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

MUSCLES OF MASTICATION

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

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

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

Mylohyoid Origin: Insertion: Action: Mandible Hyoid Bone 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

Cleido- mastoid Origin: Insertion: Action: Clavicle Mastoid Process Pulls Head Laterally and Pulls Clavicle Craniad

MUSCLES OF HYOID, LAYRNX, & TONGUE

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

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

Thyrohyoid Origin: Insertion: Action: Thyroid Cartilage of Larynx 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: Insertion: Action: Occipital Bone and Cervical and Thoracic Vertebrae Insertion: Scapula and clavicle Action: Raises Clavicle, Adducts, Elevates and Depresses Scapula

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

RhomboideusCapitis Origin: Insertion: Action: Lamboidal Ridge Scapula Pulls Scapula Craniad (up)

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

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

Levator Scapulae Ventralis Origin: Occipital Bone and Atlas (C1) Insertion: Scapula Action: Pulls Scapula Craniad (toward head)

MUSCLES THAT ATTACH PECTORAL APPENDAGES TO VENTRAL AND BODY WALL

Pectoante- brachialis (cat only) Origin: Sternum Insertion: Forearm (proximal end) Action: Adducts Arm

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

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

Xiphi-humeralis (cat only) Origin: Xiphoid Process Insertion: Humerus Action: Adducts Arm

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

MUSCLES OF THE SHOULDER

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

(Deltoid) Acromio- deltoid 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: Insertion: Action: Scapula Humerus Extends Humerus

Infra-spinatus Rhomboideus major Teres major Origin: Insertion: Scapula Insertion: Humerus Action: Rotates Humerus Outward

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

Sub-Scapularis Origin: Insertion: Action: Scapula Humerus Pulls Humerus Medially

MUSCLES OF UPPER ARM

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

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

Brachialis Origin: Humerus Insertion: Ulna Action: Flexes Forearm

MUSCLES OF THE TRUNK Thoracic Region

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

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: Insertion: Action: Ilium Patella and Tibia Extends Thigh, Aids in Abduction and Rotation

Caudo-femoralis Origin: Insertion: Action: 2 and 3 Caudal Vertebrae Patella Action: Abducts Thigh and Extends Shank

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

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

Dorsal Femoral Group (Flexors) MUSCLES OF THE THIGH Dorsal Femoral Group (Flexors)

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

Semi-membranosus Origin: Insertion: Action: Ischium Femur Extends Thigh

Semi-tendinosus Origin: Ischium Insertion: Tibia Action: Flexes Shank

Ventral Femoral Group (Extensors) MUSCLES OF THE THIGH Ventral Femoral Group (Extensors)

Sartorius Origin: Insertion: Action: Ilium Patella 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: Insertion: Action: Ischium and Pubis Tibia Adducts Thigh and Pulls Caudad

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

Adductor Femoris Origin: Insertion: Action: Pubis & Ischium Femur 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: Insertion: Action: Tibia and Fibula First Metatarsals Action: Flexes Foot