Cardiac - Muscle - Autonomics - Important Terms Flashcards
1
Q
Mechanoreceptors
A
stretch, sound waves
2
Q
Osmoreceptors
A
Solute concentration
3
Q
Chemoreceptors
A
Specific chemicald (smell, taste, O2, CO2, glc, aa, fats)
4
Q
Antagonistic Dual Innervation
A
actions of the SNS and PSNS counteract each other
can work on same or different cells
5
Q
Complementary Dual Innervation
A
Actions produce similar effects
6
Q
Cooperative Dual Innervation
A
actions produce different effects that work together to produce desired effect
7
Q
Parasympathetic Tone
A
Parasympathetic nervous system dominates in dual innervation
8
Q
Sympathetic Tone
A
Sympathetic nervous system dominates in dual innervation
9
Q
Sympathetic Vasomotor Tone
A
a base firing frequency of sympathetics
10
Q
Muscarinic Receptor (mAChR)
A
Autonomic NT receptor
Binds GTP
Slower
11
Q
Metabotropic Receptors
A
G Protein-Coupled Receptor
slower
a lot of metabolic steps
bind GTP
muscarinic receptor
12
Q
Ionotropic Receptor
A
Ligand-gated ion channel
Faster
nicotinic
13
Q
Single Unit Smooth Muscle
A
only a few muscle fibers innervated in each group
stimulatd together, contract together
14
Q
Slow Wave Potentials
A
coordinate muscle contractions in the gut by controlling the appearance of a second type of depolarizing event
15
Q
Multiunit Smooth Muscle
A
neurogenic
requiring stimulation by autonomic nerves
16
Q
Singleunit smooth muscle
A
myogenic
able to initiate its own contraction w/o any external influence due to automatic shifts in ion fluxes
17
Q
Sarcomere: Light Band
A
I Band
18
Q
Sarcomere: Dark Band
A
A Band
19
Q
Sarcomere: I Band
A
Remaining portion of thin filaments that are not included in A band
only thin filaments
shortens
20
Q
Sarcomere: Z Line
A
middle of I Band
stabilizes thin filament
entire sarcomere
21
Q
Sarcomere: H Zone
A
Lighter area in middle of A Band
Thin filaments do not reach
only thick filaments
shortens
22
Q
Sarcomere: M Line
A
mid point of sarcomere
stabilizes tick filament
23
Q
Sarcoplasmic Reticulum (SR)
A
modified ER
consists of interconnecting tubules surrounding each myofibril like a mesh sleeve
Bring action potentials from surface to center of cell
24
Q
T-Tubule
A
invagination of plasma membrane that runs perpendicular to the surface and bring action potentials into the muscle fiber
25
Black Widow Spider Venom
Alters Release of ACh
toxin can form pores in presynaptic membrane
explosive release of ACh
results in respiratory failure
26
Clostridium Botulinum Toxin
Blocks release of ACh
interferes with share proteins
can result in respiratory failure
used as medicine
27
Curare
Reverisbly binds to ACh receptor, blocking it from activating
antagonist
causes paralyzation and respiratory failure
28
Myasthenia Gravis
antibodies inactivate ACh receptor, blocking it
29
Organophosphates
Irreversibly inhibits AChase, preventing inactivation of ACh
results in respiratory failure
30
Graded Potential
Resultant change in membrane potential causes by ionic movements through open membrane channels
31
Synapse
A junction between 2 neurons
Excitatory (EPSP) or inhibitory (IPSP)
32
Neuromuscular Junction (NMJ)
Exists between a motor neuron and a skeletal muscle fiber
always excitatory (EPP)
33
Slow Twitch fibers
Type 1
Oxidative metabolism
used for walking and posture
fatigue resistant
34
Fast Twitch a fiber
Type IIa
moderatly high ox capacity
high glycolytic capacity
not as common as Type I and Type IIx
35
Fast Twitch x fiber
used for power
low oxidative capacity
highest glycolytic capacity
36
Motor Unit
1 motor neuron + all the muscle fibers it innervates
37
Isometric (static) contraction
Muscle produces force but does not change length
Joint angle does not change
Myosin cross-bridges for and recycle, no sliding
38
Isotonic (dynamic) contraction
Muscle produces force and changes length
Joint movement produced
39
Concentric Contraction
Muscle shortens while producing force
most familiar type of contraction
sarcomere shorten, filaments slide toward center
40
Eccentric Contraction
Muscle lenthens while producing force
Cross-bridges form but sarcomere lengthens
41
Muscle Fibers
long, cylindrical, multinucleated muscle cells
42
Saromere
