1. Chapter 10—The Muscular System

2. Ch. 10 Muscular system-- Study Guide
Critically read Chapter 10 pp Also read Tables 10.4 and 10.5 (pp )
Comprehend Terminology (those in bold in the textbook) within the reading scope above
Study-- Figure questions, Think About It questions, and Before You Go On (section-ending) questions (within the reading scope above) . Before You Go On Questions 1-6 (on p. 325) and Questions (on p. 349).
Do end-of-chapter questions—
Testing Your Recall— 2, 11-13, 17-20
True or False– 1
10-2 2 2

3. I. Introduction & connective tissues of a muscle

4. § Introduction of Muscles
600 Human skeletal muscles
The study of muscles– M___________

5. § The Functions of Muscles
Movement of body parts and body contents– Examples
Maintain posture and prevent unwanted movement— resist the gravity etc.
Communication –
Control of openings and passageways– Examples-- eyelids, __________________
Heat production– 85% of our body heat is from skeletal muscle contraction

6. § Connective Tissues of a Muscle
5. Tendon
4. Deep fascia
3. Epimysium
2. Perimysium
Muscle fascicle
1. Endomysium
Muscle fiber

7. Connective Tissues of a Muscle
Endomysium
thin areolar tissue around each muscle fiber
allows room for ____________________
Perimysium
slightly thicker layer of connective tissue
surrounds bundle of cells called a fascicle
Epimysium
covers whole muscle belly
blends into CT sheets called fascia (next slide)

8. Location of Fascia Deep Fascia Femur Skin Deep fascia
found between adjacent muscles; no fat
Superficial fascia (adipose tissue; hypodermis)
between skin and muscles
Superficial Fascia
Deep Fascia
Femur
Skin

9. § Ways of Muscle Attachments
To bone directly--
epimysium is continuous with periosteum of a bone
Ex.– intercostal muscles
To bone indirectly--
epimysium continues as tendon that merges into periosteum
Ex.-- many including biceps brachii to scapula
To fascia or tendon of another muscle--
To collagen fibers (dermis)--
Ex.--muscles for facial expression
To a broad sheetlike tendon, aponeurosis--
Ex.--certain abdominal muscles (Fig )

11. II. General anatomy of skeletal muscles and classification of muscles

12. § Anatomy of Skeletal Muscles
Origin—
stationary end of a muscle when contracts
Belly--
thicker, middle region of muscle
Insertion—
mobile end of muscle
Detail fig. next slide
Biceps brachii

14. § Muscle types based on fascicle direction-1

15. Skeletal Muscle types —based on fascicle direction-2
Fusiform muscles
Features:
biceps brachii m., gastrocnemius of the calf
Parallel muscles; long, uniform width, having parallel fascicles
rectus abdominis m., sartorius of the thigh, zygomaticus major
Convergent muscle; fan-shaped, broad at origin and tapering to a narrower insertion
pectoralis major of the chest
Fig

17. Skeletal Muscle type—based on fascicle direction-3
Pennate muscles (feather-shaped)
fascicles insert obliquely on a tendon, like the shaft of the feather
Unipennate—fascicles approach the tendon from one side; palmar interosseus (hand) (Fig.)
Bipennate—fascicles approach the tendon from both sides; rectus femoris (thigh) (Fig.)
Multipennate--like feathers with their quills on a single point; deltoid (shoulder) (Fig.)
Circular muscles (sphincters)
Features:
orbicularis oculi (eyelids), orbicularis oris, urethral and anal sphincters
10-17

18. Figure 10.29c

19. Fig a

20. Fig a

21. III. Action of muscle groups and muscle innervation

22. § 4 categories of muscles based on actions
Action— movement produced by a muscle
Prime mover or agonist
produces . . .
Example: in flexing the elbow, the prime mover is the brachialis
Synergist aids the prime mover
May stabilize the nearby joint
Or modify the direction of movement
Example: works with brachialis, biceps brachii as a synergist to flex the elbow
* In some textbooks 1 and 2 are opposite.

23. § 4 categories of muscles based on actions
Antagonist is a muscle that . . .
opposes the _____________
Moderates the speed or range of the agonist; preventing excessive movement and injury
Example: Triceps brachii
Fixator is a muscle that . . .
prevents _______________
Elbow flexion– the rhomboids holds the scapula in place (Fig )
10-23

25. In-class activity Question--Muscle Actions during Elbow Flexion
ID which specific muscle of the upper arm is responsible for the above action. (based on the text)
Prime mover (agonist) = ?
Synergist = ?
Antagonist = ?
Fixator = ?

26. § Skeletal Muscle Innervation
Cranial nerves arising from the brain
exit the skull through foramina
numbered I to XII (Fig )
Innervate muscles of the ______________
Spinal nerves arising from the spinal cord
Muscles elsewhere are supplied by these nerves
From spinal cord and exit the vertebral column through intervertebral foramina (Fig. 13.1, 8.23b)

28. Oh Olfactory (I)
Once Optic (II)
One Oculomotor (III)
Takes Trochlear (IV)
The Trigeminal (V)
Anatomy Abducens (VI)
Final Facial (VII)
Very Vestibulocochlear (VIII)
Good Glossopharyngeal (IX)
Vacations Vagus (X)
Are Accessory (XI)
Heavenly Hypoglossal (XII)

29. Figure 13.1b; posterior view

30. Figure 8.23b

31. § How Muscles are Named Terminologia Anatomica
system of Latin names developed in 1895
updated since then
English names for muscles are slight modifications of the Latin names.
Table 10.1 = terms used to name muscles; Examples:
Major = large (Criteria: ____); pectoralis major
Deltoid = triangular (Criteria: _____); Deltoid
Quadriceps = having 4 heads; quadriceps femoris etc.

