Phrd 307: Anatomy And Physiology [Chpt 10]

Front 1

What are 3 types of Muscle Tissue?

Back 1

Skeletal
Cardiac
Smooth

Front 2

Define SKELETAL MUSCLES?

Back 2

Are organs composed primarily of skeletal muscle tissue, but they also contain connective tissue, nerve, and blood vessels.

Front 3

Each cell in skeletal muscle tissue is a single ____ _____.

Back 3

muscle fiber

Front 4

True or False: All skeletal muscle are directly attached to the bones of the skeleton?

Back 4

False some are directly while other are indirectly attached to the bones of the skeleton.

Front 5

Skeletal muscles perform 6 functions, what are they?

Back 5

Produce skeletal movements, where muscle contraction pull on tendons and move the bones of the skeleton.

Maintain posture and body position.

Support soft tissues, support the weight of visceral organs and shield internal tissue from injury

Guard entrances and exit: provide voluntary control over swallowing, urination

Maintain body temperature: whenever energy is used in the body, some of it is converted to heat.

Store Nutrients Reserves : inadequate protein can result in the breakdown of skeletal muscles.

Front 6

There are 3 types of connective tissue for each muscle, what are these connective tissue called?

Back 6

Epimysium
Perimysium
Endomysium

Front 7

What are the differences between Epimysium, Perimysium, and Endomysium?

Back 7

Epimysium is a dense layer of collagen fibers and separates the muscle from the surround tissue and organs.

Perimysium divide the skeletal muscle into a series of compartments each containing a bundle of muscle fibers call fascicle.

Endomysium surrounds the individual skeletal muscle cells or muscle fibers and loosely interconnects adjacent muscle fibers.

Front 8

Between the three layers of connective tissues, which one is the most dense (Epimysium, Perimysium, and Endomysium)?

Back 8

Epimysium

Front 9

Of the 3 connective tissue (Epimysium, Perimysium, and Endomysium), which one possesses collagen and elastic fibers, blood vessels, and nerves?

Back 9

Perimysium

Front 10

Define FASCICLE?

Back 10

Bundles of Muscles

Front 11

Between the three layers of connective tissues, which one is the most delicate (Epimysium, Perimysium, and Endomysium)?

Back 11

Endomysium

Front 12

Between the three layers of connective tissues, which one is found within a fascicle (Epimysium, Perimysium, and Endomysium)?

Back 12

Endomysium

Front 13

Between the three layers of connective tissues, which one maintain blood flow and innervate the muscle fibers within the fascicles (Epimysium, Perimysium, and Endomysium)?

Back 13

Perimysium

Front 14

What does the endomysium connective tissue layer contain?

Back 14

Capillary networks that supply blood to the muscle fibers

Myosatellite cells

Nerve fibers that control the muscle

Front 15

What are MYOSATELITE CELLS?

Back 15

Embryonic stem cells that function in the repair of damaged muscle tissue

Front 16

Which two connective tissue layers will form interwoven and blend into another through the use of the collagen fibers?

Back 16

Perimysium
Endomysium

Front 17

At each end of the muscle, the collagen fibers of the epimysium, perimysium, and endomysium come together to form either a bundle or a broad sheet, what are the terms?

Back 17

Tendon: bundle

Aponeurosis: Broad sheet

Front 18

Between the three layers of connective tissues, which two contain the blood vessels and nerves that supply the muscle fibers (Epimysium, Perimysium, and Endomysium)?

Back 18

Endomysium
Perimysium

Front 19

Skeletal muscles contract only under stimulation from the ____ ____ ____?

Back 19

Central Nervous System

Front 20

Skeletal muscles are involuntary or voluntary?

Back 20

Voluntary muscles because we have control over their contractions

Front 21

What are some distinctive features of skeletal muscles?

Back 21

Large in size
Multinucleate

Front 22

Define SARCOLEMMA?

Back 22

Plasma membrane of a muscle fiber that surrounds the scarcoplasm.

Front 23

Define SCARCOPLASM?

Back 23

Cytoplasm of the muscle fiber

Front 24

Typically what the first step before muscle fibers contract?

Back 24

Change in the transmembrane potential

Front 25

In order for the skeletal muscle fiber to contract simultaneously, the signal to contract must be distributed quickly throughout the interior of the cell and this signal is conducted through what?

