Cat+Muscles

COMPARATIVE VERTEBRATE ANATOMY CAT MUSCLES (partial description & OIA) based on L.H. Hyman

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I. Abdominal Wall 1. External Oblique: large muscle; outermost layer of the abdominal wall O - Lumbodorsal fascia & posterior ribs by separate slips I - Extensive neurosis which passes to the linea alba & pubis A - Constrictor of abdomen 2. Internal Oblique: under the dorsal portion of external oblique; short O - Second sheet of the lumbodorsal fascia & border of the pelvic girdle I - Linea alba by the extensive aponeurosis A - Compressor of abdomen 3. Transverse (Transversus Abdominis) O - Second sheet of the lumbodorsal fascia & border of the pelvic girdle I - Linea alba by the extensive aponeurosis A - Compressor of abdomen 4. Rectus Abdominis: long slender muscle on each side of the linea alba; pubic symphysis to anterior part of thorax; crossed by regular intervals of white lines (myosepta) O - Anterior end of pubic symphysis I - Sternum & costal cartilages A - Retracts ribs & sternum & compresses abdomen II. Epaxial Muscles 1. Multifundus Spinae: slender, narrow median portion 2. Sarcospinalis: very thick lateral portion → Semispinalis → Longissimus → Iliocostalis III. Muscles of the Chest 1. Pectoantibrachialis: anterior & most superficial of the chest muscles O - Manubrium I - By a flat tendon on the fascia of the forearm A - Draws the arm toward the chest 2. Pectoralis Major O - Sternum & median ventral raphe I - Humerus I - Draws the arm toward the chest 3. Pectoralis Minor: divisible into several parts O - Sternum I - Humerus A - Draws the arm toward the chest 4. Xiphihumeralis: thin, flat long muscle O - Xiphoid process of the sternum I - Humerus A - Draws the arm toward the chest IV. Muscle of the Neck & Throat 1. Sternomastoid: superficial muscle of the ventral side of the neck; the external jugular vein crosses its surface; appears divisible into two muscles O - Median raphe & manubrium of sternum I - On the skull from the labdoidal ridge onto the mastoid process by the thick tendon; passes internal to the submaxillary gland & the parotid gland A - Singly turn the head, together depress the head on neck 2. Sternohyoid O - First costal cartilage I - Body of the hyoid bone A - Draw the hyoid posteriorly 3. Cleidomastoid O - Clavicle I - Mastoid process A - Pulls clavicle craniad or turns head, acting singly, or lowers head on neck 4. Cephalobranchial: long muscle on the side of the neck and passing over the ventral surface of the sholder to the foramen. → Clavotrapezius: upper part of cephalobranchial; skull to clavicle → Clavobranchial: lower part of cephalobrancial; clavicle to foramen O - Clavicle (inner surface of the muscle in the shoulder region) & fibers of the clavotrapezius I - Ulna A - Flexor of the forearm 5. Masseter: great thick muscle covering the angle of the jaws; in front of the submaxillary & parotid glands; covered by a very tough shinning fascia O - Zygomatic arch I - Posterior half of the lateral surface of the mandible A - Elevator of the lower jaw 6. Temporal: on the temporal fossa O - Posterior nuchal line to zygomatic process; zygomatic arch I - Coronoid process of mandible

COMPARATIVE VERTEBRATE ANATOMY CAT MUSCLES (partial description & OIA) based on L.H. Hyman A - Elevator of jaw

