Exam 2 Prep Flashcards
(129 cards)
1
Q
Define permeability
A
The ease with which substances can cross the cell membrane
2
Q
Cell membranes are _________ permeable
A
Selectively
3
Q
Define passive transport
A
Cell doesn’t expend energy
4
Q
Define active transport
A
Cell expends energy
5
Q
Carrier mediated transport requires a _______
A
Transport protein
6
Q
Diffusion is ________
A
Movement of a substrate from an area of high concentration to lower concentration
7
Q
Give 3 examples of diffusion from lecture
A
-oxygen moves from lungs into blood, into interstitial fluid, into a cell
-CO2 moves from cells into interstitial spaces, into blood, out through lungs
-water moves across epithelium of digestive tract into body tissues
8
Q
The lipid bilayer is ______ to O2 and ________ to most large molecules
A
Permeable
Nonpermeable
9
Q
Define osmosis
A
Diffusion of water across a semi permeable membrane in response to solute differences
10
Q
Osmotic pressure is
A
The force of water movement into a solution
11
Q
Define isotonic
A
Equal concentrations, no net gain or loss of water
12
Q
Define tonicity
A
The effects of various solutions on a cell
13
Q
Define Hypotonic
A
Net gain of water into cell
14
Q
Define hypertonic
A
Net water flow out of cell
15
Q
Factors influencing diffusion
A
Faster diffusion if:
-short distance
-molecule is smaller
-higher temp
Concentration gradient is higher
16
Q
Facilitated diffusion
A
-substance moves down concentration gradient
-requires transport protein
17
Q
Co-transport facilitated diffusion
A
One substance moves down concentration gradient
-another substance moves against it’s concentration gradient
18
Q
Active transport is ________ of concentration gradients and consumes _______
A
Independent, ATP
19
Q
——— Na move out of a cell while _______ K into cell
A
3, 2
20
Q
At rest cells have more ________ charge inside than outside
A
Negative
21
Q
Resting potential sits at ______ mV
A
-70
22
Q
Chemically regulated channels/Ligand gated channels do what?
A
Open or close when they bind specific Chemicals
23
Q
Voltage regulated channels open or close in response to ________
A
Level of transmembrane potential
24
Q
Example of chemically regulated channel
A
ACh gated sodium ion channel
-ACh binds to receptor on gated sodium channels in muscle membrane causing sodium channel to open
25
Define Depolarization
Trans-membrane potential becomes less negative
26
Define Hyperpolarization
Transmembrane potential becomes more negative
27
Define repolarization
Trans-membrane potential returns toward resting potential after being depolarized
28
Skeletal muscles attach to _______, are _______ and have _______ movement
Bone, striated, voluntary
29
Cardiac muscle is found in ______, are ______, and ________ movement
Heart, striated, involuntary
30
Smooth muscles line __________ are _________ and have __________ movement
Hollow organs, no striated, involuntary
31
Functions of skeletal muscles
(There are 6)
-produce skeletal movement
-maintain posture
-support soft tissues
-gaurd entrances and exits
-Maintain body temperature
-Nutrient Reserves
32
Skeletal muscles include
Skeletal muscle tissue, connective tissue, blood vessels, nerves
33
Define muscle origin
Attached to bone that remains relatively stationary during movement
34
Define muscle insertion
Attached to the bone that moves
35
The endomysium is the ________ layer and has what function
Innermost layer
Covers individual muscle fibers
36
The perimysium is the ______ layer and has what function?
Middle layer
Sheathes bundles of muscle fibers called fascicles
Contains collagen, elastic fibers, blood vessels, and nerve supply
37
The epimysium is the _________ layer and has what function?
Outermost layer
Surrounds a muscle
Contains blood supply, nerve fibers, muscle repair
38
Define deep fascia of muscles
Wrap groups of cooperating muscle together
39
Definition of a muscle cell
Muscle fiber
40
Define multinucleate
Hundreds of nuclei
41
Each muscle cell is as _______ as _______
Long
Muscle fiber
42
How are muscle cells first made in Embryogenesis?
end to end fusion of uninucleate myoblasts forming individual multinucleate skeletal fiber
43
Actin are _______ myofilaments
Thin
44
Myosin are _________ myofilaments
Thick
45
What are myofibrils?
