Physiology Final Flashcards
(230 cards)
1
Q
The main job of the renal system is
A
regulation of osmolarity and water balance
2
Q
if a substance is neither reabsorbed nor secreted, then its excretion rate is equal to
A
the GFR
3
Q
GFR will increase when there is
A
decreased afferent arteriole resistance (PS)
4
Q
the diffusion of water across a tubule is driven by differences in _______________ across the membrane
A
osmolarity
5
Q
An increase in fluid flow into the glomerulus will increase pressure and finally decrease filtration into bowmans space True or False
A
FALSE -
6
Q
The most important ingredient for normal driving force in glomerular filtration is
A
capillary hydrostatic pressure
7
Q
Renin secretion from the juxtaglomerular cells of the afferent and efferent arterioles of the glomerulus is dependent on
A
NaCL concentration in the distal tubule
8
Q
Autoregulation of GFR is accomplished by
A
Low NaCl flow at the Macula Densa
Juxtaglomerlar Apparatus Feedback
Macula Densa regulation of renal blood pressure
9
Q
Strong sympathetic stimulation of the afferent and efferent arterioles of the glomerulus could stop fluid flow and thus decrease urine production - True or False?
A
TRUE
10
Q
True or False - Material that enters the Lumen of the renal tubules is excreted unless it is resorbed.
A
True
11
Q
True or False, Bradykinin is a protein secreted by damaged skin tissue which will cause vasoconstriction decreasing blood flow to the damaged area
A
False - Bradykinin causes vasodilation, and causes an increase in urine production
12
Q
Baroreceptors respond to
A
the changes in stretch of the blood vessel wall
13
Q
True or false, the cardiovascular system usually has a sympathetic tone regulating blood pressure
A
true
14
Q
inflammation (fluid and solute increase in the interstitium may be caused by)
A
1) increased capillary filtration
2) increased capillary permeability
3) histamine secretion by mast cells
15
Q
when a baroreceptor reflex is activated, what alters
A
heart rate
stroke volme
tpr
16
Q
what humoral substance(s) control high blood pressure aound the cardiovascular network?
A
vasopressin
17
Q
sympathetic response to a decrease in blood pressure (cardiac)
A
vasoconstriction of arteries and veins
increased acetylcholine release
increased heart rate and ventricular contaction
18
Q
Renin secretion from the Juxtaglomerular cells of the afferent and efferent arterioles of the glomerulus is dependent on
A
NaCl concentrations in the distal tubule
19
Q
Loss of glucose in the urine is an example of
A
glucose exchangers in the walls of the nephron being saturated
20
Q
True or False - water reabsorption is by simple diffusion in the proximal convoluted tubule and descending loop of henle; while water is not necessarily permeable to the walls of the distal convoluted tubule and collecting ducts (permeable only if ADH secretion)
A
true
21
Q
what part of the nephron reabsorbs the largest quantity of the glomerular filtrate?
A
proximal convoluted tubule
22
Q
potassium concentration can be low during times of dehydration. What is one of the main reasons for this?
A
increased Na+/K+ pump activity in the walls of the nephron
23
Q
Disabling the Na+/K+ pump in the cells of the proximal convoluted tubule will
A
Generate an increase in the amount of urine produced
24
Q
What happens to sodium in the proximal tubule
A
Na+ remains the same because water and sodium are being resorbed equally
25
True or False, in the ascending thick loop of henly, Na+, K+ and Cl- concentrations decrease because either the ions are being pumped out of the tubule lumen (reabsorbed) and/or water is not permeable to the tubule wall.
True
26
What happens to glucose in the proximal tubule
It is reabsorbed
27
the concentration of PAH in the thick loop of Henle is getting smaller because it is being reabsorbed from the nephron
FALSE - it is getting smaller because the water concentration is increasing
28
In the model for quiet, relaxed breathing, the breathing rhythm is maintained by the
inspiratory neurons in the dorsal respiratory center
29
what factors affect hemoglobin affinity for O2
2,3 BPG, pH, temperature
30
surfactant secretion is vital for
reducing surface tension in the alveoli
31
the enzyme necessary to convert H20 and CO2 to H2CO2 is
carbonic anhydrase
32
central chemoreceptors are neurons in the medulla that respond directly to
pH levels outside of the blood vessels
33
the most plentiful gas in our atmosphere is
nitrogen
34
true or false - the inspiratory neurons of the dorsal respiratory center stimulate motor neurons in the phrenic nerve, which stimulates contraction of the diaphragm
true
35
exercise will cause the hemoglobin dissociation curve to move to the right showing that affinity of hemoglobin for oxygen is dropping and therefore more oxygen is free for the tissues to use
true or false
true
36
true or false - peripheral chemoreceptors associated with respiration are mainly sensitive to O2 partial pressures
true
37
hemoglobin disassociation curve moving to the left means
affinity for oxygen is increasing, less oxygen is free
38
true or false - an artery is designed to allow exchange of materials with surrounding tissue
false
39
how many microns across is the diameter of an arteriole?
