Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

From Flashcardlet > Chapter 10 - Skeletal Muscular Tissue > Flashcards

Chapter 10 - Skeletal Muscular Tissue Flashcards

0
Q

Cardiac muscle tissue

A

Forms most of heart wall
Striated
Involuntary
Alternating contraction and relaxation not consciously controlled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Skeletal muscle

A

Striated
Voluntary
Consciously controlled by neurons (nerve cells)
Part of somatic (voluntary) division of nervous systems
Controlled subconsciously to some extent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Autorhythmicity

A

Built in rhythm of cardiac muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Smooth muscle tissue

A

Located in walls of hollow internal structures (blood vessels, organs of abdominal pelvic cavity)
Found in skin, attached to hair follicles
Non striated
Involuntary action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Muscular tissue function

A
  1. Producing body movements
  2. Stabilizing body positions
  3. Storing and moving substances within the body
  4. Generating heat - thermogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Producing body movements

A

Skeletal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Stabilizing body positions

A

Skeletal muscle

Postural muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Storing and moving substances within the body

A

Sphincters - prevent outflow of contents of hollow organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Generating heat

A

Muscular tissue contraction produces heat - thermogenesis

Used to maintain body temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Properties of muscular tissue

A

Electrical excitability
Contractility
Extensibility
Elasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Electrical excitability

A

Muscle and nerve cells

Ability to respond to certain stimuli by producing electrical signals (action potentials)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Action potentials

A

Muscle action potentials

Nerve action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Action potential triggers

A

Electrical signals - arising in muscle (pacemaker)

Chemical stimuli - neurotransmitter released by neurons, hormones distributed by blood, local changes in ph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Contractility

A

Ability of muscle to contract forcefully when stimulated by an action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Extensibility

A

Ability of muscle tissue to stretch within limits without being damaged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Elasticity

A

Ability of muscular tissue to return to its original length and shape after contraction or extension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Connective tissue

A

Surrounds and protects muscular tissue
SubQ layer (hypodermis) separates muscle from skin
Composed of areolar connective tissue and adipose tissue
Pathway for nerves, blood vessels, lymphatic vessels to enter and exit muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Fascia

A

Dense sheer or broad band of irregular connective tissue that lines the body wall and limbs
Supports and surrounds muscles and other organs of the body
Holds muscles with similar functions together
Allows free movement of muscles
Carries nerves, blood vessels, lymphatic vessels
Fills spaces between muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Layers of connective tissue

A

Extend from fascia to protect and strengthen skeletal muscle

  1. Epimysium
  2. Perimysium
  3. Endomysium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Epimysium

A

Outer layer
Encircles entire muscle
Dense irregular tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Perimysium

A

Layer of dense irregular connective tissue
Surrounds groups of 10-100 or more muscle fibers
Separates muscle fibers into fascicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Fascicles

A

Muscle fiber bundles

Example - grain of meat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Endomysium

A

Penetrates the interior of each fascicle
Separates individual muscle fibers from one another
Mostly reticular fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Tendon

A

Attaches a muscle to the periosteum of a bone

Ex: Achilles’ tendon - attaches the muscle to the heel bone (calcaneus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Aponeurosis

A

Broad flat sheet of connective tissue

Ex: epicranial aponeurosis - top of the skull between the frontal and occipital bellies of the occipitofrontalis muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Fribromyalgia

A

Chronic painful nonarticular rheumatic disorder

Affects fibrous connective tissue components of muscles” tendons, and ligaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Anatomy of skeletal muscle fiber

A 
Sarcolemma
Transverse (T) tubules
Sarcoplasm
Myofibrils
Sarcoplasmic reticulum
Filaments
Sarcomere
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Sarcolemma

A

Plasma (cell) membrane of muscle fiber (cell)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Transverse (T) tubules

A

Tiny invaginations of sarcolemma
Tunnel in from surface toward center of muscle fiber
Filled with interstitial fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Sarcoplasm

A

Cytoplasm of a muscle fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Myoglobin

A

Red colored protein
Contained in sarcoplasm
Binds oxygen molecules that diffuse into muscle fibers from interstitial fluid
Releases oxygen when it is needed by mitochondria for ATP production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Myofribrils

A

Thread like structures extending longitudinally through muscle fiber
Striated
Make entire muscle fiber appear striped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Sarcoplasmic reticulum

