microscopic anatomy and organization of skeletal muscle 14 & 15

8/2/2019 Microscopic Anatomy and Organization of Skeletal Muscle 14 & 15

1/11

Ske le ta l M u sc le C e lls and T h e ir P ackag in g in to M u sc le s1. What capability is most highly expressed in muscle tissue? --""'o"'I1 "'t,_ '"-o:.:'.::ti"ij""y'--- _2... Use the items on the right to correctly identify the Structures described on the left.

g; perimysi~rm L connective tissue ensheathing a bundle of muscle. cells a. endomysium2. bundle of muscle cells b. epunysium

c. fascicleJ. contractile unit of muscled. fiber

4. a muscle cell e. myofilament5. thin reticular connective tissue investing each muscle cell f. myofibril6. plasma membrane of the muscle fiber g perimysium7. a long filamentous organelle with a banded appearance found within h. sarcolemmamuscle cells i. sarcomere8. actin- or myosin-containingstructure j. sarcoplasm9 . cord of collagen fibers that attaches a muscle to a bone k. tendon

C jascicte

i: sarComered; f ibera: endomysium11 ; sa r co lemma

f, myofibril

e' myofilament

k; tendon

.3 . Why are the connective tissue wrappings of skeletal muscle important? (Give at [east three reasons.)Th_ cOllnec/h,. t iss". wrappings (a) bundle .the",usclefibers logether, i"",""(lSing coordinat iolt or/heir acl ivi/y;(oj add , 'IJ 'Onglh /olhomuscle; and (e) provide a route for entry andex it of blood ves sel s and nerves 10the musci e f ibers.

4. Why are indirect-that is, tendinous-muscle attachments to bone seen more often than direct attachments?They C onseJ" space (less bu lky than fleshy m uscle attachm ents) and are m ore durable that! muscle / i . , , , " wher bony promi'W'cesmust be spa~rl'le.d.

5. How does an aponeurosis differ from a tendon? An aponeuros is i s a sheet of whit ej ibrous connect ive { iSSue;" t e"doll i sQ band orcord, of the same tissue. Both serve to attach muscles to bones (or 10 othermuscles).

Review Sheet 14 177


2/11

6. The diagram illustrates a small portion of a muscle myofibril . Using letters from the key,correctly identify each structure in-dicated by a leader l ine or a bracket. Below the diagram make a sketch of how this segment of the myofibril would look ifcontracted.Key: a. actin filamentb. A band

c. J bandd. myosin filamente. sarcomeref. Z . disc

eI I

1 =

: - r -Ji " " I fb d a7. On the following figure, label blood vessel, endomysium, epimysium, fascicle, muscle cell, perimysium. and tendon.

Perimysium

Tendon Epimysium Fascicle

178 Review Sheet 14


3/11

T h e N eu r o m u s c u l a r J u n c t i o n8. Complete the following statements:

T he junction between a motor neuron's axon and th e muscle cell membrane iscalled a neuromuscular junct ion or a ~~l_junction. A motor neuron and all of theskeletal muscle cells it stimulates is called 11 _2_. The actual gap between theaxonal terminal and the muscle cell is called a_3_. Within the axonal terminalare many smal l vesicles containing a neurotransmitter substance calJed_4_.When the ~ reaches the ends of the axon, the neurotransmitter is released anddiffuses to the muscle ceil membrane to combine with receptors there. The com-bining of the neurotransmitter with the muscle membrane receptors causes themembrane to become permeable to both sodium and potassium. The greater influxof sodium ions results in _6_ of the membrane. Then contraction of the musclecell occurs. Before a muscle cell can be stimulated to contract again, _7~.~ mustoccur.

1. myoneural

2. motor unit

3. synOptic cleft4 . Qcery lcholine5. nerve impulse (aCliO'lj!olemia/)6. depolarization

7. r ep o { a rf zatlon

. 9. The "vents that occur at a neuromuscular junction are depicted below. Ident ify by labeling every structure provided with a .leader line.

Actionpotential

[a l

c -,.

