Muscle Physiology Flashcards
1
Q
Articulations
A
Where joints come together
Can be moveable joint or immoveable joint
2
Q
Synarthrosis
A
Immovable joint
3
Q
Sutural Joint
A
Joints of the skull
Immoveable, barely any movement
Example: Joints of the skull
4
Q
Gomphosis
A
Joint in between the teeth, mandible, and maxilla.
Immoveable
5
Q
Synchondrosis
A
Cartilage
Epiphyseal Plate. Growth Plate. No movement.
Still have cartilage in between the bones
6
Q
Synostosis
A
Boney Fusion
3 Bones of the OS Coxa fused at the acetabulum
No movement at this joint. No growth Plate.
7
Q
Amphiarthrosis
A
Continuous slightly moveable joint
8
Q
Syndesmosis
A
Fibrous
Interosseus membrane in between the tibia and fibula
9
Q
Symphasis
A
Cartilage
Pubic Symphasis
Slightly immoveable
10
Q
Diarthrosis
A
Freely moveable joint
Commonly called synovial joint
Example: Hyaline Cartilage and synovial membrane, joint space, or joint capsule
11
Q
Muscle Tissue
A
One of the four main tissue types
12
Q
Muscles do one thing only
A
Contract
13
Q
4 Main Tissue Types
A
Epithelial Tissue
Connective Tissue
Muscular Tissue
Nervous Tissue
14
Q
Three Muscle Types in the Body
A
Smooth, Cardiac, and Skeletal Muscles
15
Q
Locomotion
A
Muscles that allows us to move our body through space
16
Q
Help Maintain Proper Temperature
A
Send blood to the parts of the body that needs it.
17
Q
Maintain Proper Posture
A
Gravity is constantly pulling us down
18
Q
Contraction of the Heart
A
Moves blood throughout the body. Propels or moves things through the body.
19
Q
Guards Entrances and Exits Throughout the Body
A
Sphincters around the eyes, mouth, and at the other end
20
Q
Protection of the Body
A
Protect from injuries and infections
21
Q
Skeletal Muscle Tissue
A
Voluntary and Striated
Fast Contracting
Conscience control of our muscle. Multi Nucleated and Striated
22
Q
Cardiac Muscles
A
Involuntary and Striated
Push Blood through the Body
Intercalated discs. Gap Junctions.
Conduct electrical impulse from one cell to the next
23
Q
Smooth Muscle
A
Involuntary and not Striated
Actin and Myosin. Slow contracting
Move materials through the body
24
Q
Superficial Fascia
A
Loose Connective tissue just below the skin that attaches the skin to the deeper tissues
25
Epimysium
Outer dense regular connective tissue
26
Perimysium
Wraps around muscle bundles
Called Fascicles
27
Fascicles
Muscle Bundles
28
Fasciculation
Small Eye Twitch
Contraction at one of the fascicles
29
Endomysium
Muscle Fiber. Muscle Cell
Predominantly Collagen Fiber
Multi-Nucleated
30
Myofibrils
Contractile units of the muscles fiber. Run from one end to the end of the muscle fibers.