32. § Learning Strategy (start with Fig. 10.4a and b)
Explore the location, origin, insertion and innervation of 160 skeletal muscles
use tabular information in this chapter.
Increase your retention
examining models and atlases
palpating yourself (atlas B)
observe an articulated skeleton
say the names aloud and check your pronunciation

33. Quadriceps femoris

35. IV. Muscles involved in respiration

36. § Muscles of Respiration
Breathing requires the use of muscles
Diaphragm (prime mover of inspiration)
external intercostal muscles
internal intercostal muscles
Contraction of first 2 produces inspiration
Expiration-- ??
Contraction of last produces-- forced expiration
Normal expiration requires little muscular activity

37. 1. Muscles of Respiration- Diaphragm
Muscular dome between thoracic and abdominal cavities
Muscle fascicles converge from the margins (Origin) toward a fibrous central tendon (Insertion)
Contraction flattens it
Increases/decreases the vertical dimension of the thorax
Central tendon

38. 2. External/internal Intercostals
External intercostals
O- inferior margin of rib above; I- superior border of next lower rib
extend downward and anteriorly from rib to rib
pull ribcage up/down (when contract)
Internal intercostals
O- and I- opposite of that in external intercostals
extend upward and anteriorly from rib to rib
pull ribcage downward/upward (during forced expiration)

39. 3. Breathing-a mechanical step
Mechanism of normal quiet inspiration (expiration are opposite)—
Diaphragm contracts and move downward
External intercostals muscles contract  the ribs elevated
 Chest volume:
 intra-alveolar pressure:
 Air flows inward; why?
Deeper inspiration, 2 neck muscles are involved

40. Inspiration Contraction of external intercostal muscles Contraction
Elevation of ribs & sternum
Increase side-to-side and front-to-back
dimensions of thoracic cavity (X & Y axes)
External
intercostal
muscles
(relaxed)
Contraction
of external
intercostal
muscles
Elevated
rib cage
Sternum
Contraction
of diaphragm
Diaphragm
(relaxed)
vertical (Z axis)
dimension increases in thoracic cavity
Before inspiration
Inspiration
Contractions of external intercostal
muscles causes elevation of ribs,
which increases side-to-side
dimension of thoracic cavity

41. Size of thorax  on contraction of inspiratory muscles
760
Size of thorax  on
contraction of
inspiratory muscles
Size of lungs  as they
are stretched to fill
the expanded thorax
759 mm Hg
During inspiration

42. 4. Muscles in breathing Muscles of active expiration Accessory
inspiration
Internal
intercostal
muscles
1. Sternocleidomastoid
2. Scalenus
Muscles
of active
expiration
1. External
intercostal
muscles
2. Diaphragm
Abdominal
muscles
Major
muscles of
inspiration

43. Active expiration Contraction of abdominal muscles Passive expiration
Relaxation
of external
intercostal
muscles
Contraction
of internal
intercostal
muscles
Contraction of internal intercostal
muscles flattens ribs and
sternum, further reducing
side-to-side and front-to-back
dimensions of thoracic cavity
Contraction
of abdominal muscles
Position of relaxed
abdominal muscles
Relaxation of
diaphragm
Contractions of abdominal
muscles cause diaphragm to
be pushed upward, further
reducing vertical dimension
of thoracic cavity
Passive expiration
Return of diaphragm, ribs, and sternum
to resting position on relaxation of
inspiratory muscles restores thoracic
cavity to preinspiratory size
Active expiration

44. § Muscles of the Abdomen
4 Pairs of sheetlike muscles
external oblique (most superficial)
internal oblique
transverse abdominal
(the first three: from superficial to deep)
rectus abdominal
Functions
support the viscera
stabilize the vertebral column
help in respiration, urination, defecation and childbirth

45. Aponeuroses (broad fibrous sheet-like tendons)– tendons of the oblique and transverse muscles
Rectus abdominis-- wrapped by rectus sheath
Linea alba (“white line”)– at the median line where aponeuroses meet

46. External Oblique & Rectus Abdominal
vertical, straplike from pubis (O) to xiphoid process (I)
3 tendinous intersections
rectus sheath encloses rectus abdominal
They meet at the median line called linea alba
External abdoominal oblique
Superficial (O-Ribs 5-12; to I-pelvis and linea alba)
Fibers downward and anteriorly
The aponeurosis of external oblique forms inguinal ligament
External oblique
Rectus abdominis

47. Internal oblique & transverse abdominis
Fibers pass upward and anteriorly
Perpendicular to those of external oblique
Transverse abdominal
Horizontal fiber orientation
Deepest layer
Transverse abdominis
Internal oblique