20
40
how many microns across is the diameter of a capillary?
5-9 microns
41
venous return is dependent on these three factors
one way valves
pumping action of the skeletal muscles
small amount muscle tone in veins
42
edema can be caused by these three factors
increase in ventral venous pressure
blood pooling in the venous system of the body
gravitational forces on the cardiovascular system
43
arteriosclerosis is a disease that reduces the compliance (increases the resistance) of the arterial system. What type of pressure would increase?
systolic
44
venous pressure in the legs is higher because of hydrostatic pressure due to gravity, true or false
true!
45
the most important vessels for reducing pressure of fluid going to the capillaries are
arterioles
46
normal reabsorption and filtration within the capillaries are dependent on
changing hydrostatic pressures in the plasma
47
which component of the cardiovascular system holds the largest percentage of the total blood volume?
the venous sustem
48
holding the hydrostatic pressure gradient constant and increasing the protein concentration within the interstitial space would do what to the outward movement of fluid?
enhance the outward movement
49
inhalation is an active or passive process?
active - contraction of the diaphragm creates negative space
50
exhalation is an active or passive process?
passive
51
what causes pneumonia?
buildup of fluids inside the thoracic cage creating too much surface tension on the alveoli
52
what does surfactant do?
keeps alveoli from overexpanding or collapsing
53
how does hemoglobin link to O2?
hemoglobin has four iron molecules, it wants to link to three oxygen. If it links to four it is saturated.
54
normal inspiration is controlled by
the dorsal respiratory group
55
nasal passages responsible for
warming, humidifying, filtering the air
56
trachea and bronchii are responsible for
air passage and mucus removal
57
bronchioles are responsible for
transition and regulation
58
respiratory bronchioles and alveoli are responsible for
gas exchange
59
Oxygen transport is dependent on
oxygen entering the lungs
blood flow
effective gas exchange
ability of the blood to carry oxygen
60
In hypoventilation
oxygen decreases, CO2 increases,
61
in hyperventilation
oxygen increases, CO2 increases
62
How does 2,3 Biphosphoglycerate affect hemoglobin affinity?
2,3 BPG binds to hemoglobin, freeing oxygen for tissues
63
which nerves signal the dorsal respiratory group
vagus and glossopharyngeal
64
how does the pneumotaxic center affect respiration?
a strong signal will shorten the respiratory cycle
| a weak signal will lengthen the respiratory cycle
65
how is the ventral respiratory group involved in breathing
can increase expiration according to respiratory drive
66
what is the hering-breuer inflation reflex?
pulmonary stretch receptors in the bronchii and bronchioles due to large inspirations signal the pneumotaxic center through the vagus nerve - the PC limits inspiration, allowing expiration to occur
67
lowered pH does what to respiration?
increases inspiration
68
the carotid body signals which cranial nerve?
glossopharyngeal
69
the aortic body chemoreceptor signals which cranial nerve?
vagus
70
PO2 < 60mmHg signals which chemoreceptors?
peripheral
71
Increased PCO2 signals which chemoreceptors?
central
72
how much of total blood volume is in the veins?
61%
73
major differences in systemic pulmonary circulation are caused by
ventricular ejection and ventricular filling
74
what is the maximum pressure a capillary can stand?
40mmHg
75
Diastolic pressure is a measure of
the minimum pressure in the arteries during ventricular filling
76
systolic pressure is a measure of
peak pressure in the arteries during ventricular contraction
77
korotokoff sounds
the sound of fluid entering arteries after being cut off, first sound is systolic, fourth sound is diastolic
78
what is normal blood pressure?
