Exam 2: Myology Flashcards Preview

Anatomy A-215 > Exam 2: Myology > Flashcards

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

Myology

-Study of muscles

2

Functions of skeletal muscle tissue

-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

Gross Anatomy

-made up of muscle fibers=muscle cells

-each skeletal muscle is an organ

-many skeletal muscles work in groups 

4

Tendons/Aponeuroses 

-tendons attach many skeletal muscles to bones (dense regualr CT)

-aponeuroses: flattened sheetlike tendon 

5

Endomysium

-surrounds muscle fiber

6

Fasicles

-groups of muscle fibers

7

Perimysium

-surrounds fasicles

8

Epimysium

-surround sentire muscle

9

Deep Fascia

-surrounds all the CT wrappings

10

Superficial Fascia

-subcutanious layer is superficial to deep fascia

11

Sarcolemma

-muscle cell membrane

 

12

Sarcoplasm

-cytoplasm of skeletal fibers

13

Internal characterists of muscle cell (sarcoplasmic reticulum)

-has organelles like lysosomes, ribosomes, and ER called sarcoplasmic reticulm 

-SR function: store calcuim ions Ca2+ and releases them when muscle contracts 

14

Transverse Tubules (T-tubules)

-conduct nerve impulses quickly from sarcolema through muscle fiber

15

Compositon of Muscle Fibers

-mainly made of myofibrils

-run length of muscle-as long as muscle fiber

-no nuclear or cellular wrapping

 

16

Myofilaments

-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

Myosin

-thick myofilaments 

-fixed length

18

Actin

-thin myofilaments

 

19

I Bands

-light bands (I-LIGHT)

-thin myofilaments only

20

A Bands

-dark bands (A=DARK)

-overlapping thick and thin myofilaments 

21

Z disc (Z Line)

-dark structure in the middle of an I band

-thick myofilaments only

 

22

H Zone (H Band)

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

23

M Line

-dark line in the middle of H zone

-thick myofilaments attach here

24

Sarcomere

-run from Z disc to Z disc 

-functional contractile unit

-many along length of muscle fiber

-shorten and narrow when muscle contracts

25

Sliding Filament Model of Contraction

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)