Muscle

Question 1

Myomesin and C-protein

Answer 1

Myosin binding protein that aligns thick filaments at M line

Question 2

Myosin binding protein C

Answer 2

Associated with the M line and important for the assembly and stabilization of the thick filament

Question 3

Titin

Answer 3

Spring like protein: keeps thick filament centered between 2 of the Z lines of the sarcomere and prevents excessive stretching

Question 4

Nebulin

Answer 4

Helps anchor thin filaments at Z line and regulates length of thin filaments during development

Question 5

A-actinin

Answer 5

Actin binding protein that bundles and helps stabilize thin filaments at Z line

Question 6

Desmin

Answer 6

Surrounds the sarcomere at Z lines attaching them to one another and to the sarcolemma.

Question 7

Sliding Filament Hypothesis of Huxley

Answer 7

Sarcomere shortens and becomes thicker, but the myofilaments remain the same length:
-Slide past one another
-Increase the amount of overlap
-Sliding action results from repeated “make and break” attachments between the heads of the myosin molecules and neighboring actin filaments
-A band remains constant
-I band and H band both decreases in size
-Z lines are drawn closer to the ends of the A bands

Question 8

Skeletal muscle fibres are stimulated [ ]

Answer 8

Individually

Question 9

Skeletal muscle needs [ ] and the loss of input leads to [ ]

Answer 9

nerve input stimulation, atrophy

Question 10

To Activate skeletal muscles: a certain protein is activated on [ ]

Answer 10

Troponin in thin filaments

Question 11

Histology of skeletal muscle

Answer 11

Striated

Question 12

Proteins in skeletal muscle

Answer 12

Actin & Myosin (2 tubules/sarcomere)

Question 13

Cardiac muscle protein communication through:

Answer 13

Gap junctions

Question 14

Does cardiac muscle require nerve stimulation to contract?

Answer 14

No: involuntary muscle contraction

Question 15

Histology of cardiac tissue

Answer 15

Striated

Question 16

Histology of smooth muscle

Answer 16

not striated, with cells tapered at the ends

Question 17

Cardiac Muscle Histology

Answer 17

Intercalated Discs

Question 18

Fascia adherens (adhering junctions)

Answer 18

-Major Structural Element
-Binds cardiac muscle cells at their ends
-Serves as attachment site for thin filaments in terminal sarcomeres
-Transverse component

Question 19

Maculae adherents (desmosomes)

Answer 19

-Bind individual muscle cells to each other
-Reinforce fascia adherens
-Found in both transverse & lateral component

Question 20

The delicate of layer of reticular fibers that immediately surrounds individual muscle fibers.

Answer 20

Endomysium

Question 21

Thicker connective tissue layer that surrounds a group of fibers to forma bundle or fascicle.

Answer 21

Perimysium

Question 22

Sheath of dense connective tissue that surrounds a collection of fascicles that constitutes the muscle

Answer 22

Epimysium

Question 23

A band

Answer 23

Marks the extent of the myosin filaments, stays the same length during muscle contraction.