Asu Bio 202

ASU BIO 201: EXAM 3 QUESTIONS AND
ANSWERS


354kinds54of54muscle54tissue54-54ans--✔✔skeletal,54cardiac,54smooth

major54purpose54of54muscle54-54ans--✔✔converting54chemical54energy54in54ATP54--
>54mechanical54energy54of54motion

muscle54functions54-54ans--✔✔-
movement54of:54whole54body,54body54parts,54organ54contents
-stability:54maintain54posture54and54prevent54mvmt.
-communication:54speech,54facial54expressions54and54writing
-control54of54openings54and54passageways:54sphincters
-body54heat54production

characterizations54of54connective54tissues54of54a54muscle54-54ans--
✔✔fascia,54epimysium,54perimysium,54endomysium

CT54elements54and54how54they54merge54with54other54tissues54-54ans--
✔✔Tendons54=54attachments54between54muscle54and54bone,54dense-
regular54CT54made54of54collagen54fibers,54epimysium54surrounding54entire54muscle54is54
continuous54with54collagen54fibers54of54tendons

role54of54collagen54in54connective54tissues54-54ans--
✔✔stretches54slightly54under54tension54and54recoils54when54released54
-resists54excessive54stretching54and54protects54muscle54from54injury
-returns54muscle54to54resting54length
-contribute54to54power54output54and54muscle54efficiency

skeletal54muscle54shapes54(with54examples)54-54ans--
✔✔Fusiform:54biceps54bracchi,54gastrocnemius
Triangular54(convergent):54pec54major,54temporalis
Parallel:54rectus54abdominus,54zygomaticus54major
Circular:54orbicularis54oculi,54urethral54and54anal54sphincters
Pennate:54rectus54femoris,54deltoid

ways54in54which54muscle54attach54to54bone54-54ans--
✔✔Indirect:54tendons54attach54muscle54to54bone54

,Direct:54fleshy54attachment54to54bone
Some54skeletal54muscles54do54not54insert54on54bone,54but54in54dermis54of54the54skin

how54tendons54attach54muscle54to54bone54-54ans--
✔✔collagen54fibers54fibers54of54endo-,54peri-,54and54epimysium54continue54into54the54te
ndon,54the54tendon54merges54into54the54periosteum54of54bone
-aponeurosis:54tendon54is54a54broad,54flat54sheet

origin54and54insertion54definition54-54ans--
✔✔Origin:54bony54attachment54at54stationary54end54of54muscle
Insertion:54bony54attachment54to54mobile54end54of54muscle

functional54groups54of54muscles54with54example54-54ans--✔✔for54elbow54flexion
Prime54mover54(agonist):54brachialis
Synergist:54biceps54brachii
Antagonist:54triceps54brachii
Fixator:54rhomboideus

intrinsic54vs54extrinsic54muscles54-54ans--
✔✔Intrinsic:54contained54within54a54region54(both54origin54and54insertion54there)
Extrinsic:54act54on54a54designated54regions,54but54has54origins54elsewhere

characteristics54of54muscle54-54ans--
✔✔Responsiveness54(excitability):54to54chemical54signals,54stretch54and54electrical54cha
nges54across54plasma54membrane
Conductivity:54local54electrical54change54triggers54a54wave54of54excitation54that54travels5
4along54the54muscle54fiber
Contractility:54shortens54when54stimulated
Extensibility:54capable54of54being54stretched54between54contractions
Elasticity:54returns54to54its54original54resting54length54after54being54stretched

properties54of54skeletal54muscle54-54ans--
✔✔voluntary,54straitaed54muscle54attached54to54one54or54more54bones

myofiber54-54ans--✔✔muscle54cell/muscle54fiber,54composed54of54myofibrils

myofibrils54-54ans--
✔✔long54protein54bundles54that54occupy54the54main54portion54of54the54interior54of54a54m
uscle54fiber,54composed54of54myofilaments

myofilament54-54ans--
✔✔protein54microfilament54responsible54for54muscle54cell54contraction,54composed54of54
myosin54or54actin54proteins

functions54of54each54part54of54a54muscle54fiber54-54ans--
✔✔Sarcolemma:54plasma54membrane54of54a54muscle54fiber

, Sarcoplasm:54cytoplasm54of54a54muscle54fiber
Mitochondria:54packed54in54spaces54between54myofibrils
Sarcoplasmic54reticulum54(SR):54smooth54ER54that54forms54a54network54around54each54
myofibril-calcium54reservoir
Terminal54cisternae:54dilated54end-
sacs54of54SR54which54cross54muscle54fiber54from54one54side54to54the54other
T54tubules:54tubular54infoldings54of54the54sarcolemma54which54penetrate54through54the54
cell54and54emerge54on54the54other54side
Triad:54a54T54tubule54and54254terminal54cisterns
Internal54proteins:54long54protein54bundles54that54occupy54the54main54portion54of54the54s
arcoplasm
Multiple54nuclei:54flattened54nuclei54pressed54against54the54inside54of54the54sarcolemma

Glycogen54and54Myoglobin54functions54-54ans--
✔✔Glycogen:54stored54in54abundance54to54provide54energy54with54heightened54exercise
Myoglobin:54red54pigment54that54stores54oxygen54needed54for54muscle54activity

Process54of54muscle54growth54and54repair54-54ans--
✔✔Repair54by54fibrosis54rather54than54regeneration54of54functional54muscle

354kinds54of54myofilaments54found54in54a54myofibril54-54ans--
✔✔Thick54filaments:54myosin54proteins
Thin54filaments:54primarily54actin54proteins
Elastic54filaments:54titin54(connectin)54proteins

Thick54Myofilaments54-54ans--✔✔made54of54several54hundred54myosin54molecules
-shaped54like54a54golf54club54(254chains54make54shaft-like54tail,54double54globular54head)
-heads54directed54outward54in54a54helical54array54around54the54bundle

Thin54Myofilaments54-54ans--
✔✔Fibrous54(F)54actin:54254intertwined54strands,54string54of54globular54(G)54actin54subun
its54each54with54an54active54site54that54can54bind54to54head54of54myosin54molecule
-Tropomyosin:54each54blocking54654or54754active54sites54on54G54actin54subunits
-Troponin54complex:54small,54calcium-
binding54protein54on54each54tropomyosin54molecule

Elastic54Myofilaments54-54ans--✔✔Titin54(connection):54huge54springy54protein
-flank54each54thick54filament54and54anchor54it54to54the54Z54disc
-help54the54cell54recoil54to54its54resting54length54(elasticity)
-
keeps54thick54and54thin54filaments54aligned:54helps54stabilize54the54thick54filament,54cent
er54it54between54thin54filaments
-prevents54overstretching