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A & P 1 > Exam 3 > Flashcards

Exam 3 Flashcards

1
Q

anchor for thin filaments

A

Z-line

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2
Q

anchor for thick filaments

A

M-line

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3
Q

dark area; extends length of thick filaments

A

A-band

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4
Q

light area; thin myofilaments only (Z line is center)

A

H-zone

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5
Q

functional unit of skeletal system; z-line to z-line

A

sarcomere

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6
Q

makes up thick myofilaments; rodlike tail and 2 globular heads

A

myosin

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7
Q

makes up thin myofilaments; made of polypeptide subunits

A

actin

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8
Q

contain active sites for myosin heads; G actin strung together; 2 twisting strands make up thin myofilaments

A

polypeptide subunits of actin

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9
Q

in thin myofilaments; rod-shaped protein that runs along actin; blocks myosin binding sites on actin when muscle relaxed

A

tropomyosin

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10
Q

in thin myofilaments; 3 polypeptide subunit complex: 1 bound to actin, tropomyosin, and calcium

A

troponin

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11
Q

organelle; smooth ER of skeletal muscle; stores and regulates intercellular levels of Ca; connects to the next myofibril; tubules run longitudinally

A

sarcoplasmic reticulum

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12
Q

part of sarcoplasmic reticulum; runs perpendicular to the myofibril; found at A and I band intersection

A

terminal cisternae

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13
Q

perpendicular located at all A and I band junction; sandwiched between terminal cistern; lumen are continuous with extracellular space; form triads

A

T-tubules

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14
Q

terminal cisternae + T-tubules; located at A and I band intersection; integral proteins sense change in membrane potential; calcium channels in membrane of sarcoplasmic reticulum

A

triads

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15
Q

Sliding filament model of contraction:
Thin filaments slide past thick filaments due to __________. Myosin head of thick filaments will bind to actin of the thin filaments forming _________. Bridges pull ________ filaments towards center of sarcomere. Greater _______ of thick and thin filaments.

A

cross bridge formation
cross bridges
thin
overlap

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16
Q

Sliding filament model of contraction:
I bands ______. Sarcomeres ________. H-zones _______. A bands _________ but _________. Myofilaments _________. Myofibrils and muscle fibers _______.

A 
shorten
shorten
disappear
move closer together but length is the same
shorten
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17
Q

How do muscles contract?
Muscle fiber stimulated by ________. Generate and propagate ________. Increase in intracellular _______ due to changes in the __________. Includes ________ and _______ systems.

A 
nerve ending
electrical impulses
calcium
sarcoplasmic reticulum
muscular and nervous
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18
Q

motor neuron involved in voluntary function; site where axon of motor neuron meets with skeletal muscle fiber; consists of axon terminal, synaptic cleft, motor end plate

A

neuromuscular junction

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19
Q

end of axon; synaptic vesicles (contain acetycholine)

A

axon terminal

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20
Q

extracellular fluid; space in between sarcolemma and muscle fiber

A

synaptic cleft

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21
Q

area of muscle fiber that makes up the neuromuscular junction (meets skeletal fiber); junctional folds (have ACh receptor)

A

motor end plate

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22
Q

_________ gated channels open when membrane potential changes. ________ gated channels open when a chemical (ligand) binds.

A

voltage; chemically (ligand)

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23
Q

_______ flows into the neuron because of levels intracellular and extracellular; more (intracellular/extracellular)

A

calcium; extracellular

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24
Q

When calcium enters the neuron it causes ______ to fuse to the motor neuron

A

synaptic vesicle

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25
Q

_________ is released into synaptic cleft via ________

A

achtylcholine; exocytosis

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26
Q

What occurs at the junctional folds?

A

ACh binds to receptors

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27
Q

difference in electrical charge across plasma membrane

A

membrane potential

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28
Q

Resting membrane potential is _____ mV. The inside of the cell has an overall _____ charge relative to the outside.

A

-70; negative

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29
Q

Muscle and nerve cells are excitable - they receive stimuli and change in ________.

A

resting membrane potential

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30
Q

What makes sodium and potassium channels open? What kind of channels are they? ____ exits and ____ enters.