120/80 or 125/85
79
what is pulse pressure?
systolic - diastolic
80
how much blood loss can be tolerated?
up to 20% because of blood reservoirs in major organs
81
capillary walls are permeable to
```
fatty acids and ions (diffusion)
exchangeable proteins (transcytosis)
```
82
from arterial end to venous end of the capillary, what happens to pressure?
it goes from +13mmHg to -7mmHg
83
what causes the pressure to decrease in the capillary tubule?
water leaving the tubule
84
a high solute concentration in the capillary tubule will cause
water to move INTO the capillary network
85
what are the driving forces in the movement of fluid in the capillary bed?
water pressure in the capillary/interstitial hydrostatic pressure
or
colloidal pressure
86
water pressure in the capillary is opposed by
interstitial fluid pressure
87
plasma colloidal osmotic pressure is
the solute concentration inside of the capillary
88
plasma colloidal osmotic pressure is opposed by
interstitial fluid osmotic pressure
89
colloidal pressure is
pressure exerted by impermeable solutes on either side of the membrane
90
explain the vasodilation theory of local blood control with oxygen/carbon dioxide
as the metabolic rate increases, oxygen demand increases, which lowers oxygen concentration in the tissues and increased carbon dioxide, this CO2/O2 imbalance acts as a vasodilator on smooth muscle, which increases blood flow and reoxygenates the tissues
91
explain the oxygen demand theory
high blood pressure increases oxygen in tissue, acting as a vasoconstrictor
92
what does endothelium derived relaxing factor do?
when blood flow is so high it is creating shear forces the shear forces stimulate nitric oxide release to reduce damage
93
how does adenosine factor in local blood control
high concentration of adenosine acts a vasodilator - adenosine cannot be bound to ATP without oxygen. Too little oxygen - lots of free adenosine
94
norepinephrine and epinephrine
hormones, neurotransmitters, vasoconstrictors for arteries and veins
95
angiotensin
vasoconstrictor for arterioles
96
vasopressin
universal vasocontrictor
97
antidiuretic hormne
universal vasoconstrictor
98
bradykinin
arteriolar vasodilator, increases capillary permeability
99
histamine
vasodilator released by mast cells
100
how does the sympathetic nervous system signal vasoconstriction?
by releasing norepinephrine and epinephrine onto alph-andregenic receptors
101
how does the sympathetic nervous system affect the body during exercise?
dilates capillaries, constricts veins, raises HR, SV, CO, and TPR, and BP, overal increases blood flow in dilated muscle and heart arteries
102
how does the parasympathetic nervous system affect the body?
parasympathetic nervous system enervates the heart and slows it down
103
which receptors respond to change in partial pressure of O2/CO2 and pH?
Carotid body and aortic body
104
which receptors respond to changes in blood pressure?
pulmonary artery receptors, carotid sinus, aortic baroreceptors, atrial receptors
105
cardio chemosensory receptors respond to low oxygen by
raising blood pressure
106
True or False, blood pressure is controlled primarily by peripheral chemoreceptors
True
107
BP less than 60 mmhg triggers
vasomotor center to cause a maximum increase in BP
108
the main cause of ischemic heart disease is
atherosclerosis - a buildup of lipids in the arterial wall.
109
what is a thrombus
blood clot in arterial wall - can break free and become embolus
110
what are the causes of death in ischemic heart disease?
cardiac shock - weakened heart cannot pump
damming of venous blood - increased atrial pressure and edema
fibrillation of ventricles - caused by injury current
rupture of cardiac muscle - muscle gets thin, buildup of fluid between epimysium and perimysium
111
cardiac failure effects - acute
decreased CO
damming of venous blood - increased atrial pressure
chest pains and fainting
sympathetic response activated - pressure continues to increase but output remains low
112
cardiac failure effects - chronic
fluid retention
salt retention
angiotensin 2 increase
heart is weak, exercise can cause heart failure
113
treatment of chronic heart failure
diuretics, digitalis
114
afferent arteriolar constriction
lowers filtration
115
efferent arteriolar constriction
increases filtration
116
GFR increases with
increased glomerular blood flow
decreased afferent arteriolar resistance
increased efferent arteriolar resistance
sympathetic stimulation
117
GFR is mediated by
tubuloglomerular feedback at the macula densa
118
Low NaCl concentration at Macula Densa results in
lowered afferent arteriolar resistance
| increased efferent arteriolar resistance
119
Explain the path of renin-angiotensin aldosterone
juxtoglomerular cells secrete renin when blood volume is low. Renin cleaved angiotensinogen released by the liver into angiotensin. Angiotensin is converted into angiotensin 2 in the lungs. Angiotensin 2 is a potent vasoconstrictor and also triggers the release of aldosterone which increases sodium reabsorption - increasing fluid in the body.
