1. MAJOR SKELETAL MUSCLES

2. Naming Muscles Muscles are often named for:
1. size (pectoralis major vs. pectoralis minor)
2. shape (rhomboideus, deltoid)
3. location (tibialis anterior, frontalis)
4. action (flexor digitorum)
5. points of attachment
(sternocleidomastoid)
6. direction of fibers (external oblique)
There are over 700 muscles in the human body
Cats have a mere 517
We will learn approx. 50 muscles that cats & humans have in common

3. Action of Muscles Flex – to bend a joint
Extend – to straighten a joint
Adduct – to move toward the midline of the body
Abduct – to move away from the midline of the body
Elevate – to raise a body part ( as in shrugging the shoulders)
Depress – to lower a body part ( drooping the shoulders)

4. Action of Muscles
Dorsiflexion – moving the ankle to bring the foot closer to the shin (walking on heels)
Plantar flexion – moving the ankle to bring the foot farther from the shin (walking on toes)
Eversion – turning the foot so plantar surface faces laterally
Inversion - turning the foot so plantar surface faces medially

7. Muscles of Facial Expression, Chewing & Movement of the Head
Epicranius (Frontalis &
Occipitalis)
Orbicularis oculi
Orbicularis oris
Buccinator
Zygomaticus Masseter Temporalis
Platysma
Sternocleidomastoid
(Sternomastoid in cat)

8. Muscles of Facial Expression
Epicranius (Frontalis & Occipitalis) – raises eyebrows
Orbicularis oculi – closes eyes
Orbicularis oris – closes & protrudes
lips (kissing muscle)
Buccinator – compresses cheeks
inward (blowing a “bugle”)
Zygomaticus – raises corners
of mouth (smiling muscle)
Platysma – pulls angle of mouth
downward (pouting)

9. Muscles of Mastication (Chewing) & Movement of the Head
Masseter – raises mandible (chewing muscle)
Temporalis – raises mandible (chewing)
Sternocleidomastoid – pulls head to side

10. Facial Muscle Practice
1- Obicularis Oculi
2- Obicularis oris
3- Buccinator
4- Zygomaticus
5- Masseter
6- Temporalis
7- Platysma
8- Sternocleidomastoid

11. Muscles that Move the Pectoral Girdle
Trapezius – elevates & lowers
scapula & shoulders
(cat has 3 separate trapezius muscles)
Rhomboid major &
minor - both raise scapula
Pectoralis Minor –
pulls scapula forward
& raises ribs

12. Muscles That Move the Upper Arm
Flexors:
Pectoralis major
Abductors:
1. Deltoid
Extensors:
Latissimus dorsi

13. Muscles That Move the Forearm
Flexors (flex forearm):
1. Biceps brachii
2. Brachialis
3. Brachioradialis
Extensors (extend forearm):
1. Triceps brachii

14. Muscles That Move the Hand
Flexors: (all flex the wrist)
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
Flexor digitorum
superficialis -
flexes fingers

15. Forearm & Hand Muscles Extensors: (both extend wrist)
Extensor carpi ulnaris
Extensor carpi radialis longus
(not present in cat)
Extensor carpi radialis brevis
Extensor digitorum –
extends fingers

16. Muscles of the Abdomen External oblique Internal oblique Transversus
abdominis
Rectus
Functions:
All tense abdominal
wall

17. Muscles of the Leg Hamstrings – Flex knee & extend thigh; include:
1. Biceps femoris
2. Semitendinosus
3. Semimembranosus
Gluteus maximus – extend
thigh at hip
Gluteus medius – abducts
thigh
Gracilis – adducts thigh & flexes
leg at knee

18. Muscles of the Leg Quadriceps – all extend leg at knee; include:
1. Rectus femoris
2. Vastus lateralis
3. Vastus medialis
Adductor longus – adducts
& flexes thigh
Sartorius – flexes knee &
hip

19. Muscles of the Lower Leg
Tibialis anterior – dorsiflexion
& inversion of foot
Ext. digitorum longus –
dorsiflexion & eversion of foot
Flexor digitorum longus –
plantar flexion & inversion
Gastrocnemius &
Soleus – plantar flexion
of foot

20. Practice Packet Review

29. Website for Cat Pics
homes.bio.psu.edu/people/faculty/strauss/anatomy/musc/muscular.htm