A

Acetylcholine; chemically gated; potassium; sodium

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31
Q

membrane potential becomes less negative during _____

A

depolarization

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32
Q

a depolarization of the sarcolemma that occurs at the motor end plate

A

end plate potential

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33
Q

triggers voltage gated sodium channels to open; more sodium enters in the area next to junctional folds (makes even less negative)

A

membrane potential

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34
Q

How depolarized does a membrane potential have to be for an action potential to occur?

A

-55 mV

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35
Q

large, transient depolarization event including polarity reversal, that is conducted along the plasma membrane of a muscle or nerve fiber; only generated if stimulus is strong enough

A

action potential

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36
Q

About how long does an action potential last?

A

1-2 milliseconds

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37
Q

Action potentials are a(n) _______ response which means that they have the same _______ and _______

A

all or none; amplitude and shape

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38
Q

another stimulus cannot cause another action potential to occur during this time because the electrical and ionic conditions have not been reestablished across the plasma membrane (resting membrane potential)

A

refractory period

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39
Q

sequence of events whereby action potential propagation leads to sliding of myofilaments (all events from stimulus to binding of myosin and actin)

A

excitation contraction coupling

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40
Q

Excitation contraction coupling:
Action potential goes down the ________ and changes shape of _______. This leads to the opening of _______ of the terminal cisternae, then goes into the ________.

A

T-tubules; voltage sensitive proteins; calcium; sarcoplasm

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41
Q

Tropomyosin and Troponin in excitation contraction coupling:
calcium will bind to ______ which is also bound to _______. Intracellular calcium is _______. _________ changes shape and pulls _________ away from myosin binding sites.

A

troponin; tropomyosin
higher
Troponin; tropomyosin

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42
Q

repetitive cyclical process of cross bridge formation, myosin propelling thin filaments toward M line and cross bridge detachment; requires ATP and calcium

A

contraction

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43
Q

What provides energy for contraction?

A

hydrolysis of ATP

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44
Q

What is responsible for hydrolysis of ATP?

A

myosin ATPase

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45
Q

Which step of contraction?

ATP changed to ADP; myosin binds to actin; myosin head in energized state

A

step 1

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46
Q

Which step of contraction?
myosin is pulling thin filaments to the center of the sarcomere; the power working stroke; myosin heads in a low energy state because they have given away their energy

A

step 2

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47
Q

Which step of contraction?
cross bridge detachment; ATP attaches to myosin; the link between myosin and actin weakens; the myosin head detaches and the cross bridge breaks down

A

step 3

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48
Q

Which step of contraction?
myosin ATPase is changing ATP to ADP; myosin head is cocked (high energy state); this cycle will continue as long as ATP is available and Ca is bound to troponin

A

step 4

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49
Q

Relaxation- When the stimulus (AP from neuron) ceases:
______ regulated channels on axon close; _______ is no longer released into synaptic cleft; _____________ break down ACh in synaptic cleft; _______ is pumped back into the sarcoplasmic reticulum via active transport (actively transported into cisternae and sarcoplasm); calcium unbinds from _______; myosin binding sites on actin molecules are covered by _________ (actin and myosin no longer bind)

A

voltage; acetylcholine; acetylcholinesterase; calcium; troponin; tropomyosin

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50
Q

Calcium:
Causes release of _________ from axon terminal; released from _______; causes ________ to expose binding sites on actin; involved in _________ (pumped back into ________); necessary for _______ and _______

A 
Ach
sarcoplasmic reticulum
troponin
relaxation
relaxation and contraction
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51
Q

muscles stiffen after death due to change in calcium permeability and lack of ATP synthesis after death

A

rigor mortis

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52
Q

autoimmune disease resulting in fewer ACh receptors; symptoms include drooping eyelids, difficulty swallowing and talking, general muscle weakness

A

myasthenia gravis

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53
Q

a motor neuron and all the muscle fibers it innervates; change force and tension of muscle; stimulus strength and frequency

A

motor unit

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54
Q

type of muscle contraction in which the muscle length changes (includes concentric and eccentric contractions)

A

isotonic

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55
Q

type of muscle contraction in which the muscle shortens when it contracts; ex. biceps curl - flexing

A

concentric

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56
Q

type of muscle contraction in which the muscle lengthens when it contracts (moving up a hill); usually setting up for a concentric contraction; ex. biceps curl - extending

A

eccentric

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57
Q

type of muscle contraction in which the muscle length doesn’t change because the load is heavier than the amount of tension the muscle can generate

A

isometric

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58
Q

a motor unit’s response to a single stimulus from the motor neuron

A

muscle twitch

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59
Q

graph showing the contractile activity of a muscle

A

myogram

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60
Q

What are the 3 phases of a muscle twitch?