A

Encircles each myofibril
Similar to smooth endoplasmic reticulum in non muscular cells
In a relaxed muscle, stores calcium ions (ca2+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Terminal cisterns

A

Dilated sacs of the sr
Butt against the T tubule from both sides
Release of ca2+ triggers muscle contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Triad

A

Transverse tubule and two terminal cisterns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Muscular hypertrophy

A

Due to increased production of myofibrils, mitochondria, sr, and other organelles
Results from forceful respective muscle activity (strength training)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Fibrosis

A

Replacement of muscle fibers by fibrous scar tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Muscular atrophy

A

Decrease in size of individual muscle fibers as a result of progressive loss of myofibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Disuse atrophy

A

Muscles are not used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Denervation atrophy

A

Nerve supply disrupted or cut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Filaments (myofilaments)

A

Smaller protein structures found within myofibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Sarcomeres

A

Contractile unit in a striated muscle fiber (cell) extending from z disc to the next z disc
Basic functional unit of myofibril

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Z disc

A

Narrow plate shaped region of dense protein

Separate one sarcomere from the next

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

A band

A

Darker middle part of the sarcomere
Extends the entire length of the thick filament
Toward each end is zone overlap (thick and thin filaments lie side by side)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

I band

A

Lighter dense area that contains the rest of the thin filaments
No thick filaments
Z disc passes through the center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

H zone

A

Center of each A band

Contains thick but not thin filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

M line

A

Supporting proteins that hold thick filaments together at center of H zone
Middle of the sarcomere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Muscle proteins

A

Contractile
Regulatory
Structural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Myosin (contractile protein)

A

Thick filament

Bind to myosin binding sites on actin molecules during muscle contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Actin (contractile protein)

A

Main component of thin filament

Each has a myosin binding site where myosin binds during muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Tropomyosin (regulatory protein)

A

Component of thin filament
Covers myosin binding sites on actin molecules
Prevents myosin binding to actin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Contractile protein

A

Generates force between muscle contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Regulatory proteins

A

Switch muscle contraction process off and on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Structural proteins

A

Keeps thick and thin filaments if myofibrils in proper alignment
Gives myofibrils elasticity and extensibility
Links myofibrils to sarcolemma and ECM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Troponin

A

Component of thin filament

Changes shape when bound with ca2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Titin

A

Connects Z disc to M line of sarcomere
Helps stabilize thick filament position
Stretches and then springs back unharmed
Accounts for elasticity and extensibility of myofibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

a-actinin

A

Structural protein of z disc

Attaches to actin molecules of thin filaments and to titin molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Myomesin

A

Forms M line of sarcomere
Binds to titin molecules
Connects adjacent thick filaments to one another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Nebulin

A

Wraps around entire length of each thin filament
Helps anchor thin filaments to Z disc
Regulates length of thin filaments during development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Dystrophin

A

Links thin filaments of sarcomere to integral membrane proteins in sarcolemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Sliding filament mechanism

A

Process where skeletal muscle shortens during contraction because thick and thin filaments slide past one another
Contraction cycle
Excitation-contraction coupling
Length-tension relationship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Contraction cycle

A

Repeating sequence of events that cause the filaments to slide
Four steps:
ATP hydrolysis
Attachment of myosin to actin to form cross-bridges
Power stroke
Detachment of myosin from actin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

ATP hydrolysis

A

Myosin head includes ATP binding site and ATPase, enzyme that hydrolyzes ATP into ADP, and a phosphate group
Reorients and energizes myosin head
Products (adp and phosphate group) still attached to myosin head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Attachment of myosin to actin to form cross bridges

A

Energized myosin head attaches to myosin binding site on actin
Releases previous hydrolyzed phosphate group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Cross bridges

A

Myosin heads attached to actin during contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Power stroke

A

Opening of site on cross bridge where ADP is still bound
Cross bridge rotates and releases ADP
Cross bridge generates force as it rotates toward the center of the sarcomere
Thin filament slides past hick filament toward M line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Detachment of myosin from actin

A

End of power stroke
Cross bridge firmly attached to actin until ATP binding
Once ATP binds to ATP binding site of myosin head- myosin detaches from actin

67
Q

Excitation-contraction coupling

A

Ca2+ release channels
Excitation-contraction coupling
Ca2+ active transport pumps
Calsequestrin

