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Physiology Flashcards

1
Q

What muscle function does this describe: Provide pressure for blood circulation

A

Cardiac

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2
Q

The functions of the muscular system

A

Movement Maintaince of Posture Stabilization of Joints Generation of Heat

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3
Q

What is the ability to respond to a stimulus?

A

Irritability

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4
Q

What us the ability to shorten

A

Contractibility

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5
Q

What is the ability to return to original dimension after shortening or stretching?

A

Elasticity

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6
Q

When muscle cells differentiate what happens?

A

They loose their ability to divide

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7
Q

What pathology of muscles is very rare?

A

Tumors

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8
Q

What us the name of a benign tumor usually found in the uterus but can also be found in arrector pilli, srotum, or nipples?

A

Leiomyoma

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9
Q

What is the name of a malignant tumor of smooth muscle usually found in uterus or GI tract?

A

Leiomuosarcoma

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10
Q

What is the name of a highly aggresive malignant tumor that originates in skeltal muscle, said to be derived from mesenchyme

A

Rhabdomyosarcoma

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11
Q

What type of muscle is found in the walls of hollowed organs?

A

Smooth muscle

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12
Q

What muscle is found throughout body attached to bones?

A

Skeletal

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13
Q

What muscle is found in walls of heart?

A

Cardiac

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14
Q

What muslce structure does this describe: Faintly striated cells, branching cells, 1-2 nuclei, intercalated disc seperate cells

A

cardiac

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15
Q

What muscle stimulation does this describe? Involuntary, self-exciting (autoryhtmic) can be controlled by ANS

A

cardiac

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16
Q

What muscle structure does this describe? long thin cells, striated, many nuclei

A

skeletal

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17
Q

What muscle function does this describe? posture, movement, joint stabilization

A

skeletal

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18
Q

What muscle stiumulation does this describe? voluntary contraction, stiumlate by somatic NS

A

skeletal

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19
Q

What muscle function does this describe: moved fluid and other body substances (food through GI)

A

smooth (peristalsis)

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20
Q

What muscle stimulation does this describe: involuntary, stiumlated by ANS

A

smooth

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21
Q

What are muscle fibers organized into?

A

Bundles

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22
Q

What is the dense irregular CT that covers the whole muscle

A

Epimysium

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23
Q

What is the CT that surrounds the fascicles?

A

Perimysium

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24
Q

What is the retucular CT that surounds a single muscle fiber within a fascile?

A

Endomysium

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25
Q

What is the name for the attachment of the muscle to the less movable bone or tissue?

A

Origin

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26
Q

What is the name for the attachment of the muscle to the more movable bone or tissue

A

Insertion

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27
Q

What is the plasma membrane of a muscle cell called?

A

Sarcolemma

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28
Q

What is the cytoplasm of a muscle cell that contains glycogen, myoglobin called?

A

Sarcoplasm

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29
Q

What is an oxygen binding pigment called?

A

Myoglobin

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30
Q

What are the large, subcellular structures that extend the length of a muscle fiber called? 80% of cells volume, muscle contraction?

A

Myofibrils

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31
Q

What is the smooth endoplasmic reticulum that has the abilioty to store CA2+ and release it during periods of contraction, ATP dependant

A

Sarcoplasmic Reticulum

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32
Q

What are the extensions of the sarcolemma that extend horizontally into the cell and that form triads with terminal cisterane on either side?

A

Transverse, or T-Tubules

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33
Q

What is the segment of a myofibril that extends between 2 Z discs, aka the functional unit of a muscle?

A

Sarcomere

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34
Q

What is the resting length of a sarcomere?

A

2 um

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35
Q

What filament is positioned laterally in the sarcomere and contains actin, troponin, and tropomyosin?

A

Thin myofilament or thin filament

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36
Q

What is a regulatory protien made of 3 polypeptides TnT, TnC, and TnI

A

Troponin

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37
Q

TnT does what?

A

Holds tropomyosin to actin

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38
Q

TnC does what?

A

binds calcium

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39
Q

TnI does what?

A

binds to actin

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40
Q

What blocks actin-myosin binding sites when the muscle is resting?

A

Tropomyosin

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41
Q

What occupies the center of a sarcomere, primarily composed of myosin and contains a “head”, or “cross bridge” where actin binds?

A

Thick filament

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42
Q

What is made of titin and holds the thick filament in position and helps prevent sarcomeres from pulling apart during contractions

A

elastic filament

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43
Q

What is the part of the sarcomere that has the thick myofilament and appears as dark band under microscope?