A
  1. latent period (latency)
  2. contraction
  3. relaxation
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61
Q

phase of muscle twitch:

all the processes that occur from a stimulus to the binding of actin and myosin

A

latent period (latency)

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62
Q

phase of muscle twitch:

myosin heads pull thin filaments toward the center; tension-power stroke

A

contraction

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63
Q

phase of muscle twitch:

actylcholinesterase, calcium pumped into sarcoplasmic reticulum

A

relaxation

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64
Q

includes changes in frequency of stimulation and changes in strength

A

graded muscle responses

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65
Q

a change in force of contraction depending on the frequency of the stimulus

A

wave or temporal summation

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66
Q

wave or temporal summation:

decreased relaxation time between consecutive twitches; some of the calcium is being pumped back

A

incomplete (unfused) tetanus

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67
Q

wave or temporal summation:

no relaxation; maximum tension

A

complete (fused) tetanus

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68
Q

force of contraction will be greater as stimulus strength increases because more motor units are recruited

A

multiple motor unit summation

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69
Q

multiple motor unit summation:

produce no observable contractions

A

subthreshold stimuli

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70
Q

multiple motor unit summation:

stimulus required for observable contraction

A

threshold stimulus

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71
Q

multiple motor unit summation:

the strongest stimulus that can increase contractile force

A

maximal stimulus

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72
Q

Which threshold is recruited first?

A

lowest

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73
Q

bacterium (clostridium tetani); causes sustained muscle contraction; starts in jaw and progresses to other muscles

A

tetanus “lockjaw”

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74
Q

Each cross bridge in muscle contraction uses _____ ATP/sec. An active muscle fiber needs _______ trillion ATP/sec.

A

100

600

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75
Q

What are the 3 places that energy can be stored?

A
  1. ATP stores
  2. Creatine phosphate
  3. Glycogen stores (in glycosomes)
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76
Q

creatine phosphate + ADP = ?

A

creatine + ATP

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77
Q

anaerobic/aerobic metabolic pathways are a part of _____ stores

A

glycogen

78
Q

What are the 2 steps of anaerobic pathways?

A
  1. glycolosis (glucose converted to pyretic acid = 2 ATP)

2. pyruvic acid converted to lactic acid

79
Q

What are the pros of anaerobic pathways?

A

fast process; can occur without oxygen

80
Q

What are the cons of anaerobic pathways?

A

lactic acid buildup (lowers body’s pH if used for long periods of time); lots of glucose needed for a small amount of ATP

81
Q

accounts for 98% of energy when exercising

A

aerobic respiration

82
Q

What are the 3 steps of aerobic respiration?

A
  1. glycolysis
  2. kreb’s cycle
  3. oxidative phosphorylation
83
Q

occurs in mitochondria; pyretic acid converted to acetyl coA; produces ATP; produces coenzymes NADH and FADH2; 1 glucose = 2 ATP

A

kreb’s cycle

84
Q

coenzymes give up electrons; electrons combine with water; energy from electrons attaches phosphorus group to ATP

A

oxidative phosphorylation

85
Q

What are the pros of aerobic respiration?

A

yields lots of ATP for each glucose; provides energy fro hours of activity; other acids can enter the cycle and yield energy

86
Q

What are the cons of aerobic respiration?

A

slow process; needs oxygen

87
Q

In short duration exercise, _______ stored in muscles is used first. ATP is formed from _______ and ______. Glycogen stored in muscles is broken down to glucose which is _______ to generate _______ (anaerobic pathway). Uses both pathways at the same time (________ process). Relies on the same process for ________ exercise.

A

ATP; creatine phosphate and ADP; oxidized; ATP; continual; long duration

88
Q

What are the 2 types of muscle fibers classified according to speed of contraction?

A

fast and slow muscle fibers

89
Q

What are the 2 types of muscle fibers classified according to the pathway for ATP formation?

A

oxidative and glycolitic

90
Q

What are the 3 types of muscle fibers classified according to a combination of speed and pathway?