Back 25

Transverse tubules or T tubules

Front 26

What are Transverse Tubules?

Back 26

Narrow tubes that are continuous with the sarcolemma and extend into the sarcoplasm a the right angles to the cell surface

Front 27

What purpose does Transverse Tubules served?

Back 27

Filled with extracellular fluid, T tubules form passageways through the muscle fibers

Front 28

Impulses that triggers for muscle fiber contraction is called what?

Back 28

Action Potential

Front 29

Myofibrils are encircled by what structure?

Back 29

Transverse Tubules

Front 30

Myofibrils consist of bundles of protein filaments, called what?

Back 30

Myofilaments

Front 31

What are two types of Myofilaments?

Back 31

Thin filaments: are composed primarily of actins

Thick filaments: are composed primarily of myosin

Front 32

Thick and thin myofilaments are organized into repeating function unit called what?

Back 32

Sarcomeres

Front 33

The structure of SARCOMERES contains what?

Back 33

Thick filaments

Thin filaments

Proteins that stabilized the position of the thick and thin filaments

Proteins that regulate the interaction between thick and thin filaments

Front 34

Thick filaments and thin filaments are associated to which bands I or A?

Back 34

I bands - light bands - thin filam

A bands - dark bands - thick fila

Front 35

Which bands includes all 3 of the following subdivisions, M line, H band, and zone of overlap?

Back 35

A band, which is the dark band, which is the thick filaments

Front 36

Purpose and location of M line?

Back 36

Located in the central portion of the each thick filaments

Stabilized the position of the thick filaments

Front 37

Purpose and location of H bands?

Back 37

Located on either side of the M line.

Contain thick filaments, but no thin filaments

Front 38

Purpose of the zone of overlap?

Back 38

Situated between the thick filaments

Front 39

Which bands composed of Z lines and Titin?

Back 39

I bands

Front 40

What purpose does Z lines serve?

Back 40

Mark the boundary between adjacent sarcomeres.

Front 41

What purpose does TITIN serves?

Back 41

Keep the thick and thin filaments in proper alignment and aids in restoring resting sarcomere length and also helps the muscle fiber resist extreme stretching that would otherwise disrupt the contraction mechanism

Front 42

Where would calcium ion generally wants to release?

Back 42

Calcium ions released by the SR enter the regions where thick and thin filaments can interact

Front 43

Thin filaments contain 4 different proteins, what are they?

Back 43

Actin
Nebulin
Tropomysin
Troponin

Front 44

Describe the structure of thin filaments

Back 44

Filamentous actin is a twised strand compose of two rows of G actin with a long strand of Nebulin in between. Each G actin molecules contain an active site that can be bind. Strands of tropomyosin cover the active sites on G actin and prevent actin myosin interaction, in which will later bind to only one molecule of troponin. The troponin-tropomysin complex must change and exposed the F actin before a contraction can take place.

Front 45

What happens when skeletal muscle fibers contracts

Back 45

H bands and I bands get smaller

Zone of overlap get larger

Z lines move closer together

Width of A band remain constant

Front 46

Skeletal muscle fibers contract under the stimulation of what system?

Back 46

Nervous system

Front 47

Communication between the nervous system and a skeletal muscle fiber occurs at a specialized intercellular connection known as what?

Back 47

Neuromuscular junction / myoneural junction

Front 48

The cytoplasm of the synaptic terminal contains mitochondria and vesicle filled with molecules of what?

Back 48

Acetylcholine

Front 49

What purpose does ACETYLCHOLINE served in the contraction of muscle fibers?

Back 49

Release of ACh from the synaptic terminal can alter the permeability of the sarcolemma and trigger the contraction of muscle fibers

Front 50

The synaptic cleft is a narrow space that separates the synaptic terminal of the neuron from the opposing sarcolemmal surface, what is the surface call?

Back 50

Motor end plate is a surface that contain membrane receptors tat bind ACh

Front 51

What enzyme break down acetylcholine?

Back 51

Acetylcholinesterase

Front 52

What signal stimulates the release of ACh?

Back 52

Arrival of an electrical impulse or action potential at the synaptic terminal

Front 53

Define ACTION POTENTIAL?

Back 53

An action potential is a sudden change in the transmembrane potential that travels along the length of the axon.