68
Q

Ca2+ release channels

A

Ca2+ flows out of the sr into sarcoplasm around thick and thin filaments
Combine with troponin causing change in shape
Change moves tropomyosin way from myosin binding sites on actin

69
Q

Excitation-contraction coupling

A

Once binding sites are free, myosin heads bind to them to form cross bridges
Contraction cycle begins
Connect excitation (muscle action potential growing along the sarcolemma and into T tubules) to contraction (sliding of filaments)

70
Q

Ca2+ active transport pumps

A

Use ATP to move ca2+ constantly from sarcoplasm to SR

71
Q

Calsequestrin

A

Molecules of calcium binding protein
Bind to ca2+
Enables more ca2+ to be sequestered or stored within SR
CA2+ concentration is 10000 times higher in SR than in cytisol of relaxed muscle fiber

72
Q

Rigor mortis

A

Leaky cellular membranes
Ca2+ leaks out of SR into sarcoplasm and allows myosin to bind to actin
ATP synthesis decreases as breathing stops
Cross bridges cannot detach from actin
Muscles are in a state of rigidity (cannot contract or stretch)
Begins 3-4 hours after death
Lasts for 24 hours
Disappears as proteolytic enzymes from lysosomes digest cross bridges

73
Q

Length-tension relationship

A

Indicates how the forcefulness of muscle contractions expends on the length of sarcomeres within a muscle “before contraction begins”.

74
Q

Neuromuscular Junction

A

The synapses between a somatic motor neuron and a skeletal muscle fiber
Includes all the synaptic end bulbs on one side of synaptic cleft and the motor end plate of the muscle fiber on the other side

75
Q

Somatic motor neurons (NMJ)

A

Neurons that stimulate skeletal muscle fibers to contract

76
Q

Synapse (NMJ)

A

Region where communication occurs between two neurons or between a neuron and a target cell (somatic neuron and muscle fiber)

77
Q

Synaptic cleft

A

In most synapses, a gap that separates two cells

78
Q

Neurotransmitter (NMJ)

A

Chemical messenger between cells

79
Q

Axon terminal

A

End of the motor neuron at the NMJ

80
Q

Synaptic end bulbs

A

Cluster of axon terminals

Neural part of NMJ

81
Q

Synaptic vessels

A

Membrane enclosed sacs suspended in the cytosol of synaptic end bulb

82
Q

Acetylcholine (ACh)

A

Molecule

Neurotransmitter released at the NMJ

83
Q

Motor end plate

A

Region of the sarcolemma opposite the synaptic end bulbs

Muscle fiber part of NMJ

84
Q

Acetylcholine receptors

A

Integral transmembrane proteins which bind to ACh
Abundant in junctional folds
Ligand-gated ion channels

85
Q

Junctional folds

A

Abundant in acetylcholine receptors
Deep grooves in he motor end plate
Provide a large surface are for ACh

86
Q

Nerve impulse (nerve action potential) to muscle action potential (NMJ)

A

Release of acetylcholine
Activation of ACh receptors
Production of muscle action potential
Termination of ACh activity

87
Q

Release of acetylcholine

A

Arrival of nerve impulses at synaptic end bulbs stimulates voltage-gated channels to open
During exocytosis, synaptic vesicles fuse with motor neuron’s plasma membrane, liberating ACh into the synaptic cleft
ACh diffuses across synaptic cleft between motor neuron and motor end plate

88
Q

Activation of ACh receptors

A

Binding of two molecules of ACh to receptor on motor end plate opens an ion channel in the ACh receptor
Once opened, cations (Na+) flows across membrane

89
Q

Production of muscle action potential

A

Inflow of Na+ (down its electrochemical gradient) makes the inside of the muscle fiber more positively charged
Change triggers a muscle action potential
Muscle action potential propagates along the sarcolemma into the T tubules
SR releases stored ca2+ into sarcoplasm and muscle fiber contracts

90
Q

Termination of ACh activity

A

ACh binding does not last because ACh rapidly breaks down by acetlcholinesterase (AChE)

91
Q

Acetylcholinesterase (AChE)

A

Attached to collagen fibers in the ECM of the synaptic cleft

Breaks down ACh into acetyl and choline (cannot activate ACh receptor)

92
Q

Electromyography (EMG)

A

Test that measures the electrical activity (muscle action potentials) in resting and contracting muscles