A

slow oxidative fibers
fast oxidative fibers
fast glycolytic fibers

91
Q

How many of the muscle fiber types will a motor unit have?

A

one

92
Q

What would happen if a stimulus intensity exceeds the maximum?

A

force of contraction would stay the same

93
Q

What are the 4 ways that marathon runners get their energy?

A
  1. ATP stored
  2. Creatine phosphate
  3. Glycolysis
  4. ATP via ETC
94
Q

What are the effects of excessive muscle contraction?

A

muscle fatigue; blood shunted from peripheral systems (puke, lose bowels); recovery

95
Q

Muscle fatigue:
What results in an ionic imbalance?
What causes lactic acid buildup?
What is the least likely cause of muscle fatigue and why?

A
  1. RMP isn’t established soon enough
  2. lower pH
  3. ATP depletion; muscles never run out of ATP
96
Q

What happens during the recovery stage of excessive muscle contraction?
Lactic acid yields _______ and ________. ______ and _______ stores are replenished.

A

pyruvic acid; glucose

Glycogen; ATP

97
Q

Smooth muscle is innervated by _____ nerve fibers, while skeletal muscle is innervated by ______.

A

autonomic; motor neurons

98
Q

swelling in nerve fibers; release transmitters into synaptic cleft (narrow synaptic cleft for skeletal)

A

varicosities

99
Q

In smooth muscle, actin and myosin are arranged in a _______ pattern (no sarcomere); when smooth muscle contracts, it causes the fiber to _______

A

diagonal; bunch up

100
Q

Smooth muscle can contract without _____ from the nervous system

A

stimulus

101
Q

In smooth muscle there is no presence of ______ and site of ______

A

t-tubules; invagination

102
Q

infoldings of plasma membrane with calcium channels

A

calveolae

103
Q

Smooth muscle is the site of calcium ________; _________ in the cytosol; when intracellular calcium levels rise ________ will bind to an enzyme and activate ________

A

regulation; calmodulin; calmodulin; myosin

104
Q

What are the 3 main differences of smooth muscle contraction from skeletal muscle contraction?

A
  1. Ca influx initiale action potential (can come from extracellular fluid or sarcoplasmic reticulum)
  2. action potential spread between cells via gap junctions
  3. Ca binds to calmodulin
105
Q

What are 4 similarities of smooth muscle and skeletal muscle contraction?

A
  1. actin/myosin interact via sliding filament mechanism
  2. need rise in intracellular Ca for contraction
  3. ATP needed for sliding of thin filament along thick filament
  4. relaxation when Ca pumped out of cell
106
Q

Skeletal muscle has the presence of _____ and site of ______. It is a site of calcium regulation in which ______ attaches to actin containing thin filaments

A

T-tubules
invagination
troponin

107
Q

What are the 3 functions of the nervous system?

A
  1. sensory
  2. integration
  3. motor output
108
Q 
function of nervous system:
sensory input (changes in internal and external environment)
A

sensory

109
Q 
function of nervous system: 
process/interpret
A

integration

110
Q 
function of nervous system:
activate effectors (muscles or glands); sent to effectors to elicit a response
A

motor output

111
Q

What are the 2 divisions of the nervous system?

A
  1. central NS

2. peripheral NS

112
Q

contains the brain and spinal cord

A

CNS

113
Q

contains the cranial and spinal nerves

A

PNS

114
Q

What are the 2 divisions of the PNS and what do they do?

A

sensory (affarent) division - impulses to CNS

motor (efferent) division - impulses from CNS

115
Q

What are the 3 impulse types classified under the sensory afferent division of the PNS?

A
  1. special senses
  2. somatic sensory fibers
  3. visceral sensory fibers
116
Q

impulses from eyes, ears, nose, and tongue (typically cranial nerves)

A

special senses

117
Q

impulses from skin, skeletal muscles, joints (mainly spinal nerves); transmit pain, changes in temperature, and pressure

A

somatic sensory fibers

118
Q

impulses from organs; transmit impulses from organs in ventral cavity (mainly spinal nerves); detect pain, pressure, changes in temperature

A

visceral sensory fibers

119
Q

What are the 2 divisions of the motor (efferent) division of the PNS?

