Test Chapter 9

Question 1

Three types of muscles

Answer 1

Skeletal, smooth, cardiac

Question 2

Structural differences between cardiac and skeletal muscles

Answer 2

Cardiac has circulated discs and one nucleus, skeletal has no circulated discs and multiple nucleus

Question 3

Muscle prefixes

Answer 3

Myo, Mys, sarco

Question 4

What are the two myofilaments

Answer 4

Actin and myosin

Question 5

What’s the thin filament

Answer 5

Actin

Question 6

What’s the thick myofiliments

Answer 6

Myosin

Question 7

What does it mean when a muscle becomes repolarized

Answer 7

Restoration of resting conditions (relaxing)

Question 8

What molecule blocks the active site on actin when a muscle relaxed

Answer 8

Tropomyosin

Question 9

Explain why energy is needed to repolarize a muscle

Answer 9

Getting calcium pumped back into the SR for us to relax

Question 10

What’s ATP

Answer 10

directed mechanical energy, usable energy

Question 11

All muscles share what 4 characteristics

Answer 11

Excitability, contractility, elasticity, extensibility

Question 12

What’s insertion

Answer 12

What’s moving

Question 13

What’s origin

Answer 13

What’s moving it

Question 14

Sheaths from big to small

Answer 14

Epimysium, perimysium, endomysium

Question 15

What’s endomysium

Answer 15

Fine areolar connective tissue surrounding each muscle fiber

Question 16

What’s the A band

Answer 16

Dark regions (contains the H-zone)

Question 17

What’s the H zone

Answer 17

Lighter region in middle of the dark A band

Question 18

What’s the M line

Answer 18

A line of protein that bisects H zone vertically

Question 19

What’s the I band

Answer 19

Lighter regions

Question 20

What’s the Z discs

Answer 20

Coin shaped sheet of proteins on midline of light I band

Question 21

Sarcoplasmic reticulum

Answer 21

Stores and releases calcium

Question 22

Four steps for a muscle to contract

Answer 22

Nerve stimulation, actin potential, propagated along sarcolemma, calcium must rise briefly

Question 23

Synaptic vesicles

Answer 23

Synaptic vesicles contain neurotransmitters acetylcholine (ACh)

Question 24

What is the neuromuscular junction

Answer 24

Where the neuron and muscle meet

Question 25

What diffuses into a muscle fiber during the end plate potential

Answer 25

Na (sodium)

Question 26

What blocks actin

Answer 26

Tropomyosin

Question 27

What’s a motor unit

Answer 27

The nerve muscle functional unit

Question 28

What are the 4 steps of the cross bridge cycle

Answer 28

Cross bridge formation, working power stroke, cross bridge detachment, cocking of myosin head

Question 29

What’s a isomeric contraction

Answer 29

When the muscle is keeping still, muscle tension increases but does not extend the load

Question 30

What’s a isotonic contraction

Answer 30

Muscle shortens because muscle tension exceeds load (moving)

Question 31

What’s muscle tone

Answer 31

Constant slightly contracted state of all muscles

Question 32

What causes muscle fatigue

Answer 32

Levels of potassium, Ca and P interfere with E-C coupling, lots of exercise interferes with Ca regulation, damages SR

Question 33

What helps a muscle recover

Answer 33

ATP and creatine phosphate reserved are resynthesizes

Question 34

How are muscle fiber type classified

Answer 34

Speed of contraction and metabolic pathways

Question 35

What’s oxidative fibers

Answer 35

Uses aerobic pathways (oxygen)

Question 36

What’s glycolytic fibers

Answer 36

Uses anaerobic glycolysis (no oxygen)

Question 37

What’s slow oxidative fibers job

Answer 37

Low intensity, endurance, like sitting uo

Question 38

What’s fast oxidative fibers job

Answer 38

Medium intensity (swimming, sprinting)

Question 39

What’s fast glycolytic fibers

Answer 39

Short intense powerful movements (hitting a baseball)

Question 40

What’s disuse atrophy

Answer 40

Where muscle goes down 5% a day

Question 41

What are the three types of connective tissue and what do they cover

Answer 41

Epimysium- surrounds entire muscle Perimysium- surrounds fascicles Endomysium- surrounds each muscle fiber