Pal10famyofibril

(b)

Key:a. ACh moleculesb. ACh receptorc. axonal terminal(I. io n channele mitochondrionf. muscle fiber

Ii g. myelinated axonh. sarcolemmai. sodium ionJ. synaptic cleftk. synaptic vesicle

(exocytosing)l. Ttubule

~~'''mM

{ eD 00 I ! 1 J ' .J 0 'V b~

(e)Review Sheet 14 179


4/11

C la ss if ica tion o f S k e le ta l M u sc le s1. Several criteria were given relative to the naming of muscles. Match the cri teria (column B) to the muscle names (columnA) Note.that more than Onecriterion may apply in some cases

ColumnA Column B..!..:..JL__ I. gluteus maxunus a. action of the muscle~ 2. adductor magnus b. shape of the muscle~ 3. biceps femoris c. location of the origin and/or insertion of the muscle_ e _ , L _ _ _ _ 4. transversus abdcminis d. number of origins~ 5. extensor carpi ulnaris e. location of the muscle relative to a hone or body region

6. trapezius f. direction in which the muscle fibers run relative to some imaginary line_ e _ , L _ _ _ _ 7. r ec tu s f e mo ri s g. relative size of the muscle_ e _ , L _ _ _ _ 8. external oblique

2. When muscles are discussed relative to the manner in which they interact with other muscles, the terms shown inthe key areoften used. Match the key terms with the appropriate definitions.Key: a. antagonist b. fixator c. prime mover d. synergist- , C : . . c : ~ p " , I . ; ; i m = e . : . : n , - , w _ v c : . : e l _ L agonist_ o " , , - , f i ' - . : ~ : : : m : : t : : . o : . _ , . 2. postural muscles, for the most part. . . : " " ' . ; _ " " = l " ' o g " ' 0 : . . c n :: : is"" 3. reverses and/or opposes the action of a prime mover_ d - " , - ~ s y : _ n _ ' - , r g , - i _ s t 4 . sta bi li ze s a joint so that the prime mover may act atmore distal joints_ d - ' ; _ s - " y _ I I _ er , c : _ ' s _ t 5. performs the same movement as the prime mover" , : v : l ; _ , f i : : : " ' : : : a : : t o : : ' _ 6. immobilizes the origin of a prime mover

~~.

ReviewSheet 15 181


5/11

M u s c l e s o f the H ead a n d N e c k3. Using choices from the list at the right, correctly identify muscles provided with leader lines on the diagram.

4. USing the terms provided above, identify the muscles described next

a. buccinatorb. corrugator superciliic. depressor anguli orisd. depressor labii inferiorise. frontalisf. levator iabii superiorisg. masseter

h. rnentahsI. occipitalisj. orbicularis oculi

'" k. orbicularis onsI. platysmam, trapeziusn. zygomaticus majorand minor

b 6. used to form th e vertical frowncrease on the forehead

n L used in smilinga 2. used to suck in your cheeks

_ J _ _ _ 3. used in blinking and squintingc 4. used to pout (pulls the comers of themouth downward)e 5. raises your eyebrows for a questioningexpression

7. your "kisser"_8 8. prime mover to raise the lower

jawbone_I 9. tenses skin of the neck duringshaving .

182 R ev iew S heet 1. 5 .;,


6/11

' :"1'~-", ..-::~ r , ~ . , ~ "I~

M usc les o f th e T runk5. Correctly identify both intact and transected (cut) muscles depicted in the diagram. using the terms given at the right. (Not

al l t erms wi ll be used in t his identi fi cati on.)

Coracoid proC85S

a, biceps brachiib. brach ial isc, coracobrachialis

Sternum d, deltoid (cut)e. external lntercostalsf. external obliqueg. internal intercostalsh internal obl iquei. latissimus dorsij, pectoralis major (cut)k. pectoralis minorL rectus abdorninism. rhomboidsn. serratus anterior0, subscapularisp. teres majorg. teres minorr. transversus abdominiss. trapezius

6. Using the key provided in question 5 above, identify the major muscles descr ibed next.L a major spine flexor ~ 7. important in shoulder adduction; an-tagonists of the shoulder abductor (two

muscles)2. prime mover for pulling the ann posteri~orly~J~'__ 3, prime mover for shoulder flexion

II S, moves the scapula forward anddownwardM!__ 4. assume major responsibility for forrningthe abdominal girdle (three pairs of rnus-

des)e 9. small, inspiratory muscles between the

ribs; elevate the ribs~, 10. extends the head

~j 5. pulls the shoulder backward an d downward~m 11. pull the scapulae medially

d 6, prime mover of shoulder abduction

Review Sheel 15 183


7/11

Musc les o f th e Upper L im b7. Using terms from the list on the right, correctly identify all muscles provided with leader lines in the diagram. (Note that [lot

al l the Iisted terms wi II b e u sed in this exercise.)a, biceps brachiib. brachial isC. brachioradialisd. extensor carpi radial is longuse. extensor digi torumf. flexor carpi radialisg. flexor carpi ulnarish. flexor digitorum superficialisi. flexor pollicis longusj. palmaris longus