93
Q

Production of ATP in muscle fibers

A

Creatine phosphate
Anaerobic glycolysis
Aerobic respiration

94
Q

Creatine phosphate

A

ATP catalyzed by creatine kinase to form creatine which forms creatine phosphate and ADP
ATP from creatine phosphate occurs faster than any other ATP production in muscle fibers
3-6x more plentiful than ATP in the sarcoplasm of a relaxed muscle

95
Q

Creatine

A

Small amino acid-like molecule synthesized in the liver, kidneys, and pancreas
Transported to muscle fibers

96
Q

Creatine supplementation

A

Believed to be performance enhancing
Synthesized in body
Can chase dehydration and kidney dysfunction

97
Q

Anaerobic glycolysis

A

Break down of glucose which leads to a rose in lactic acid where oxygen is absent or at a low concentration
Glucose is broken down to two molecules of pyruvic acid which is converted to lactic acid

98
Q

Aerobic respiration

A

Series of oxygen requiring reactions (krebs cycle, electron transport chain) that produces ATP, carbon dioxide, water, and heat
Slower than anaerobic glycolysis, yields more ATP
Supplies enough ATP for muscles during periods of rest or light to moderate exercise

99
Q

Muscle fatigue

A

Inability of muscle to maintain force of contraction after prolonged activity

100
Q

Central fatigue

A

Feelings of tiredness and desire to cease activity

Caused by changes in the central nervous system (brain and spinal cord)

101
Q

Oxygen debt

A

Added oxygen over and above the resting oxygen consumption taken into the body after exercise
Extra oxygen is used to payback or restore metabolic conditions to the resting level
1. Convert lactic acid back into glycogen stores in the liver
2. Resynthesize creatine phosphate and ATP in muscle fibers
3. Replace oxygen removed from myoglobin

102
Q

Recovery oxygen uptake

A

Elevated use of oxygen after exercise

103
Q

Motor units

A

Somatic motor neuron and all of the skeletal muscle fibers it stimulates
Muscle fibers in one motor unit contract in unison
Dispersed throughout a muscle

104
Q

Twist contraction

A

Brief contraction of all muscle fibers in a motor unit in response to a single action potential in its motor neuron

105
Q

Myogram

A

Record of a muscle contraction

106
Q

Latent period

A

Delay between the stimulus and the beginning of a contraction
Muscle action potential sweeps over sarcolemma and calcium ions are released from the SR

107
Q

Contraction period

A

Ca2+ binds to troponin,
myosin binding sites on actin are exposed,
cross bridges are formed
Peak tension develops in muscle fiber

108
Q

Relaxation period

A

Ca2+ is actively transported back into the SR
Myosin binding sites are covered by tryptomyosin
Myosin heads detach from actin
Tension in the muscle fiber decreases

109
Q

Refractory period

A

Period of list excitability
Characteristic of all muscle and nerve cells
Duration varies with muscle involved

110
Q

Wave summation

A

Stimuli arriving at different times cause large contractions
Occur when additional ca2+ is released from SR by subsequent stimuli while ca2+ in sarcoplasm are still elevated from the first stimulus

111
Q

Unfused (incomplete) tetanus

A

Sustained but wavering contraction
Partial relaxation between stimuli
Skeletal muscle fiber is stimulated 20-30 times per second

112
Q

Fused (complete) tetanus

A

Sustained contraction in which individual twitches cannot be detected
Skeletal fiber stimulated at a higher rate of 80-100x per second

113
Q

Motor recruitment

A

Process in which the number of active motor units uncrease

One factor responsible for producing smooth movements rather than a series of jerks

114
Q

Anaerobic training

A

Activity that relies on anaerobic production if ATP through glycolysis
Stimulate synthesis of muscle proteins
Increases muscle size (muscle hypertrophy)
Athlete should have adequate amount of protein which allow body to synthesize muscle proteins and increase muscle mass
Builds muscle strength for short term

115
Q

Aerobic training

A

Builds endurance for prolonged activities

116
Q

Interval training

A

Incorporates both types of training

117
Q

Muscle tone

A

Small amount of tautness or tension in the muscle due to weak, involuntary contraction of its motor unit
Established by neurons in the brain and spinal cord that excite the muscle’s motor neurons

