3.3 Muscle 1

Question 1

what are the 5 developmental origins for skeletal muscle tissue?

Answer 1

• mesoderm
• myoblasts
• myotubes
• muscle fibers
• myofibrils

Question 2

A _______ is an undifferentiated cell that can fuse into fibers and turn into a muscle cell

Answer 2

myoblast

Question 3

muscle fiber

Answer 3

single muscle cell

Question 4

what are the 2 types of muscle tissue

Answer 4

striated, smooth

Question 5

where are 3 the types of striated muscle?

Answer 5

• skeletal (arm, back etc)
• visceral (tongue)
• cardiac (heart)

Question 6

_____ is cytoplasm in muscle cells

Answer 6

sarcoplasm

Question 7

_____ is the ER in muscle cells

Answer 7

sarcoplasmic reticulum

Question 8

_____ is like the plasma membrane in a muscle cell

Answer 8

sarcolemma

Question 9

what is the smallest contractile unit in the muscle cell? (Z to Z)

Answer 9

sarcomere

Question 10

what are characteristics of skeletal muscle? (shape, nucleus, striations?)

Answer 10

• long, cylindrical individual cells
• multinucleated (nuclei at periphery)
• cross-striations
• voluntary (strong/quick/forceful contractions)

Question 11

what are the Visceral striated muscles involved in?

Answer 11

speech, breathing, swallowing

Question 12

where can you find visceral striated muscles? and what are they similar to morphologically?

Answer 12

• tongue, pharynx, lumbar diaphragm, upper esophagus
• ID to skeletal muscle

Question 13

what are some characteristics of cardiac muscle?

Answer 13

• short/branched individual cells
• single nucleated cells that are centrally located
• cross-striations
• involuntary movements
• strong jxns
• intercalated disks

Question 14

smooth muscle characteristics

Answer 14

• short/tapered cells
• single nucleated cells with GAP jxn connections
  -NON striated
  -involuntary weak/slow contractions by ions traveling through gaps
• gut has 2-3 layers

Question 15

The ___ band is dark and wide. it has all the myosin

Answer 15

A

Question 16

The __ Band is light bc its made of actin

Answer 16

I

Question 17

The ___ line is the dark line that dissects the I band. It is the connection/anchor of the actin

Answer 17

Z

Question 18

myosin heads move along _______

Answer 18

actin filaments

Question 19

actin _____ stain dark with H&E

Answer 19

doesnt

Question 20

what is the organization of muscle tissue from out–>in

Answer 20

-Epimysium: dense irregular connective tissue
-Perimysium: fasicles, delicate CT
-Endomysium: reticular fibers and basal lamina

Question 21

how do muscle cells store energy? (2)

Answer 21

• energy rich Pi compounds (ATP, phosphocreatine)
• glycogen depots

Question 22

the nerve is inside the basal lamina and determines the _____

Answer 22

fiber phenotype

Question 23

the _______ controls the muscle fiber type

Answer 23

innervation

Question 24

organization of skeletal muscle (smallest to largest)

Answer 24

myofilaments, myofibril, muscle fiber, muscle fascicles, muscle

Question 25

_______ are the three protein filaments of myofibrils in muscle cells (actin/myosin)

Answer 25

myofilaments

Question 26

_____ is a cytoskeletal contractile unit that is surrounded by sarcoplasmic reticulum

Answer 26

myofibril

Question 27

a ______ is a muscle cell that is surrounded by sarcolemma and endomysium

Answer 27

muscle fiber

Question 28

a _____ is surrounded by epimysium ( dense connective tissue )

Answer 28

muscle

Question 29

_____ are the section of muscle surrounded by Perimysium

Answer 29

muscle fasicles

Question 30

the _____ stores calcium

Answer 30

sarcoplasmic reticulum

Question 31

There are mitochondria and extensive Sarcoplasmic reticula in the ______

Answer 31

sarcolemma

Question 32

myosin is ______, actin is ______, and ____ is the line that separates.

Answer 32

dark, light, Z

Question 33

_______ is the myosin type responsible for producing muscle contraction in muscle cells in most animal cell types

Answer 33

2

Question 34

______ is the line at the center of a sarcomere to which myosin bind

Answer 34

M line

Question 35

does actin go away during a contraction?

Answer 35

NO, myosin heads walk down the actin and the actin just slides. it doesnt go away

Question 36

____ is the zone of the thick filaments that has no actin

Answer 36

H

Question 37

The __ band is the area in the center of the sarcomere where thick and thin filaments overlap.

Answer 37

A

Question 38

there are __ heads on every myosin tail

Answer 38

2

Question 39

All actin monomers are the same but they can be different as______

Answer 39

actin associated proteins

Question 40

Ca+ causes the movement of ______ so that myosin heads can bind to ______

Answer 40

tropomyosin, myosin binding site

Question 41

______ from the nerve causes the Ca+ to be released

Answer 41

Action potential

Question 42

_____ can help the muscle regenerate

Answer 42

satellite cells

Question 43

What is in thin filaments?

Answer 43

- globular G-actin - tropomyosin - troponin

Question 44

tropomyosin

Answer 44

- in f actin groove. - covers 7 g-actin

Question 45

troponin

Answer 45

3 types: - TnT: tropomyosin attachment - TNC- CaBP - TnI: inhibitory to actin-myosin

Question 46

contractile cycle

Answer 46

-myosin head binds to myosin binding site on tropomyosin - ATP hydrolyzes to ADP+P as cross cycle happens and it pulls the actin