Bundles of myofilaments
46
What is the Sarcoplasm
Muscle cell cytoplasm
47
What is the Sarcolemma?
Cell membrane of a skeletal muscle cell
48
What is the Sarcoplasmic Reticulum (SR)
Modified ER
49
The Sarcolemma conducts __________, have _______, and _________ with the SR
Action potentials deep into cells
Have transverse tubules (T tubes)
Comes into close contact with SR
50
The Sarcoplasmic Reticulum (SR) is _______ to the ER, forms a ______ around ______, and stores high concentrations of ______ ions needed for muscle contraction
Similar to the ER
Forms a tubular network around each myofibril
Calcium
51
In the SR terminal ______ form _____ with T tubes
Cisternae, triads
52
Two types of myofilaments
Thin (actin)
Thick (myosin)
53
Myofibril are ________ and are anchored to the inner surface of the ________ at either end
Bundles of myofilaments
Sarcolemma
54
Define I bands
Light bands containing only thin filaments
55
Define A bands
Dark band containing thick filaments and some overlap with thin filaments
56
Define H band
Contains only thick filaments
57
Define Z disk/line
Border between sarcomeres
58
Review the Sarcomere Structure
59
Thin filaments slide over thick filaments shortening the ________
Myofibril
60
Thin actin filaments attach to the ______ disk
Z
61
As a muscle contraction occurs
Thin filaments move towards the center of the ________
Thin filaments slide over _______
____ lines are pulled closer together
I bands and H bands _______
A band _______
Sacromere
Thick filaments
Z limes
Narrow
Stays the same
62
Is this sarcomere relaxed or contracted?
Relaxed
63
Is this sarcomere relaxed or contracted?
Contracted
64
How do thin and thick myofilaments slide across each other?
Myosin filaments bind to sites on actin forming cross bridges. Cross bridges then change shape using ATP to pull actin past myosin.
65
Interactions between myosin head and actin are prevented by _______ at rest
Tropomyosin
66
Strands of tropomyosin cover ______ active sites at rest
Actin
67
Myosin molecules have ______, ______ head, are golf clubbed shaped
Elongated tails, globular
68
Myosin heads form _______
Cross bridges
69
Actin strands are composed of _______ two row individual globular molecules
Twisted
70
Each actin molecule has a ______ to which a ______ can attach
Active site, myosin heads
71
Calcium is _____ around sarcomere at rest
Low
72
Sliding Filament theory/ cyclic process:
1 Calcium binds to ________
2 Troponin moves, moving ______ and exposing _____ active sites
3 _____ head forms cross bridge to ______, bending ______ center of sarcomere thus ______ the actin
4 ATP allows _______ of _______
1 troponin
2 tropomyosin, actin
3 Myosin, actin, towards, pulling
4 formation, cross bridge
73
Concentration of _____ around sarcomere controls ________
Ca, sarcomere contraction
74
Action potential in Sarcolemma and T tubes causes _______ channels of SR to open and release Ca into _______ and ________
Ca, Sarcoplasmic, sarcomere
75
When Ca levels _______ tropomyosin covers ______ sites ending contraction
Fall, actin active
76
Define motor neuron
Nerve cell that controls muscle contraction
77
Define neuromuscular junction
Synapse between motor neuron and muscle cell
78
As sodium ions flow into muscle cells it _______ the muscle cells membrane and starts an ______
Depolarize, action potential
79
Acetylcholinesterase (AChE) is located in ______ and rapidly breaks down _______
Synaptic gap, acetylcholine
80
Action potential along ______ causes release of calcium from _____ of SR
T-tubes, cisternae
81
Duration of contraction depends on
1
2
3
1 duration of stimulation
2 presence of calcium
3 availablity of ATP
82
Muscle relaxation requires ______
ATP
83
Steps that initiate a muscle contraction
(There are 5)
ACh released and binds
Action potential spread across membrane along t tubes
SR releases Ca
Calcium binds to troponin exposing active sites forming cross bridges after myosin binds
Contraction begins and is repeated
84
Steps that end a muscle contraction
(There are 5)
ACh is broken down by AChE
SR reabsorbs Ca
Tropomyosin return to covering active sites
Contraction ends
Muscle relaxes
85
Tension in a muscle depends on the _____ that develops in individual muscle cells during contraction and the ______ of muscle cells that contract
Tension
Number
86
Amount of tension depends on number of _______ formed
Cross bridges
87
Define a twitch
Cycle of contraction, stimulus, and relaxation produced by a action potential in a muscle cell
88
Latent phase of a twitch
Action potential occurs, no contraction until Ca is released from SR
89
Contraction phase of a twitch
Tension rises, Ca moves tropomyosin off actin actin sites, myosin cross bridges form
90
Relaxation phase of a twitch
Tension falls to rest, Ca pumped back into SR, actin sites covered, no cross bridge remains
91
Summation is?
