Anatomy Review Cat Muscles Written by Eduardo Alvarez

Anatomy Review Cat Muscles Written by Eduardo Alvarez & Roberto Martinez Students of Professor Gonsalves’ LACC Anatomy 1 Class

MUSCLES OF MASTICATION

Masseter • Origin: – Zygomatic Bone • Insertion: – Mandible • Action: – Elevates Mandible

Temporalis • Origin: – Temporal Bone • Insertion: – Mandible • Action: – Elevates and Retracts Mandible

Digastric • Origin: – Occipital Bone and Mastoid Process • Insertion: – Mandible • Action: – Depresses Lower Jaw

Mylohyoid • Origin: – Mandible • Insertion: – Hyoid Bone • Action: – Raises Floor of Mouth and Pulls Hyoid Forward

NECK MUSCLES THAT MOVE THE HEAD

Sternomastoid (only in cats) • Origin: – Sternum • Insertion: – Mastoid Process • Action: – Turns and Depresses Head

Cleidomastoid • Origin: – Clavicle • Insertion: – Mastoid Process • Action: – Pulls Head Laterally and Pulls Clavicle Craniad

MUSCLES OF HYOID, LAYRNX, & TONGUE

Sternohyoid • Origin: – First Rib (Intercostal) • Insertion: – Hyoid Bone • Action: – Pulls Hyoid Caudally, Raises Ribs and Sternum

Sternothyroid • Origin: – First Rib (Intercostal) • Insertion: – Larynx • Action: – Pulls Larynx Caudal (down)

Thyrohyoid • Origin: – Thyroid Cartilage of Larynx • Insertion: – Hyoid Bone • Action: – Raises Larynx

Geniohyoid (deep to Mylohyoid) • Origin: – Mandible • Insertion: – Hyoid Bone • Action: – Pulls Hyoid Craniad (up)

MUSCLES THAT ATTACH PECTORAL APPENDAGES TO THE VERTEBRAL COLUMN

Trapezius • Origin: – Occipital Bone and Cervical and Thoracic Vertebrae • Insertion: – Scapula and clavicle • Action: – Raises Clavicle, Adducts, Elevates and Depresses Scapula

Latissimus Dorsi • Origin: – Thoracic and Lumbar Vertebrae • Insertion: – Humerus • Action: – Pulls Arm Dorsad (back) and Caudad (down)

Rhomboideus Capitis • Origin: – Lamboidal Ridge • Insertion: – Scapula • Action: – Pulls Scapula Craniad (up)

Rhomboideus Minor capitis • Origin: – Thoracic Vertebrae • Insertion: – Scapula • Action: – Pulls scapula dorsally and medially

Rhomboideus Major capitis • Origin: – Thoracic Vertebrae • Insertion: – Scapula • Action: – Pulls Scapula Dorsally (toward back) and Medially (towards midline)

Levator Scapulae Ventralis • Origin: – Occipital Bone and Atlas (C 1) • Insertion: – Scapula • Action: – Pulls Scapula Craniad (toward head)

MUSCLES THAT ATTACH PECTORAL APPENDAGES TO VENTRAL AND BODY WALL

Pectoantebrachialis (cat only) • Origin: – Sternum • Insertion: – Forearm (proximal end) • Action: – Adducts Arm

Pectoralis Major • Origin: – Sternum • Insertion: – Humerus • Action: – Adducts Arm

Pectoralis Minor • Origin: – Sternum • Insertion: – Humerus • Action: – Adducts Arm

Xiphihumeralis (cat only) • Origin: – Xiphoid Process • Insertion: – Humerus • Action: – Adducts Arm

Serratus Ventralis • Origin: – First 10 Ribs • Insertion: – Scapula • Action: – Pulls Scapula Forward & Depresses Scapula

MUSCLES OF THE SHOULDER

(Deltoid) Clavodeltoid • Origin: – Clavicle and Clavotrapezius muscle • Insertion: – Humerus • Action: – Flexes Forearm

(Deltoid) Acromiodeltoid • Origin: – Scapula • Insertion: – Humerus • Action: – Flexes Humerus and Rotates it Outward

(Deltoid) Spinodeltoid • Origin: – Scapula • Insertion: – Humerus • Action: – Flexes Humerus and Rotates it Outward

