ASU BIO 201 EXAM 3 PRACTICE QUESTIONS AND CORRECT ANSWERS
1 view 0 purchase
Course
BIO 201
Institution
BIO 201
3 kinds of muscle tissue skeletal, cardiac, smooth
Major purpose of muscle converting chemical energy in atp --> mechanical energy of motion
Muscle functions -movement of: whole body, body parts, organ contents -stability: maintain posture and prevent mvmt. -communication: speech, facial expre...
ASU BIO 201 EXAM 3 PRACTICE
QUESTIONS AND CORRECT ANSWERS
3 kinds of muscle tissue ✅skeletal, cardiac, smooth
Major purpose of muscle ✅converting chemical energy in atp --> mechanical energy of
motion
Muscle functions ✅-movement of: whole body, body parts, organ contents
-stability: maintain posture and prevent mvmt.
-communication: speech, facial expressions and writing
-control of openings and passageways: sphincters
-body heat production
Characterizations of connective tissues of a muscle ✅fascia, epimysium, perimysium,
endomysium
Ct elements and how they merge with other tissues ✅tendons = attachments between
muscle and bone, dense-regular ct made of collagen fibers, epimysium surrounding
entire muscle is continuous with collagen fibers of tendons
Role of collagen in connective tissues ✅stretches slightly under tension and recoils
when released
-resists excessive stretching and protects muscle from injury
-returns muscle to resting length
-contribute to power output and muscle efficiency
Ways in which muscle attach to bone ✅indirect: tendons attach muscle to bone
Direct: fleshy attachment to bone
Some skeletal muscles do not insert on bone, but in dermis of the skin
How tendons attach muscle to bone ✅collagen fibers fibers of endo-, peri-, and
epimysium continue into the tendon, the tendon merges into the periosteum of bone
-aponeurosis: tendon is a broad, flat sheet
Origin and insertion definition ✅origin: bony attachment at stationary end of muscle
Insertion: bony attachment to mobile end of muscle
,Functional groups of muscles with example ✅for elbow flexion
Prime mover (agonist): brachialis
Synergist: biceps brachii
Antagonist: triceps brachii
Fixator: rhomboideus
Intrinsic vs extrinsic muscles ✅intrinsic: contained within a region (both origin and
insertion there)
Extrinsic: act on a designated regions, but has origins elsewhere
Characteristics of muscle ✅responsiveness (excitability): to chemical signals, stretch
and electrical changes across plasma membrane
Conductivity: local electrical change triggers a wave of excitation that travels along the
muscle fiber
Contractility: shortens when stimulated
Extensibility: capable of being stretched between contractions
Elasticity: returns to its original resting length after being stretched
Properties of skeletal muscle ✅voluntary, straitaed muscle attached to one or more
bones
Myofiber ✅muscle cell/muscle fiber, composed of myofibrils
Myofibrils ✅long protein bundles that occupy the main portion of the interior of a
muscle fiber, composed of myofilaments
Myofilament ✅protein microfilament responsible for muscle cell contraction, composed
of myosin or actin proteins
Functions of each part of a muscle fiber ✅sarcolemma: plasma membrane of a muscle
fiber
Sarcoplasm: cytoplasm of a muscle fiber
Mitochondria: packed in spaces between myofibrils
Sarcoplasmic reticulum (sr): smooth er that forms a network around each myofibril-
calcium reservoir
Terminal cisternae: dilated end-sacs of sr which cross muscle fiber from one side to the
other
T tubules: tubular infoldings of the sarcolemma which penetrate through the cell and
emerge on the other side
Triad: a t tubule and 2 terminal cisterns
Internal proteins: long protein bundles that occupy the main portion of the sarcoplasm
Multiple nuclei: flattened nuclei pressed against the inside of the sarcolemma
, Glycogen and myoglobin functions ✅glycogen: stored in abundance to provide energy
with heightened exercise
Myoglobin: red pigment that stores oxygen needed for muscle activity
Process of muscle growth and repair ✅repair by fibrosis rather than regeneration of
functional muscle
3 kinds of myofilaments found in a myofibril ✅thick filaments: myosin proteins
Thin filaments: primarily actin proteins
Elastic filaments: titin (connectin) proteins
Thick myofilaments ✅made of several hundred myosin molecules
-shaped like a golf club (2 chains make shaft-like tail, double globular head)
-heads directed outward in a helical array around the bundle
Thin myofilaments ✅fibrous (f) actin: 2 intertwined strands, string of globular (g) actin
subunits each with an active site that can bind to head of myosin molecule
-tropomyosin: each blocking 6 or 7 active sites on g actin subunits
-troponin complex: small, calcium-binding protein on each tropomyosin molecule
Elastic myofilaments ✅titin (connection): huge springy protein
-flank each thick filament and anchor it to the z disc
-help the cell recoil to its resting length (elasticity)
-keeps thick and thin filaments aligned: helps stabilize the thick filament, center it
between thin filaments
-prevents overstretching
Regulatory and contractile proteins of myofilaments ✅regulatory: tropomyosin and
troponin, like a switch that starts and stops contraction
-contraction activated by release of ca into sarcoplasm and its binding to troponin
-troponin changes shape and moves tropomyosin off the active sites on actin
Contractile: myosin and actin, do the work of contracting the muscle
Functions of accessory proteins ✅-anchor the myofilaments
-regulate length of myofilaments
-alignment of myofilaments for optimal effectiveness
Dystrophin = most clinically important
-links actin in outermost myofilaments to transmembrane proteins and eventually to
fibrous endomysium surrounding the entire muscle cell
-transfers forces of muscle contraction to connective tissue around myofiber
How defects in dystrophin result in muscular dystrophy ✅genetic defects in dystrophin
produce this disabling disease
-normal allele makes dystrophin, the absence leads to torn cell membranes ->
degeneration of skeletal muscles and are replaced with scar and adipose tissue
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller twishfrancis. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.99. You're not tied to anything after your purchase.
