Chapter 10 Muscular Tissue Flashcards
1
Q
Contractive organelles of skeletal muscle?
A
Myofibrils
2
Q
Dilated end sacs of the sarcoplasmic reticulum?
A
Terminal cisterns
3
Q
Fluid filled system of membranous sacs?
Encircles each Myofibrils?
A
Sarcoplasmic Reticulum
4
Q
Formed by a transverse tubule and 2 terminal cisterns on either side?
A
Triad
5
Q
Stored by the SR. When in a relaxed muscle fiber
A
Calcium Ions (Ca+2)
6
Q
From the terminal cisterns of the SR. Triggers muscle contraction?
A
Release of Ca+2
7
Q
Darker middle part of a sarcomere. Extends the entire length of thick filament
A
A Band
8
Q
Narrow plate shapes regions of dense protein. Separates one sarcomere from the next
A
Z discs
9
Q
Basic functional unit of a myofibril
A
Sarcomere
10
Q
Small protein structures within Myofibrils
A
Filaments or myofilaments
11
Q
Where the thick and thin filaments lie side by side
A
Zone of overlap
12
Q
Lighter less dense area that contains the rest of the thin filament but no thick filaments.
A
I band
13
Q
Contains thick but not thin filaments, in the center of each A band
A
H zone
14
Q
Formed when supporting proteins that hold the thick filaments together at the center of the H line. At the middle of the sarcomere
A
M line
15
Q
Twisted golf club handles point towards the M line in the center of the sarcomere
A
Myosin tail
16
Q
The 2 projections of each myosin molecule.heads project outward from the shaft in a spiraling fashion each extending toward one of the 6 thin filaments that surround each thick filament
A
Myosin head
17
Q
3 muscle proteins
A
Contractile - generate force during contraction
Regulatory - help switch the contraction process off and on
Structural- keep the thick and thin filaments in the proper alignment, give myofibril elasticity and extensibility
18
Q
2 contractive proteins
A
Myosin - main component of thick filaments and functions as motor protein
Actin- motor protein pull various cellular structures to achieve movement by converting electrical in ATP to mechanical energy
19
Q
Components of sarcomere
A
Z discs A band I band H zone M line
20
Q
Where a myosin head can attach
A
Myosin binding site
21
Q
Main component of thin filaments anchored to Z discs. Individual actin molecules join to form an actin filament that is twisted into a helix
A
Actin
22
Q
Thin filaments contain
A
Actin
Troponin
Tropomyosin
23
Q
Contractile proteins can generate force during contraction
A
Myosin and actin
24
Q
Regulatory proteins, help switch contraction on and off
A
Troponin and Tropomyosin
25
When muscle activity continues and the supply of creatinine phosphate within the muscle fiber is depleted. Glucose is catabolized to generate ATP
Anaerobic glycolysis
26
Pyruvic acid generated from glycolysis is converted to
Lactic acid
27
Muscular activity lasting more than 30 seconds. This system of ATP production involves biological oxidation
Aerobic cellular respiration
28
A small amino acid like molecule that is synthesized in the liver, kidneys and pancreas and then transported to muscle fibers
Creatine
29
Unique to muscle fibers an energy rich molecule that's is found in muscle fiber. The enzyme Creatine kinase catalyzes the transfer of the high energy phosphate group from ATP to Creatine forming Creatine phosphate and ADP
Creatine phosphate
30
From Creatine phosphate. By anaerobic glycolysis. By aerobic respiration. Production of ATP in muscle fibers
Muscle metabolism
31
Used to diagnose certain muscle disorders . Measures the electrical activity in resting and contracting muscles
Electromyography
32
Acetylcholine released at the neuromuscular junction triggers a muscle action potential which leads to muscle contraction
Summary of events of the contractions and relaxation in a skeletal muscle fiber
33
Blocks removal of ACh from receptors so strengthens weak muscle contractions of myasthenia gravia. Also an antidote for curare after surgery is finished
Neostigmine (anticholinesterase agent)
34
Release of acetylcholine
Activation of ACh receptors
Production of muscle action potential
Termination of ACh activity
Events occurring after a nerve signal
35
Neurons that stimulate skeletal muscle fibers to contract
Somatic motor neurons
36
Plant poison from poison arrows . Relax muscle during surgery
Curare
37
Produced by the bacterium clostridium botulinum. Bl is exocytosis of synaptic vesicles at the NMJ as a result ACh is not released and muscle contraction does not occur
Botulinum toxin
38
Usually near the midpoint of a skeletal muscle fiber, the synapse between the somatic motor neuron and a skeletal muscle fiber
Neuromuscular Junction
39
Chemical messenger released when the 1st cell communicates with the second cell
Neurotransmitter
40
Deep groves in the motor end plate that provide a large surface area for ACh
Junction folds
41
All of the synaptic end bulbs in one side of he synaptic cleft plus the motor end plate of the muscle fiber on the other side
Neuromuscular junction
42
Ligand gates ion channels, abundant in junction folds , integral transmembrane proteins to which ACh binds
Acetylcholine receptors
43
The region of the sarcolemma opposite the synapse end bulbs
Motor end plate
44
Neurotransmitter released at the NMJ
Acetylcholine
45
Hundreds of membrane enclosed sacs containing thousands of molecules of acetylcholine the neurotransmitter released at the NMJ
Synaptic vesicles
46
Swelling of axon terminals . Contain synaptic vesicles filled with ACh
Synaptic end bulbs
47
Small gap that separates the neuron cell and target cell
Synaptic cleft
48
Located at the end of the motor neuron at the NMJ. Divides into a cluster of synaptic end bulbs
Axon terminal
49
The forcefulness of muscle contraction depends on the length of the sarcomeres within a muscle before contraction begins.