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7. Digastric: along the medial surface of each half of the mandible O - Jugular & mastoid processes of skull I - Mandible A - Depressor of the lower jaw 8. Mylohyoid: thin transverse sheet passing across between the two digastrics from one half of the mandible to the other O - Mandible I - Median raphe A - Raises floor of the mouth and brings hyoid forward 9. Geniohyoid: pair of long, slender muscles O - Mandible near the symphysis I - Body of hyoid A - Draws hyoid forward 10. Sternothyroid: one on each side of the trachea O - Sternum in common with the sternohyoid I - Thyroid cartilage of the larynx A - Pulls the larynx posteriorly 11. Thyrohyoid: short, narrow muscle on each side of the thyroid cartilage O - Thyroid cartilage I - Posterior horn of the hyoid A - Raises the larynx V. Muscles of the Upper Back & Shoulder and Back of the Neck 1. Latissimus Dorsi: large flat muscle extending obliquely forward from the middle of the back to the upper arm O - Neural spines of the last thoracic & most of the lumbar vertebrae & from the lumbodorsal fascia I - By a tendon on the medial surface of the humerus A - Pulls the limb dorsally & caudally 2. Trapezius Muscles: thin, flat muscles covering the back and the neck anterior to the preceeding → Spinotrapezius (posterior trapezius) OSpines of the thoracic vertebrae IFascia of the scapula ADraws the scapula dorsad & caudad → Acromiotrapezius (middle trapezius) ONeural spines of the cervical & first thoracic vertebrae IMetacromion process & spine of the scapula & fascia of the preceding muscle ADraws scapula dorsad & holds the two scapulae together → Clavotrapezius (anterior trapezius) OSuperior nuchal line & median dorsal line of neck IClavicle; continuous with the clavobranchial muscle ADraws the clavicle dorsad & craniad 3. Levator Scapulae Ventralis: along the ventral border of the acromiotrapezius & continuous with it O - Transverse process of the atlas & occipital bone I - Metacromion process & neighboring fascia A - Draws the scapula craniad 4. Rhomboideus: thick muscle beneath acromiotrapezius O - Neural spines of the vertebrae & adjacent ligaments I - Vertebral border of the scapula A - Draws scapula dorsad → Rhomboideus Capitis: most ventral of rhomboideus; practically separate muscle OSuperior nuchal line IScapula ADraws the scapula craniad & rotates it 5. Splenius: large sheet of muscle covering the back of the neck in front of the rhomboideus O - Middorsal line 7 fascia I - Superior nuchal line A - Raises or turns the head 6. Supraspinatus: stout muscle occupying the supraspinous fossa of the scapula O - Whole surface of supraspinous fossa I - Greater tuberosity of humerus A - Extends the humerus 7. Deltoids → Clavodeltoid = Clavobranchialis → Acromiodeltoid: short, thick muscle OAcromion process ISurface of other muscle of the shoulder ARaise & rotate the humerus → Spinodeltoid: passes to the upper arm, across the upper ends of the muscles of the upper arm OSpine of scapula I - Ridge (deltoid ridge) of the humerus, the insertion being concealed by the acromiodeltoid ARaise & rotate the humerus

COMPARATIVE VERTEBRATE ANATOMY CAT MUSCLES (partial description & OIA) based on L.H. Hyman

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8. Infraspinatus O - Whole surface of the infraspinous fossa I - Greater tuberosity of the humerus A - Rotates the humerus 9. Teres Major: stout muscle immediately behind the infraspinatus O - Axillary border of the scapula & fascia of neighboring muscles I - By a tendon on the medial surface of the humerus A - Rotates the humerus & lowers it 10. Teres Minor: posterior border of the infraspinatus & somewhat covered by it O - Axillary border of the scapula I - Greater tuberosity A - Assists infraspinatus 11. Subscapularis: covers the inner or medial surface of the scapula O - Subscapular fossa I - Lesser tuberosity of the humerus A - Pulls the humerus medially 12. Serratus Ventralis: large, fan-shaped muscle from the ventral border of the scapula to the sides of the thorax & neck O - By slips from the first nine or ten ribs and the anterior part from the transverse processes of the last five cervical vertebrae I - Scapula near the vertebral border A - Draws the scapula craniad, ventrad & against the thoracic wall 13. Serratus Dorsalis O - By means of an aponeurosis from the median dorsal line I - Last ribs A - Draws the ribs forward 14. Scalenes: several long muscles in the chest wall ventral to the origin of the serratus ventralis and in front of the anterior boundary of the external oblique O - Ribs I - Transverse processes of the cervical vertebrae A - Draw the ribs forward & bend the neck 15. Intercostals: set of muscles extending from one rib to the next; chief respiratory muscles of the thoracic wall → External intercostals: chest wall between the origins of the serratus ventralis & dorsalis → Internal intercostals: inside the external intercostals A - External: bring the ribs forward; Internal: draw them back again 16. Epaxial Muscles of the Thorax: thoracic region; cutting through the aponeurosis of the serratus dorsalis → Semispinalis Dorsi: dorsal part next to the median line

