Download CHAPTER 10 THE MUSCULAR SYSTEM

CHAPTER 10 THE MUSCULAR SYSTEM
I. Functions
A. movement
B. posture and joint stability
C. communication
D. control of body passages
E. heat generation
F. glycemic control
II. Connective tissue sheaths (inout)
A. endomysium
1. fine sheath of areolar conn. tissue surrounds
each muscle fiber (cell)
B. perimysium
1. bundles groups of muscle fibers into fascicles
C. epimysium
1. dense irr. conn. tissue wraps entire muscle
2. blends into fascia
D. all sheaths continuous w/ each other and w/ tendons
E. attachments
1. direct or indirect
a. direct – epimysium fused w/ periosteum
or perichondrium
b. indirect – epimysium joins tendon or
aponeurosis, or collagen fibers of dermis
2. origins and insertions
III. Arrangement of fascicles
A. circular
1. sphincters
B. convergent – broad origin, small insertion
C. parallel
D. fusiform - spindle-shaped
E. pennate – attach obliquely to central tendon
1. uni, bi, and multipennate
2. high amt. of muscle fibers = more power
IV. Skeletal muscle interactions
A. agonists (prime movers)
B. antagonists
C. synergists
1. add extra force to same movement
2. reduce undesirable movements
D. fixators – synergists that immobilize a bone or
a muscle’s origin
V. Names of skeletal muscles
A. location
B. shape
C. relative size
D. direction of muscle fibers and fascicles
E. number of origins
F. location of attachments
G. action
MUSCLES TO KNOWFigures & Tables, p. 330-381; chapter review
…..check your lab list ……
Frontalis - draws scalp forward, raise eyebrows, wrinkle forehead
Occipitalis - draws scalp backward
Orbicularis oris - moves lips
Zygomaticus major - draws angle of mouth up = smile
Buccinator - compresses cheek, cave in, like sucking straw
Orbicularis oculi - closes the eye
Masseter - elevates mandible
Temporalis - elevates and retracts mandible
Sternocleidomastoid-flex cervical vertebrae, rotates face to side
Scalenus - flexes and rotates the neck
Rectus abdominis - compresses abdomen, flexes lumbar vertebrae
External oblique - both - compress abdomen,
one side - bend vertebral column laterally, lateral rotation of vert. column
Internal oblique - same as external oblique
Diaphragm - floor of throacic cavity, contracts for inhalation
Internal intercostals - draws adjacent ribs together during forced exhalation
External intercostals - elevates ribs during inhalation
Pectoralis major - flex, adduct and rotate arm medially
Pectoralis minor - depress and move scapula anteriorly
Serratus anterior - rotates scapula upward and laterally, elevates ribs
Trapezius - elevates clavicle, adducts scapula
Levator scapulae - elevates scapula and rotates slightly downward
Rhomboideus major - adducts scapula and rotates slightly downward
Rhomboideus minor - same as above
Latissimus dorsi - extend, adduct and rotate arm medially
Deltoid - abducts, flexes, extends, medially and laterally rotates arm
Teres major - extends arm, assists in adduction
Teres minor - rotates arm laterally, extends and adducts arm
Biceps brachii - flexes and supinates the forearm, flexes the arm
Brachialis - flexes forearm
Brachioradialis - flexes forearm, role in supination, pronation of forearm
Triceps brachii - extends forearm and arm
Pronator teres - pronates forearm and hand, flexes forearm
Flexor carpi radialis - flex and abduct wrist
Flexor carpi ulnaris - flex and adduct wrist
Extensor carpi ulnaris - extend and adduct wrist
Extensor carpi radialis longus - extend and abduct wrist
Extensor digitorum - extend phalanges
Gluteus maximus - extends, rotates thigh laterally
Gluteus medius - abducts and rotates thigh medially
Tensor fasciae latae - flexes and abducts thigh
Adductor longus - adducts, medially rotates and flexes thigh
Piriformis - rotates thigh laterally, abducts thigh
Quadriceps femoris: Rectus femoris - extend leg, flex thigh
Vastus lateralis - extend leg
Vastus medialis - extend leg
Vastus intermedius - extend leg
Hamstrings: Biceps femoris - flex leg, extend thigh
Semitendinosus - flex leg, extend thigh
Semimembranosus - flex leg, extend thigh
Gracilis - adducts thigh, flex leg
Sartorius - longest - flex leg, flex thigh, rotate thigh
Gastrocnemius - plantar flexion of foot (point toe), flex leg
Soleus - plantar flexes foot
Peroneus longus - plantar flexes and everts the foot
Tibialis posterior - plantar flexes, inverts foot
Tibialis anterior - dorsiflexes, inverts foot
Flexor digitorum longus - plantar flexes, inverts foot, flex toes
Extensor digitorum longus - dorsiflexes and everts foot, extends toes
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BY NOW YOU SHOULD KNOW TO DO THESE:
Answer Testing Your Recall questions 1, 2, 4, 6-14, 18-20 8-16; True or False; Testing
Your Comprehension 1-5
LEARNING OUTCOMES FOR CHAPTER 10
Know the function of muscles
Describe how muscle fibers are organized within specific connective tissue sheaths
Define aponeurosis
Describe the appearance of muscles in terms of the arrangement of their fascicles
Define agonist, antagonist, synergist, fixator in terms of the roles of skeletal muscle
Describe how skeletal muscles are named
Identify the location of skeletal muscles from the lab list and give their functions
SAMPLE QUESTIONS FOR CHAPTER 10
1. Which of the following bones of the foot forms a joint with the lower leg bones and
most directly accepts the weight of the body when standing?
a. calcaneus
d. navicular
b. cuboid
e. talus
c. cuneiform
2. Which group of muscles flexes and rotates the neck?
a. the scalenes
d. the splenius
b. the iliocostalis
e. the medial pterygoid
c. the spinalis
3. Which of these describes the fasicular pattern of the sartorius?
a. convergent
d. multipennate
b. parallel
e. bipennate
c. circular
4. Which these is a quadriceps muscle?
a. piriformis
d. biceps femoris
b. adductor longus
e. soleus
c. vastus lateralis
5. Which of the above is a hamstring muscle?
6. In the figure below (note that in the figure on the right, muscle A has been removed),
the muscle labeled “A” is
a. the soleus
d. the gastrocnemius
b. the gracilus
e. the semitendinosus
c. the tibialus posterior
7. Using the choices above, which is muscle B?
8. A broad, sheet-like tendon is
a. an endomysium
b. an epimysium
c. a perimysium
d. an aponeurosis
e. an agonist
9. Which of the above surrounds the sarcolemma?