Exam 1 Flashcards
1
Q
what is physiology
A
the study of the functioning of living organisms
2
Q
what are the 7 levels that physiology is studied on
A
molecules, cells, tissue, organs, organ systems, organisms, populations
3
Q
what is a teleological explanation
A
why it happens
(what function or benefit it provides)
4
Q
what is a mechanistic explanation
A
how it happens
(what is the mechanism/steps in the process)
5
Q
what are the 4 themes in physiology
A
structure and function
biological energy use
information flow
homeostasis
6
Q
what are two subtypes of structure and function
A
molecular interactions
compartmentation
7
Q
what is homeostasis
A
the ability of the body to maintain a relatively constant internal environment
8
Q
what are examples of regulated variables that cells require a narrow range for
A
temperature, ph, ion concentration, nutrient availability
9
Q
what is the setpoint
A
the desired range that the body keeps regulated variables within
10
Q
what is the function of the control system
A
maintain homeostasis
11
Q
what is the stimulus
A
regulated variable that deviates from normal range
12
Q
what is the sensor
A
what monitors the regulated variable
13
Q
what is the integrating center
A
evaluates all inputs and sends instructions
(often neuron or endocrine cells)
14
Q
what is the target/effector
A
performs the physiological response
15
Q
what is feedforward
A
occurs in anticipation of change
16
Q
what is feedback
A
occurs in response to change
17
Q
what are the two types of feedback
A
negative and positive
18
Q
what is negative feedback
A
restores normal value/homeostasis
19
Q
what is positive feedback
A
enhances change (ex. childbirth)
20
Q
what is homeostatic dysregulation
A
body cannot maintain homeostasis
21
Q
what can homeostatic dysregulation cause
A
dysfunction, disease, death
22
Q
what are the three types of biological work
A
chemical
mechanical
transport
23
Q
what is chemical work
A
making/breaking bonds
24
Q
what is mechanical work
A
moving things (moving around inside of a cell)
25
what is transport work
moving things across membrane of cells or organelles
26
what provides the capacity to do work
energy
27
what are the two types of energy
kinetic and potential
28
what are examples of potential energy
chemical bonds
concentration gradients
electrical gradients
29
what are examples of kinetic energy
movement of molecules, cells, etc
heat
30
what are the fluid compartments of the body
intracellular fluid and extracellular fluid
31
what is extracellular fluid made of
plasma and interstitial fluid
32
what fluid compartment are all cells in direct contact with
extracellular fluid
33
what forms the transition between intracellular fluid and external environment
extracellular fluid
34
what moves freely among compartments by osmosis
water
35
what is different about each of the fluid compartments
they contain different concentrations of each solute
36
what can concentration gradients be used for
an energy source
37
where is the concentration of Na+ high
ISF and plasma
38
where is the concentration of Na+ low
ICF
39
where is the concentration of K+ high
ICF
40
where is the concentration of K+ low
ISF and plasma
41
where is the concentration of Cl- high
ISF and plasma
42
where is the concentration of Cl- low
ICF
43
where is the concentration of HCO3- high
ISF and plasma
44
where is the concentration of HCO3- low
ICF
45
where is the concentration of proteins high
ICF and plasma
46
where is the concentration of proteins low
ISF
47
what separates the ECF and the ICF
plasma membrane
48
what does selectively permeable mean in the context of the plasma membrane
permeable to some particles but impermeable to others
49
how something is transported is dependent on what
physical and energy requirements
50
what are some of the physical requirements that determine how something is transported
size
lipid solubility (hydrophobic/hydrophilic)
51
what is passive transport
flowing down the gradient from high to low
52
what is passive transport driven by
concentration
(charged ions are driven by electrical forces also)
53
what is active transport
flowing against gradient from low to high
54
what does active transport use
ATP (directly or indirectly)
55
what are three types of transport mechanisms
simple diffusion
protein-mediated diffusion
vesicular transport
56
what is simple diffusion
diffusion across the lipid bilayer by nonpolar molecules
57
what is protein-mediated transport
moves small polar molecules across bilayer
58
what is vesicular transport
moves large molecules across the bilayer using vesicles
59
what is Fick's Law
diffusion rate is increased by:
1. increased surface area
2. increased concentration gradient
3. increased lipid solubility
4. decreased size of molecule
5. decreased diffusion distance
60
what causes increased membrane permeability
increased lipid solubility
decreased size of molecule
(also affected by composition of bilayer)
61
what are the two types of protein mediated transport
channel proteins
carriers
62
what are channel proteins used for
ions and water
63
what does a channel protein form
continuous connection between ICF and ECF
64
what are the two types of channels
leakage (open)
gated (regulated)
65
what are the three types of gated chanels
chemically gated
mechanically gated
voltage gated
66
