Muscle Physiology

Question 1

Origin

Answer 1

Closest to the trunk or to more stationary bone

Question 2

Insertion

Answer 2

More distal or more mobile attachment

Question 3

Brings bones together; muscle that is connected to a flexible joint (contraction)

Answer 3

Flexor

Question 4

Moves bones away

Answer 4

Extensor

Question 5

Flexor-extensor pairs form _____ muscle groups

Answer 5

Antagonistic

Question 6

These cells differentiate into muscle for growth or repair

Answer 6

Satellite cells (stem cells)

Question 7

Muscle cells are called ____

Answer 7

muscle fibers

Question 8

Holds muscle to bone with tendon

Answer 8

Connective tissue

Question 9

Cell membrane

Answer 9

Sarcolemma

Question 10

Sarcoplasm

Answer 10

Cytoplasm

Question 11

Sarcoplasmic reticulum

Answer 11

Endoplasmic Reticulum

Question 12

Function of T-tubules

Answer 12

Bring action potentials into interior of muscle fiber

Question 13

Type of thin filament that forms a cross bridge with thick filaments

Answer 13

Actin

Question 14

Type of thick filament with the ability to create movement

Answer 14

Myosin

Question 15

2 Regulatory proteins

Answer 15

Tropomyosin and troponin

Question 16

Accessory proteins (2)

Answer 16

Titin and Nebulin

Question 17

The contractile unit of the myofibril

Answer 17

Sarcomere

Question 18

___ disks have filaments between them

Answer 18

Z disks

Question 19

___ band is made of thin filaments only (actin)

Answer 19

I band

Question 20

____ band is made of darker regions where both light and heavy filaments overlap

Answer 20

A band

Question 21

____ zone is a clear band in the middle of the A band, heavy filaments only

Answer 21

H zone

Question 22

___ line represents the proteins to which heavy filaments attach

Answer 22

M line

Question 23

What is the function of titin?

Answer 23

Provides elasticity and stabilizes myosin

Question 24

Function of Nebulin

Answer 24

Aligns actin filaments

Question 25

The force created by muscle

Answer 25

Muscle tension

Question 26

Weight or force opposing contraction

Answer 26

Load

Question 27

Creation of tension in muscle

Answer 27

Contraction

Question 28

What happens at neuromuscular junction:

Answer 28

Conversion of AcH signal from somatic motor neuron into an electrical signal in the muscle fiber

Question 29

Process in which muscle action potentials are translated into calcium signals

Answer 29

Excitation-contraction coupling (E-C)

Question 30

Sliding filament theory of contraction

Answer 30

Contraction-relaxation cycle

Question 31

Myosin cross bridge swivels and pulls actin toward M line; initiated by calcium signal

Answer 31

Power stroke

Question 32

Are myosin heads released in unison?

Answer 32

No

Question 33

Energy by ATP ___ hydrolysis is trapped by myosin and stored as energy

Answer 33

hydrolysis

Question 34

What neurotransmitter is released from the somatic motor neuron and initiated E-C coupling?

Answer 34

Acetylcholine

Question 35

ACh binds to receptors on the _____

Answer 35

sarcolemma

Question 36

Calcium binds with ___ to initiate contraction

Answer 36

Troponin

Question 37

What happens during relaxation?

Answer 37

Calcium is pumped back to sarcoplasmic reticulum via Ca-ATPase

Question 38

The short delay between muscle AP and beginning of muscle tension development

Answer 38

Latent period

Question 39

Resting muscle stores energy from ATP in bonds of ______

Answer 39

phosphocreatine

Question 40

Anaerobic glycolysis produces (2)

Answer 40

lactate and acid

Question 41

Which one releases the largest amt of energy: aerobic or anaerobic respiration?

Answer 41

Aerobic - but is also slow

Question 42

Central fatigue is due to factors that are centered in ____

Answer 42

CNS

Question 43

Peripheral fatigue due to factors from ______

Answer 43

neuromuscular junction to muscle contraction

Question 44

Short-duration maximal exertion leads to ____

Answer 44

increased levels of Pi

Question 45

What 2 things is skeletal muscle classified by?

Answer 45

Speed and fatigue resistance

Question 46

Maximal contraction

Answer 46

Tetanus

Question 47

Stronger contraction when the muscle does not relax completely between action potentials

Answer 47

Summation

Question 48

What is a motor unit composed of?

Answer 48

One motor neuron and its muscle fibers

Question 49

___ contractions move loads: ____ contractions create force without movement

Answer 49

Isotonic; isometric

Question 50

Isotonic "concentric" action is a ______ action, while "eccentric" is a ____ action

Answer 50

Shortening; lengthening

Question 51

Bones form levers while joints form ___

Answer 51

fulcrums

Question 52

Contraction pattern of PHASIC smooth muscles

Answer 52

Periodic

Question 53

Contraction pattern of TONIC smooth muscles

Answer 53

Continuous

Question 54

Can sustain contractions for extended periods without fatiguing

Answer 54

Smooth muscle

Question 55

Smooth muscle is controlled by the ____ and lacks ____

Answer 55

autonomic nervous system; sarcomeres

Question 56

In smooth muscle contraction, the calcium comes from what two places?

Answer 56

ECF and sarcoplasmic reticulum

Question 57

yIn smooth muscle contraction, Calcium binds ____

Answer 57

Calmodulin

Question 58

Calmodulin activates ____ which then phosphorylates MLC (enhancing myosin ATPase activity)

Answer 58

Myosin light chain kinase (MLCK)

Question 59

Dephosphorylation due to myosin light chain phosphorylase (MLCP) controls ___ sensitivity

Answer 59

Calcium

Question 60

Contraction caused by electrical signaling

Answer 60

Electromechanical coupling

Question 61

Contraction caused by chemical signaling

Answer 61

pharmacomechanical coupling