zoo lab cat muscular system

• Muscles of the Abdominal Wall

  • External Oblique (Origin: lumbodorsal fascia & posterior ribs) (Insertion: extensive neurosis passing through the linea alba) (Action: constrictor of the abdomen)
  • Internal Oblique (Origin: second sheet of the lumbordorsal fascia; border of the pelvic girdle) (Insertion: Linea alba (through extensive aponeurosis) (Action: compressor of the abdomen)
  • Transversus (same OIA with Internal Oblique)
  • Rectus abdominis (Origin: anterior end of the pubic symphysis) (Insertion: sternum and costal cartilages) (Action: retracts ribs and sternum; compressor of the abdomen)
• Muscles of the Chest

  • Pectoantebrachialis (Origin: manubrium) (Insertion: flat tendon on the fascia of the forearm) (Action: draws arms towards the chest)
  • Pectoralis major (Origin: sternum; median ventral raphe) (Insertion: humerus) (Action: draws arms towards the chest)
  • Pectoralis minor (Origin: sternum) (Insertion: humerus) (Action: draws arms towards the chest)
  • Xiphihumeralis (Origin: sternum) (Insertion: humerus) (Action: draws arms towards the chest)
• Muscles of the Neck and Throat Part I

  
  

  • Mylohyoid (Origin: mandible) (Insertion: median raphe) (Action: raises floor of the mouth; brings hyoid forward)
  • Digastric (Origin: jugular and mastoid process of skull) (Insertion: mandible) (Action: depressor of mandible)
  • Geniohyoid (Origin: mandible near symphysis) (Insertion: body of the hyoid) (Action: draws hyoid forward)
• Muscles of the Back and ShoulderPart I

  • Spinotrapezius (O: spines of the thoracic vertebrae) (I: fascia of scapula) (A: draws scapula dorsad and caudad)
  • Rhomboideus (O: neural spines of vertebrae and adjacent ligaments) (I: vertebral column of scapula) (A: draws scapula dorsad)
  • Rhomboideus capitis (O: superior nuchal line) (I: scapula) (A: draws scapula craniad; rotates scapula)
  • Splenius (O: middorsal line and fascia) (I: superios nuchal line) (A: raises or turns the head)
• Muscles of the Upper Arm

  • Triceps brachii (anconeus) - (O: distal end of the humerus) (I: lateral surface of ulna) (A: strengthens elbow joint; rotates ulna)
  • Epitrochlearis/ Extensor antibrachii - (O: latissimus dorsi) (I: olecranon) (A: rotate the ulna)
  • Biceps brachii (O: glenoid fossa) (I: radius) (A: flexor of the forearm)
  • Brachialis (O: lateral surface of humerus) (I: ulna) (A: flexor of the forearm)
• Muscles of the ForearmPart I

  • Extensor carpi ulnaris (O: lateral epicondyle of humerus; semilunar notch of ulna) (I: proximal end of 5th metacarpal) (A: extends 5th digit and ulnar side of wrist)
  • External digitorum lateralis (O: lateral surface of humerus above the lateral epicondyle) (I: tendons internal to wrist ligaments) (A: extends 3-4 digits)
  • External digitorum communis (O: lateral surface of humerus above the lateral epicondyle) (I: tendons internal to wrist ligaments) (A: extends 3-4 digits)
• Muscles of the Thigh Part I

  • Gluteus medius (Origin: adjacent fascia; crest of ilium) (Insertion: greater trochanter of femur) (Action: abduct thigh)
  • Gluteus maximus (Origin: fascia and transverse process of last sacral and first caudal vertebra) (Insertion: fascia) (Action: abduct thigh)
  • Caudofemoralis (O: transverse process of 2nd and 3rd caudal vertebra) (I: patella) (A: abduct thigh, extends shank)
  • Sartorius (O: crest and ventral border of ilium) (I: proximal end of the tibia and patella and fascia and ligaments between) (A: adductor and rotator of the thigh; extensor of shank)
• Muscles of the Shank Part I