120
Water and sodium transport in the nephron
Diffusion or osmosis
121
Glucose and Amino Acid transport in the nephron
cotransport
122
Hydrogen ion transport in the nephron
countertransport
123
Filtration is equal to
plasma concentration times GFR
124
Tell me about the proximal tubule
65% of filtration
Complex cells
Reabsorption of glucose, amino acids, water, ions, calcium
Secretion of Hydrogen Ions, organic acids and bases, many drugs
Isoosmotic
125
Tell me about the thin loop of henle
10% of filtration
Water leaves lumen
Salt enters lumen
hyposomotic to interstitum
126
Tell me about the thick loop of henle
Ions secreted
25% of filtraton
No aquaporins, no movement of water
Hypoosmotic
127
Tell me about the distal convoluted tubule
```
Permeable to water and ions
Hydrogen Ions and buffers
90% principal cells
10% intercalated cells to maintain acid/base balance
Ca++ reabsorption increased
```
128
Low Ca++ in plasma causes parathyroid to secrete _______which causes ___________
Parathyroid Hormone
Increased Ca++ reabsorption from DCT
Increases Ca++ reabsorption from intenstine
Release of Ca++ from bones
129
Body Acid-Base controls are located in
Late distal convoluted tubule and collecting duct
130
How do tubule cells affect body pH?
Secrete more H+ if pH is too low, secrete less H+ if pH is too high
131
Effects of metabolic Acidosis
depression of the CNS
| Increased respiratory rate and depth
132
Causes of metabolic Acidosis
•Diarrhea - excess loss of sodium bicarbonate
•Uremia - failure of kidney filtration of H+
•Diabetes Mellitus - excess production of glucose based acids
(acetoacetic acid)
133
Effects of metabolic Alkalosis
overexcitability of CNC (Muscle tetany)
134
Causes of metabolic Alkalosis
•Excessive Ingestion of Alkaline Drugs
•Excessive Vomiting (loss of Cl-)
•Excess Aldosterone (reabsorption of Na+, release of
H+)
135
Renal Clearance - Filtered Substances
No secretion or reabsorption, Renal clearance rate is equal to GFR
Example - Inulin
136
Renal Clearance - Secreted substanced
Have renal clearance greater that GFR
| Example PAH
137
Renal Clearance - Reabsorbed Substances
Have renal clearance less than GFR - ex: Glucose
138
Excess fluid osmolarity is detected in the brain by
the anteroventral border of the third ventricle
139
Increased extracellular fluid osmolarity will cause the hypothalamus to secrete ______________ which will induce ____________
Antidiuretic Hormone
| Thirst
140
ADH effects on the body
• Vasoconstriction
• Stimulate reabsorption of Water from the Distal
Convoluted Tubule and Collecting Ducts
• Binds to receptors on the basolateral membrane of the epithelial cells.
• Initiates a second (intracellular) messenger
(cAMP)
• Cause the fusion of vesicles (containing pores) to
the luminal membrane.
• Water rushes from the lumen into the cell and into
the interstitium.