118
Q

flaccid

A

state of limpness in which muscle tone is lost

motor neurons serving a skeletal muscle are damaged or cut

119
Q

flaccid paralysis

A

loss of muscle tone, loss or reduction of tendon reflexes, and atrophy and degeneration of muscle

120
Q

hypertonia

A

increased muscle tone

expressed in two ways: 1) spasticity 2) rigidity

121
Q

spasticity

A

increased muscle tone (stiffness) associated with an increase in tendon reflexes and pathological reflexes (Babinski sign)

122
Q

spastic paralysis

A

partial paralysis in which the muscles exhibit spasticity

123
Q

Rigidity

A

increased muscle tone in which reflexes are not affected
ex: tetanus - disease caused by bacterium (clostridium tetani) that enters the body through exposed wounds - leads to muscle stiffness and spasms that can become life threatening

124
Q

Muscle Contractions can be

A

Isotonic

Isometric

125
Q

Isotonic contraction

A

the tension developed in the muscle remains almost constant while the muscle changes its length
used for body movements and for moving objects
two types: concentric and eccentric

126
Q

Concentric Isotonic contraction

A

tension generated is great enough to overcome the resistance of the object to be moved, the muscle shortens and pulls on another structure (tendon) to produce movement and to reduce the angle at a joint
ex: picking up a book from a table uses biceps brachii muscle in arm

127
Q

Eccentric isotonic contraction

A

When the length of a muscle increases during a contraction
The tension exerted by the myosin cross bridges resists movement of a load and slows the lengthening process
produce more muscle damage and more DOMS that concentric isotonic contractions
ex: lowering the book to place it back on the table

128
Q

Isometric contraction

A

tension generated is not enough to exceed the resistance of the object to be moved
muscle does not change its length
stabilize some joints as others are moved
ex: holding a book steady using an outstretched arm
most activities include both isotonic and isometric contractions

129
Q

Types of skeletal muscle fibers

A

slow oxidative fibers
fast oxidative-glycolytic fibers
fast glycolytic fibers

130
Q

Slow oxidative fibers

A

appear dark red due to large amounts of myoglobin and many blood capillaries
have many large mitochondria
generate atp mainly by aerobic respiration
“Slow” fibers because ATPase in myosin heads hydrolyzes ATP relatively slowly and and contraction cycle proceeds at a slower pace
resistant to fatigue
capable of prolonged sustained contractions for many hours
used for maintaining posture, aerobics, and endurance type activities

131
Q

Fast oxidative-glycolytic fibers

A

largest fibers
contain large amounts of myoglobin and many blood capillaries
generate considerable ATP by aerobic respiration (high resistance to fatigue)
Higher intracellular glycogen level gnerates ATP by anaerobic glycolysis
Fast - APTase in myosin heads hydrolyzes ATP 3-5x faster than myosin ATPase in SO fibers
Contribute to activies: walking and sprinting

132
Q

Fast Glycolytic Fibers

A

low myoglobin content
few blood capillaries and few mitochondria
appear white in color
contain large amounts of glycogen
generate ATP mainly by glycolysis
contract strongly and quickly due to ATP hydrolyzation
Used with weight lifting or throwing a ball

133
Q

Anabolic Steroids

A

similar to testosterone
taken to increase muscle size by increasing the synthesis of proteins in in muscle and thus increasing strength during athletic contests
side effects include: liver cancer, kidney damage, risk of heart disease, stunted growth, mood swings, acne, increased irritability and aggression. females: breast and uterus atrophy, menstrual irregularities, sterility, facial hair growth, voice deepening

134
Q

Cardiac muscle tissue

A

principal tissue in heart wall
between the layers of cardiac muscle fibers, contractile cells of the heart
sheets of connective tissue that contain blood vessels, nerves, and the conduction system of the heart
have same arrangement of actin, myosin, and same bands as skeletal
muscle fibers
has a endomysium and perimysium (no epymysium)
remains contracted for 10-15x longer than skeletal muscle tissue due to prolonged delivery of ca2+ into sarcoplasm
contracts when stimulated by its own autorhythmic muscle fibers

135
Q

Intercalated discs

A

unique to cardiac muscle fibers
irregular transverse thickenings of the sarcolemma that connect the ends of cardia muscle fibers to one another
contain desmosomes (hold fibers together) and gap junctions (allow muscle action potentials to spread from one cardiac muscle to another

136
Q

Physiological enlarged heart

A

cardiac muscle fibers that undergo hypertrophy in response to an increased work load

