Physiology Length-Tension Relationship

Question 0

Total tension=

Answer 0

Active tension + passive tension

Question 1

Length tension relationship

Answer 1

Relationship between the resting length of the muscle at rest before a contraction, and the force developed upon contraction from that resting length

Question 2

Active tension is due to

Answer 2

Crossbridge cycling

Question 3

Passive tension is due to

Answer 3

Series elastic element (SEE)

Question 4

What is happening with crossbridge activity when actin and myosin have less overlap?

Answer 4

There is less crossbridge activity

Question 5

More crossbridges= (more/less) force?

Answer 5

More

Question 6

What trauma is likely to occur when actin and myosin fibers do not have much overlap when muscle contraction begins?

Answer 6

Tearing

Question 7

Stretch insufficiency

Answer 7

Less force development due to muscle being in a stretched position at beginning of contraction

Question 8

Crossbridge polarity

Answer 8

Crossbridges are only able to push in one direction: toward center of sarcomere

Question 9

Muscle shorten weakness

Answer 9

Muscle weakness due to contraction beginning when the sarcomere is shorter than normal

Question 10

Underlying causes of muscle shorten weakness

Answer 10

1 Crossbridges are pushing against each other because actin can’t really go anywhere
2 Myosin filaments are impinging which will also mechanically interfere with force development

Question 11

Load

Answer 11

Amount of force developed by the muscle

Question 12

Velocity

Answer 12

Velocity of muscle shortening

Question 13

What is it called when the velocity of shortening is 0?

Answer 13

Isometric

Question 14

What happens as load decreases?

Answer 14

Velocity of muscle shortening increases

Question 15

Why does smooth muscle have its name?

Answer 15

No striations, like skeletal muscle has

Question 16

Does smooth muscle have actin and myosin filaments?

Answer 16

Yes, just not in the arrangement seen in skeletal muscle

Question 17

Does smooth muscle have sarcoplasmic reticulum? Why?

Answer 17

No.

1. Cells are much smaller than muscle cells, so they are able to depend only on the calcium diffusing from outside
2. Smooth muscle is not required to have rapid contraction

Question 18

Does smooth muscle have troponin and tropomyosin?

Answer 18

No

Question 19

Calmodulin

Answer 19

Protein in smooth muscle cells that regulates the contraction

Question 20

Process of muscle contraction in smooth muscle

Answer 20

1. Calcium attaches to calmodulin
2. Calmodulin attaches to inactive myosin light chain kinase (MLCK) on S2 head, activating it
3. MLCK cleaves ATP
4. Crossbridge cycling occurs

Question 21

Study graphs

Answer 21

Load velocity relationship
Length tension curve
Length tension relationship

Question 22

Where does most alcohol absorption occur?

Answer 22

Small intestine