Front 54

What happens when action potential reach the synaptic cleft?

Back 54

Permeability changes in the membrane and trigger the exocytosis of ACh into the synaptic thru vesicles

Front 55

Once ACh diffuse through the synaptic cleft, where will it head to?

Back 55

Motor end plate, because there are receptors

Front 56

Once ACh binds to the receptor of the end motor plate, what will happen?

Back 56

ACh bindings changes he permeability of the motor end plate and allow a rush of Sodium ion to come through

Front 57

How would you stop the influx of Sodium ions?

Back 57

Acetylcholinesterase remove ACh from the cleft and eventually ACh will diffuse off the receptors and into the cleft

Front 58

The arrival of an action potential at the synaptic terminal thus leads to the appearance of an action potential in what?

Back 58

Sarcolemma

Front 59

What is EXCITATION-CONTRACTION COUPLING?

Back 59

This coupling occurs at the triad, in which an action potential triggers the release of calcium from the cisterne of the sarcoplasmic recticulum.

Front 60

Why is the effect of calcium release on the sarcomere almost instantaneous for contraction?

Back 60

Because the terminal cisternae are situated at the zone of overlap, where thick and thin filaments interact

Front 61

What blocks the active sites from being inaccessible?

Back 61

Tropinin

Front 62

How can the active sites become accessible?

Back 62

Calcium

Front 63

When troponin is only bind to actin and tropmyosin, and the binding site of calcium is empty, what is happening?

Back 63

Nothing, the muscle fiber is at rest

Front 64

At what point can contaction cycle begin?

Back 64

Binding of calcium, changes the shape of troponin molecule and weaken the bond between tropinin and actin, rolling the tropomysin strand away from the active sites

Front 65

During the contraction cycle, the myosin head function as _____ and at the start of the contraction cycle, each myosin head has already split a mole of _____.

Back 65

ATPase, an enzyme that can break down ATP

ATP

Front 66

What is the breakdown product of ATP?

Back 66

ADP and phosphate

Front 67

Once the active sites are exposed, the energized myosin head binds to the active site forming what?

Back 67

Cross bridges

Front 68

True or False: Since cocking the myosin head requires energy, the breakdown of ATP. That both the ADP and phosphate are no longer bound to the mysoin head?

Back 68

False. both the ADP and phosphate are still bound to the myosin head

Front 69

The duration of contraction depends on what?

Back 69

The duration of stimulation at the neuromuscular junction

The presence of free calcium ions in the scaroplasm

Availability of ATP

Front 70

What is the primary energy source of muscle contraction?

Back 70

ATP

Front 71

What is the primary function of ATP?

Back 71

Transfer of energy from one location to another rather than the long term storage of energy

Front 72

At rest, a skeletal muscle fiber produces more ATP than it needs and then ATP transfers energy to what?

Back 72

Creatine

Front 73

What is creatine?

Back 73

Creatine is a small molecule that muscle cells assemble from fragments of amino acids

Front 74

By having ATP transferring energy to creatine, it created another high energy compound called?

Back 74

Creatine phosphate or phosphorylcreatine (CP)

Front 75

In previous chapters, we learned that during contraction, myosin heads break down ATP and produces ADP + phosphate group. How can ATP be restore again?

Back 75

The energy store in creatine phosphate is then used to recharged ADP converting it back to ATP.

Front 76

What is the enzyme utilize in the reaction of ADP and creatine phosphate to re-create ATP?

Back 76

Creatine Phosphokinase (CPK)

Front 77

What are 2 ways cells in the body generate ATP?

Back 77

Aerobic metabolism in the mitochondria

Glycolysis in the cytoplasm

Front 78

For each molecule o pyruvic acid fed into the Kreb cycle, the cell gains how many ATP molecules?

Back 78

17

Front 79

Resting skeletal muscle fibers rely almost exclusively on the aerobic metabolism of ___ ____ to generate ATP?

Back 79

Fatty acids

Front 80

What source allows cell to continue to contract for an extended period, even without any external source of nutrients?

Back 80

Skeletal muscle fiber contain large amounts of glycogen that shift from fatty acid metabolism to glucose metabolism

Front 81

What is GLYCOLYSIS?

Back 81

Glycolysis is the breakdown of glucose to pyruvic acid in the cytoplasm of a cell.