what kind of transport do channel proteins mediate
passive transport (down gradient) by facilitated diffusion
67
what does the rate of passive transport depend on
gradient and number of channels
68
what do carrier proteins do
bind to molecules and change shape to carry them across the membrane
69
do carrier proteins form a continuous connection between ICF and ECF
no
70
which is slower: channel or carrier
carrier
71
which can move larger molecules: channel or carrier
carrier
72
which can move molecules against their gradient: channel or carrier
carrier
73
what are the types of carrier proteins
uniporter (one kind of molecule)
symporter (2 in same direction)
antiporter (2 in different direction)
74
what are cotransporters
symporters and antiporters
75
what is the rate of the flow through carrier proteins affected by
gradient and number of carriers
76
what do the transported molecules bind to in carrier proteins
binding sites
77
what are the three characteristics of carrier proteins
specificity (binds one substrate)
competition (1 molecule can block another from binding)
saturation (increased conc of solutes will saturate the carrier if too many solutes are trying to move across)
78
what is passive transport
facilitated diffusion (down gradient)
79
what is active transport
uses ATP to move something against its gradient
80
what is primary active transport
binds ATP directly
81
what is secondary active transport
uses ATP indirectly
(energy stored in a concentration gradient)
82
what transports large molecules/particles
vesicular transport
83
what does vesicular transport use for energy
ATP
84
what is endocytosis
cell membrane pinches off to form vesicle and the molecule is taken into the cell
85
what is exocytosis
vesicle fuses with cell membrane and the molecule is released out of the cell
86
what is phagocytosis
used to engulf large objects
87
what kind of membrane protein are aquaporins
channel proteins
88
why are aquaporins needed
because water cannot cross the lipid bilayer due to it being polar
89
how do cells regulate the rate of osmosis
by varying the number of aquaporins
90
which direction does water move during osmosis
moves across membrane toward the side with the higher solute concentration
(evens out the water concentration)
91
does osmolarity have units
yes
92
what is osmolarity used for
to compare solute concentration between two solutions
93
what does isosmotic mean
equal number of solute particles per L
94
what does hyperosmotic mean
more particles per L
95
what does hypoosmotic mean
fewer particles per L
96
does tonicity have units
no
97
what is tonicity used for
to predict water movement in/out of a cell
98
what does tonicity depend on
the concentration difference in nonpenetrating solutes across the cell membrane
99
assuming nonpenetrating solutes, if the surrounding solution is hyperosmotic to the cell, what is the solution to the cell
hypertonic
(water moving out of cell)
100
assuming nonpenetrating solutes, if the surrounding solution is hypoosmotic to the cell, what is the solution to the cell
hypotonic
(water moving into the cell)
101
what are the three steps to cell volume changing
tonicity --> water movement --> cell volume change
102
what is the relationship between the solution and the cell when the cell swells
the solution is hypotonic to the cell
103
what is the relationship between the solution and the cell when the cell shrinks
the solution is hypertonic to the cell
104
what is the membrane potential
the charge separation at the membrane
105
what is the charge of the ICF and ECF
electroneutral (charge separation is only at the membrane)
106
what is the Vm
electrical potential difference inside the cell compared to the outside
107
what do excitable cells communicate with
electrical signals (changes in membrane potential)
108
what are the two things that give rise to membrane potential
ion concentration gradients
ion permeabilities
109
which ions affect the membrane potential the most
the ones that move freely across the membrane
110
what is the chemical diffusion force
diffuse down a concentration (chemical) gradient
111
what is the electrical force
the force from the interaction of ionic charge with charge separation across the membrane
112
what is the chemical force of Ca
into the cell since the conc of Ca outside cell is higher
113
what is the electrical force of Ca
into the cell since the inside of the cell is negative
114
what is the chemical force of Na
into the cell because there is a higher conc of Na outside the cell
115
what is the electrical force of Na
into the cell because the inside of the cell is negative
116
what is the chemical force of K
out of the cell because the conc of K is higher inside the cell
117
what is the electrical force of K
into the cell because the inside of the cell is negative
118
what is the chemical force of Cl
into the cell because the conc of Cl is higher outside of the cell
119
what is the electrical force of Cl
out of the cell because the outside of the cell is positive
120
when will an ion species be at electrochemical equilibrium
when there is no net electrochemical force (no electrochemical gradient)
121
what two forces are equal and opposite
electrical and chemical
122
what is the equilibrium potential
membrane potential that results in an electrical force that exactly counterbalances the chemical force