A

A band, or anisotropic (doubly refractive)

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44
Q

What is the portion of sarcomere that contains thin filament?

A

I band, isotrpic (singly refractive)

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45
Q

What is the end of the sarcomere that thick and thin filaments attach to?

A

Z disc

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46
Q

What is a region of A band that contains thick myofilaments only?

A

H zone

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47
Q

What bisects the H zone and made of proteins that connect thick and thin filaments

A

M line

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48
Q

What band contains thin filaments only and shortens during contraction?

A

I band

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49
Q

What band contains thick filaments only and shortens during contraction?

A

H band

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50
Q

What band contains thick and thin filaments and does not change in length during contraction?

A

A band

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51
Q

This is when the stiumlation of a muscle lead to a internal change which include shortening of a sarcomere

A

Coupling/ Contraction

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52
Q

This is when cellular mechanisms stop the contraction process and lead to rest

A

Relaxation

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53
Q

Where are skeletal muscle stimulated?

A

Neuromuscular junction or myoneural junction

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54
Q

What is the neurotransmitter that is stored in the vesicles in the motor neuron ending?

A

Ach, or acetylcholine

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55
Q

What is the highly folded area of the sarcolemma that lies in the area of the synaptic cleft and contains ACH receptors?

A

Motor End Plate

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56
Q

What is the enzyme associated with the sarcolemma of the motor end plate that is used to degrade ACH

A

Acetylcholinesterase (Ache)

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57
Q

What is the first step in the excitation mechanism?

A

The action potential reaches the end of a motor neuron

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58
Q

What is the second step in the excitation mechanism?

A

The voltage sensitive Calcium channels in the mem. of neuron open and calcium diffuses into neuron

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59
Q

What is the 3rd step of excitation mechanism?

A

Influx of Ca causes Ach to be released into the gap via exocytosis

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60
Q

What is the 4th step of excitation mechanism?

A

Ach diffuses across gap and binds to Ach receptors on the motor end plate

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61
Q

What is the 5th step excitation mechanism?

A

Binding of Ach to receptor initiates the action potential in sarcolemma along the muscle fiber surface and is is transmitted via T-tubules

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62
Q

What happens after Ach is degraded by AChase?

A

Acetate diffuses into synaptic cleft and choline is taken to motor nerve ending and can be used to make more ach

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63
Q

What is it called when the action impulse spreads into the muscle fiber via the T-tubules and the impulse causes Ca to diffuse?

A

Coupling/ Contraction

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64
Q

Where do calcium channels open?

A

Terminal Cisternae of sarcoplasmic reticulum

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65
Q

What happens when calcium binds to troponin?

A

The troponin/ tropomyosin blockade is removed and myosin cross bridge binds to actin molecules of the thin myofilament

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66
Q

What happens as the cross bridge continues to attach to the actin?

A

It pulls the center of the sarcomere and then detaches and as a result the sarcomere shortens

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67
Q

This is when the cross bridge activity stops and when calcium is removed from troponin, the calcium is removed by calcium pumps in SR

A

Relaxation

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68
Q

Used as a medicine in Brazil, blocks neuromuscular movements,causes paralysis,can affect breathing muscles and cause death by respiratory paralysis

A

Curare

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69
Q

This blocks the release of Ach

A

Botulinum Toxin

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70
Q

Relases Aplha-Larotoxin that appears to open the motor neuron Ca channels and leads to massive release of Acg and depletes Ach at synapse

A

Black widow spider

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71
Q

Consists of a single motor neuron plus the muscle cells (fibers) that is innervates

A

Motor Unit

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72
Q

Motor neuron disease, progressive and fatal, muscle weakness/wasting impaired speaking swallowing and breathing, due to degeneration of motor neurons

A

Amyotrophic Lateral Sclerosis

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73
Q

What is the average number of muscle fibers per motor unit?

A

150

74
Q

What do muscles used for precision movements have?

A

smaller motor units and few muscle fibers

75
Q

What do muscles used for large movements have?

A

large motor units and large number of muscle fibers

76
Q

Why does the strength of a contraction increase?

A

When increasing numbers of motor units are activated

77
Q

What is the process of generating force in a muscle as a result of cross bridge activity, may or may not lead to shortening?

A

Contraction

78
Q

What is the force exerted by a muscle on a load?

