1. Ch. 10 The Muscular System

2. I. Introduction A. Types of Muscles by function
1. Agonist or Prime mover - main responsibility for movement
Synergists:
fixators stabilize origin
2. Antagonist:

3. B. Naming Skeletal Muscles
1. Direction of fibers
Rectus = straight
2. Relative size
Maximus = largest

4. 3. By location
Temporalis
4. By number of origins
Triceps , Biceps

5. Naming Skeletal Muscles
5. By origin/insertion location
Sternocleidomastoid
6. By shape
Deltoid = triangular
7. By action
Flexor and extensor

6. C. Arrangement of muscle fibers into Fascicles: can be circular or straight, long or short
Figure 6.14

7. What To Know for lab– MUSCLES
**Identify muscle
Muscles Groups (Quadriceps …)
*Actions from lab book
Prime Mover, Synergistic, Antagonistic
*Origin & Insertion: from Lab Book and general location on bone– distal, middle proximal

8. II. Muscles that cause facial expressions and that move the head
Epicranius
Galea
aponeurotica
Corrugator
supercilii
*Frontal belly
(Frontalis)
*Orbicularis oculi
Occipital
belly
Levator labii
superioris
*Zygomaticus
minor and major
*Temporalis
*Buccinator
*Masseter
Risorius
*Sternocleidomastoid
*Orbicularis oris
*Trapezius
Mentalis
Splenius capitis
Depressor
labii inferioris
Depressor anguli oris
Platysma
Figure 10.6

10. Head and Neck Muscles- Muscle to do in Lab
Figure 6.15

11. A. MUSCLES OF MASTICATION AND TONGUE MOVEMENT
Temporalis
Four pairs:
1. Prime movers of jaw closure
a) Temporalis and masseter
Cranial Nerve VII, Facial
Do in lab
2. Grinding movements
b) Medial and lateral pterygoids Cranial nerve V (trigeminal nerve)
See LAB BOOK for INSERTIONS, ORIGINS, and ACTIONS
Masseter
Medial & Lateral pterygoid muscles

12. Temporalis
Orbicularis
oris
Masseter
Buccinator
(a)
Figure 10.7a

13. Lateral pterygoid Medial pterygoid Masseter pulled away (b)
Figure 10.7b

14. B. Facial Expression Muscles-- SEE LAB BOOK
a) Epicarnius-Frontal Belly = Frontalis
Elevates eyebrows & wrinkles forehead
b) Orbicularis muscles = muscle forms a ring around a part of the face
i) Orbicularis Oculi: encircles eye
Closes eye
ii) Orbicularis Oris: encircles lips/mouth
Brings lips together, kissing
c) Zygomaticus (two parts)
Elevates sides of mouth, smiling
d) Buccinator– mostly deep to iand below the most- inferior zygomaticus
- Compresses checks inward-- wistling

15. C. Muscles of the Neck that move Head
FLEXION
a) Sternocleidomastoid—
If both sides contract together causes head flexion
If one side contracts only, causes lateral rotation
b) Scalenes—
- deep to Sternocleidomastoid
- Cause lateral head rotation
EXTENSION
Trapezius: upper back muscle that extends to back of head
- Extends head and other movements will do later
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16. Base of occipital bone 1st cervical vertebra Mastoid process Middle
scalene
Sternocleido-
mastoid
Anterior
scalene
Posterior
scalene
(a) Anterior
Figure 10.9a

17. END Platysma (cut) Mylohyoid Omohyoid (superior belly) Sternohyoid
Figure 10.9b Muscles of the anterior neck and throat used in swallowing.
Platysma
(cut)
Mylohyoid
Omohyoid
(superior belly)
Sternohyoid
Sternocleido-
mastoid
END
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18. © 2013 Pearson Education, Inc.
Figure 10.10b Muscles of the neck and vertebral column that move the head and trunk.
Mastoid process
Splenius
capitis
Spinous
processes
of the
vertebrae
Splenius
cervicis
Posterior
© 2013 Pearson Education, Inc.

19. © 2013 Pearson Education, Inc.
Figure 10.10d Muscles of the neck and vertebral column that move the head and trunk.
Ligamentum
nuchae
Mastoid process
of temporal bone
Semispinalis
capitis
Longissimus capitis
Semispinalis
cervicis
Iliocostalis cervicis
Longissimus cervicis
Semispinalis
thoracis
Iliocostalis thoracis
Longissimus thoracis
Spinalis thoracis
Iliocostalis
Erector
spinae
Longissimus
Spinalis
Multifidus
Iliocostalis
lumborum
Quadratus
lumborum
External oblique
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