1. Ch. 10 The Muscular System
ASSIGNMENT: Do the following slides on your own by reading the text and filling the power point notes.
Slides: 3-4, 8(except Circular),

2. I. Introduction A. Types of Muscles by function
1. Agonist or Prime mover:
Predicting Actions:
Synergists:
Fixators:
2. Antagonist:
- Example: Biceps & Triceps Brachii
3. Prime Movers and
their Antagonist are
on opposite sides
of the Joint/Bones

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. Muscle Mechanics: Lever Systems
1. Components of a lever system in the Body
a) Lever—rigid bar = insertion bone that moves on a fixed point or fulcrum = joint
b) Effort—force = muscle contraction applied to a lever to move a resistance (load)
c) Load—resistance = insertion bone + tissues + any added weight moved by the effort
(c) Third-class lever
Arrangement of the elements is
load-effort-fulcrum
Effort
Load
Fulcrum
In the body: Flexing the forearm by the
biceps brachii muscle exemplifies
third-class leverage. The effort is exerted
on the proximal radius of the forearm, the
fulcrum is the elbow joint, and the load is
the hand and distal end of the forearm.

7. C. Muscle Mechanics: Lever Systems
2. Power versus Speed-- A lever allows a given muscle contraction to move a heavier body part OR to move a body part farther or faster
Power Lever
Load (insertion bone and tissues) close to joint & muscle contraction farther from joint
Purpose: A small effort exerted over a large distance can move a large load over a small distance
Mechanical Advantage
(b) Second-class lever
Arrangement of the elements is
fulcrum-load-effort
Effort
Load
Fulcrum
In the body: Second-class leverage is
exerted when you stand on tip-toe. The
effort is exerted by the calf muscles
pulling upward on the heel; the joints of
the ball of the foot are the fulcrum; and
the weight of the body is the load.

8. C. Muscle Mechanics: Lever Systems
2. …
Speed Lever
Load is far from the joint and muscle contraction force is closer to joint
Force of Contraction must be greater than the Load
Purpose: allow a load to be moved rapidly over a large distance
Mechanical Disadvantage
(c) Third-class lever
Arrangement of the elements is
load-effort-fulcrum
Effort
Load
Fulcrum
In the body: Flexing the forearm by the
biceps brachii muscle exemplifies
third-class leverage. The effort is exerted
on the proximal radius of the forearm, the
fulcrum is the elbow joint, and the load is
the hand and distal end of the forearm.

9. 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
TIPS
The Insertion and Origin indicate what the Actions are. You must know what side of the bones they are on and whether they attach on the proximal or distal parts of the bones; then it is easier to predict the Actions.
The best way to learn Actions is to act out the movement while feeling for the muscle contracting and considering where the insertions and origins are.
** Really Important
* Important

10. 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

11. C. Arrangement of muscle fibers into Fascicles: 1. Circular:
* Students Do Rest
Figure 6.14

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

13. 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

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

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

16. 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

17. 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)
© 2013 Pearson Education, Inc.

18. Base of occipital bone 1st cervical vertebra Mastoid process Middle
scalene
Sternocleido-
mastoid
Anterior
scalene
Posterior
scalene
(a) Anterior
Figure 10.9a

19. 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
© 2013 Pearson Education, Inc.

20. END

21. Use for Practice Quiz

22. (a) Mechanical advantage with a power lever
Effort x length of effort arm = load x length of load arm (force x distance) = (resistance x distance)
Effort 10 kg
0.25 cm
Effort
25 cm
Fulcrum
Load
10 x 25 = 1000 x = 250
1000 kg
Load
Fulcrum
(a) Mechanical advantage with a power lever
Figure 10.2a