A
  1. somatic NS

2. autonomic NS

120
Q

somatic motor neurons; voluntary nervous system; sleep paralysis

A

somatic nervous system

121
Q

interruption to REM sleep but somatic NS is asleep

A

sleep paralysis

122
Q

visceral motor neurons; involuntary; from CNS to cardiac cells, smooth muscle, and glands

A

autonomic NS

123
Q

What are the 2 divisions of the autonomic NS?

A
  1. sympathetic NS

2. parasympathetic NS

124
Q

speeds up heart rate, breathing, sweating; dilation of airways to increase oxygen to tissues; fight or flight

A

sympathetic NS

125
Q

directs vital activities; rest and digest

A

parasympathetic NS

126
Q

What are the 2 types of nervous cells?

A
  1. neurons

2. neuroglia (surrounding)

127
Q

nervous cells require a constant supply of ______

A

oxygen (can only last 5 minutes without)

128
Q

clusters of cell bodies in the CNS

A

nuclei

129
Q

clusters of nerve cell bodies in the PNS

A

ganglia

130
Q

receptive region of the neuron (branched)

A

dendrites

131
Q

slender process of the neuron that generates and conducts and action potential and can branch and have many axon terminals

A

axon

132
Q

cone shaped region where the axon ends (where action potentials are generated because there are lots of Na channels)

A

axon hillock

133
Q

branches of the axons

A

axon collaterals

134
Q

branches at the end of an axon

A

terminal branches

135
Q

knob endings of axon (also called synaptic knobs or buttons)

A

axon terminal

136
Q

cell membrane surrounding an axon

A

axolemma

137
Q

protects, insulates neurons, and aids in the speed of conduction

A

myelin sheath

138
Q

The myelin sheath is formed by _____ in the PNS and _____ in the CNS

A

schwann cells

oligodendrocytes

139
Q

gaps in the myelin sheath

A

nodes of ranvier

140
Q

neurons are myelinated; lots of layers of phospholipid bilayers

A

white matter

141
Q

cell bodies or axons are unmyelinated

A

gray matter

142
Q

What does the structural classification of neurons refer to and what are the 3 structural classifications?

A

number of processes; unipolar, bipolar, multipolar

143
Q

What does the functional classification of neurons refer to?

A

direction of nerve impulse relative to CNS

144
Q

single short processes; mostly sensory neurons; found mainly in PNS; distal (peripheral) process associated with sensory receptors

A

unipolar neurons

145
Q

two processes - axon and dendrite; mostly sensory neurons; found in some special sense organs (retina of eye); rare in the body

A

bipolar neurons

146
Q

3 or more processes - axon and dendrites; most are interneurons; some are motor neurons; most common type in CNS

A

multipolar neurons

147
Q

What are the 3 functional classifications of neurons?

A
  1. sensory (afferent) neurons
  2. motor (efferent) neurons
  3. interneurons
148
Q

impulses from sensory receptor to CNS; most unipolar; some bipolar

A

sensory (afferent) neurons

149
Q

impulses from CNS to effectors (muscles and glands); all multipolar

A

motor (efferent) neurons

150
Q

between sensory and motor neurons (can transmit both ways); most multipolar; 99% of neurons in body within CNS

A

interneurons

151
Q

support/protect neuron; speed up nerve impulse conduction

A

neuroglia (glial cells)

152
Q

What are the 4 types of neuroglia in the CNS?

A
  1. oligodendrocytes
  2. astrocytes
  3. microglia
  4. ependymal cells
153
Q

functional equivalent of schwann cells; wrap around multiple neurons; purpose is for rapid impulse transmission

A

oligodendrocytes

154
Q

star cell; control chemical environment; wrap around capillaries; neuron is in constant contact with its nutrient supply; control exchange of substances between neurons and blood (around capillaries and neurons); can sop up extra potassium ions and neurotransmitters; blood/brain barrier

A

astrocytes

155
Q

barrier between capillaries feeding the brain and extracellular fluid of brain (tight junctions regulate substances that enter the brain)

A

blood/brain barrier

156
Q

phagocytize microorganisms/dead neurons; immune cells cannot enter CNS

A

microglia

157
Q

form permeable barrier between brain/spinal cord and cerebrospinal fluid (CSF); cilia help circulate CSF

A

ependymal cells

158
Q

What are the 2 types of neuroglia in the PNS?