31
Muscle Fiber Cell
Contractile units called Myofibrils
32
Myofibril
Travel from one end to the other
Functional unit of the cell
Contraction can shorten the muscle fiber or belly
33
Myoblasts
Immature Muscle Cell
Precursor Cells
34
Sarcolemma
Inner Membrane
Muscle cell membrane
35
Sarcoma
Cancerous or tumor from muscle tissue
36
Endomysium
Made out of collagen fiber
37
Nuclei
Inside the cell membrane around the perimeter
38
Satellite Cell
Muscle Blast Cell
Involved in muscle tissue repair and regeneration
Undergo mitotic activity to increase number of muscle cells to increase the number of muscle cells
39
Myofibrils
Connect end to end inside the muscle cell
Divided into repetitive units
40
Sarcomere
Repetitive Functional Component or unit of the myofibril
Goes from Z line to Z line
41
Z Lines
Separate one sarcomere from the next. Zig Zag lines
42
Microfilament
Small filaments
43
Myofilaments
Small muscle filaments
44
Actin
First of the group
Thin Contractile Filaments
45
Myosin
The thick contractile filaments
46
M Line
Backbone of the myosin
Attaches to the actin filaments
47
Z Line
Sarcomere goes from Z line to Z line
Attaches to the actin filaments
48
A Band
Represents all the myosin fibers
Edge to Edge of the myosin on one side to the other edge of the myosin
Includes zone of overlap
49
H Band
Represents only the myosin
Only have the myosin in the zone
50
I Band
Represents only the actin
Edge of the myosin to the other edge of the myosin
51
Zone of Overlap
Where actin and myosin overlap each other
52
Accessory Players
Viable to Proper Muscle Contraction
Sarcoplasmic Reticulum
Transverse Tubule - "T Tubule"
Terminal Cisternae
Triad
53
Sarcoplasmic Reticulum
Sarco Means Muscle
Membranous network of tubules running through the muscle fiber that surrounds each myofibril
Function is to store calcium
54
Transverse Tubule "T-Tubule"
Tube that connects the sarcolemma directly with the sarcoplasmic reticulum
55
Sarcolemma
Comes in direct contact with the sarcoplasmic reticulum and also the cell membrane
56
Terminal Cisternae
Enlarged ends of the Sarcoplasmic Reticulum
Store most of calcium
57
Triad
T-Tubule and 2 Adjacent Terminal Cisternae
Reside over the Zone of Overlap
58
Good Storage Reservoir for Calcium
Bones. Steal Calcium from the bones to put it into the blood. Need it for muscle contractions.
59
Muscle Contraction
The Protein Filaments
Associated Molecules
60
The Protein Filaments
Contractile Filaments inside the muscle (myosin and actin can bind with each other under the right circumstances)
61
Myosin Protein Filament
The Thick Filament. ATP binds to the myosin head. Myosin head splits ATP into ADP and P which cocks the head into open and ready position
62
Actin Protein Filament
The Thin Filament. Consists of two twisted protein stands with active sites located on these strands that allow it to bind with the myosin head
63
Associated Molecules
Tropomyosin
Troponin
64
Tropomyosin Associated Molecules
Filamentous (long) stand of protein that covers the active site on the actin when muscle is at rest. Prevents binding of actin and myosin
65
Troponin
Globular Protein that attaches to tropomyosin. When calcium binds to the troponin, the troponin will rotate tropomyosin off of the active sites of the actin
66
Sliding Filament Theory
States that actin and myosin slide over each other during muscle contraction
67
The Contraction Cycle (5 Steps)
1. Calcium ions bind to the troponin, rotating tropomyosin off the active site on the actin.
2. Crossbridging occurs between the active site on the actin and the myosin head
3. Myosin head pivots or ratchets toward the center of the sarcomere, pulling the Z Lines closer together causing contraction (ADP and P are released at this point)
4. Crossbridging detachment - the bond remains intact until the myosin head binds with another ATP molecule. Rigor Mortis.
5. Myosin Activation. The free myosin head splits the ATP into ADP and P which recocks the head again for the next cycle. The cycle stops when calcium levels return to low levels
68
Rigor Mortis
There is no more ATP Production, so the muscle will remain contracted until the enzymes break it down
69
The Neuromuscular Junction
Connects the nervous system to the muscular system via synapses between efferent nerve fibers and muscle fibers, also known as muscle cells.
70
Nerve Impulse Perpetuation 6 Steps Causing Muscle Contraction
1. The nerve impulse travels down the axon causing an influx of calcium into the synaptic knob which causes synaptic vessicles to fuse with nerve cell membrane.
2. Vessicles dump neurotransmitters (acetylcholines) into the synaptic cleft.
3. NT Binds to receptor sites on sarcolemma (Post Synaptic Membrane)
4. NT Binds to receptor sites opening ion channels in receptor protein allowing sodium in to the muscle changing membrane polarity causing depolarization of the sarcolemma.