137
Q

Pathological enlarged heart

A

related to significant heart disease

138
Q

Smooth muscle tissue

A

activated involuntarily

two types: visceral (single unit) and Multiunit

139
Q

Visceral (single unit) smooth muscle tissue

A

found in the skin and in tubular arrangements that form part of the walls of small arteries and veins, hollow organs (stomach, intestines, uterus, and urinary bladder)
autorhythmic
connect to one another by gap junctions
when one fiber is stimulated, all other neighboring fibers contract in unison

140
Q

Multiunit smooth muscle tissue

A

consists of individual fibers
each has its own motor neuron terminals with few gap junctions between neighboring fibers
stimulation of one multiunit fiber causes contraction of that fiber only
found in walls of large arteris, airways to lungs, arretor pili muscle that attach hair follicles, muscles of iris (adjust pupil diameter) and in ciliary body (adjust focus of the eye lense)

141
Q

Intermediate filaments

A

single oval centrally located nucleus smooth muscle fibers
no regular pattern of overlap
do not exhibit striations

142
Q

Caveolae

A

small pouchlike invaginations of plasma membrane
contain extracellular ca2+ (can be used for muscle contraction)
smooth muscle

143
Q

Dense bodies

A

smooth muscle
attached to thin filaments
functionally similar to Z discs in striated muscle fibers
some dispersed throughout sarcoplasm - others attached to sarcolemma

144
Q

Calmodulin

A

regulatory protein
regulates contraction and relaxation of smooth muscle cells
binds to ca2+ in the cytosol
activates an enzyme called myosin light chain kinase - uses ATP to add a phosphate group to a portion of the myosin head

145
Q

Smooth muscle tone

A

provided by a prolonged presence of ca2+ in the cytosol

state of continued partial contraction

146
Q

Stress relaxation response

A

allows smooth muscle to undergo great changes in length while retaining the ability to contract effectively

147
Q

Hypertrophy

A

enlargement of existing cells

148
Q

Hyperplasia

A

increase in the number of fibers

149
Q

Muscle Development

A

Mesoderm

Somites

150
Q

Mesoderm

A

all muscles of the body are derived from mesoderm

151
Q

Somites

A

columns of mesoderm
undergo segmentation into cube-shaped structures
number can be correlated to the approximate age of the embryo

152
Q

Three regions of somites

A

myotome
dermatome
sclerotome

153
Q

myotome (somite)

A

forms the skeletal muscles of the head, neck, and limbs

154
Q

dermatome (somite)

A

form the connective tissues including dermis of the skin

155
Q

sclerotome

A

gives rise to the vertebrae

156
Q

Mesodermal cells and cardiac muscle

A

CM develops from mesodermal cells - migrate to and envelop the heart while it is still in the endocardial heart tubes

157
Q

Mesodermal cells and smooth muscle

A

Smooth muscle develops from mesodermal cells that migrate to and envelop the developing gastrointestinal tract and viscera

158
Q

Abnormal contractions of skeletal muscle

A 
spasm
cramp
tic
tremor
fasciculation
fibrillation
159
Q

spasm

A

sudden involuntary contraction of a single muscle in a large group of muscles

160
Q

cramp

A

painful spasmodic contraction

caused by inadequate blood flow to muscles, overuse of a muscle, dehydration, injury, etc.

161
Q

Tic

A

spasmodic twitching made involuntarily by muscles that are ordinarily under voluntary control
ex: twitching of eyelid and facial muscles

162
Q

Tremor

A

rhythmic, involuntary, purposeless contraction that produces a quivering or shaking movement

163
Q

Fasciculation

A

involuntary, brief twitch of the entire motor unit that is visible under the skin
occurs irregularly and is not associed with movement of the affected muscle
may be seen in multiple sclerosis or amyotrophic lateral sclerosis (Lou Gehrig’s disease)

164
Q

Fibrillation

A

spontaneous contraction of a single muscle fiber that is not visibile under the skin
can be recorded by electromyography
signal destruction of motor neurons

165
Q

Exercise induced muscle damage

A

torn sarcolemmas in some muscle fibers
damaged myofibrils
disrupted Z discs

166
Q

DOMS

A

Delayed onset muscle soreness
accompanied by stifffness, tenderness, swelling
microscopic muscle damage

From Flashcardlet (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions