Exam 2: Myology Flashcards Preview

Anatomy A-215 > Exam 2: Myology > Flashcards

Flashcards in Exam 2: Myology Deck (25)
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1
Q

Myology

A

-Study of muscles

2
Q

Functions of skeletal muscle tissue

A
  • Body movement
  • Maintenance of posture: muscle tone (continual contraction) keeps body from collapsing/falling
  • Temperature regulation: heat produced when muscles contract
  • Storage and movement of materials: sphincters (circular muscles around openings) open and close
  • Support: helps hold organs in place ex: abdominal and pelvic floor muscles
3
Q

Gross Anatomy

A
  • made up of muscle fibers=muscle cells
  • each skeletal muscle is an organ
  • many skeletal muscles work in groups
4
Q

Tendons/Aponeuroses

A
  • tendons attach many skeletal muscles to bones (dense regualr CT)
  • aponeuroses: flattened sheetlike tendon
5
Q

Endomysium

A

-surrounds muscle fiber

6
Q

Fasicles

A

-groups of muscle fibers

7
Q

Perimysium

A

-surrounds fasicles

8
Q

Epimysium

A

-surround sentire muscle

9
Q

Deep Fascia

A

-surrounds all the CT wrappings

10
Q

Superficial Fascia

A

-subcutanious layer is superficial to deep fascia

11
Q

Sarcolemma

A

-muscle cell membrane

12
Q

Sarcoplasm

A

-cytoplasm of skeletal fibers

13
Q

Internal characterists of muscle cell (sarcoplasmic reticulum)

A
  • has organelles like lysosomes, ribosomes, and ER called sarcoplasmic reticulm
  • SR function: store calcuim ions Ca2+ and releases them when muscle contracts
14
Q

Transverse Tubules (T-tubules)

A

-conduct nerve impulses quickly from sarcolema through muscle fiber

15
Q

Compositon of Muscle Fibers

A
  • mainly made of myofibrils
  • run length of muscle-as long as muscle fiber
  • no nuclear or cellular wrapping
16
Q

Myofilaments

A
  • compose myofibrils
  • many needed to run length of muscle
  • protein filaments
  • each thick myofilament surrounded by 6 thin myofilaments
  • arrangement of thick and thin filaments gives muscle its striations
17
Q

Myosin

A
  • thick myofilaments
  • fixed length
18
Q

Actin

A

-thin myofilaments

19
Q

I Bands

A
  • light bands (I-LIGHT)
  • thin myofilaments only
20
Q

A Bands

A
  • dark bands (A=DARK)
  • overlapping thick and thin myofilaments
21
Q

Z disc (Z Line)

A
  • dark structure in the middle of an I band
  • thick myofilaments only
22
Q

H Zone (H Band)

A

-a lighter central region in the middle of an A band

23
Q

M Line

A
  • dark line in the middle of H zone
  • thick myofilaments attach here
24
Q

Sarcomere

A
  • run from Z disc to Z disc
  • functional contractile unit
  • many along length of muscle fiber
  • shorten and narrow when muscle contracts
25
Q

Sliding Filament Model of Contraction

A

When Muscle Contracts:

  • thick and thin myofilaments slide over one another
  • length of each sarcomere shortens and narrows, muscle contracts
  • H zones narrow and I bands narrow

**Z disc, M line, A band, thick and thin myofilaments stay the same size (do not shorten or narrow)