141
Urination is controlled by
Sympathetic, Parasympathetic, an Somatic Motor neuron activity
142
Lactose is a disaccharide composed of
galactose and glucose
143
True or false - Enzymes are usually one dimensional in shape and function
False
144
The Extracellular compartment is composed of
Plasma and interstitium
145
True or False - Mitochondria can vary in number from cell to cell, use aerobic mechanisms to produce ATP, and uses phospholipids for its membrane
True
146
Energy from the metabolism of glucose and other fuel substrates is temporarily stored by the body as
ATP
147
The property of phospholipids can best be described as
hydrophilic heads and hydrophobic tails that face each other
148
True or false, Rough Endoplasmic reticulum in involved with the production of proteins
true
149
Homeostasis refers to
maintaining a stable internal environment
150
True or false - the golgi apparatus is the powerhouse of the cell
false - the mitochondria is the powerhouse of the cell
151
If the amount of sodium in the blood decreases, then a negative feedback control mechanism for sodium would be expected to
increase the amount of sodium in the blood
152
The nerntz potential for sodium does not suggest that the concrentration of his ion is equal on both sides of the membrane, true or fale
true
153
True or false, the movement of water across a membrane is always an active process requiring primary active transport
false
154
The Nernst Equation is important for
determining the electrical potential difference for a single ion needed to counter the concentration difference
155
true or false, when determining the equilibrium potential for Sodium we must assume the membrane is permeable to all solutes
false - we must assume it is permeable only to sodium
156
any difference in potential energy across a membrane is considered the _________ which pushes a molecule in one direction or another
driving force
157
a cell that is exposed to a substance that will stop the sodium/potassium pump will
cause the membrane to slowly depolarize and eventually have a 0 mV difference
158
Which substance is most responsible for maintaining the electrochemical gradient of a resting membrane
Sodiumm/Potassium pumps
159
If a positively charged ion is more concentrated inside the cell, the electrical forced required to balance the chemical gradient would be directed _______, thus the equilibrium for this ion would be ________________
inward, negatively
160
if, under resting conditions, the membrane is much more permeable to sodium than potassium, the resting membrane would approach which ion's equilibrium potential
sodium
161
True or false, when determining sodium's equilibrium potential we have to assume the membrane is permeable only to sodium
true
162
true or false, the larger the motor units in a muscle, the more precisely controlled the gradations of contraction
false - smaller motor units have finer contractability
163
the main cellular structure that stores Ca++ in skeletal muscle cells is the
Sarcoplasmic Reticulum
164
true or false, when t-tubules actively pump calcium to the extracellular space it makes muscles relax
false - muscle relaxation is triggered by - acetylcholine being destroyed by acetylcholinesterase, lack of an action potential, and return of the troponin tropomyosin complex returns to its blocking posisition
165
describe the process of muscle contraction
Ca++ released from sarcoplasmic reticulum links to troponin. Troponin changes shape and moves to tropomyosin which moves, exposing myosin binding site. Myosin links, snaps ATP, pulling actin filament. Myosin stays linked until another ATP comes along.
166
true or false - different levels of muscle contraction can be accomplished by stimulating different synapses on a muscle cell
false - different levels of contraction are stimulated by recruitment
167
which molecule is responsible for physically blocking the myosin head from binding to actin?
tropomyosin
168
what is the functional unit of a muscle fiber?
sarcomere
169
what is the property of skeletal muscle where repeated action potentials enhance the force developed by a muscle cell
summation
170
what is crossbridge cycling?
the repeated, oscillation interaction between actin and myosin that results in the generation of force by the skeletal muscle cell
171
T or F: When thinking of the postsynaptic membrane (second nerve cell) during “nerve cell to nerve cell” or nerve cell to muscle communication, the opening of K+ (potassium) channels is the first step to depolarizing the post-
synaptic membrane.
false - a sodium channel is the first to open
172
The fusing of synaptic vesicles with the terminal button membrane is initiated by Ca++ influx (entering) into the cell.
True
173
3. Acetylcholine is a neurotransmitter that will stimulate the postsynaptic membrane to depolarize by
Opening sodium channels
174
How does myelin affect action potentials?
A. The thinner the myelin coating the slower the action potential travels down the axon
B. The fewer “Nodes of Ranvier”, the faster the action potential travels down the axon
C. On the parts of the axon covered by myelin there are very few, if any receptor channels
175
The spreading of the action potential across the cell body of a neuron is usually described as
“Graded”.
true
176
The larger the number of “Nodes of Ranvier” for a neuron, the _________________.
Smaller the resistance on the spreading of the action potential
177
The neuromuscular junction consists of ______________________________?
synaptic cleft, postsynaptic terminal, presynaptic terminal
178
Adding more Acetylcholinesterase to the neuromuscular junction could cause
a decrease in the ability of the neurotransmitter Acetylcholine to spread across the synaptic cleft
179
There are many different types of receptors for any one neurotransmitter.
true
180
what causes flaccid paralysis?