an ordered arrangement of thick and thin filaments
43
Neurogenic
only contracts when externally stimulated by a nerve
44
steric inhibition
troponin-tropomyosin complex slips back into its blocking position
45
Sliding filament mechanism
the relationship between the length of the muscle and the tension it can develop
46
Optimal Length
active force generated is maximal
47
Immediate ATP pathway for contraction
high energy phosphates from stored creatine phosphate
48
Non-oxidative pathways muscles obtain ATP for contraction
synthesize ATP w/o O2 and uses glycogen stores and generates lactic acid
ex: glycogenolysis and glycolysis
49
Oxidative phosphorylation pathway muscles use to obtain ATP for contraction
efficiently extracts large amounts of ATP from nutrient molecules but requires suffiecent O2
50
Right Heart
Volume Pump
Delievers high volumes of blood at low pressures
51
Pulmonary Vessels
Function in blood-gas exchange and serve as volume reservoirs
52
Left Heart
Pressure Pump
The energy source for the circulatory system
53
Elastic Arteries (Aorta)
Their basic behavior allows them to serve as a "surge pump"
Energy is stored in the elastic fibers during the contraction phase(systole) and released during the relaxation phase (diastole)
54
Systole
Contraction Phase
Ventricles contracted
Tricuspid and Mitral Valves closed
Pulmonic and Aortic Valves open
Increased Ca2+ in cell
55
Diastole
Relaxatio Phase
Ventricle Relaxation
Tricuspid and Mitral valves open
Pulmonic and Aortic Valves closed
Decreased Ca2+ in cell
56
Muscular Arteries
Function as low resistance conduits that rapidly deliver blood to the tissues
57
Arterioles
Collectively termed "resistance vessels"
Serve as resistors that regulate the flow of blood into capillary beds
58
Capillaries
One cell layer separates blood from tissue space
Site of nutrent and waste exchange
59
Venous Vessels
Serve as volume reservior
These vessels function in both the storage and mobilizatio of blood
60
Pulmonary Circulation
Blood flows through lungs
61
Systemic Circulation
Blood flows through all organs of the body except lungs
62
Systemic Circulation: Arterials
LV to Capillaries
High Pressure
Low Volume
63
Systemic Circulation: Venous
Low Pressure
High Volume
High Compliance
64
Epicardium
Outer muscle layer in the heart
65
Edocardium
Inner muscle layer in the heart
66
Pulmonary Capillary Wedge
Estimation of LA pressure
67
Endothelium Derived Relaxing Factor (EDRF)
Relaxation
Nitric Oxide
Vasodilater
68
Endothelin
Vasoconstrictor
69
Endothelial Cells
Line the cardiovascular system
produce vasodilators and vasoconstrictors
70
Cardiac Output
CO = HR x SV
71
Cardiac Muscle Action Potential: Phase 0
Threshold ~ -65 mV
Fast Na+ channels open
Na+ permeability is high
K+ permeability is low
Membrane potential becomes positive
72
Cardiac Muscle Action Potential: Phase 1
Fast Na+ Channel inactivation
73
Cardiac Muscle Action Potential: Phase 2
Voltage-Gated Ca2+ channels open
Fast Na+ channels reopen (Na+ moves in with Ca2+ slowly)
Ca2+ increases in cell, pemeability increases
K+ decreases in cell
Membrane Voltage is constant
74
Cardiac Muscle Action Potential: Phase 3
More K+ channels open
Na+ and Ca2+ Channels close
75
Cardiac Muscle Action Potential: Phase 4
RMP
76
Tetradotoxin
Blocks Fast Na+ Channels
77
Dilitiazem
Ca2+ Channel Blocker
Blocks L-Type Calcium Channels
Shortens Phase 2
Decreases contraction force
78
Absolute Refractory Period (ARP)
During this period, no stimulus can elicit an action potential
Prevents another AP from being fired off before cardiac muscle contraction finishes
Protects the heart from Tetanus
79
Relative Refractory Period (RRP)
An action potential can be elicited but it would require greater than normal stimulus
80
Super Normal Period (SNP)
Stimulus of less strength can stimulate cell and generate an action potential
Action potentials propagate slowly
81
Overdrive Suppresion
Ensures that dominate packemaker suppresses the other pacemaker
82
SA Node
Dominate Pacemaker
Determines rate an AP propagates around the heart
83
AV Node
Takes over if the SA Node fails as a pacemaker
Slowest conduction velocity
84
SA Node Action Potential: Phase 0
Increase in Ca2+ Permeability
