1. Chapter 10, reviewed and continued
Gross and microscopic anatomy of skeletal muscles
Nerve to muscle: excitation-contraction coupling
Factors affecting how much force is exerted
Muscle diversity
fast-twitch vs. slow-twitch
skeletal vs. cardiac vs. smooth

2. Muscle metabolism, continued…
A new sports drink advertises, “Includes ATP for rapid fueling of exercising muscles!” Are you tempted to buy it? Why or why not?
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3. Fast-Twitch vs. Slow-Twitch Muscle Fibers
Overall function (speed? strength? endurance?)
Myosin type
(I? II?)
SR abundance
(low? high?)
Mitochondrial density (low? high?)
Capillary density
Substrates used
(carbs? lipids?)

4. Can exercise training convert fast fibers to slow fibers or vice versa
Can exercise training convert fast fibers to slow fibers or vice versa? (Or are we prisoners of our genes?)

5. The heart: the ultimate slow-twitch muscle
10th Martini,
Figure 10-22

6. Intercalated discs Intertwined cell membranes of adjacent cells
Gap junctions
Desmosomes

7. High levels of troponin have been found in a patient’s blood
High levels of troponin have been found in a patient’s blood. What could this mean?

8. Smooth muscle Relaxed (sectional view) Relaxed (superficial view)
10th Martini,
Figure 10-23b
Smooth muscle
Relaxed (sectional view)
Relaxed (superficial view)
Contracted (superficial view)

9. Skeletal vs. Cardiac vs. Smooth (Table 10-3)
Property
Skeletal Muscle
Cardiac Muscle
Smooth Muscle
Fiber size
Nuclei
Organization of contractile proteins
Control mechanism
Calcium source
Calcium regulation
Contraction speed/endurance
Energy source

10. Clinical Case: myasthenia gravis
Usually an autoimmune disease (can you think of others?)
Acetylcholine (Ach) receptors are attacked
Treatment strategies?
Figure 10-9

11. Worksheet: end-of-chapter review questions

12. 10th Martini, Chapter 11: An Introduction to the Muscular System
General concepts
Fascicle arrangements
Levers
Naming conventions
Lots and lots of muscles!

13. Muscle fascicles are arranged in different ways
PARALLEL
CONVERGENT
PENNATE
CIRCULAR
contracted
relaxed
10th Martini, Figure 11-1

14. 11-1 Fascicle Arrangement
Circular Muscles
Also called sphincters
Open and close to guard entrances of body
For example, orbicularis oris muscle of the mouth
© 2015 Pearson Education, Inc.

15. Parallel vs. Pennate: How does this affect muscle function?
On page 334, your textbook says:
“A pennate muscle contains more muscle fibers – and thus more myofibrils – than does a parallel muscle of the same size. For this reason, the pennate muscle produces more tension.”
This is completely wrong!

16. Parallel vs. Pennate Muscles: a better explanation?
= 1 “unit” of muscle proteins (relaxed)
bone
bone
bone
bone
contract
bone
bone
contract
bone
bone
contract
bone
bone
bone
bone

17. Muscles and Levers
Lever = “a rigid structure … that moves on a fixed point called a fulcrum”
Levers move when an applied force (AF) overcomes any load (L) that would prevent movement
Bones are levers
Joints are fulcrums
Muscles provide applied force
10th Martini, Figure 11-2

18. Optimized for speed or effective force?
10th Martini,
Figure 11-2

19. 11-3 Muscle Attachments to Other Tissues
Origins and Insertions
Origin: fixed point of attachment
Insertion: moving point of attachment
Most muscles originate or insert on the skeleton
Origin is usually proximal to insertion
“Knowing which end is the origin and which is the insertion is ultimately less important than knowing where the two ends attach and what the muscle accomplishes when it contracts.”
© 2015 Pearson Education, Inc.

20. 11-3 Muscle Attachments to Other Tissues
Remember the movement terms from the previous lab? (abduction/adduction, pronation/supination, etc.)
Now we can see how muscles achieve these movements!

21. 11-3 Muscle Attachments to Other Tissues
Muscle Terminology Based on Function
Agonist (or prime mover)
Antagonist
Synergist

22. Muscles you will need to know (Exercise 13)
Muscles of Facial Expression:
occipitofrontalis (frontalis)
orbicularis oris
levator labii
zygomaticus
lateral rectus
Muscles of Mastication:
temporalis
Muscles of Tongue, Throat, and Anterior Neck:
sternohyoid
sternocleidomastoid
Muscles of the Neck and Vertebral Column:
longissimus cervicis
semispinalis thoracis

23. Muscles you will need to know (Exercise 13)
Muscles of the Thorax: Movement of the Scapula:
levator scapulae
rhomboideus major
serratus anterior
trapezius
Muscles of the Shoulder and Arm:
pectoralis major • flexor carpi radialis
deltoid • palmaris longus
supraspinatus • extensor digitorum
coracobrachialis • adductor pollicis
triceps brachii
biceps brachii
brachioradialis

24. Muscles you will need to know (Exercise 13)
Muscles of the Hip and Leg:
iliacus
gluteus medius
sartorius
adductor longus
adductor magnus
quadriceps femoris:
rectus femoris, vastus lateralis, vastus medialis, vastus intermedius
hamstrings:
biceps femoris, semitendinosus, semimembranosus
tibialis anterior
flexor digitorum longus
gastrocnemius

25. 11-4 Naming Skeletal Muscles
Names for skeletal muscles can indicate any of the following:
1. Location in the body
2. Origin and insertion
3. Fascicle organization
4. Relative position
5. Structural characteristics
6. Action
The following slides are meant to help but do not need to be memorized.
© 2015 Pearson Education, Inc.

26. 11-4 Naming Skeletal Muscles
1. Location in the body
For example, temporalis muscle
2. Origin and insertion
First part of name indicates origin
Second part of name indicates insertion
For example, genioglossus muscle
3. Fascicle organization
For example, rectus (straight), transversus (crosswise), oblique (slanting)
© 2015 Pearson Education, Inc.

27. 11-4 Naming Skeletal Muscles
4. Position
Externus (superficialis) =
Internus (profundus) =
Extrinsic
Muscles ______ an organ
Intrinsic
© 2015 Pearson Education, Inc.

28. 11-4 Naming Skeletal Muscles
5. Structural characteristics
Nature of origin
Biceps (__ heads)
Triceps (__ heads)
Quadriceps (__ heads)
Shape
Deltoid (triangle)
Orbicularis (circle)
Pectinate (comblike)
Piriformis (pear-shaped)
Platy- (flat)
Pyramidal (pyramid)
• Rhomboid (parallelogram)
• Serratus (serrated)
• Splenius (bandage)
• Teres (round and long)
• Trapezius (trapezoid)
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29. 11-4 Naming Skeletal Muscles
5. Structural characteristics (continued)
Other striking features
Alba (white)
Brevis (short)
Gracilis (slender)
Lata (wide)
Latissimus (widest)
Longissimus (longest)
Longus (long)
• Magnus (large)
• Major (larger)
• Maximus (largest)
• Minimus (smallest)
• Minor (smaller)
• Vastus (great)
© 2015 Pearson Education, Inc.

30. 11-4 Naming Skeletal Muscles
6. Actions
Abductor =
Adductor =
Depressor =
Extensor =
Flexor =
Levator =
Pronator =
Supinator =
Tensor =
© 2015 Pearson Education, Inc.