Ch 6 The Muscular System

Question 0

Which property of the muscle tissue can respond to stimuli?

Answer 0

Excitability

Question 1

What are the 4 important properties of the muscle tissue?

Answer 1

Excitability
Contractility
Extensibility
Elasticity

Question 2

Which property of the muscle tissue can shorten?

Answer 2

Contractility

Question 3

Which property of the muscle tissue can stretch?

Answer 3

Extensibility

Question 4

Which property of the muscle tissue can return to its original length after shortening or stretching?

Answer 4

Elasticity

Question 5

Which muscle tissue is involuntarily controlled? Found in the walls of the heart and function to pump blood.

Answer 5

Cardiac muscle

Question 6

Which muscle tissue is involuntarily controlled and is found in the walls of hollow organs and functions to move eggs, sperm, urine, food, hairs, etc ?

Answer 6

Smooth muscle

Question 7

Which muscle tissue is voluntarily controlled and it is usually attached to the bones via tendons?

Answer 7

Skeletal muscle

Question 8

A bundle of muscle cells is called a?

Answer 8

Fascicle

Question 9

A muscle cell consists of many?

Answer 9

Myofibrils

Question 10

Skeletal muscle consists of many bundles of ?

Answer 10

Muscle cells

Question 11

What is a bundle of myofilaments?

Answer 11

Myofibril

Question 12

Special long contractile proteins (actin and myosin)?

Answer 12

Myofilaments

Question 13

The striped appearance of a skeletal muscle cell is due to the regular arrangement of?

Answer 13

Myofilaments

Question 14

The short, repeating functional units of myofibrils?

Answer 14

Sarcomeres

Question 15

The myosin heads bend “uncock”, pulling the actin toward the center of the sarcomere, as the ADP and Pi are released is called?

Answer 15

The “ power stroke”

Question 16

New ATP binds to the myosin heads, causing them to release the actin is called?

Answer 16

Cross-bridge detachment

Question 17

The ATP splits into ADP and Pi re-energizing the myosin heads again, is called?

Answer 17

Myosin reactivation

Question 18

All-or-none in skeletal muscle fiber contraction means?

Answer 18

All the sarcomere in a single muscle fiber contract together maximally when the fiber is stimulated

Question 19

One motor neuron and all the muscle fibers that it innervates is?

Answer 19

The motor unit

Question 20

The stimulation of additional motor units.

When a stronger contraction of the whole muscle is needed.

Answer 20

Recruitment

Question 21

A low level of tension in skeletal muscle that is present at all times (but not enough tension to produce movement), causing healthy muscle to feel solid and firm to the touch, even at rest.

Answer 21

Muscle tone

Question 22

What are the functions of a muscle tone?

Answer 22

Stabilizes bones and joints.
Maintains body position (posture).
Allows more rapid activation of the whole muscle when needed.
Energy usage when muscles are at rest.
Looking good

Question 23

What energy source is used in the first 6 seconds of maximal intensity (sprinting)?

Answer 23

ATP stored in muscles

Question 24

What energy source is used in the first 10 seconds of maximal intensity (sprinting)?

Answer 24

ATP formed from creatine phosphate and ADP

Question 25

What energy source is used in the next 30-40 seconds of maximal intensity (sprinting)?

Answer 25

ATP generated from glycogen stored in muscles and broken down to form glucose. ``` Oxygen limited (anaerobic) Glucose oxidized to lactic acid ```

Question 26

What is made up of thousands of sarcomeres arranged end to end?

Answer 26

Myofibril

Question 27

At What muscle contraction is the ATP has attached to the myosin heads and split into ADP and Pi, releasing energy to "cock" the myosin heads into a "high-energy" position?

Answer 27

Muscle contraction 1: At Rest

Question 28

What is the muscle contraction 2?

Answer 28

Stimulus

Question 29

Muscle contraction 3?

Answer 29

Cross bridge formation

Question 30

Calcium ions permit contractions by causing the binding sites on actin to be exposed. Myosin heads then bind to actin. During?

Answer 30

Cross bridge formation

Question 31

This cycle of events is repeated over and over (as long as Ca and ATP are high enough), shortening the sarcomeres and thus the entire muscle, creating a pulling force(tension) on the attached bone....

Answer 31

The "power stroke" Cross bridge detachment Myosin reactivation

Question 32

Where does the energy source come from for submaximal intensity? Longer duration of energy

Answer 32

ATP generated aerobically in mitochondria from glucose, fats, or proteins. (Rate of oxygen delivery meets demand) (Very efficient, and no acid buildup)

Question 33

``` Muscles of abdomen and of posture. Can't produce fast and react like sprinting. Designed for endurance Contract slowly Strong, sustained contraction Steady supply of energy... ```

Answer 33

Slow twitch muscle cells

Question 34

Designed for rapid, powerful response Contract rapidly Short, powerful contraction because there is more actin and myosin Deepens more heavily on anaerobic ATP, fatigue faster Contract fast but fatigue faster

Answer 34

Fast twitch muscle cells