85
SA Node Action Potential: Phase 4
Less negative at RMP
Less K+ permeability at RMP
RMP gradually depolarizes over time
86
Reentry
Occurs when an excitation wave reexcites some region through which it has recently passed
circuits can eithe rbe random or ordered
87
Procaine
Reduces irritability of the cardiac muscle
used in ventricular arrhythmias
slows opening of Na+ gates, reduces depolarization current, and slows conductin from cell to cell
88
Quinidine
Used in treatment of atrial fibrillation, atrial flutter, and paroxysmal ventricular tachycardia
slows opening of Na+ gates, reduces depolarization current, and slows conductin from cell to cell
89
Reduced Refactory Periods
Periods of time during an action potential when cardiac excitability is reduced
90
Full Recovery Time (FRT)
The interval between depolarization and recovery of normal resting excitability
A normal action potential with normal speed propagation can generate
91
AN Zone
Transitional Zone
Cell types in this region are a mixture of atrial and nodal fibers interspersed with connective tissue
92
N Zone
Middle portion of the AV Node
93
N-H Zone
Transitional Zone
Nodal fibers gradually merge with fibers from te Bundle of His
94
Preload
Force present in relaxed muscle
Stretch that's placed on a muscle (LV) prior to contraction
Resting Length
Determined by EDV
95
End Diastolic Volume (EDV)
Volume present in ventricle prior to contraction
96
Afterload
The force a muscle has to overcome to shorten
The force exerted by a shortening muscle
Tension or stretch in the wall of the LV just before the aortic valve opens
Related to aortic pressure
97
Frank-Starling Relationship
Length-dependent change of cardiac function
Increase Preload -> Increase CO up to the optimal length
98
Contractility
Change in cardiac function not related to length
Vaiable state of muscle performance at a given muscle length
Performance of the heart at a given preload and afterload
99
Contractility determined by dP/dt
Measure of the rate of pessure development
100
Positive Chronotrope
Increase Heart Rate
NE and EPI
101
Negative Chronotrope
Decrease Heart Rate
ACh
102
Positive Inotrope
Increase Contractility -> Increase SV
NE, EPI
103
Negativev Inotrope
Decrease Contractillity -> Decrease SV -> ACh
104
Ejection Fraction
Percent of blood ejected from your heart (LV) with each beat
EF = SV/EDV
105
Cadiac Cycle
All events that occur in a beat
106
Atrial Systole
LA and LV pressure are about equal
Blood moves from Atria to Ventricle
Atrial pressure increases
107
Isovolumic Contraction
Mitral/Tricuspid Valves closed
LV contracts
LV pressure increases
Aortic/Pulmonary Valve opens
108
Rapid Ejection
Blood ejected from LV to Aorta
109
Reduced Ejection
Blood moves away from heart
LV starts to relax, pressure decreases
Ejected full SV
110
Isovolumiv Relaxation
Aortic/Pulmonary valves close
LV Pressure drastically decreases
111
Rapid Ventricular Filling
Mitral/Tricuspid Valves open
Atrial pressure is higher than LV
112
Reduced Ventricular Filling
Diastasis
113
LVEDV
Max volume in ventricle prior to contraction -> preload
114
Pulmonary Capillary Wedge Pressure
Approximate measurement of LV pressure
115
Hypertrophic
Less volume in the chamber
116
Pressure
Force produced by LV and RV when contracting
Force in a fluid system
117
Blood Pessure
Pressure inside artery during contraction
118
Transmural Pressure
Pressure across the wall
119
Compliance
relates to any hollow organ
depends on how stretchy the hollow organ is
Lower volume = higher compliance
120
Q
Volume Flow
121
v
Velocity Flow
122
Resistance
In the cardiovascular system can be calculated as the change in pressure (mmHg) divided by the flow in mL/min or L/min
Caused by venoconstriction
123
Resistance Effect
Pressure between resistors and LV
Flow from arterioles to capillaries
124
Viscosity
The difficulty in seperating lamina of flow
Increase viscosity, increase flow
The internal friction of a fluid which opposes the separation of its laminae
A force must be applied to overcome this
125
Hematocrit
Percent volume of RBC's in Blood
126
r^4
Changing radius of arterioles
127
Pulse Pressure (PP)
Systole - Diastole