Palmar aponeurosis k, pronator quadratusL pronator teresm. supinatorn. tr iceps brachii

8. Use the terms provided in question I to identify the muscles described next,

~ L places the palm upward (two muscles) h 6. flexes wrist and middle phalanges" 2. flexes the forearm and supinate; the hand k, I 7. pronate the hand (two muscles)p, c 3, forearm flexors; no role in supination (two 8. flexes the thumbmuscles)

d 9, extends and abducts the wristII 4. elbow extensor

e 10, extends the wrist and digitsf 5. power wrist flexor and abductor _ i _ . __ n. flat muscle that is a weak wrist flexor

184 R ev iew S heet 1 5


8/11

; . : ' . : .;-':

Musc les o f the Low er L im b9. Using the terms l isted to the right, correct ly ident ify all muscles provided with leader l ines in [he diagram below. (Not all

listed terms will be used In this exercise)

10. Use the key terms in exercise 9 to respond to the descriptions below._ f 1. flexes the great toe and inverts the ankle_ d _. _e _ _ 2. lateral compartment muscles thai plantar

flex and evert the ankle (two muscles)i." 3. move the thigh laterally to take the "atease" stance (two muscles}h 4. used to extend the hip when climbing stairs

;l'o"I___ 5. prime movers of ankle plantar flexion (twomuscles)

,_ P 6. major foot inverter

a. adductor groupb. biceps femorisc. extensor digitorum longusd. f ib ula ri s b re v i se. fibularis longusf. flexor hallucis longusg. gastrocnemiush. gluteus rnaxirnusi. gluteus mediusj. rectus femorisk. semimembranosus1. semitendinosusm. soleusn. tensor fasciae lataeo. tibialis anteriorp. tibialis posteriorq. vastus lateralis

" 7. prime mover of ankle dorsiflexion8. allow YOLl to draw your legs to themidline of your body, as when stand-ing at attention

c 9. extends the toes~ 10. extend thigh an d flex knee (three mUSdes)_j 11. extends knee and flexes thigh

Review Sheet 15 185


9/11


10/11

12. Identify each of the lettered muscles in this diagram of the human posterior superficial musculature by matching its letter toone of the following muscle names:t 1. adductor rnagnusu 2. biceps femorisb 3. brachialisc 4. brachioradialism 5. deltoidc t 6 . e xte ns or carpi rad ia lis longus

_I___ 7. extensor carpio ulnaris_L_____ 8. extensor digitorurn_q___ 9. external oblique_e 10 . flexor carpi ulnaris_' 11. gastrocnemius

s 12. gluteus rnaxirnus_r 13. gluteus medius_ v _ .o _ _ 14. gracilis_h 15 . iliotibial tract (tendon)_n 16 . infraspinatus..J!.____ 17 . latissimus dorsi.L:__ 18. occipitalis_ " X _o " _ _ 19 . semimembranosus

w 20. semitendinosus.s 21. sternocleidomastoid

o 22. teres major_' 23. trapezius_a 24. triceps brachii

Review Sheet 15 187


11/11

G en era l R ev iew : M uscle D escription sB. Identify m e muscles described below by complet ing the s ta tement s:L The . . . . : d : : : e ; : : l l : : _ o , : : : d ~ v : . : t lS = t i , and g lu t e us m ax im us a n d m e d iu s

are commonly used for intramuscular injections (three muscles).2. The insertion tendon of the - , q , " " = , , , c = d r , , , i c c c e = < p , , , s ~ _ ~ group contains a large sesamoid bone, me patella.3. The triceps surae insert in common int o me _ c : _ : < l _ ; , / c " , Q " , n " , e " , a : _ 1 tendon.4. The bulk of the tissue of a muscle tends to lie - ' p ' - r " O , ; _ x " i m _ _ : o _ ; , I t o t he part of t he body it causes to move.S. The extrinsic muscles of the hand originate on the _ . h - : : : u : : : , , : : : , , : : : n = l S , ..a .. d . . i l - : - I S . , . : : I I : : . : n d : : . . . : : " : : : / , , : : : < i : . _ _6. Most flexor muscles are located on the _ " c _ I l _ ; , I ' - . e r . . : _ i o : _ : ' aspect of the body; most extensors

are located p o s t e r i o r l y . An except ion t o this generali zati on is the extensor-flexormusculature of the . . , ; k n : : : : : : : e , : ; e _

188 ReviewSheet 15

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IIir,.t. . . ,' ..... ,

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microscopic anatomy and organization of skeletal muscle 14 & 15

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