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Neck region: semispinalis semispinalis cervicis et capitis ▫ Biventer cervicis: medial ▫ Complexus: lateral → Longissimus: median → Iliocostalis: ventral ° Composed of a number of separate bundles with prominent tendons between them and lies on the ribs to which it is attached I - Transverse process of the vertebrae in contact with the origin of the serratus ventralis (longissimus capitis) VI. Muscles of the Upper Arm 1. Triceps Branchii (Anconeus): small triangular muscle at the elbow joint, covered by the distal end of the lateral head O - Distal end of the humerus I - Lateral surface of the ulna A - Strengthens the elbow joint and possibly rotates the ulna 2. Epitrochlearis/Extensor Antibrachii: medial side of the long head of the triceps; thin sheet O - Latissimus dorsi I - Olecranon A - Strengthens the elbow joint, tending also to rotate the ulna 3. Biceps Brachii: under the insertions of the pectoral muscles O - Glenoid fossa I - Radius A - Flexor of the forearm 4. Brachialis: lateral to the biceps, in contact with the lateral head of the triceps O - Lateral surface of the humerus I - Ulna A - Flexor of the forearm VII. Muscles of the Forearm 1. Extensor Carpi Ulnaris: outer surface of the forearm next to the ulna O - Lateral apicondyle of the humerus & semilunar notch of the ulna I - Proximal end of the 5th metacarpal A - Extends 5th digit & ulna side of the wrist 2. Extensor Digitorum Lateralis O - Lateral surface of the humerus above the lateral epicondyle

COMPARATIVE VERTEBRATE ANATOMY CAT MUSCLES (partial description & OIA) based on L.H. Hyman I - Tendon passes internal to wrist ligament A - Go to three or four digits, which they extend

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3. Extensor Digitorum Communis O - Above the extensor digitorum lateralis I - Tendon passes internal to wrist ligament A - Go to three or four digits, which they extend 4. Branchioradialis/Supinator Longus: on the periaxial border of the forearm; loose O - Middle of the humerus I - Lower end of radius & adjacent ligaments A - Rotates hand to supine position 5. Extensor Carpi Radialis: underlies the branchioradialis & extends onto the inner or medial surface of the arm → Longus : long → Brevis: short O - Humerus near the other extensors I - 2nd & 3rd meracarpals A - Extends hand 6. Pronator Teres: broader upper end, slants proximally towards the radius O - Medial epicondyle of the humerus I - Radius A - Rotates radius to prone position 7. Flexor Carpi Radialis O - Medial epicondyle of humerus; muscle narrows to a tendon which is much bound to adjacent ligaments & finally passes through a deep groove between the capitate (3rd carpale) & the 1st metacarpal I - 2nd & 3rd metacarpals A - flexes 2nd & 3rd metacarpals 8. Palmaris Longus: flat mucle forming outer surface of forearm O - Medial epicondyle of humerus I - Flat tendon passes through wrist ligaments & divides into 4 or 5 tendond which pass to pads of palm & phalanges A - Flexor of digits 9. Flexor Profondus Digitorum: has five parts O - Ulna & humerus and converging to a broad flat tendon under the tendon of palmaris longus I - Basal phalanges A - General flexor of fingers 10. Flexor Carpi Ulnaris: consists of two nearly separate muscles which form the ulnar border of the forearm from the medial view O - Medial epicondyle of the humerus in commorn with one of the heads of flexor profondus digitorum; ulna I - (Both heads join to a tendon) pisiform bone of the wrist A - flexes ulnar side of wrist VIII.Muscles of the Thigh 1. Tensor Fasciae Latae: lateral (outer) surface of the thigh → Fascia Lata: tough fascia covering the anterior part → Tensor Fasciae Latae: thick triangular muscle in the dorsal part O - Ilium & neighboring fascia I - Fascia lata A - Tightens the fascia lata 2. Biceps Femoris: large muscle on the lateral surface of the thigh posterior to the fascia lata & covering more than half of the surface of the thigh; one head in the cat O - Tuberosity of the ischium I - Patella & tibia by a tendon and the fascia of the shank A - Abductor of the thigh & flexor of the shank 3. Caudofemoralis: between the median dorsal line & thigh; narrow, flat; passes from one side of the root of the tail toward the dorsal end of the biceps femoris O - Transverse processes of the 2nd & 3rd caudal vertebrae I - Patella A - Abductor of the thigh, extensor of the shank 4. Gluteus Maximus: thin, flat muscle immediately anterior to the caudofemoralis O - From the fascia & from the transverse processes of the last sacral & first caudal vertebrae I - Fascia lata & to a slight extent on the greater trochanter A - Abductor of the thigh 5. Gluteus Medius: very large, triangular muscle immediately in front of the gluteus maximus & partially covered by it O - Adjacent fascia, crest of ilium & lateral surface of the ilium and transverse processes of the last sacral & first caudal vertebrae I - By a strong tendon on the greater trochanter of the femur A - Abductor of the thigh 6. Sartorius: forms the anterior margin from the lateral view of the thigh O - Crest & ventral border of the ilium I - Proximal end of the tibia & the patella and the fascia & the ligaments between A - Adductor & rotator of the thigh, extensor of the shank → Quadriceps Femoris = rectus femoris + vastus muscles