Effected directly by SV and inversly by Aortic Compliance
128
Total Periperal Resistance (TPR)
Description of whether vessels are constricted or dilated
Increase constriction -> increase TPR
129
Autoregulation
The intrinsic ability of an orga to aintain blood flow constance depsite changes in perfusion pressure
130
Autoregulatory Range
Area where pressure increases but fow stays constant
resistance increases
131
Hyperemia
Increased blood flow
132
Active Hyperemia
Active increase in blood flow during increase in metabolic activity
133
Reactive Hyperemia
Increased blood flow in response to a period of decreased (or interupption of) blood flow
134
Flow-induced Vasodilation
Blood flowing through the vessel causes vasodilation
135
Endothelial Sheer Stress
Spatial gradient of blood velocity sensed vy endotheliaol cell layer
changes based on location in the system
136
Angiotensin II
potent vasoconstrictor
137
Kinase II
ACE
Converts angiotensin I to angiotensin II
138
ANP/ANF
Vasodilator
Increases Na+ excretion
139
Adenosine
Balancs oxygen supply and demand
Vasodilator
140
Baroreceptor Reflex
Helps regulate sympathetic and parasympathetic innervation to vasculature
stretch receptors
141
Afferent Barorecptors
Periphery to CNS
142
Efferent Baroreceptors
CNS to periphery
143
Vasomotor Tone
Partial state of contraction in blood vessel caused by continuous slow firing of neurons
Tonic neural activity always present in sympathetic efferent fibers from the pressor centers in the medulla
144
Baroreceptors
They are sensors that function as mechanoreceptors and respond to changes in length (stretch) of theh vessel wall)
145
Cardiopulmonary Baroreceptors
Located in the atria, ventricles, andn pulmonary vessels
Stretch receptors that are important in regulation of heart rate, blood pressure, and blood volume
146
Microcirculation
All vessels less than 100 um in diameter
including; arterioles, capillaries, and venules
147
Metarterioles
branch from arterioles and give rise to capillaries or serve as bypass channels to the venules
148
Vasomotion
The variation in flow rate in the capillaries due to contraction and relaxation of precapillary vessels
149
Nutrient Flow
Blood flows through the capillaries which provides for exchange of nutrients and metabolites
150
Non-nutrient flow
Shunt
The blood flow bypasses the capillaries and passes directly from arterioles to venules
True shunts exist in areas of the body like the fingertips
151
Exchange Vessels
any vessel that permits bidirectional tranpsort across its wall
152
Flow limited diffusion
For small miolecules less than 60,000 molecular weight, theh primary limiation to diffusion nacross the capillary wall is the rate of delivery of the substance in the blood flow
153
Diffusion limited diffusion (transport)
Diffusion can be limited by either the size of the milecule or the diffusion distance between the capillary and the parenchymal cell.
In this condition, even at high rates of flow, diffusion becomes the limiting factor
154
Ultrafiltrate
Plasma which has been seperated from its large molecular weight proteins (colloids)
155
Bulk Flow (Ultrafiltration)
Exchange vessels behave as highly porus filters which allow bulk flow of plasma water and dissolved crystalloids (electrolytes and glucose) but essentially prevents the movement of plasma proteins
Two-directional process
One of the means by which plasma volume is regulated
156
Hydrostatic Pressure
the principle force favoring filtration across the capillary wall
157
Osmotic (oncotic) pressure
the main force opposingn filtration exerted by plasma proteins
related to the negative chareg on albumin and its ability to interact with other osmotically active particles
158
Pc
Capillary Hydrostatic Pressure
159
Pi
Interstitial fluid hydrostatic pressure
160
Pip
Plasma protein oncotic pressure
161
PiI
Interstitial fluid oncotic pressure
162
k
FIltration constant for the capillary membrane\
163
Dynamic Center (Equilibrium Point)
The point where there is no net movement of fluid in the capillary
164
Edema
Abnormal increase in the volume of interstitial fluid in a tissue or organ
165
Hypoproteinemia
reduced plasma protein
166
Hypoalbuminemia
Decreased plasma oncotic pressure
