Anatomy ReviewCat 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

Cleido-mastoid

• 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)

RhomboideusCapitis

• Origin: – Lamboidal Ridge

• Insertion: – Scapula

• Action: – Pulls Scapula Craniad (up)

RhomboideusMinor

• Origin: – Thoracic Vertebrae

• Insertion: – Scapula

• Action: – Pulls scapula dorsally and medially

capitis

RhomboideusMajor

• Origin: – Thoracic Vertebrae

• Insertion: – Scapula

• Action: – Pulls Scapula Dorsally (toward back) and Medially (towards midline)

capitis

LevatorScapulaeVentralis

• 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: – Sternum

• Insertion: – Humerus

• Action: – Adducts Arm

Pectoralis Minor

• Origin: – Sternum

• Insertion: – Humerus

• Action: – Adducts Arm

Xiphi-humeralis(cat only)

• Origin: – Xiphoid Process

• Insertion: – Humerus

• Action: – Adducts Arm

SerratusVentralis

• 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)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: – Scapula

• Insertion: – Humerus

• Action: – Extends Humerus

Infra-spinatus

• Origin: – Scapula

• Insertion: – Humerus

• Action: – Rotates Humerus Outward

Teres major

Rhomboideus major

Teres Major

• Origin: – Scapula

• Insertion: – Humerus

• Action: – Flexes forearm and Rotates it inward

Rhomboideus major

Sub-Scapularis

• Origin: – Scapula

• Insertion: – Humerus

• Action: – Pulls Humerus Medially

MUSCLES OF UPPER ARM

Triceps Brachii

• Origin: – Long Head: Scapula Lateral Head and Medial Head: Humerus

• Insertion: – Ulna

• Action: – Extends Forearm

Lateral head

Medial head

Long head

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)

• Origin: – Cranial border of one

rib

• Insertion: – Caudal border of rib

above

• Action: – Draw Adjacent Ribs

Together and Lower Rib

Internal Intercostals

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

Caudo-femoralis

• 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

Semi-membranosus

• Origin: – Ischium

• Insertion: – Femur

• Action: – Extends Thigh

Semi-tendinosus

• 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