Inhibitor of the Ach-receptor binding
Blocker of Acetylcholine release at the synapse
Increase of Acetylcholinesterase activity
181
To start muscle contraction, released Ca++ inside the cell (intracellular) will bind to which protein molecule?
cal-modulin
182
T or F: Heart muscle has a long refractory period due to extended K+ channel opening
false
183
The plateau phase of the cardiac muscle cell action potential is
calcium channels remaining open
184
The generation of the action potential by cardiac muscle cells is due mainly to the
leaky calcium channels
185
True or False - Cardiac muscle uses two types of calcium to initiate contraction -
true
186
Which of the following is not part of the process whereby skeletal muscles relax?
calcium pumps actively removing calcium to the sarcoplasmic reticulum
187
The relationship between muscle length and active tension generation (force) by skeletal muscle, as indicated by the length-tension curve is created by _______________.
the interaction between actin and myosin
188
Describe Fast Glycolytic Fibers
large cells, large force, low mitochonria, low capillary density, low fatigue resistance
189
Describe Slow oxidative fibers
smaller muscles, detail work, low glycolytic capacity, low capillary density
190
The rate of Ca+ diffusion across a membrane is dependent on
permeability, concentration gradient, carriers
191
sodium concentration plays a role in osmolarity, even if it is not permeable to the membrane
unk
192
the rate of diffusion is dependent on
concentration temperature and viscosity
193
in smooth muscle, Ca++ binds to
calmodulin
194
in skeletal muscle Ca++ binds to
troponin
195
In smooth muscle, calmodulin activates what enzyme?
myosin kinase
196
In smooth muscle, what is myosin kinase responsible for?
phosphorylation of myosin heads
197
haustral contactractions
move feces along the large intestine
198
true or false - Smooth muscle can shorten more and have greater force than skeletal muscle
true
199
swallowing motility
reflex inhibition, stretch reflex, contraction
200
process of deglutition
roll food to the back of the oral cavity, info to the brainstem, close pharynx and raise larynx, relax esophagus, begin peristaltic activity
201
the body of the stomach secretes
mucus pepsinogen and HCL
202
the antrum of the stomach secretes
mucus pepsinogen and gastrin
203
hormonal regulation of stomach emptying is caused by
secretion of gastrin
204
neural regulation of stomach emptying is signaled by
stomach wall stretch, the vagus nerve, and the myenteric plexus
205
what hormones increase peristalsis?
gastrin, insulin, serotonin, CCK
206
defecation, sympathetic or parasympathetic
parasympathetic
207
the frank starling mechanism states
stroke volume increases in response to blood volume increase (end diastolic volume)
208
the nernst equation
Energy of the ion = 61/valence * log10 * concentration of the ion outside/concentration of the ion inside
209
the electrical potential of a membrane at rest is closest to potassiums resting potential because
more potassium channels are open, allowing more potassium to move into the cell *******
210
true or false, an Ion's overall electrochemical gradient will tend to force that ion across the membrane in a direction that will cause that ion's membrane potential to move towards that ion's equilibrium potential
true*******
211
which of the specialized muscle tissues of the heart can create the greatest number of action potentials in a minute?
the sino-atrial node is the pacemaker of the heart
212
true or false - ventricular cardiac cells demonstrate none of the slow depolarization of pacemaker cells
true*****
213
pressure in the right atria of the heart is
around zero
214
botulinum causes
flaccid paralysis
215
tetanus toxin causes
rigid paralysis
216
true or false the SA node requires external stimulation to generate an action potental
false - the SA node is a pacemaker cell with leaky sodium channels.
217
true or false - the long refractory period of the heart prevents tetanic contractions
true
218
the heart has a long refractory period due to extended _______ channel opening
calcium - allows sodium to leak across
219
increased activity in the parasympathetic nervous system will cause changes in what areas of the heart
SA and AV nodes, primarily
220
cardiac action potentials do not require a neurotransmitter - true or false
true
221
t-tubules of cardiac muscle cells
allow for the rapid transmission of action potential
222
depolarizing a membrane by ~10mv will initiate
increased Na+ conductance
223
when cell becomes negative
Na+ enters, and K+ leaves the cell
224
when cell becomes positive
K+ enters, and Na+ leaves the cell
225
active transport
a solute moving uphill - requires energy
226
facilitated diffusion
a solute moving downhill - does not require energy
227
voltage
pressure that moves ions through a circuit
228
current
a flow of electrical charge - number of electrons per unit of time
229
resistance
the opposite of conductance
230
conductance
the ease at which current passes