A muscle fiber develops its greatest tension when there is an optimal zone of overlap between thick and thin filaments.
Length- Tension Relationship
50
Molecules of calcium binding protein found inside the SR. Bind to the Ca2+ enabling even more Ca2+ to be sequestered or stored within the ST
Calsequestrin
51
Composed of hundreds to thousands of cells. Muscle cells and muscle fiber are 2 terms for the same structure.
Muscle fibers
52
Long cylindrical and multinucleated
Muscle cells
53
Muscle cell membrane, the muscle cell cytoplasm and contains a large amount of glycogen and myoglobin.
Sarcolemma
54
Filled with tiny threads called Myofibrils and myoglobin
Sarcoplasm
55
Consist of thin and thick filaments
Myofibrils
56
Tiny invagination of the sarcolemma that quickly spread the muscle action potential to all parts of the muscle fiber
T tubules
57
Invaginations of the sarcolemma into the center of the cells . Filled with extracellular fluid , carry muscle action potentials
T transverse tubules
58
Lie in rows throughout the cell near the muscle proteins that use ATP during contraction
Mitochondria
59
A tendon that extends as a broad flat layer
Aponeurosis
60
A cord of dense connective tissue that attaches a muscle to the periosteum of a bone
Tendon
61
Neurons that stimulate skeletal muscle to contract. Consist of threadlike axon that extends from the brain or spinal cord to a group of skeletal muscle fiber
Somatic motor neurons
62
Used during contraction, muscle fiber synthesizes
ATP
63
Small mesodermal cell. Muscle fiber arises during embryonic development from the fusion of a hundred or more mesoderm cells
Myoblasts
64
3 layers of connective tissue
Epimysium - surround the whole muscle
Perimysium- surrounds bundles (fascicles ) of 10-100 muscle cells
Endomysium- separates individual muscle cells
65
2 main types of stimuli that trigger action potential
Autorythmic - electrical signals arising I the muscular tissue
Chemical stimuli such as neurotransmitters released by neuron's hormones distributed by the blood or even local changes in pH
66
Properties of muscular tissue
excitability conductivity contractibility extensibility elasticity
67
Functions of a muscular tissue
Providing body movements stabber lysing body positions storing in moving substances within the body generating heat
68
Types of muscular tissue
Skeletal muscle tissue cardiac muscle tissue smooth muscle tissue
69
Located in the walls of hollow internal structures found in skin attach to hair follicles non striated in voluntary has autorhythmicity
Smooth muscle tissue
70
Forms most of the heart wall
Straited
Action is in voluntary alternating contraction and relaxation of the heart not consciously controlled has a natural pacemaker
Cardiac muscle
71
Connective tissue
Striated
Voluntary
Controlled by neuron's or nerve cells part of the somatic division controlled subconsciously
Skeletal muscle tissue
72
Transform chemical energy into mechanical energy to generate force perform work and produce movement stabilize body position regulate organ volume generate heat and propel fluids and food matter through various body systems
Primary function of muscle
73
Allow an impulse to travel over long and short distances
Action potentials
74
Wasting away of muscle caused by disuse or severing of the nerve supply the transition to connective tissue cannot be reversed
Atrophy
75
Increase in the diameter of muscle fibers resulting from very forceful repetitive muscular activity in and increase and Myofibrils SR mitochondria
Hypertrophy
76
The muscle growth that occurs after birth occurs by enlargement of existing muscle fibers
Muscular Hypertrophy
77
Chronic painful nine articular rheumatic disorder. That affects the fibrous connective tissue components off muscles tendons and ligaments
Fibromyalgia
78
State off muscular rigidity that begins 3 to 4 hours after death and lasts about 24 hours since ATP synthesis has ceased cross bridges cannot detached from Actin until proteolytic enzymes begin to digest the decomposing cells.