COMPARATIVE VERTEBRATE ANATOMY CAT MUSCLES (partial description & OIA) based on L.H. Hyman I - Patella & adjacent ligaments A - Extensor of the shank 7. Vastus Lateralis: large, stout muscle which was covered by the fascia lata O - Greater trochanter & surface of the femur

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8. Rectus Femoris: O - Ilium near acetabulum 9. Vastus Medialis: covered externally by the sartorius O - Femur 10. Vastus Intermedius: next to the shaft of femur O - Surface of the femur 11. Gracilis: large, flat muscle forming the posterior half of the medial surface of the thigh O - Ischial & pubic sumphyses I - By an aponeurosis which passes to the tibia A - Adductor of the leg 12. Adductor Longus (anterior) & Adductor Femoris (medial): of three muscles passing from the ventral medial line to the femur O - Pubis I - Femur A - Adductor of the thigh 13. Semimembranosus: covered by gracilis; more or less divisible into two parts O - Ischium I - Medial epicondyle of the femur & proximal end of the tibia A - Extensor of the thigh 14. Semitendinosus: most posterior of the muscle of the thigh O - Ischiac tuberosity I - Tibia A - Flexor of the shank 15. Tenuissimus: beneath biceps femoris; narrow, long O - Transverse process of the 2nd caudal vertebrae, in common with the caudofemoralis I - Same fascia as the insertion of the biceps IX. Muscles of the Shank 1. Tibialis Anterior: lateral (outer) surface of the shank; most ventral, whose ventral border is in contact with the tibia O - Proximal parts of the tibia & fibula I - (By a strong tendon) first metatarsal A - flexor of the foot 2. Extensor Digitorum Longus O - Lateral epicondyle of the femur I - (By a stout tendon diverging into four tendons) one on each digit A - Extensors of the digits 3. Peroneus: three (fused) ending in a tendon each O - Fibula I - Metatarsals & digits A - Extensors & flexors of the foot 4. Gastrocnemius: large muscle forming the posterior/caudal surface of the shank; divisible into two large portions (medial surface & lateral surface of the shank); lateral (sub-divisible into four heads) O - Surface fascia, femur and tendon & fascia of the plantaris muscle I - (By a strong tendon) heel bone (calcaneus) A - Extensor of the foot 5. Soleus: internal to the lateral head of the gastrocnemius; flat muscle in contact with the peroneus muscles ventrally O - Fibula I - Calcaneus A - Extensor of the foot 6. Plantaris: internal to & between the two heads of the medial head of the gastrocnemius; O - Patella & femur I - (By a thick tendon) divides into four slips on the surface of the calcaneus; each attached to a digit A - flexor of the digits 7. Flexor Digitorum Longus: immediately dorsal to the tibia; consists of two parts somewhat separated O - Tibia, fibula & adjacent fascia I - (terminate in slender tendons which unite distally into a broad tendon, which eventually divides into four tendons) inserted on the digits A - flexor of the digits 8. Tibialis Posterior: muscle of the long tendon between the two parts of the flexor digitorum longus O - Fibula, tibia & fascia I - Scaphoid & medial cuneiform of the ankle A - Extensor of the foot