Muscles

Question 1

True or False:

Muscles don’t have to cross a joint.

Answer 1

False - Muscles must cross at least one joint

Question 2

What’s another name for muscle fibers?

Answer 2

Striations

Question 3

Where do striations always point?

Answer 3

To their attachment

Question 4

A muscle that moves ventral to ventral - decreasing the angle

Answer 4

Flexor

Question 5

A muscle that moves dorsal to dorsal - increasing the angle

Answer 5

Extensor

Question 6

Smallest Component of Muscle Tissue

Answer 6

Filament

Question 7

Filaments clustered together

Answer 7

Myofibrils

Question 8

Myofibrils clustered together

Answer 8

Muscle Fibers

Question 9

A cluster of muscle fibers

Answer 9

Fascicle

Question 10

Fascicles clustered together

Answer 10

Muscle

Question 11

How many attachments do muscles have to have?

Answer 11

At least 2

Question 12

Epimysium

Answer 12

layer of connective tissue around whole tissue

Question 13

Perimysium

Answer 13

surrounds individual fascicles w/ in each muscle

Question 14

Endomysium

Answer 14

covering each muscle fiber

Question 15

Sarcomere

Answer 15

the “functional unit” of the muscle cell/fiber where contraction occurs

Question 16

Name the #1 part of the Sarcomere

Answer 16

Z lines (thin actin filaments are anchored here)

Question 17

Name the #2 part of the Sarcomere

Answer 17

A band (thick myosin filaments)

Question 18

Name the #3 part of the Sarcomere

Answer 18

I band (thin actin filaments)

Question 19

Name the #4 part of the Sarcomere

Answer 19

H zone (space between actin filaments)

Question 20

How long is a sarcomere?

Answer 20

Z line to Z line

Question 21

What filament has a long tail, double heads, and a cross bridge?

Answer 21

Myosin

Question 22

What is the purpose of the cross bridge?

Answer 22

Grabs the actin and pulls

Question 23

What filament is just a strand of beads?

Answer 23

Actin

Question 24

What is the name for the beads of actin?

Answer 24

G-actin (G=globular)

Question 25

What is the name of the strands of actin?

Answer 25

F-actin (F=fibrous)

Question 26

How are the F-actin strands organized?

Answer 26

Twisted around each other like a double helix

Question 27

What protein runs along the actin to give it strength?

Answer 27

Tropomyosin

Question 28

What protein blocks binding sites where cross bridges can grab actin?

Answer 28

Tropomyosin

Question 29

What element binds to the troponin complex to move Tropomyosin?

Answer 29

Calcium

Question 30

What is the sarcomplasmic reticulum's job?

Answer 30

to pump and transport calcium in and out of the cell

Question 31

How many sodium ions are pumped out of the cell for how many potassium ions?

Answer 31

3 Na+ out and 2 K+ in

Question 32

What are the 3 parts of the muscle twitch?

Answer 32

1. Latent Period 2. Period of Contraction 3. Period of Relaxation

Question 33

What happens in the latent period?

Answer 33

Motor neuron stimulates SR - SR releases Ca+ - Ca+ binds to troponin complex - Opening binding sites

Question 34

What happens during the contraction period?

Answer 34

cross bridges attach and power stroke follows

Question 35

What happens during the relaxation period?

Answer 35

Stimulus ends- Ca+ is pumped back into the SR - binding sites close

Question 36

What causes cramps or tetanus?

Answer 36

when ATP runs out leaving myosin left in powerstroke

Question 37

What causes more powerful contractions?

Answer 37

When repetitive contractions occur leaving Ca+ in the matrix

Question 38

What is a treppe?

Answer 38

A graph showing repetitive contractions that get stronger and stronger until they cause cramps - displayed in a stair shape

Question 39

What is isometric exercise?

Answer 39

muscle is contracting but can not move the load - good for rehabilitation

Question 40

What is isotonic exercise?

Answer 40

muscle contracts and can move the load - most common exercise

Question 41

What is concentric exercise?

Answer 41

muscle is shortened

Question 42

What is eccentric exercise?

Answer 42

when the muscle is lengthened in a controlled manner

Question 43

Summary of Contraction

Answer 43

1. Motor neuron stimulates SR to release Ca+ 2. Ca + binds to TnC to open binding sites 3. Cross bridge attachment 4. Power Stroke 5. Cocking (as long as ATP is available) 6. Neural stimulus ends - Ca+ is pumped out - binding sites close - relaxation

Question 44

What causes lactic acid build up?

Answer 44

When oxygen is low in the muscle

Question 45

What can cause muscle cramping?

Answer 45

Dehydration, electrolyte imbalances, lack of ATP