Rigor Mortis
79
The inability of the muscle to maintain force of contraction after prolonged activity
Muscle fatigue
80
Feelings of tiredness and desire to cease activity
Central fatigue
81
The added oxygen over and above the resting oxygen consumption that is taken into the body after exercise
Oxygen debt
82
Convert lactic acid back into glycogen resynthesized creatinine phosphate and ATP in muscle fibers and replace oxygen removed from myoglobin
Restore metabolic conditions to the resting level in three ways
83
Consists of a somatic motor neuron plus all of the skeletal muscle fibers it stimulates
Motor units
84
Brief contraction of all muscle fibers in a motor unit in response to a single action potential in its motor neuron
Twitch contraction
85
The record of a muscle contraction
Myogram
86
The delay which lasts about 2M second The muscle action potential sweeps over the sarcolemma and calcium ions are released from the sarcoplasmic reticulum
Latent period
87
Lasts 10 to 100 msec calcium ion binds to troponin Myosin binding sites on Actin Are exposed and cross bridges form
Contraction period
88
Also last thing 10 to 100 m sec calcium ion is actively transported back into the sarcoplasmic reticulum myosin binding sites are covered by Tropomyosin myosin heads detach from Actin and tension in the muscle fiber decreases
Relaxation period
89
The period of lost excitability
Refractory period
90
When a second stimulus occurs after the refractory period of the first stimulus is over but before The skeletal muscle fiber has relaxed the second contraction Will actually be stronger than the first this phenomenon in which stimuli arriving at different times cause large contractions
Wave summation
91
Wavering contraction
Unfused
92
Rigid tense
Tetanus
93
When a skeletal muscle fiber is stimulated at a higher rate of 80 to 100 times per second it does not relax at all the result is?
A sustained contraction which individual twitches cannot be detected
Fused tetanus
94
The process in which the number of active motor units increases typically the different motor units of an entire muscle are not stimulated to contract in unison
Motor unit recruitment
95
Is the workout regiment that incorporates both types of training example alternating sprints with jogging
Interval training
96
A small amount of taughtness
| or tension in the muscle due to weak involuntary contractions of it's motor units
Muscle tone
97
When the motor neurons serving a skeletal muscle are damaged or cut the muscles become?
State of limpness in which muscle tone is lost
Flaccid
98
The tension developed in the muscle remains almost constant while the muscle changes its length
Isotonic contraction
99
Is great enough to overcome the resistance off the object to be moved the muscle shortens and pulls on another structure such as tendon to produce movement into reduce the angle at a joint
Con centric iso tonic contraction
100
When the length of a muscle increases during a contraction
eccentric isotonic contraction
101
Measure or length the tension generated is not enough to exceed the resistance off the object to be moved and the muscle does not change in length
Isometric contraction
102
A regulatory proteins that bind to Calcium ion in the cytosol
Calmodulin
103
Two types of smooth muscle tissue
Visceral single unit found in the skin and in tubular arrangements that form part of the walls of small arteries and veins and of hollow organs
Multi unit small muscle tissue consists of individual fibers each with its own motor neuron terminals and with a few gap junctions between neighboring fibers
104
Various filaments have no regular pattern of overlap smooth muscle fibers do not exhibit striations causing a smooth appearance smooth muscle fibers also lack transverse tubules and have a small amount ofSR for storage of Ca2+
Intermediate filaments
105
The thin filaments attach to structures
Dense bodies
106
All muscles of the body are derived from
Mesoderm
107
Columns of mesoderm undergo segmentation into a series of cube shaped structures
Somites
108
Three regions of somite
Myotome forms the skeletal muscle
Dermatome form the connective tissue
Sclerotome gives rise to the vertebrae
109
Increase in the number of fibers
Hyperplasia
110
Stem cells found in association with blood capillaries and small veins
Pericytes
111
Protein found only in muscles? Binds oxygen molecules that diffuse into muscle fibers from interstitial fluid? Releases oxygen when it is needed by the mitochondria for ATP production
Myoglobin