Front 82

Is Glycolysis an aerobic or anerobic process?

Back 82

Anerobic

Front 83

What is the net gain of glycolysis?

Back 83

2 ATP molecules and 2 pyruvic acid molecules from each glucose molecules

Front 84

When comparing GLYCOLYSIS and AEROBIC METABOLISM (KREB CYCLE), which cycle is more sufficient in producing ATP?

Back 84

Aerobic metabolism (kreb cycle) because this cycle can generate a total of 17 ATP using one molecule of pyruvic acid, whereas Glycolysis which utilizes 2 pyruvic acid only to generate 2 ATP

Front 85

If AEROBIC METABOLISM is so much more efficient than Glycolysis, why is it use to produce ATP?

Back 85

Glycolysis is important only because it provides the substrate for aerobic metabolism and it can proceed in the absence of oxygen, glycolysis becomes an important source of energy when energy demands are high and the availability of oxygen is limited

Front 86

True or False: During period of recovery and oxygen is abundance, lactic acid can be recycled by converting it back to pyruvic acid?

Back 86

True

Front 87

Why is lactic acid so dangerous to the body?

Back 87

Lactic acid can lower the pH of the blood and tissue

Front 88

Define CORI CYCLE?

Back 88

The shuffling of lactic acid to the liver and glucose back to muscle cells

Front 89

Muscle performance can be considered in terms of two factors, what are they?

Back 89

Force
Endurance

Front 90

Define FORCE?

Back 90

Force is the maximum amount of tension produced by a particular muscle or group of muscle

Front 91

Define ENDURANCE?

Back 91

Endurance is the amount of time during which the individual can perform a particular activity

Front 92

Identify the 3 types of SKELETAL MUSCLE FIBERS?

Back 92

Fast fibers
Slow fibers
Intermediate fibers

Front 93

Of the three types of skeletal muscle fibers, which one is more predominate in the body?

Back 93

Fast fibers

Front 94

What is MYOGLOBIN?

Back 94

Myoglobin is a globular protein that is structurally related to hemoglobin, in which they both reversibly bind to oxygen molecules

Front 95

Myoglobin is most found in which skeletal muscle fibers?

Back 95

Slow fibers

Front 96

What purpose does fast and slow skeletal muscle fibers serve?

Back 96

Fast Fibers: rapid activities

Slow Fibers: continue contracting for extended periods

Front 97

What is an advantage of Fast fiber but is also consider a disadvantage of Slow fibers?

Back 97

Fast Fibers: faster peak tension; large glycogen reserves

Slow Fibers: slower peak tension; small glycogen reserves

Front 98

What are the advantages of Slow fiber over Fast fibers

Back 98

Fast Fibers:

Slow Fibers: surrounded by more capillaries thus higher oxygen supply to support mitochondrial activity; Contain myoglobin resulting in substantial oxygen reserves that be mobilize during contraction

Front 99

Fast fibers using which more anerobic or aerobic process?

Back 99

Anerobic

Front 100

What is the difference between HYPERTROPHY and ATROPHY?

Back 100

Hypertrophy is an enlargment of the stimulated muscle.

Atrophy: reduction in muscle size, tone, and power

Front 101

What are ANAEROBIC ENDURANCE is supported by what kind of energy activity?

Back 101

Glycolysis

Front 102

What are AEROBIC ENDURANCE is supported by what kind of energy activity?

Back 102

Mitochondria activity

Front 103

Which two muscles are striated?

Back 103

Skeletal
Cardiac

Front 104

Between CARDIAC AND SKELETAL muscle fibers, which one is smaller in diameter?

Back 104

Cardiac

Front 105

Between CARDIAC AND SKELETAL muscle fibers, which one has a central nuclei?

Back 105

Cardiac

Front 106

Between CARDIAC AND SKELETAL muscle fibers, which one contains TRIADS?

Back 106

Skeletal

Front 107

Between CARDIAC AND SKELETAL muscle fibers, which one lack terminal cisternae?

Back 107

Cardiac

Front 108

Between CARDIAC AND SKELETAL muscle fibers, which one is completely dependent on aerobic metabolism?

Back 108

Cardiac

Front 109

What is an intercalated disc and what happens at that connective site?