Repeated stimulation produced before relaxation phase is complete
92
Complete tetanus
Maximum tension production in a muscle cell
93
Small motor unit has ______ control and innervates a _____ number of muscle fibers for a ______ contraction
Precise, small. Slow
94
Large motor unit has _____ movement control, and innervates a ____ number of muscle fibers for a ______ contraction
Gross, large, fast
95
Two types of Isotonic contractions
Concentric
Eccentric
96
Concentric contraction- muscle tension ______ resistance and muscle _____
Exceeds, shorten
97
Eccentric contractions- peak tension developed is ______ than the resistance, muscle _______
Less, elongates
98
Isometric contraction- ______ rises, muscle length remains ______
Tension, constant
99
Muscle cells must generate ______ at the ______ rate as it is used
ATP, same
100
Creatine Phosphate reserves _______ stored energy to convert _____ to ATP when _____ is needed
Release, ADP, ATP
101
Resting muscle fibers rely on _______ metabolism to generate ATP
Aerobic
102
Excess ______ is used to store glucose as _______ and create ______
ATP, glycogen, creatine phosphate
103
Anaerobic respiration converts pyruvate into _____
Lactic acid
104
Define muscle fatigue
A. muscle that can no longer preform at required level of activity
105
The recovery period rebuilds _____, _______ and _____ and recycles _______
ATP, CP, glycogen
Lactic acid
106
Types of skeletal muscle fibers
Slow fibers
Intermediate fibers
Fast fibers
107
Slow fibers take ____ as long to contract after stimulation, uses ______ metabolism with high ______ content
3x, aerobic, myoglobin
108
Fast fibers are large in diameter with large _____ reserves, use _______ respiration and ______ quickly
Glycogen, anaerobic, fatigue
109
Dark (red) muscles are mostly _____ fibers
Slow
110
Pale (white) muscles are mostly _____ fibers
Fast
111
Define hypertrophy
Increase in diameter of muscle
112
Define Atrophy
Decrease in diameter of a muscle
113
Define muscle spasm
Strong sudden usually painful
114
Define Muscle spasticity
Excessive muscle tone
115
Define muscle flaccidity
Very low muscle tone
116
Smooth muscle is present in ________
Almost all organ systems
117
Cardiac muscle cells are linked by _______ and _______ into functional syncytium
Gap junctions, desmosomes
118
In intercalated disks _______ provide structural attachment
Sarcolemma
119
Cardiac muscle contraction time are determined by ______ muscle cells
Pacemaker
120
Cardiac muscles rely on ______ metabolism with ____ myoglobin and mitochondria content
Aerobic, high
121
122
What are the results of aging on the muscular system?
Reduction in size, strength, and endurance of muscles
Skeletal muscles become less elastic
123
Botulism causes ______
Blockage of release of acetylcholine
124
Polio causes _______
Loss of motor neuron
125
Tetanus causes ________
Excessive stimulation of motor neuron
126
Inherited muscle disorders include _______
Muscular dystrophies such as Duchennes MD
127
Myotonic dystrophy is ________
Chromosome 19 disorder
128
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