Chapter 12

Question 1

What are the three types of muscles?

Answer 1

Skeletal, cardiac, and smooth

Question 2

What is a group of muscle fibres bundled together in connective tissues called?

Answer 2

Muscle fascicle

Question 3

What does a multinucleate muscle fibre contian?

Answer 3

Myofibrils

Question 4

What is a sarcomere?

Answer 4

The basic contractile unit of muscle fiber, the drawing in class

Question 5

What are Z-discs?

Answer 5

Attachment for filaments

Question 6

What is an m-line?

Answer 6

Connection between adjacent think filaments

Question 7

What is an a-band?

Answer 7

Gap between the filaments (no actin)

Question 8

What is the difference between actin and myosin?

Answer 8

Actin is thinner

Question 9

Does myosin have cross bridges?

Answer 9

Yes, with two heads

Question 10

What does tropomyosin do?

Answer 10

Wraps around actin filaments and in resting skeletal muscle prevents actin and myosin from generating force

Question 11

What does troponin do?

Answer 11

Controls binding between tropomyosin and actin and myosin

Question 12

How far does titan span and what’s its function?

Answer 12

Stabilizes the myosin, and spans from z disk to m line
Fun fact - longest protein in the human body

Question 13

What do the H-zone and I-band do when filaments overlap?

Answer 13

Narrow

Question 14

When contraction happens is calcium released or absorbed?

Answer 14

Released

Question 15

What is the power stroke?

Question 16

How does ATP provide energy?

Answer 16

1. ATP binds to myosin
2. ATPase splits atp
3. Power stroke
4. Myosin releases ADP

Question 17

What are the three roles of ATP

Answer 17

Energize, unbind, and Active transport of Ca2+

Question 18

What is a motor unit?

Answer 18

A group of muscle fibers that function together and the single somatic motor neuron that controls them

Question 19

Recruitment and asynchronous recruitment

Answer 19

System increases contraction force, and A-sync helps avoid fatigue

Question 20

When a muscle single twitches it is different from summation why?

Answer 20

Because a single twitch a muscle relaxes completely, whereas summation means no relaxation fully

Question 21

What does summation leading to unfused tetanus mean?

Answer 21

Stimuli are far enough part to allow muscle to relax momentarily

Question 22

What does summation leading to complete tetanus mean?

Answer 22

Steady tension, and tension decreases rapidly

Question 23

What type of muscle is the fastest to contract and relax?

Answer 23

Skeletal