5. This wave of depolarization travels over the surface of the sarcolemma and down into the T Tubules
6. This causes the release of calcium from the terminal cisternae which causes the actin active sites to be exposed
71
Muscle Fatigue
A Muscle is fatigued when it can no longer contract despite continued stimulus
72
Aerobic Depletion
During aerobic activity muscle fatigue is due to depletion of glucose, not oxygen
73
Anaerobic Depletion
During intense short bursts of exercise the oxygen usage exceeds oxygen availability
74
Anaerobic Threshold
Boundary between aerobic energy usage (glucose and oxygen) and anaerobic energy usage (pyruvate)
75
Muscle Restoration Period
Can take up to one week
76
Muscle contraction of Muscle Mechanics
Latency Phase
Contraction Phase
Relaxation Phase
77
Latency Phase
2 Milliseconds between beginning of nerve stimulation and start of muscle contraction. Action Potential is sweeping over sarcolemma and calcium is being released.
78
Contraction Phase
20 milliseconds. When cross bridging occurs, increasing muscle tension, increasing intensity
79
Relaxation Phase
Cytoplasmic calcium decreases, cross bridge detachment occurs and muscle tension decreases as well.
80
All or None Principle
Either a motor unit fires or doesn't fire. There is no in between regarding muscles.
81
Graded Contractions
Muscle responses are actually graded contractions.
When we are contracting our muscles, we have smooth graded contractions. Can Fire quickly or move the muscles quickly, or can move slowly. Can exert tremendous amount of force or small amount of force
82
Gluconeogenesis
Makes glucose, would happen during anaerobic depletion
83
1:5 Nerve Fiber to Muscle Fiber Ratio
1 Nerve to 5 muscle fibers to allow dexterity, fine motor function, to move the eyeball in a certain pattern to focus in on something
84
1: 2000 to 3000 Nerve Fiber to Muscle Fiber Ratio
Large ratio is for power. We need the large ratios to get away from bears. More motor units we can recruit the more forceful contraction we can get.
85
Types of Muscle Contractions
Multiple Motor Unit Summation
Wave Summation
Incomplete Tetanus
Complete Tetanus
Treppe
86
Muscle Motor Unit Summation
AKA Recruitment. It is a smooth and steady increase in muscle tension from increasing the number of active motor units
87
Wave Summation
It is a second more powerful muscle stimulus arriving before the relaxation phase of the previous contraction has completely set in. Continuing to summate or add, but we see a wavelike pattern. Closest thing to wave summation is like a sewing machine.
88
Incomplete Tetanus
A series of muscle contractions producing a peak tension during rapid cycles of contraction and relaxtion
Start to get fatigue and the leg of calf would start bouncing around something similar. Muscle stimulation.
89
Complete Tetanus
A series of muscle contractions where the rate of stimulation is such that the relaxation phase has been eliminated.
90
Treppe
A series of muscle contractions where the muscle is stimulated a second time immediately after the relaxation phase has ended. The following contraction will have a slightly higher tension due to calcium remaining outside the terminal cisternae.
Looks a lot like wave summations with a slight variance. The peak will be a little higher than the previous peak. With each successive contraction starts at 0.
91
Muscle Tone
the resting tension within a muscle. All muscles should exhibit some type of muscle tone. 5-8% motor units are always firing, help maintain muscle tone.
92
Function of Muscle Tone
Serves as a protective mechanism for the structures that travel through the muscle. Blood vessels and nerves are examples
93
Isotonic Contractions
Tension in the muscles increases enough to overcome resistance that is weight and gravity. Allows muscle to shorten. Tension builds up enough to overcome resistance and allowing the muscle belly to shorten. Recruit enough to shorten muscle belly to lift up something
94
Isometric Contractions
Tension in the muscle belly increases, but we're not overcoming gravity or resistance so the muscle belly doesn't shorten. For example lifting a car, can sit there all day long to contract the muscle and increase the tension within the muscle, but don't change the position of the body and the car doesn't move.