Supraspinatus • Origin: – Scapula • Insertion: – Humerus • Action: – Extends Humerus

Infraspinatus Rhomboideus major Teres major • Origin: – Scapula • Insertion: – Humerus • Action: – Rotates Humerus Outward

Teres Major Rhomboideus major • Origin: – Scapula • Insertion: – Humerus • Action: – Flexes forearm and Rotates it inward

Sub. Scapularis • Origin: – Scapula • Insertion: – Humerus • Action: – Pulls Humerus Medially

MUSCLES OF UPPER ARM

Triceps Brachii Lateral head Medial head Long head • Origin: – Long Head: Scapula • Insertion: – Ulna • Action: – Extends Forearm Lateral Head and Medial Head: Humerus

Biceps Brachii • Origin: – Scapula • Insertion: – Radius • Action: – Flexes and Supinates Forearm

Brachialis • Origin: – Humerus • Insertion: – Ulna • Action: – Flexes Forearm

MUSCLES OF THE TRUNK Thoracic Region

External Intercostals • Origin: – Caudal border of one rib • Insertion: – Crainal border of rib caudad • Action: – Raises Rib (Inhalation) Internal Intercostals • Origin: – Cranial border of one rib • Insertion: – Caudal border of rib above • Action: – Draw Adjacent Ribs Together and Lower Rib

Extenal Abdominal Oblique • Origin: – Last nine Ribs • Insertion: – Linea Alba from Sternum to Pubis • Action: – Compresses Abdomen

Transversus Abdominis • Origin: – Costal cartilage of False Ribs, Lumbar Vertabrae, and Ilium • Insertion: – Linea Alba • Action: – Compresses the Abdomen

Extensor dorsi communis • Muscle Groups: – Spinalis – Longissimus – Iliocostalis • Action: – Extends Vertebral Column

MUSCLES OF THE HIP REGION

Tensor fascia latae • Origin: – Ilium • Insertion: – Patella and Tibia • Action: – Extends Thigh, Aids in Abduction and Rotation

Caudofemoralis • Origin: – 2 and 3 Caudal Vertebrae • Insertion: – Patella • Action: – Abducts Thigh and Extends Shank

Gluteus Maximus • Origin: – Sacral and Caudal Vertebrae • Insertion: – Femur • Action: – Abducts Thigh

Gluteus Medius • Origin: – Sacral and Caudal Vertebrae & Ilium • Insertion: – Femur • Action: – Abducts Thigh

MUSCLES OF THE THIGH Dorsal Femoral Group (Flexors)

Biceps Femoris • Origin: – Ishium • Insertion: – Patella & Tibia • Action: – Adducts Thigh, Flexes Shank

Semimembranosus • Origin: – Ischium • Insertion: – Femur • Action: – Extends Thigh

Semitendinosus • Origin: – Ischium • Insertion: – Tibia • Action: – Flexes Shank

MUSCLES OF THE THIGH Ventral Femoral Group (Extensors)

Sartorius • Origin: – Ilium • Insertion: – Patella • Action: – Adducts and Rotates Femur, Extends Tibia

Quadriceps Rectus femoris • Origin: – Ilium • Insertion: – Patella • Action: – Extends Lower Leg

Quadriceps Vastus Lateralis • Origin: – Femur • Insertion: – Patella • Action: – Extends Lower Leg

Quadriceps Vastus Medialis • Origin: – Femur • Insertion: – Patella • Action: – Extends Lower Leg

MUSCLES OF THE THIGH Medial Femoral Group

Gracilis • Origin: – Ischium and Pubis • Insertion: – Tibia • Action: – Adducts Thigh and Pulls Caudad

Adductor Longus • Origin: – Pubis • Insertion: – Femur • Action: – Adducts Thigh

Adductor Femoris • Origin: – Pubis & Ischium • Insertion: – Femur • Action: – Extends Thigh

MUSCLES OF THE LOWER LEG

Gastrocnemius • Origin: – Femur • Insertion: – Calcaneus • Action: – Extends Foot

Soleus • Origin: – Fibula • Insertion: – Metatarsals • Action: – Extends Foot

Tibialis Anterior • Origin: – Tibia and Fibula • Insertion: – First Metatarsals • Action: – Flexes Foot