A
  1. satellite cells

2. schwann cells

159
Q

function like astrocytes in CNS; surrounds cell body; also surrounds capillaries

A

satellite cells

160
Q

wrap around axon and form myelin sheath; nerves are white in color due to myelin

A

schwann cells

161
Q

Myelination speeds __________ due to insulating property of myelin sheath and nodes of ranvier; salutatory conduction (action potential and depolarization)

A

impulse conduction

162
Q

myelinated long processes
PNS - nerves
CNS - tracts

A

white matter

163
Q

unmyelinated and cell bodies
PNS - ganglia (cluster of cell bodies)
CNS - nuclei

A

gray matter

164
Q

DCT covering peripheral nerves

A

epineurium

165
Q

DCT at fascicles (bundles of nerve fibers aka axons)

A

perineurium

166
Q

DCT at neuron processes (around individual axons - all DCT)

A

endometrium

167
Q

autoimmune disease attacks myelin sheath; conversion of myelin sheath into sclerosis (hardened lesions - scar tissue); reduces rate of nerve transmission; symptoms (blindness, weakness/paralysis, speech disturbances); can slow progression but not cure; can go into remission (when body produces more sodium channels; increase nerve impulse transmission)

A

multiple sclerosis

168
Q

junction between 2 neurons or neuron and effector

A

synapse

169
Q

conducts impulses towards synapse

A

presynaptic neuron

170
Q

conducts impulse away from synapse

A

postsynaptic neuron

171
Q

ion channel with no gate, always open

A

leakage channels

172
Q

ion channel where part of the protein functions as a gate

A

gated channels

173
Q

ion channel that opens when appropriate chemical attaches to the protein

A

chemically (ligand) gate

174
Q

ion channel that opens and closes in response to changes in membrane potential

A

voltage gated channels

175
Q

ion channel that opens in response to physical deformation of membrane

A

mechanically gated channels

176
Q

Na+/K+ pumps (active transport) maintains the _________. __ Na+ out for ever ____ K+ in

A

RMP

3 for 2

177
Q

short lived, localized changes in membrane potential; can be depolarizations or hyperpolarizations; decrease in magnitude with distance; vary with stimulus strength

A

graded potentials

178
Q

local graded depolarization events; NT bind to receptors on dendrites or cell body of postsynaptic neuron; opens Na+ and K+ channels —> net depolarizations; if current strong enough to spread through cell body to axon hillock; may trigger action potential

A

excitatory post-synaptic potentials (EPSPs)

179
Q

local graded hyper polarization events; NT bind to recepters on dendrites or cell body of postsynaptic neuron; opens Cl- or K+ channels —-> hyperpolarization; if current is strong enough to spread through the cell body to the axon hillock, it reduces the chance of an axon generating an action potential

A

inhibitory post-synaptic potentials (IPSPs)

180
Q

post synaptic neuron stimulated (or inhibited) simultaneously by large number of presynaptic axon terminals; resulting EPSPs and IPSPs add together

A

spatial summation

181
Q

postsynaptic neuron stimulated (or inhibited) in quick succession by one or more; resulting EPSPs or IPSPs ad together

A

temporal summation

182
Q

Voltage-gated channels located at ________. Graded potentials spreading to axon hillock cause channels to _____. If ion movement causes depolarization to threshold, it triggers _______

A

axon hillock
open
action potential

183
Q

membrane potential becomes less negative than resting potential

A

depolarization

184
Q

negative membrane potential is reestablished

A

repolarized

185
Q

membrane potential becomes more negative than resting potential

A

hyperpolarized

186
Q

closed when cell is in resting state; open when plasma membrane depolarizes

A

voltage sensitive activation gate; K+ activation gate

187
Q

open when cell is in resting state; slowly close soon after activation gate opens

A

inactivation gate

188
Q

where axon joins cell body; enough Na+ ions have to reach AH to initiate an AP

A

axon hillock

189
Q

responsible for generation and propagation

A

VR Na+/VR K+

190
Q

neuron cannot respond to another stimulus; period between opening of Na+ channels until Na+ channels reset to resting state

A

absolute refractory period

191
Q

only strong stimulus can stimulate another action potential; during depolarization Na+ channels in resting state, some K+ channels still open

A

relative refractory period

A & P 1 (6 decks)

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