A 5 Muscle

Question 1

Where do you find intercalated disks?

Answer 1

cardiac muscle only.

Question 2

which types of muscles have branched fibers?

Answer 2

cardiac

Question 3

which type of muscle has a largest diameter? smallest?

Answer 3

largest = skeletal
middle = cardiac
smallest = smooth

Question 4

which types of muscles are striated?

Answer 4

skeletal and cardiac only

Question 5

what is the epimysium?

Answer 5

covers entire muscle

Question 6

what is the perimysium?

Answer 6

covers fascicles

Question 7

what is the endomysium?

Answer 7

covers muscle fibers.

Question 8

what is the order of muscle from largest to smallest?

Answer 8

muscles, fascicle, muscle fiber, fibril, sarcomere.

Question 9

How would you describe skeletal muscle?

Answer 9

voluntary
multinucleated
striated

Question 10

which cells repair damaged skeletal muscle?

Answer 10

satellite cells

Question 11

I band

Answer 11

only thin filaments (actin)

Question 12

z line

Answer 12

where thin filament attaches (also alpha actinin)

Question 13

A band

Answer 13

the entire length of the thick (myosin) filament

Question 14

H zone

Answer 14

the area with only myosin. centered on the m line.

Question 15

M line

Answer 15

the mysosin attachment site

Question 16

sarcomere

Answer 16

z line to z line

Question 17

How would you describe cardiac muscle?

Answer 17

involuntary, 1-2 nuclei, intercalated disks, striated, many mitochondria, a lot of glycogen.

Question 18

Which three things are found in all intercalated disks?

Answer 18

desmosomes, gap junctions, and fascia adherins.

Question 19

How would you describe smooth muscle?

Answer 19

involuntary, no striations, thick/thin filaments with dense bodies, a lot of mitochondria, a lot of elastin, collagen, and proteoglycans because smooth muscle can make these three.

Question 20

what is tropomyosin?

Answer 20

a band of protein that covers up the actin binding sites.

Question 21

what is troponin?

Answer 21

it sits on tropomysosin and acts as a receptor to displace tropomyosin when calcium binds it.

Question 22

what is nebulin?

Answer 22

an actin binding protein that regulates actins length during sarcomre assembly.

Question 23

what is alpha actinin?

Answer 23

dense bodies ( smooth muscle) = z line (in skeletal muscle)

help to anchor the actin filaments to the z line or dense body

Question 24

what is tropomodulin?

Answer 24

a protein that binds the caps of the negative ends of actin preventing the spontaneous dissociation of the actin polymer.

Question 25

what is titin?

Answer 25

it connects the z line to the m line in striated muscles only, and also acts as a molecular spring.

Question 26

during the contraction of muscle, what happens when atp binds to myosin?

Answer 26

the mysoin head can be released from actin.

Question 27

what is rigor mortis?

Answer 27

when the myosin is stuck to actin because there is no atp to release it.

Question 28

when calcuim enters to muscle to promote contraction, what is bound to the myosin?

Answer 28

ADP + Pi

Question 29

what causes the power stroke to occur?

Answer 29

the release of Pi

Question 30

what causes the ADP to fall off of myosin during muscle contraction?

Answer 30

The addition of another ATP.

Question 31

what does creatine kinase do?

Answer 31

Allows for ATP +Cr —-> ADP + PCr

Question 32

what is the optimal length of a sarcome to generate the maximum contraction?

Answer 32

about 2.3 micormeters.

Question 33

what is the golgi tendon organ?

Answer 33

Its an inhibitory signal that prevents over stretching/contraction of a muscle.

Question 34

what is calmodulin?

Answer 34

A calcium binding protein in smooth muscle. Recall its analog in skeletal muscle would be troponin.