Back 109

Plasma membrane of two cardiac muscle are intertwined and bound together by gap junctions and demosomes. These connection help stabilize the relative position and maintain the 3D structures of the tissue

Front 110

What purpose does the GAP JUNCTION served?

Back 110

Allow ions and small molecules to move from one cell to another and creates a direct electrical connection between the two muscle cells

Front 111

What are 4 functions of CARDIAC Muscles?

Back 111

Cardiac muscle tissue contracts without neural stimulation (automaticity).

Innervation by the nervous system can alter the pace established by the pacemaker cells and adjust the amount of tension produced during a contraction

Cardiac muscle cell contraction last roughly 10 times longer and have longer refractory periods and do not fatigue easily

Cardiac muscle cannot produce tetanic contractions

Front 112

Since cardiac muscle are considered automaticity, what cardiac specialize muscle cell is mainly responsible for it's contraction?

Back 112

Pacemaker Cells

Front 113

Between Smooth, Cardiac, and Skeletal muscles, which one has cells that is spindled in shaped?

Back 113

Smooth

Front 114

Between Smooth, Cardiac, and Skeletal muscles, which one have Tubules??

Back 114

Skeletal
Cardiac

Smooth contains NO Tubules

Front 115

Between Smooth, Cardiac, and Skeletal muscles, which one has non striated muscle?

Back 115

Smooth

Front 116

Between Smooth, Cardiac, and Skeletal muscles, which one have myofibrils and sacromeres?

Back 116

Skeletal
Cardiac

Front 117

What are attach to the thin filaments in smooth muscle cells?

Back 117

Dense Bodies

Front 118

What are dense bodies?

Back 118

Structures distributed throughout the sarcoplasm in a network of intermediate filaments compose of the protein desmin.

Front 119

What function does dense bodies serve?

Back 119

The dense bodies are firmly attached to the sarcolemma and anchor the thin filaments the cell would shortens

Front 120

What triggers smooth muscle contraction?

Back 120

Free calcium ions in the cytoplasm

Front 121

Once there is an influx of calcium ion into the sarcoplasm, the calcium ions interact with what calcium binding protein?

Back 121

Calmodulin

Front 122

Calmodulin can activate what enzyme?

Back 122

Mysoin light chain kinase, enables attachment of myosin heads to actin

Front 123

What is the difference between excitation-contraction coupling of smooth muscle to cardiac or skeletal muscle fibers?

Back 123

In skeletal and cardiac, the trigger for contraction is the binding of calcium ions to troponin

Front 124

What is an important characteristics of smooth muscle when it comes in relation to length-tension relationship?

Back 124

Plasticity: the ability to function over a wide range of lengths and smooth muscle are able to acquire this characteristic is because thick and thin filaments are not organized into sarcomeres in smooth muscle

Front 125

What factors determine the number of cross bridges?

Back 125

Depends on the degree of overlap between thick and think filaments

Front 126

What factor can influence tension?

Back 126

Formation of Cross bridges

Front 127

Define TWITCH?

Back 127

A single stimulus contraction relaxation sequence in the muscle fiber

Front 128

A single twitch can be divided into 3 kinds of periods, what are they?

Back 128

Latent
Contraction
Relaxation

Front 129

What happens during the LATENT PERIOD?

Back 129

Action potential sweeps across the sarcolemma and releases calcium ions

Front 130

What happen during the CONTRACTION PERIOD?

Back 130

Calcium are bind to tropoinin, active sites are exposed and cross bridges are forming

Front 131

What is happening during the RELAXATION PHASE?

Back 131

Calcium level decrease as well as cross bridges

Active sites are covered by tropomyosin

Front 132

What is the difference between isotonic and isometric contractions?

Back 132

Isotonic contraction is when tension rises and the skeletal muscle lengthen

Isometric: the muscle as whole doesn't lengthen and tension produced never exceeds the loads

Front 133

What are two types of ISOTONIC CONTRACTION/

Back 133

Concentric
Eccentric

Front 134

Give an example of Isotonic contraction

Back 134

Lifting an object, running and walking

Front 135

What is the difference between CONCENTRIC CONTRACTION and ECCENTRIC CONTRACTION?

Back 135

Concentric: The muscle tension exceeds the load and the muscle shortens.

Eccentric: tension is less than the load and muscle elongates