Muscles

Question 1

What does the Epimysium surround?

Answer 1

The entire muscle

Question 2

What does the Perimysium surround?

Answer 2

The bundles of muscle fibers

Question 3

What does the Endomysium surround?

Answer 3

Each individual muscle fiber

Question 4

What part of contraction do Sarcomeres perform?

Answer 4

Shortening in contraction

Question 5

Where is the sarcomere located?

Answer 5

Between Z discs in a myofibril

Question 6

What is a Z disc?

Answer 6

It separates sarcomeres and defines the boundaries of each

Question 7

What does a thin filament consist of?

Answer 7

Two strands of actin twisted into a helix, and the two regulator proteins troponin and tropomyosin

Question 8

What is the function of troponin?

Answer 8

It promotes muscle contraction by binding Ca+ which moves tropomyosin away

Question 9

What is the purpose of Tropomyosin?

Answer 9

It blocks muscle contraction

Question 10

What is Dystrophin?

Answer 10

It links the outermost thin myofilaments to sarcolemma, which strengthens muscle fibers

Question 11

What happens to myofilaments during contraction?

Answer 11

Thin filaments slide past thick filaments causing actin and myosin to overlap more

Question 12

What is a cross bridge?

Answer 12

When myosin heads bind to actin which causes sliding (contraction) process to begin

Question 13

What are the four steps of muscle fiber contraction?

Answer 13

1. Nerve stimulation
2. Action potential (electrical current generated in sarcolemma)
3. Action potential is propagated along sarcolemma
4. Intracellular Ca2+ levels rise

Question 14

What is spastic paralysis?

Answer 14

A state of continual contraction of the muscles because pesticides bind to acetylcholinesterase and prevent the degrading of AcH

Question 15

What is flaccid paralysis

Answer 15

A state in which the muscles are limp and cannot contract

Question 16

What is curare

Answer 16

A plant poison that competes with ACh for receptor sites, but do not stimulate the muscles

Question 17

What is direct phosphorylation?

Answer 17

Uses the ATP already in muscles. A big burst of ATP to jumpstart activity. About 15 seconds of energy provided.

Question 18

What is an anaerobic pathway?

Answer 18

The anaerobic fermentation of glycolysis into pyruvate.

Question 19

What is an aerobic pathway

Answer 19

When oxygen is used to release energy from carbohydrates and lipids

Question 20

Slow-oxidative fibers

Answer 20

Low intensity, endurance activities. Ex: Maintaining posture

Question 21

Fast-oxidative fibers

Answer 21

Medium intensity. Ex: Sprinting or walking

Question 22

Fast glycolytic fibers

Answer 22

Short term, intense or powerful movements. Ex: Hitting a baseball

Question 23

What are the characteristics of cardiac muscles?

Answer 23

-Located in walls of the heart
-Contracts without need for nerve stimulation, much like a pacemaker with rhythmically set off contractions
-Uses aerobic respiration
-Highly fatigue resistant

Question 24

What are the characteristics of smooth muscle?

Answer 24

-Found in walls of most hollow organs except heart
-Spindle shaped fibers. Thin and short.
-Only contains endomysium

Question 25

What controls the contraction of smooth muscle?

Answer 25

Nerves, hormones or local chemical changes

Question 26

What chemical factors can be included in the contraction of smooth muscle

Answer 26

Hormones, high CO2, pH, low oxygen

Question 27

What is one special feature of smooth muscle contraction?

Answer 27

The response to stretch. It responds briefly and then adapts to new length. Can contract on demand. Lets stomach and bladder temporarily store contents.