A

Tension (Effort)

79
Q

What is any force that opposes the tension (effort) generated by muscle contraction?

A

Load( Resistance)

80
Q

Contraction when muscle shortens as it moves the load

A

Concentric

81
Q

Contraction when muscle lengthen to move the load, can result in greater muscle soreness

A

Eccentric

82
Q

Contraction when tension is generated in muscle but it does not change in length

A

Isometric

83
Q

This involves lifting weights all or part of one body’s weight or moving the body against some externally imposed resistance

A

Resistance Training

84
Q

Contraction with limb movement can be concentric or eccentric

A

isotonic

85
Q

Contraction without shortening or movment of the muscle occurs at beginning and end of exercise helps stabilize

A

isometric

86
Q

Response of a skeletal muscle to a single, brief stimulus

A

Twitch

87
Q

Short period of time after stimulation when excitation/ coupling is occurring

A

Latent (Lag) Period

88
Q

Cross bridge activity leads to tension development, amount of tension depends on number of motor units recruited (activated)

A

Contraction Period

89
Q

Cross bridge activity stops as calcium is pumped back into the SR and muscle tension falls

A

Relaxation Period

90
Q

Contractions of a muscle that vary in strength

A

Graded muscle contractions

91
Q

What are the 2 ways to produce graded muscle contractions?

A

Change rate of stimulation and strength or stimulus

92
Q

This is when a 2nd stimulus is applied to a muscle before it is finished relaxing

A

Wave (temporal) stimuli

93
Q

This is when a 2nd stimulus is applied to a muscle before it is finished relaxing, but the stimuli is delivered very frequently

A

Incomplete Tetanus

94
Q

This is prolonged, smooth contractions that result from very rapid stimulus

A

Complete Tetanus

95
Q

This is when pulses of an increasing voltage are delivered to a recruitment muscle and the result is increased motor units and stronger muscle contractions

A

Multiple Motor Unit Summation

96
Q

This is when a strength of a muscle contraction increases with repeated stimulation , the first few contractions cause the muscle to “warm up”

A

Treppe (staircase effect)

97
Q

All muscles slightly contracted even when they seem relaxed, maintained by nervous system , prevents atrophy, maintains stability and posture

A

Muscle Tone

98
Q

This is the preferred fuel for muscle contraction and needed for relaxation as well

A

ATP

99
Q

This is when the cross bridges move from low energy to high energy positions

A

When ATP fuels the power stroke

100
Q

How does ATP aid in sarcomere relaxation?

A

Pumps calcium back into the SR

101
Q

Muscle cells store very little _____

A

ATP

102
Q

THis is when creatine looses a phosphate (creatine kinase) which is added to ADP and forms ATP

A

Creatine Synthesis

103
Q

THis takes place in sarcoplasm, little ATP is generated from each glucose used for quick, short term, and vigorous activity

A

Anaerobic Respiration

104
Q

This takes place in the mitochondria it is a slower pathway but is used for prolonged activities like jogging

A

Aerobic Respiration

105
Q

The length of time that a muscle can continue to contract using aerobic pathways

A

Aerobic Endurance

106
Q

The point at which a muscle metabolism switches from aerobic to anaerobic

A

Anaerobic threshold

107
Q

A state in which muscle is physiologically unable to contract because ATP production rate is less than ATP consumption

A

Muscle Fatigue

108
Q

The amount of oxygen needed to restore muscle to its resting metabolic state

A

Oxygen debt

109
Q

What does lactic acid do in the muscle cell?

A

It combines with oxygen to produce pyruvic acid and then forms ATP carbon dioxide and water

110
Q

What happens to lactic acid in the liver?

A

Turns to glucose and than broken down into glycogen

111
Q

What does strength of a muscle contraction depend on?

A

of motor units recruited, size of muscle, rate of stimulation, and the starting length of a sarcomere ( degree of muscle stretch)

112
Q

The greater number of motor neurons stimulated the greater the _____________ (3 words)

A

Force of Contraction

113
Q

An increased rate of stimulation allows more ____ to develop

A

force

114
Q

An optimum sarcomere length allows for maximum_________( 1 word)

A

Contraction

115
Q

What is the optimum length of a sarcomere?

A

The resting length of a skeletal muscle

116
Q

How is the rate of a contraction measured?

A

Velocity

117
Q

What does velocity depend on?

A

Characteristics of a load

118
Q

What are the three types of muscle fibers?