123
what does Ex depend on
ions concentration gradient (across the membrane) and valence
124
what is the Ex of K
-90mV
125
what is the Ex of Na
+60mV
126
what is the Ex of Cl
-63mV
127
what is the Ex of Ca
+122mV
128
what is Ex
the ion species's ideal state
what the ion wants the membrane potential to be so that it can be at electrochemical equilibrium
129
at the resting membrane potential, what ions are at their equilibrium potential (Ex)
no ion species
130
what does the membrane potential (Vm) arise from
the ions concentration gradient and the ions permeability
131
what does the ions concentration gradient give us
the Ex (or desired Vm)
132
what does an ion want to move toward: Vm or Ex
it wants to move the Vm toward its Ex
133
what determines the rate of ion flow
the difference between the Vm and Ex (Vm-Ex) will act as a driving force
134
what does the membrane potential result from
weighted contributions of the equilibrium potentials
135
what calculates the weight of each ions contribution
the ion species' membrane permeability
136
what is permeability due to
leakage (open) channels
137
what is Vrest (or the Vm of a resting cell)
-70mV
138
what influences equilibrium potential
concentration
139
what influences membrane potential
concentration and permeability
140
why will a gated channel open or close
changes in an ion's membrane permeability
changes in Vm
141
which direction to ions flow to change the membrane potential (Vm)
toward equilibrium potential
142
what happens to Vm with depolarization
Vm becomes more positive
143
what happens to Vm with hyperpolarization
Vm becomes more negative
144
what happens to Vm with repolarization
Vm returns to original value
145
are changes in the membrane potential due to bulk changes in ion distributions
no
146
what are changes in membrane potential due to
small changes in local charge separation at the membrane
147
what changes during electrical signaling
permeability
(concentrations do not change)
148
what are gap junctions
direct cytoplasmic transfer of a signal
149
what are juxtacrine signals
direct contact between membrane molecules of 2 cells
150
what is an autocrine signal
signal diffuses to the cell that secreted it
151
what is a paracrine signal
signal diffuses to nearby cells
152
what are the four types of local cell-to-cell communication
gap junctions, juxtacrine, autocrine, paracrine
153
what are the two types of long-distance cell-to-cell communication
hormones and neurons
154
what are hormones
secreted into blood by endocrine cells
155
what are neurons
electrical signal that travels along the cell
156
what are the three types of neurocrines (neuron secretions)
neurotransmitter, neurohormone, meuromodulator
157
what are the two main characteristics of a neurotransmitter
1. diffuse across synapse a short distance
2. have a rapid effect
158
what is the main characteristic of a neurohormone
secreted into the blood a long distance
159
what are the main characteristics of neuromodulators
1. travel short distance
2. slower, longer lasting effects
3. modifies the effect of neurotransmitters
160
what are the two main receptor types
lipophilic signal molecules
lipophobic signal molecules
161
what side of the cell is the binding site for a lipophilic signal molecule
intracellular (inside)
162
what kind of response does a lipophilic receptor have
slow, long lasting response (gene expression)
163
what side of the cell membrane is the binding site for a lipophobic membrane receptor
membrane receptor
-extracellular binding site where the protein spans the membrane
164
what kind of response does a lipophobic receptor have
rapid, brief response
165
which receptor type is water soluble: lipophilic or lipophobic
lipophobic
166
what are the four types of lipophobic signal molecule
receptor channel
G protein coupled receptor
receptor-enzyme
integrin receptor
167
which lipophobic signal molecule has the fastest response
receptor-channel
168
which lipophobic signal molecule is the most common
G protein coupled receptor
169
what is it called when the receptor itself is an enzyme
receptor-enzyme
170
where do integrin receptors bind
extracellular matrix
171
what is signal transduction
converting a signal from one form (extracellular) to another (intracellular)
172
what does the signal molecule (ligand/1st messenger) do
binds to the membrane receptor
173
what does the membrane receptor activate
intracellular signal
174
what does activating the intracellular signal activate
the target/effector proteins
175
what is produced when the target proteins are activated
cellular response
176
what is a cascade in a signal transduction pathway
each activated molecule in turn activated the next molecule
177
what is amplification in a signal transduction pathway
one ligand results in many intracellular signal molecules
178
what is an amplifier enzyme in a signal transduction pathway
produces second messenger molecules
179
what is a second messenger molecule
small, fast-diffusing molecule
180
what does a protein kinase do
phosphorylate (activate or inactivate) other proteins
181
what does an ion channel affect
Vm
182
what is a GPCR made of
cytoplasmic tail linked to a G proteins
183
what happens when a GPCR is activated
it exchanges GDP for GTP
184