We're not changing the shape or length of the muscle of the belly. Not changing the shape of the muscle, not shortening or lengthening of the muscle belly.
95
Three types of Skeletal Muscle Fibers
Fast Fiber - White Fiber
Slow Fiber - Red Fiber
Intermediate
96
Fast Fiber - White Fiber
Majority of the muscle fibers (Skeletal)
All the muscles of the body have a overwhelming ratio of fast to slow fibers
Contract over 3 times the weight of the slow twitch. Can contract in about between .01 seconds. Larger in diameter. Packed with more myosin then actin.
Have more glycogen in them with fewer mitochondria
97
Slow Fiber - Red Fiber
Half the diameter of the white fibers and will take 3 times as long to contract. Still fast. More mitochondria and less glycogen. They have an extensive capillary network. They have a protein pigment similar to hemoglobin within that muscle called Myoglobin. Myoglobin helps keep oxygen resident in the muscle cells. Bring and hold more oxygen in that cell.
98
Myoglobin
Is a red pigment similar to hemoglobin
99
Intermediate
Have properties of both fast and slow. Look like fast fibers, but resist fatigue better.
100
Quadriceps Muscles
Allows us to get down and contract; Allow knee extension to occur. We have muscle belly's that are shaped differently to overcome those narrow power arcs.
101
Muscle Fiber Contraction
All muscle fibers have an optimum length for producing maximum contraction
102
Muscle Fiber Contraction #1 Stretch Too Far
If you stretch too far, you do not have enough zone of overlap for forceful contraction
103
Muscle Fiber Contraction #2 Near or at full contraction
Maximum Overlap - Full contraction all of the actin and myosin are completely overlapped, nowhere to go from here. Not an efficient position.
104
Maximal Tension
This concept applies to entire muscle. All muscles have a small range of motion where maximal tension is reached. Applies to the entire muscle. All muscles have a small range of motion where maximal tension is reached. Example: Elbow.
105
Line Of Drive
When we contract the muscle, what happens in the joint and the bones when we contract the muscle, the force being generated is actually compressing the joint. Not an effective position for generating a lot of force.
106
Full Extension
Less tension generated due to less overlap of the filaments.
Full extension is not efficient because contraction compresses the joints together.
107
Flexion
90% Optimum Angle or 90 Degree Angle. Optimum Zone of Overlap. More efficient. Line of drive is going vertical. More torque, more power.
108
Full Flexion
3rd Position more distracting. 130 degree full flexion. We are at maximum zone of overlap. Maintain quite a bit of force. The line of drive is going back. Contraction starts to separate the joint. Not very efficient.
109
Muscle Power Arcs
The range of motion or degrees where the muscle exerts most of its force. Muscles overcome the narrow ranges of motion where the muscle is most efficient by evolving different muscle shapes. It can be more efficient in different portions of the full range of motion of the muscle or externum
110
Muscle Shapes
Parallel
Convergent
Unipennate
Bipennate
Circular
111
Parallel Muscle Shape
The muscle fibers are all lined up in the same direction. Should fire through the entire range of motion of the extremity.
Example: Rectus Femoris, Biceps Brachii
112
Convergent Muscle Shape
Fan Shape Muscle. All the fibers converge to one central tendon.
Example: Pectoralis muscle is a good example of convergent or fan shaped. A large belly and then it converges to a relatively small central tendon and it inserts into the upper arm
113
Unipennate Muscle Shape
Looks like a feather.
Example: Extensor Digitorum
Function: Brain controls how this muscle contracts. So when we start contracting first, the other parts contracts first and as we continue to go through the range of motion, the middle portion contracts and then we get full contraction when the bottom portion contracts
114
Bipennate Muscle Shape
is a pennate muscle type that consists of two rows of oblique muscle fibers, facing in opposite diagonal directions, converging on a central tendon.
