Muscular System

Question 1

What are the three types of muscles?

Answer 1

Cardiac, smooth, and skeletal

Question 2

Where are cardiac muscles found?

Answer 2

The heart

Question 3

What type of contraction occurs in cardiac muscles?

Answer 3

Involuntary contraction

Question 4

What controls the cardiac muscles?

Answer 4

Nerves of the autonomic nervous system

Question 5

Are cardiac muscles striated or not?

Answer 5

Striated

Question 6

What is the cardiac muscle, meaning that it is self-excitable stimulating contraction without a required electrical impulse coming from the central nervous system?

Answer 6

Myogenic

Question 7

Where are smooth muscles found?

Answer 7

The lining of many organs and in hollow parts of the body

Question 8

What are some organs that smooth muscles are found in?

Answer 8

Stomach, esophagus, uterus, and walls of blood vessels

Question 9

What type of contraction occurs in smooth muscles?

Answer 9

Involuntary contraction

Question 10

Are smooth muscles striated or not?

Answer 10

Non-Striated

Question 11

What are skeletal muscles?

Answer 11

Muscles that are attached to bone

Question 12

What type of contraction occurs in skeletal muscles?

Answer 12

Voluntary contraction

Question 13

What controls the voluntary contraction of skeletal muscles?

Answer 13

The somatic nervous system

Question 14

What attaches skeletal muscles to bones?

Answer 14

Tendons

Question 15

What is 80% of all energy used in muscle contraction lost as?

Answer 15

Heat

Question 16

Are skeletal muscles striated or not?

Answer 16

Striated

Question 17

What happens to muscles when they contract?

Answer 17

Shorten

Question 18

What happens to muscles when they relax?

Answer 18

Lengthen

Question 19

What sends excitatory or inhibitory nerve impulses to the skeletal muscles, causing them to either contract or relax?

Answer 19

The central nervous system

Question 20

Skeletal muscles are composed of many bundles of cells called what?

Answer 20

Fibres

Question 21

What are the fibres enclosed within?

Answer 21

A membrane called sarcolemma

Question 22

What is within the muscle fibre that are bundled together?

Answer 22

Myofilaments

Question 23

What are the two main types of myofilament?

Answer 23

Thin myofilament and thick myofilament

Question 24

What is thin myofilament composed of?

Answer 24

Actin (light bands)

Question 25

What is thick myofilament composed of?

Answer 25

Composed of myosin (dark bands)

Question 26

These two types of myofilaments overlap to produce what type of appearance?

Answer 26

Striated

Question 27

What is released from a nerve to the muscles, signalling contraction?

Answer 27

A neurotransmitter

Question 28

What does the muscles cell’s endoplasmic reticulum release near the actin?

Answer 28

Calcium (Ca2+ ions)

Question 29

What do the calcium ions attach to?

Answer 29

The actin

Question 30

What is allowed to attach to the actin after the the calcium ions?

Answer 30

Myosin

Question 31

What is formed when myosin attaches to actin?

Answer 31

Actin-myosin cross-bridge

Question 32

The actin and myosin continually attach and de-attach over and over, with each re-attachment of the actin what happens to the muscles?

Answer 32

The muscle fibres get pulled closer together carrying on until full contraction of the muscles occurs

Question 33

Calcium ions also start the break down of ATP, which allows the actin to do what?

Answer 33

De-attach each time from the myosin and also provides energy for the reaction to occur (when ATP is broken down energy is given off)

Question 34

What occurs if no ATP is present?

Answer 34

Rigor mortis

Question 35

When does rigor mortis occur?

Answer 35

After death; myosin and actin stay attached leaving the muscles fully contracted

Question 36

What is muscle soreness, fatigue, burning, tightness, etc. attributed to?

Answer 36

Due to the fact that very little ATP can be stored in the muscle tissue; as a result Aerobic CR constantly provides/replenishes most of the energy in the form of ATP

Question 37

As soon as the ATP is used up and converted back to ADP, what compound ensures all ADP is converted back to ATP?

Answer 37

Creatine phosphate

Question 38

What is a supplement used by athletes to increase muscle strength?

Answer 38

Creatine

Question 39

When will fatigue occur?

Answer 39

If ATP demands can not be met

Question 40

What happens that causes fatigue?

Answer 40

Lactic acid begins to build up, muscles tighten up, and fatigue takes over

Question 41

What is atrophy?

Answer 41

The reduction in size, tone and power of a muscle due to decreased use and stimulation; can eventually lead to permanent loss of muscle function

Question 42

What is hypertrophy?

Answer 42

An exercise-induced increase in muscle mass resulting from an increase in the size of individual muscle fibres

Question 43

Does atrophy and hypertrophy result in a change in the number if muscle fibres?

Answer 43

No

Question 44

What is a muscle twitch?

Answer 44

A muscular contraction that lasts for a fraction of a second

Question 45

What is the latent stage?

Answer 45

Time between stimulus and initiation of the contraction; 1

Question 46

What is the contraction stage?

Answer 46

Time it takes for the muscle fibres to shorten; Ca2+; 2

Question 47

What is the relaxation stage?

Answer 47

Time it takes for the muscle to return to its regular length; ATP; 3

Question 48

What are slow-twitch fibres?

Answer 48

Fibres that contract slowly and resist fatigue because they are surrounded by more blood vessels and have more mitochondria; aerobic

Question 49

What are fast twitch-fibres?

Answer 49

Fibres that contract quickly to give more power, but depend upon aerobic energy production. They are rich in glycogen, and have fewer mitochondria and blood vessels surrounding them; anaerobic

Question 50

What type of training impacts slow-twitch fibres?

Answer 50

Endurance training; no impact on size

Question 51

What type of training impacts fast-twitch fibres?

Answer 51

Strength/resistance training; thickens

Question 52

What is tetanus?

Answer 52

A state of constant muscle contraction

Question 53

What are muscle spasms?

Answer 53

Involuntary contraction of a muscle, often caused by a pinched nerve