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 (C1)
• 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
SubScapularis
• 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