Muscle

Question 1

Myo and sarco mean what?

Answer 1

muscle

Question 2

What are the tree types of muscle groups?

Answer 2

Striated: Skeletal= voluntary
Cardiac= involuntary
Non-striated: Smooth= invountary

Question 3

Muscles are bunches of _______, which are bunches of muscle fibers.

Answer 3

Fascicles

Question 4

Sarcoplasm is muscle ________, has a lot of mitochondria.

Answer 4

cytoplasm

Question 5

Each muscle fiber is a long thin cell with multiple _______ and many ______.

Answer 5

nuclei

myofibrils

Question 6

Each myofibril consists of many ________ wurrounded by the sarcoplamic reticulum and t-tubule system.

Answer 6

sarcomeres

Question 7

_________ proteins are thick and thin filaments.

Answer 7

Contractile

Question 8

Thick filaments are _______. Intertwind heavy chains with globular heads.

Answer 8

myosin

Question 9

What are 2 strands of F actin in a helix?

Answer 9

Actin

Question 10

F actin is made up of many _____ molecules and has _____ binding sites.

Answer 10

G actin

myosin

Question 11

What is a double stranded helix around actin. Covers the myosin binding site.

Answer 11

Tropomyosin

Question 12

What is bound to tropomyosin?

Answer 12

Troponin complex

Question 13

This connects sarcomere to sarcolemma and ECM.

Answer 13

Dystrophin, mutations cause the most common form of Muscular dystrophy

Question 14

This holds thin filaments apart from one another?

Answer 14

Nebulin

Question 15

This holds thin filaments to z-disc.

Answer 15

Alpha- actinin

Question 16

This is a spring that runs through heavy chain and connects it to the z-disc.

Answer 16

Titan

Question 17

This bisects the sarcomere and bare zone.

Answer 17

M-line

Question 18

__________ is the functional unit of muscle.

Answer 18

Sarcomere

Question 19

Smallest part of muscle that can still perform its function.

Answer 19

Sarcomere contraction

Question 20

A band thick or thin filaments?

Answer 20

Both. Dark striation

Question 21

I band thick or thin filaments?

Answer 21

Only thin, light striation

Question 22

Holes of the sarcolemma membrane allows crosses of myocyte between myofibrils.

Answer 22

T-tubules

Question 23

Smooth ER that has been massively modified to function as Calcium store. How does it run?

Answer 23

Sarcoplasmic Reticulum (SR)
Parallel along myobfibrils

Question 24

More of a ligand gated calcium release channel.

Answer 24

Ryanodine receptor

Question 25

True/False: In skeletal muscle the DHPR, RyR and SR are all far apart along the T-tubule system.

Answer 25

False, very close together, | so close that changes in DHPR shape can affect RyR shape

Question 26

AP begun in the NMJ depolarizes down sarcolemmal membrane and down T-tubule system.

Answer 26

Excitation contraction coupling

Question 27

IMPORTANT: RyR allows Ca++ from ___ into _______.

Answer 27

Sarcoplasmic Reticulum | Cytosol

Question 28

____________ is how myosin binds to actin and then pulls Z discs together toward the M-line.

Answer 28

Cross bridge cycling

Question 29

At rest ________ cover myosin binding site on actin.

Answer 29

Tropomyosin

Question 30

Myosin has bound ___ so it is cocked and has high affinity for actin, but it can't because Tropomysoin is in the way.

Answer 30

ATP

Question 31

Calcium binds TnC, this does what?

Answer 31

Moves tropomyosin off actin's myosin binding pocket, and is excited, then it can bind to actin. Goes through power stroke, pulling on actin, and releases ADP. ATP binds to myosin, releases ADP, hydrolyzes ATP and is recocked and cycle repeats. (as long as there is ATP and Ca++ available)

Question 32

Motor neurons synapse on varying number of _________.

Answer 32

myocytes | -neuron and all synapsed myocytes make a motor unit

Question 33

True/False: Fewer cells per nerve lead to fine movements.

Answer 33

True

Question 34

Each time a motor neuron fires, you get a single __________.

Answer 34

muscle twitch

Question 35

Recruit more motor units is what?

Answer 35

Spatial summation

Question 36

Stimulate the same unit numerous times.

Answer 36

Temporal summation