final exam p1 Flashcards
(135 cards)
1
Q
What is muscle tissue?
A
A primary tissue responsible for contraction and movement
2
Q
What does skeletal muscle move?
A
Move the body by pulling on bones
3
Q
What does cardiac muscle pump?
A
Pumps blood through the cardiovascular system
4
Q
What does smooth muscle push?
A
Pushes fluids and slides through internal passageways and organs
5
Q
What is excitability (responsiveness)?
A
Ability to receive and respond to stimuli
6
Q
What is contractility?
A
Ability of cells to shorten
7
Q
What is extensibility?
A
Ability of the muscle to stretch
8
Q
What is elasticity?
A
Ability of the muscle to recoil to its resting length
9
Q
What are skeletal muscle fibers (cells)
A
Large, multinucleate cells
10
Q
How do skeletal muscle fiber cells develop?
A
They develop by fusion of embryonic cells called myoblasts
11
Q
Why are skeletal muscle fiber cells also known as striated muscle cells?
A
Also known as striated muscle cells due to the presence of visible striations
12
Q
What is sarcolemma?
A
The plasma membrane of a muscle fiber
13
Q
What does the Sarcolemma surround?
A
Surrounds the sarcoplasm (cytoplasm of a muscle fiber)
14
Q
What are transverse tubules (T tubules)?
A
Narrow tubes continuous with the sarcolemma which extend from the surface of the muscle fiber deep into the sarcoplasm
15
Q
What is sarcoplasmic reticulum (SR)?
A
A tubular network similar to the smooth endoplasmic reticulum
16
Q
What kind of chambers does the sarcoplasmic form and what do they attach to?
A
Terminal cisternae that attach to T tubules
17
Q
What forms a triad?
A
2 terminal cisternae plus a T tubule
18
Q
What are myofibrils?
A
Organized collections of myofilaments that are responsible for muscle contraction
19
Q
What are myofilaments?
A
Bundles of contractile protein filaments
20
Q
What are the 2 types of filaments?
A
Thin & thick
21
Q
What are thin filaments composed of?
A
Composed primarily of actin
22
Q
What are thick filaments composed of?
A
Composed primarily of myosin
23
Q
What are sarcomeres?
A
Repeating structural and functional units of a myofibril
24
Q
What does each sarcomere contain?
A
Thin & thick filaments, proteins that stabilize the position of the thin and thick filaments, proteins that regulate the interactions between the thin and thick filaments
25
What are excitable membranes?
All cells maintain a negative resting membrane potential
26
What is the resting membrane potential of skeletal muscle cells?
-85mV
27
What happens to the membrane potential in depolarization?
The membrane potential becomes less negative due to influx of sodium ions
28
What happens to the membrane potential in hyperpolarization?
The membrane potential becomes more negative due to outflow of potassium ions
29
What happens to the membrane potential in repolarization?
Return to the resting membrane potential after depolarization
30
What do neuron and muscle cells have and produce?
Have electrically excitable membranes and can produce electrical impulses called action potentials that can propagate along the plasma membrane
31
What is the contraction cycle?
A series of molecular events that enable muscle contraction
32
What does the contraction cycle involve the formation of?
Involves the formation of cross-bridges
33
What are cross-bridges?
The myosin head binds to the active sites on actin
34
What is a power stroke?
The myosin head uses energy from ATP to pivot and pull on active towards the M line
35
What is tension?
Pull force generated by the muscle when it contracts
36
What does the amount of tension produced by an individual muscle fiber depend on?
Depends on the number of power strokes, the resting length of the muscle fiber at time of stimulation (length-tension relationship), and the frequency of stimulation
37
What is a motor unit?
A motor neuron and all the muscle fibers it controls
38
What do motor units may contain?
May contain a few muscle fibers or thousands
39
What time do fibers in a motor unit contract?
They contract at the same time
40
What do smaller units allow?
Allow for finer control of movement
41
What is fasciculation?