A

Slow oxidative, fast oxidative, and fast glycolic

119
Q

The quantity of the three type of muscle fibers determines what about muscle contraction?

A

the velocity and duration

120
Q

Name the muscle fiber based on its structure: ATPase responds slowly, aerobic adapted, myoglobin(red), vascular, many mitochondria, small diameter

A

Slow Oxidative

121
Q

Name this muscle fiber based on its function: Slow speed of contraction

A

Slow Oxidative

122
Q

Name this muscle fiber based on it properties: fatigue resistant, used for endurance and prolonged contraction

A

slow oxidative

123
Q

Name this muscle fiber based on its structure: ATPase responds quick, aerobic, pink (less myoglobin), vascular, mitochondrial, intermediate diameter

A

Fast oxidative

124
Q

Name these muscle fiber based on its function: fast speed of contraction

A

Fast Oxidative, Fast Glycolytic

125
Q

Name this muscle fiber based on it properties: fatigue resistant, used for endurance and rapid contractions

A

Fast oxidative

126
Q

Name this muscle fiber based on structure: ATPase responds quick, anaerobic, white, no blood supply, few mitochondria, large

A

Fast Glycolytic

127
Q

Name this muscle fiber based on these properties: fatigue easy, not intense for short term movements

A

Fast Glycolytic

128
Q

Name this muscle type: small spindle shaped fibers, central nuclei, no striations, little SR and no T-tubules, sarcolemma sequesters calcium

A

Smooth muscle

129
Q

Name this muscle type: small spindle shaped fibers, central nucleus, no striations, little SR and no T-tubules, sarcolemma sequesters calcium

A

Smooth muscle

130
Q

What is absent in smooth muscle and what is present?

A

Absent= Troponin, Present= Tropomyosin

131
Q

How are thick and thin myofilaments arranged in smooth muscles?

A

Diagonally, when the cell contracts it twist like a corkscrew

132
Q

What are the fibers that are attached to dense bodies that are attached to the sarcolemma and thin myofilaments in smooth muscle?

A

Non contractile intermediate filaments

133
Q

In smooth muscles fibers are not always organized into_______

A

Fascicles

134
Q

In most organs smooth muscle fibers are arranged into cellular sheets with ___ or ___ orientation

A

circular or longitudinal

135
Q

What is neural regulation of smooth muscle stimulated by?

A

The ANS

136
Q

What are the neurotransmitters of smooth muscle?

A

Ach, norepinephrine

137
Q

What is some smooth muscle controlled by?

A

Pacemaker cells, chemical factors

138
Q

Name this smooth muscle type: contracts as one unit, rhythmically and automatically EX: walls of hollow organs like uterus

A

Single unit or visceral

139
Q

Name this smooth muscle type: Lacks synchrony, graded contractions, many nerve endings in muscle Ex: Blood Vessels and Bronchi

A

Multi unit

140
Q

A rigid structure that movies about a fixed point, classified as simple machines because they can do work

A

Lever

141
Q

What is the fixed point a lever moves around?

A

Fulcrum

142
Q

What is the muscle that assists the PM by performing same movement or preventing opps. movement

A

Synergist

143
Q

What is the muscle that stabilizes the bone of the muscle?

A

Fixator

144
Q

What causes disuse atrophy?

A

Prolonged bed rest, casting, or local nerve damage

145
Q

What are the characteristics of disuse atrophy?

A

Reduction on size of muscle fibers

146
Q

What are the causes of muscle cramps?

A

Circulatory Impairment or heart disorders that can lead to electrolyte problems

147
Q

What are the characteristics of muscle cramps?

A

Sustained involuntary contractions of a skeletal muscle

148
Q

What causes muscular dystrophy?

A

X linked recessive disorder in half of cases, defective gene causes dystrophin to be absent

149
Q

What muscle pathology does this describe: reduction in muscle fibers, necrosis muscle replaced with CT or fat, delayed sitting, standing and walking

A

Muscular Dystrophy

150
Q

What causes myasthenia gravis?

A

defective transmissions at neuromuscular junction due to decreased ACH receptors

151
Q

What muscle pathology does this describe? Fatigue, chronic respiratory infections, weakness

A

myasthenia gravis

152
Q

what are the functions of the nervous system?