Example: Gastrochnemius, Calf of Belly
115
Circular Muscle Shape
Sphincters. Very common shape in the body. Attach to the deep fascia and into the skin. Muscles of facial expression originate and insert into the skin, or they can arrange for it to be off of the bone. Sphincters typically around the eye, mouth, and we call them sphincters.
116
Three Classes of Biomechanical Levers
First Class
Second Class
Third Class
117
First Class
Has the fulcrum between the resistance and the effort. Teeter totter.
Example: Human Body. Weight of the skull. Anterior to the fulcrum. Need a bunch of muscles (effort) at the back of the skull. Job is to pull the head back. Head balances of the skull.
118
Second Class
Resistance is located in between the effort and the fulcrum
Example: Wheel barrel. Benefit of this in the human body. Allows the body to carry a lot of stuff with minimal effort. 2nd Class lever is powerful. The Foot. Resistance is the entire human body between the two points. Calf Muscles can lift entire body off the ground very easily even with one foot with the muscles because of its second class lever.
119
Third Class
The effort is between the fulcrum and the resistance. Not very powerful but very fast. Large amount of movement out on the forearm and hands. Resistance of the entire weight of your arm. Not very powerful but it is very fast.
120
Three parts of a muscle
Origin
Muscle Belly
Insertion
121
Origin
beginning of muscle base, typically the most proximal portion, the immovable end of the attachment. Closest to the axial skeleton. Extremities as an example. Less moveable end of the attachment. Insertion will be distal. Pectoralis – Torso – the part that’s closest to the center of the body.
122
Muscle Belly
the body or bulk of the muscle fibers where the muscle belly is.
123
Insertion
the attachment site of a muscle that is typically at the distal end. Also the more movable end of the attachment sit away from the axial skeleton. Further away from the center or for more distal attachment. More moveable portions.
124
Agonist 'Prime Mover'
a muscle whose contraction is chiefly responsible for a particular movement or motion. (biceps-forearm flexion). Brachialis muscle is the primary mover or agonist for elbow flexion.
125
Synergist
assists the prime mover. stabilizes during motion. Muscle that moves in conjunction with the primary mover. Biceps brachii will be the Synergist muscle. It will assist the brachialis for the elbow flexion.
126
Antagonist
also prime movers, but their action opposes the agonist being considered. (forearm flexion-triceps). Work against primary mover - elbow flexion the antagonist muscle to elbow flexion is triceps for example. They Oppose prime motion.
127
Rectus
Straight
128
Medius
Medial
129
Obliqus
Fibers run at an oblique angle
130
Transversus
Fibers run transverse
131
Superficialis
More Superficial
132
Profundus
More Deep
133
Superioris
Closer toward head
134
Minimus
Smaller
135
Maximus, Majorus
Larger
136
Internus
Inside
137
Brevis
Short
138
Flexion
Reduces the angle between articular elements
139
Extension
Increases the angle between articular elements
140
Hyperextension
Extension which continues past the anatomical position
141
Abduction
Refers to moving the distal end of an extremity or body away from the body or midline in a coronal plane
142
Adduction
Refers to moving the distal end of an extremity or body part toward the body or midline in a coronal plane
143
Rotation
Movement of a body part about its long axis
144
Supination
Refers to the forearm, internal rotation of the palm, or rotation of the forearm about it's long axis to the posterior palm position
145
Circumduction
Active or passive circular movement of the limbs or eyes
146
Depression
General Term, to lower a body part inferiorly
147
Elevation
General term, to raise up a body part superiorly
148
Protraction
Moving a body part backward in the horizontal plan
149
Inversion
Refers to the ankle, turning the sole of the foot inward in a coronal plane
150
Eversion
Refers to the ankle, turning the sole of the foot outward in a coronal plane
151
Plantar Flexion
Refers to the foot and ankle, flexing the foot in a plant direction
152
Dorsiflexion
Refers to the foot and ankle, flexing the foot superiorly toward the head. Not called extension