Involuntary “muscle twitch” which is caused by the synchronous contraction of one motor unit
42
What is muscle tone?
The resting tension of a skeletal muscle
43
Without causing movement what do motor units actively do?
Stabilize the positions of bones and joints, maintain balance and posture
44
What does elevated muscle tone increase?
Increases resting energy consumption
45
What does normal muscle function require?
Substantial intracellular energy reserves, a normal circulatory supply, normal blood oxygen level, normal pH
46
What is ATP (adenosine triphosphate)?
It's the only energy source used directly for muscle contraction (contracting muscles use a lot of ATP)
47
What do muscles store?
Muscles store ATP but available stores are depleted within 4-6 seconds in active muscles
48
ATP transfers energy in which form and to create what?
ATP transfers energy in the form of a phosphate to creatine to create creatine phosphate (CP)
49
What do the growth hormones and testosterone stimulate?
Stimulate protein synthesis and skeletal muscle enlargement
50
What do thyroid hormones elevate?
Elevate the rate of energy consumption in resting and active muscles
51
What does epinephrine stimulate?
Stimulates muscle metabolism, increases both the duration of stimulation and the force of contraction
52
What is muscle hypertrophy?
Muscle growth from heavy training
53
What does muscle hypertrophy increase?
Increase in the diameter of muscle fibers, the number of myofibrils, the number of mitochondria, and the glycogen reserves
54
What is muscle atrophy?
Reduction of muscle size, tone, and power due to lack of activity
55
What happens in muscle atrophy if severe and muscle fibers die?
If severe and muscle fibers die, they are not replaced
56
What is muscle fatigue?
When muscles can no longer perform at a required level
57
Where is cardiac muscle tissue found?
Only in the heart
58
What are cardiac muscle cells?
Small, branched, striated cells with a single nucleus
59
What do cardiac muscle cells have
Have short wide T tubules and no triads
60
What are cardiac muscle cells almost totally dependent on?
Aerobic metabolism
61
What are intercalated discs?
Specialized connections that join the sarcolemma’s of adjacent cardiac muscle cells by gap junctions and desmosomes
62
What are intercalated discs functions? (3 functions)
Stabilizing the position of adjacent cells, maintaining the 3 dimensional structure of cardiac muscle tissue, allowing ions to move from one cell to another so cardiac muscle cells beat in rhythm
63
What is automaticity?
Able to contract without neural stimulation
64
What do pacemaker cells generate?
Generate the electrical signals that initiate contraction
65
What can the nervous system alter?
It can alter pace and tension of contractions
66
What happens when there are longer contractions than those in skeletal muscle?
Longer refractory periods and resistance to fatigue
67
What do contractions require?
Require both intracellular and extracellular calcium ions
68
Where is smooth muscle tissue found?
Found around other tissues and internal organs
69
Where is smooth muscle tissue in the cardiovascular and respiratory systems?
Around blood vessels and airways regulates blood pressure and airflow
70
What does smooth muscle tissue do in the digestive and urinary systems?
Moves materials along and out of the body and forms sphincters
71
Describe smooth muscle
Long, slender, spindle shaped cells. There's no T tubules, myofibrils or sarcomeres its a nonstriated muscle
72
In smooth muscle where do thin filaments attach to?
Dense bodies
73
What do dense bodies connect to?
Connect adjacent cells, transmitting contractions throughout the tissue
74
What are parallel muscles?
Fascicles are parallel to the long axis of muscle
75
What are some examples of parallel muscles?
Biceps brachii, rectus abdominis (parallel muscle with tendinous bands), supinator (wrapping muscle)
76
How much do muscles shorten when contracting?
30%
77
What are convergent muscles?
Muscle fascicles spread in a broad area on one side and converge on an attachment site on the other
78
What is an example of a convergent muscle?
Pectoralis
79
What is a raphe?
Slender band of collagen fibers
80
What are pennate muscles?
The fascicles form a common angle with the tension
81
What are examples of pennate muscles?
