Muscle

Question 1

Epimysium

Answer 1

surrounds the entire muscle and forms tendons

Question 2

Perimysium

Answer 2

surrounds the fasicles

Question 3

Endomysium

Answer 3

surrounds individual muscle cells

Question 4

What is the functional unit of a myofibril

Answer 4

A sarcomere

Question 5

Is skeletal muscle multinucleate?connected by gap junctions?
They are formed by the fusion of what

Answer 5

Multinucleate bc they are formed by the fusion of many myoblasts, not connected by gap jxns

Question 6

What are satellite cells in muscle

Answer 6

residual myoblasts in mature muscle. can creat new muscle if there is damage

Question 7

, where do you see the nuclei in skeletal muscle

Answer 7

periphery

Question 8

Z disks

Answer 8

mark the boundaries of a sarcomere, contains actin and myosin

Question 9

I band

Answer 9

Contains only actin filaments (thin)–looks light

Question 10

A band

Answer 10

has actin and myosin –looks dark.

Question 11

H Zone

Answer 11

Only has myosin (thick) filaments

Question 12

How do the lengths of I, A and H change during contraction

Answer 12

I gets smaller, H gets smaller, A does not change

Question 13

What protein is at the end of z disks

Answer 13

Desmin

Question 14

Which protein is associated with actin? myosin?

Answer 14

Actin: alpha actinin, nebulin
Myosin: Titin

Question 15

What neurotransmitter is at the synapse between a motor nerve axon and a skeletal muscle cell

Answer 15

Acetylcholine

Question 16

Is ATP attached to myosin during contraction?

Answer 16

No, when Adp is attached to Myosin there is no binding/contraction. When released there is a conformational change that lets them attach and drags actin twoard center of sarcomere

Question 17

What specific protein does Calcium cause a conformational change in to allow contraction?

Answer 17

Troponin which is bound to tropomyosin on actin. With Calcium it moves to allow contraction

Question 18

Where is calcium stored in muscle

Answer 18

sarcoplasmic reticulum

Question 19

What is the Sarcoplasmic Reticulum receptor that leads to the release of calcium? What leads to the uptake

Answer 19

ryanodine receptor leads to release, Ca@+ ATPase leads to uptake

Question 20

What is a triad

Answer 20

Action potential to release Ca travels down transverse tubule. A triad is where the t tubule has a sarcoplasmic reticulum on either side initiating release.

Question 21

What is type 1 skeletal muscle

Answer 21

Red/Slow Twitch -oxidative

Question 22

What is type 2B skeletal muscle

Answer 22

White/Fast Twitch -Glycolytic

Question 23

Does type 1 or 2 skeletal muscle have a richer vascular supply

Answer 23

1

Question 24

Does type 1 or 2 skeletal muscle have a larger fiber diameter?

Answer 24

2B- larger, stronger contraction.

Question 25

Does type 1 or 2 skeletal muscle have a larger contraction speed? which one fatigues easier?

Answer 25

type 2

Question 26

Does type 1 or 2 skeletal muscle have more myoglobin?

Answer 26

type 1

Question 27

Does type 1 or 2 skeletal muscle have more mitochondria?

Answer 27

type 1

Question 28

Does type 1 or 2 skeletal muscle have oxidative enzymes?

Answer 28

type 1

Question 29

Does type 1 or 2 skeletal muscle have extensive sarcoplasmic reticulum

Answer 29

type 2

Question 30

Does type 1 or 2 skeletal muscle have large diameter nerve fibers?

Answer 30

type 2

Question 31

Is ADP or ATP bound during treadmilling

Answer 31

No myosin cannot bind to Actin with ADP attached when it is hydrolysed it moves along. When ATP/ADP bound they have low affinity for each other

Question 32

What is troponin attached to

Answer 32

Attached to tropomyosin protein between actin filaments.

Question 33

What do you stain for to see the difference between type 1 and 2B muscle? what is the difference

Answer 33

succinate dehydrogenase | 1 is darker

Question 34

What causes Duchenne Muscular Dystrpohy? what does it look like on a slide

Answer 34

it causes an inability to make dystrophin (a protein that binds actin to cytoskeleton) - replacement of degenerative skeletal muscle cells by fatty and fibrous connective tissue - in stains see evidence of muscle damage (nuclei in center because they are new nuclei being made)

Question 35

What kind of innervation do extrafusal fibers get

Answer 35

motor

Question 36

Do extrafusal or intrafusal fibers serve as proprioceptors

Answer 36

Intrafusal

Question 37

What are the twi types of intrafusal fibers

Answer 37

nuclear bag and nuclear chain (based on where the nuclei are) -they both receive sensory and gamma motor neurons

Question 38

Is cardiac muscle uninucleated or multinucleated? does it regenerate? does it store glycogen?

Answer 38

uninucleated no it does not regenerate yes it stores glycogen

Question 39

What are the three components of the intercalated disks

Answer 39

-fascia adherens, dsemosomes, gap junctions

Question 40

Where does the actin bind in cardiac muscle cells

Answer 40

fascia adherens

Question 41

Do cardiac muscles have triads

Answer 41

No they have diads, there is only SR on one side of the t tubule

Question 42

What is the pacemaker of the heart

Answer 42

the SA node. it has the smallest myocytes so it beats at the highest frequency

Question 43

What is the special kind of fibers in the AV Node

Answer 43

Purkinje fibers

Question 44

What is special about purkinje fibers

Answer 44

they are specialized for conduction, contain few peripheral myofibrils, they are large cells rich in glycogen and mitochondria

Question 45

What is inside atrial granules

Answer 45

atrial natriuretic peptide

Question 46

What does atrial natriuretic peptide do

Answer 46

it lowers blood pressue by increasing sodium excretion and relaxing blood vessel smooth muscle. -serves regualtory endocrine function

Question 47

Do smooth muscles go in all directions

Answer 47

yes, in a slide see them going longitudinally and cross

Question 48

Where are the nuclei for smooth muscle

Answer 48

central

Question 49

Where do you find smooth muscle

Answer 49

walls of hollow organs like th gut, blood vessels, ducts, uterus.

Question 50

Which kind of muscle has dense bodies

Answer 50

smooth

Question 51

what are dense bodies

Answer 51

netowrks of actin demisn and vimentin filaments that distribute strain during contraction