  • Tibialis anterior (Origin: proximal parts of the tibia and fibula) (Insertion: first metatarsal) (Action: flexor of foot)
  • Extensor digitorum longus (Origin: lateral epicondyle of femur) (Insertion: tendon inserted on each digit) (Action: extensor of digits)
  • Peroneus (Origin: fibula) (Insertion: metatarsals and digits) (Action: extensor and flexor of foot)
  • Gastrocnemius (Origin: surface fascia; femur, tendon, and fascia of plantaris) (Insertion: calcaneus) (Action: extensor of foot)
• Muscles of the Neck and Throat Part II

  • Sternomastoid (Origin: median raphe and manubrium) (Insertion: lambdoidal ridge into mastoid process) (Action: turn head; draw head to neck)
  • Sternohyoid (Origin: sternum) (Insertion: basihyoid) (Action: draws hyoid posteriorly)
  • Sternothyroid (Origin: sternum) (Insertion: thyroid cartilage of the larynx) (Action: pulls larynx posteriorly)
  • Thyrohyoid (Origin: thyroid cartilage) (Insertion: posterior horn of the hyoid) (Action: raises the larynx)
• Muscles of the Neck and Throat Part III

  • Cleidomastoid (Origin: mastoid process of temporal) (Insertion: clavicle) (Action: pulls clavicle craniad or turns head; draw head to neck)
  • Clavobrachialis (Origin: clavicle; fibers of clavotrapezius) (Insertion: ulna) (Action: flexor of the arm)
  • Masseter (Origin: zygomatic arch) (Insertion: posterior half of lateral surface of mandible) (Action: elevator of lower jaw)
  • Temporal (Origin: superior nuchal line to zygomatic process; part of the zygomatic arch) (Insertion: coronoid process of mandible) (Action: elevator of lower jaw)
• Muscles of the Shank Part II

  • Soleus (Origin: fibula) (Insertion: calcaneus) (Action: extensor of foot)
  • Plantaris (Origin: patella and femur) (Insertion: calcaneus) (Action: flexor of digits)
  • Flexor digitorum longus (Origin: tibia, fibula, adjacent fascia) (Insertion: phalanges) (Action: flexor of digits)
  • Tibialis posterior (Origin: tibia, fibula, fascia) (Insertion: scaphoid and medial cuneiform of ankle) (Action: extensor of foot)
• Tensor fascia latae(Muscle of the Thigh)

  • Origin: ilium and neighboring fascia
  • Insertion: fascia lata
  • Action: tightens the fascia latae
• Biceps femoris(Muscles of the Thigh)


  • Origin: tuberosity of ischium
  • Insertion: patella and tibia; fascia of shank
  • Action: abduct thigh; flexes shank
• Gracilis(Muscle of the Thigh)


  • Origin: ischial and pubic symphysis
  • Insertion: aponeurosis which passes to tibia
  • Action: adducts leg
• Adductor longus and Adductor femoris(Muscles of the Thigh)

  • Origin: pubis
  • Insertion: femur
  • Action: adduct thigh
• Semimembranosus(Muscle of the Thigh)

  • Origin: ischium
  • Insertion: medial epicondyle of femur, proximal end of tibia
  • Action: extends thigh
• Semitendinosus(Muscle of the Thigh)


  • Origin: transverse process of second caudal vertebrae
  • Insertion: fascia of shank
  • Action: extends thigh
• Quadriceps Femoris (Muscle of the Thigh)

  1. Vastus lateralis (O: greater trochanter and surface of femur) (I: patella and adjacent ligaments) (A: extensor of the shank)
  2. Rectus femoris (O: ilium near acetabulum) (I: patella and adjacent ligaments) (A: extensor of the shank)
  3. Vastus medialis (O: femur) (I: patella and adjacent ligaments) (A: extensor of the shank)
  4. Vastus intermedius (O: surface of femur) (I: patella and adjacent ligaments) (A: extensor of shank)
• Muscle of the Forearm Part II