Extensor digitorum (unipennate muscle), rectus femoris (bipennate muscle), deltoid (multipennate muscle)
82
What are circular muscles (sphincters)?
The fascicles are concentrically arranged around an opening
83
What is an example of a circular muscle?
Orbicularis oris
84
What is origin?
Fixed (less moveable) point of attachment of a muscle to a bone
85
What is insertion?
More movable point of attachment of a muscle to a bone
85
What do the origin and insertion both produce?
Actions
85
What are the 4 function types of muscles?
Agonist, antagonist, synergist, and fixator
85
What is the agonist?
Prime mover, the main muscle responsible for producing a particular movement
85
What is antagonist?
Opposes the movement of the agonist
86
What is synergist?
A smaller muscle that assists an agonist
87
What is a fixator?
A synergist that assists an agonist by preventing movement at another joint
88
What is externus (superficialis)?
Muscles visible at body surface
89
What is internus (profundus)?
Deeper muscles
90
What is extrinsic?
Superficial muscle that positions or stabilizes an organ
91
What is intrinsic?
Located entirely within an organ
92
What is transversus?
Runs across the longitudinal axis of the body
93
What is oblique?
Runs at a slant to the longitudinal axis of the body
94
What is rectus?
Straight muscle that runs along the longitudinal axis of the body
95
For origin and insertion what does the first part of the name indicate and what does the second part of the name indicate?
First part of name indicates origin(1) and second part of name indicates insertion (2)
Example: genio(1) glossus (2)
96
What does teres mean by shape?
Round and long
97
What does brevis mean by size?
Short
98
What does longissimus mean by size?
Longest
99
What does longus mean by size?
Long
100
What does magus mean by size?
Large
101
What does major mean by size?
Larger
102
What does maximus mean by size?
Largest
103
What does minimus mean by size?
Smallest
104
What does minor mean by size?
Smaller
105
What do axial muscles position?
Position the axial skeleton
106
How much skeletal muscles are in the axial muscles?
60%
107
What do appendicular muscles support?
Support and move the appendicular skeleton
108
How are axial muscles grouped?
Grouped based on location , function , or both
109
What do the muscles of the head and neck move?
Move the face, tongue, larynx
110
Axial muscles are muscles of the..?
Vertebral column
111
What do the oblique and rectus muscles form?
Forms the walls of the trunk and found in the neck
112
What do the muscles of the pelvic floor form?
Form the perineum
113
What do muscles of the tongue do?
Maneuver food, and used for speech
114
What is glossus?
Tongue
115
What does palatoglossus do?
Elevates tongue, depresses soft palate
116
What does styloglossus do?
Retracts tongue and elevates its sides
117
What does genioglossus do?
Depresses and protracts the tongue
118
What does hyoglossus do?
Depresses and retracts tongue
119
What does the sternocleidomastoid do?
Both bellies together flex the neck. One at a time flex head toward shoulder and rotate face to opposite side
120
What do the scalene muscles do?
Flex the neck and elevate ribs
121
What do the external and intercostal muscles do?
Aid in breathing by elevating and depressing the ribs respectively
122
What does the transversus thoracis do?
Depresses ribs
123
What does the serratus posterior superior do?
Pulls ribs up
124
What does the serratus posterior inferior do?
Pulls ribs down
125
What does the external and internal oblique do?
Compress abdomen, depress ribs and flex spine
126
What does the transversus abdominis do?
Compresses abdomen
127
What does the diaphragm do?
Expands the thoracic cavity and compresses the abdomen
128
What is the diaphragm a major muscle for?
Major muscle used in breathing
129
What do appendicular muscles do? (2 functions)
Position and stabilize the pectoral and pelvic girdles and move the upper and lower limbs
130
What are the 2 groups of appendicular muscles?
Muscles of the shoulders and upper limbs and muscles of the pelvis and lower limbs
131
What does the trapezius do? (3 functions)
Large, superficial muscle that elevates the clavicle, move the scapula and extends the neck
