flexor extending from the tibial crest and tuberosity distally to insert on the metatarsus.

Long digital extensor

spindle-shaped muscle extending from the extensor fossa of the femur to the extensor process of the distal phalanx.

It extends the digit and flexes the tarsus

Peroneus longus

spindle-shaped muscle arises from the distal part of the lateral collateral ligament of the stifle joint

Peroneus brevis

arises from the lateral surface of the distal 2/3 of the fibula and tibia and inserts on the proximal end of the 5th metatarsal

Lateral digital extensor

thin muscle arising from the fibula. It aids the long digital extensor in tarsal flexion and digital extension.

Extensor hallucis longus

small, discrete muscle associated with medial digit;

originates on the cranial border of fibula and inserts on the proximal part of digit

Gastrocnemius

large two-bellied muscle arising from the distocaudal surface of the femur;

its heads enclose the proximal end of the superficial digital flexor; distally it inserts on the calcaneal tuberosity.

It extends the tarsal joint and flexes the stifle joint.

Superficial digital flexor

thin muscle arising from the caudal aspect of the distal femur deep to the heads of the gastrocnemius muscle;

extending distally, its tendon wrap medially around the gastrocnemius tendon and attaches superficially to the calcanean tendon.

Deep digital flexor

large muscle composed of two or three bellies extending from the caudal surface of the tibia and fibula to the distal phalanx.

It flexes the digits and extends the tarsus

Caudal tibial muscle

arises from the medial part of the proximal end of fibula and inserts on the medial ligament of the tarsus

Popliteus

small muscle lies directly over the caudal aspect of the joint.

It arises from the lateral condyle of the femur and inserts on the proximal third of the caudal surface of the tibia.

It flexes the stifle and rotates the distal part of the limb

Short digital extensor

arises from the distal part of the calcaneus and on the ligamentous tissue on the flexor surface of the tarsus and inserts on digit IV (lateral head), digits III and IV (intermediate head), and digit II and III (medial head)

Lumbricales

similar to those in the thoracic limb

Interflexorii

arises from the metatarsal pad, from the plantar surface of the tendon of the deep digital flexor proximal to the tarsus and inserts on the metatarsophalangeal joints on the tendons of DDF of digits III and IV

Quadratus plantae

arises from the lateral tuberosity of the calcaneus and the lateral collateral ligament of the tarsus and inserts on the tendons of the deep digital flexor

Abductor digiti V

arises from the lateral aspect of tuber calcanei, deep to the tendon of superficial digital flexor and inserts on the base of 5th metatarsal bone, together with the fibularis brevis

• Abductor digiti I

• Flexor digit I brevis

• Adductor digiti I

Special Muscles of the Digit I