  • Supinator longus/ Brachioradialis (O: middle of humerus) (I: lower end of radius and adjacent ligaments) (A: rotates hand to supine position)
  • Extensor carpi radialis (O: humerus) (I: 2nd & 3rd metacarpals) (A: extends hand)
  • Pronator teres (O: medial epicondyle of humerus) (I: radius) (A: rotates radius to prone position)
  • Flexor carpi radialis (O: medial epicondyle of humerus) (I: 2nd & 3rd metacarpals) (A: flexes 2nd & 3rd metacarpals)
• Muscles of the Forearm Part III

  • Palmaris longus (O: medial epicondyle of humerus) (I: tendons passing through wrist ligaments) (A: flexor of digits)
  • Flexor profundus digitorum (O: ulna and humerus) (I: basal phalanges) (A: general flexor of fingers)
  • Flexor carpi ulnaris (O: medial epicondyle of humerus; olecranon) (I: pisiform bone of wrist) (A: flexes ulnar side of wrist)
• Supraspinatus


  • Origin: whole surface of supraspinous fossa
  • Insertion: greater tuberosity of humerus
  • Action: extends the humerus
• Infraspinatus


  • Origin: whole surface of infraspinous fossa
  • Insertion: greater tuberosity of humerus
  • Action: rotates the humerus
• Subscapularis


  • Origin: subscapular fossa
  • Insertion: lesser tuberosity of humerus
  • Action: pulls the humerus medially
• Clavodeltoid (also Clavobrachial)


  • Origin: clavicle and fibers of the clavotrapezius
  • Insertion: ulna
  • Action: raises and rotates the humerus
• Acromiodeltoid


  • Origin: acromion of scapula
  • Insertion: surface of other deltoids
  • Action: raises and rotates the humerus
• Spinodeltoid


  • Origin: spine of scapula
  • Insertion: surface od other deltoids
  • Action: raises and rotates the humerus
• Teres major


  • O: axillary border of scapula; fascia of neighboring muscles
  • I: tendon on medial surface of humerus
  • A: rotates the humerus and lowers the humerus
• Teres minor


  • O: axillary border of scapula
  • I: greater tuberosity
  • A: assists the infraspinatus
• Serratus ventralis


  • O: slips from first 9 or 10 ribs; transverse process of last 5 cervical vertebrae
  • I: scapula near vertebral border
  • A: draws the scapula craniad; ventrad and against thoracic wall
• Serratus dorsalis


  • O: aponeurosis from medial dorsal line
  • I: last ribs
  • A: draws the ribs forward
• Scalenes

  • O: ribs
  • I: transverse process of cervical vertebra
  • A: draws rib forward, bend the neck
• External intercostals


  • O: posterior margin of the rib
  • I: anterior margin of adjacent posterior rib
  • A: bring ribs forward
• Internal intercostals


  • O: anterior margin of the rib
  • I: posterior margin of adjacent posterior rib
  • A: draws ribs back
• Multifidus spinae


  • O: lumbar pleurapophyses
  • I: neural spine of the vertebra
  • A: extends vertebral column
• Sacrospinalis (Muscle of the Back and Shoulder)

  1. Semispinalis
  2. Longissimus
  3. Iliocostalis

  All of them have the same OIA

  O: various parts of more posterior sacral, lumbar, thoracic, and cervical vertebrae

  I: neural processes of more anterior vertebrae

  A: extends and flexes vertebral column
• Latissimus dorsi


  • Origin: neural spine of last thoracic and most lumbars; lumbodorsal fascia
  • Insertion: tendon on medial surface of humerus
  • Action: pulls forelimb dorsally and caudally
• Levator scapulae ventralis


  • Origin: transverse process of atlas and occipital bone
  • Insertion: metacromion process and neighboring fascia
  • Action: draws the scapula craniad
• Clavotrapezius


  • Origin: superios nuchal line; median dorsal line of the neck
  • Insertion: clavicle
  • Action: draws clavicle dorsad and craniad
• Acromiotrapezius

  • Origin: neural spines of cervical and first thoracic
  • Insertion: metacromion process and spine of scapula; fascia of clavotrapezius
  • Action: draws scapula dorsad and holds two scapula together