A
  1. ) monitors the internal and external environments.
  2. ) integrates sensory information.
  3. ) coordinates voluntary and involuntary responses of many organ systems
153
Q

CNS vs. PNS

A 
CNS= brain and spinal cord
PNS= nerves
154
Q
  • the membrane potential of a normal cell under homeostatic conditions (-70mV)
  • the membrane potential at which and action potential begins
  • chemical compound released to affect the membrane potential of a neuron
A
  • resting potential
  • threshold potential
  • release of a neurotransmitter
155
Q

what are the steps at neuromuscular junction

A

1) action potential arrives at axon terminal 2) voltage gated sodium channels open and sodium rushes in 3) vesicles exocytose acetylcholine 4) neurotransmitters diffuse across synaptic cleft and binds to neurotransmitters receptors on the post synaptic cleft 5) binding of neurotransmitters opens ion channels resulting in a graded potential (change in shape) gives channel for ion to flux and change membrane potential 6) neurotransmitters are terminated

156
Q

acetylcholinesterase

A

degrades acetylcholine

157
Q

how are neurotransmitters classified

A

by structure and function

158
Q

Spatial Summation

A

2 different stimuli at the same time but different place so they are added

159
Q

Summation

A

one EPSP cannot cause an action potential however a sum of them can

160
Q

what are the two types of postsynaptic potential

A

EPSP and IPSP

161
Q

EPSP

A

excitatory (+) pushes membrane potential closer to threshold sodium influx is greater then potassium and causes depolarization

162
Q

IPSP

A

inhibitory (-) brings membrane potential further away from threshold neurotransmitter opens channels for K+ to leave and Cl- to come in… removes ability to provide an action potential

163
Q

what are the 3 ways that neurotransmitters are terminated

A

1)Reuptake~ most common 2)degraded~ enzymes go into synaptic cleft and chews it up 3) Diffusion~Neurotransmitters bind to receptors and diffuse away

164
Q

Temporal Summation

A

rapid impulse sent to the same location at different times closer so the look like they are being added

165
Q

acetylcholine

A

first neurotransmitter discovered, degraded by the enzyme acetylcholinesterase, released by all neurons that stimulate skeletal muscle

166
Q

what are the 6 steps of cross bridge cycling

A

1) exposure of binding sites on Actin 2) binding of myosin to actin 3) power stroke of the cross bridge that causes sliding of thin filaments 4) binding of ATP to cross bridge head 5) hydrolysis of ATP receptors cross bridge head 6) active transport of ca stops to Sr?terminal cysteine

167
Q

where do the calcium ions come from to begin this process

A

terminal cisternae

168
Q

why don’t you remain in rigamortis

A

you do not remain in rigor mortis is because myosin, actin, and muscle cells begin to disintegrate, or die

169
Q

what are the two layers of smooth muscle

A

longitudinal~ outside circular~ inside

170
Q

what don’t smooth muscles have

A

troponin, myosin, T Tubules

171
Q

what are gap junctions

A

a gap junction is a junction between two cells that allows ion to transfer from cell to cell, allows action potentials to flow from cell to cell

172
Q

what are the steps to smooth muscles contraction

A

1) calcium enters smooth cell 2) calcium binds to and activates calmodulin 3) activated calmodulin activates the myosin light chain kinase enzymes 4) the activated kinase enzymes catalyze transfer of phosphate to myosin activating the myosin ATPases 5) activated myosin forms cross bridges with actin of the thin filaments and shortening begins

173
Q

contraction mechanism

A

-actin and myosin interact according to the sliding filament mechanism -the final trigger for contraction is a rise in intracellular calcium -calcium is released from SR and from the extracellular space -calcium interacts with calmodulin and (read final steps above) -very energy efficient (slow ATPase) -Myofilaments may maintain a latch state for prolonged contractions

174
Q

what does relation require

A

~calcium detachment from calmodulin ~active transport of calcium into SR and ECF ~dephosphorylation of myosin to reduce myosin ATP activity

175
Q

duchenne muscular dystrophy

A

only expressed in males diagnosed between ages 2-10 victims usually don’t live past 20 caused by a lack of cytoplasmic protein dystrophin no cure, some treatments being tested example: myoblast transfer therapy: inject diseased muscle with healthy myoblast cell that fuse with unhealthy ones

176
Q

disc junctions

A

anchor cardiac cells

177
Q

desosomes

A

prevent cells from separating from contraction

178
Q

how is the cardiac muscle stimulated

A

stimulated by nerves and is self-excitable

179
Q

what is the absolute refractory period

A

long at about 250ms

180
Q

syncytium

A

allow heart to function as one muscle

Myology (8 decks)

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