what does the GTP-bound form of a GPCR do
activated other proteins
185
what does GTPase do in a GPCR
converts GTP to GDP
186
is the GDP-bound form of the GPCR active or inactive
inactive
187
in the GPCR-cAMP system, what does the activated G protein activate
adenylyl cyclase
188
in the GPCR-cAMP system, what does adenylyl cyclase convert ATP into
cyclic AMP
189
in the GPCR-cAMP system, what does cAMP activate
protein kinase A
190
in the GPCR-cAMP system, what does protein kinase A do
phosphorylates other proteins
191
what is the 2nd messenger in the GPCR-cAMP system
cAMP
192
what is the amplifier enzyme in the GPCR-cAMP system
adenylyl cyclase
193
what activates phospholipase C in the GPCR-phospholipase C system
the activated G protein
194
what two things does phospholipase C convert the phospholipid into in the GPCR-phospholipase C system
diacylglycerol (DAG) and inositol triphosphate (IP3)
195
what does DAG activate
protein kinase C
196
where is DAG located
in the membrane
197
what does IP3 open
Ca2+ channels
198
where is IP3 located
not stuck in the membrane
199
where is Ca2+ released from
the ER
200
what are the three second messengers in the GPCR-phospholipase C system
Ca2+, DAG, IP3
201
what is the amplifier enzyme in the GPCR-phospholipase C system
phospholipase C (because it produces the 2nd messenger)
202
what is used in the fastest signaling pathway
gated ion channels
203
what are the two kinds of gated ion channels
directly-gated channels
indirectly-gated channels
204
what are the three kinds of directly-gated channels
chemically gated
voltage gated
mechanically gated
205
what happens in indirectly gated channels
the ligand activated the GPCR which gates the ion channel (either directly or via another molecule)
206
what 5 changes can occur with cellular response to signals
motor proteins
enzyme activity
exocytosis
membrane transporters / receptor proteins
gene expression
207
can receptors have more than one ligand
yes
208
can ligands have more than one receptor
yes
209
what determines a cells response to a ligand
the presence/absence of a receptor for the ligand
specific signal transduction pathway is activated
210
what are specific signal transduction pathways linked to
different receptor isoforms
211
what is an endogenous ligand
normally produced in the body
212
what is an exogenous ligand
from outside the body (drugs, toxins)
213
what is an agonist
competing ligand that binds and elicits a response
214
what is an antagonist
competing ligand that binds and elicits no response
215
what does an antagonist do to receptor activity
it blocks it
216
what is upregulation
increase cell response by adding receptors
217
what is down regulation
decrease cell response by removing receptors or decreasing their binding affinity
218
what are 5 ways that a signal can be terminated
inactivate/remove ligand
GTPase activity of G proteins
inactivate the 2nd messenger
pump calcium back into ER
protein phosphatases
219
what are two ways to inactivate or remove the ligand
break down the ligand
reuptake of the ligand
220
what breaks down the 2nd messenger cAMP
phosphodiesterase (PDE)
221
what do protein phosphatases do
dephosphorylate
222
what is tonic control
signal is always present but changes in intensity
(ex. involves one neuron that changes the signal rate)
223
what is antagonistic control
opposing signals send parameter in opposite directions
(ex. two different neurons to speed heart rate up and slow it down)
224
when does the endocrine system coordinate body functions
when duration is required but not speed
225
what are hormones
signal molecules for long distance communication
226
what are hormones secreted into the blood by
endocrine cells
227
where will hormones elicit a response
in cells that have receptor (target cells)
228
will hormones exert effects at low or high concentrations
low concentrations
229
how do hormones stop eliciting a response
the signal must be terminated
230
what is the half life of a hormone
amount of time required to reduce concentration by half
231
what is the half life of a hormone due to
metabolism and excretion
232
what are the three classifications of hormones
peptide
steroid
amine
233
what category do the majority of hormones fall into
peptide hormones (ex insulin)
234
what is a preprohormone
the initial protein in the rough ER that eventually will make a peptide hormone
235
what is the preprohormone converted to
prohormone
236
where is the prohormone transported to
golgi complex
237
what happens to the prohormone in the golgi complex
conversion to active hormone and storage in a secretory vesicle
238
how are peptide hormones released
exocytosis
239
are peptide hormones water soluble
yes
(hydrophilic and lipophobic)
240
can peptide hormones cross the lipid membrane
no
241
do peptide hormones have a long or short half life
short
242
what do peptide hormones bind to
membrane receptors (mostly GPCR)
243
what do peptide hormones usually effect
gate ion channels
modify enzymes or transporters
(rapid, short-lived effects)
244
what are steroid hormones derived from
cholesterol
245
are steroid hormones water soluble
no
(hydrophobic and lipophilic)
246
can steroid hormones be stored
not in vesicles
247
how are steroid hormones synthesized
on demand in the smooth ER and mitochondria
248
how are steroid hormones released
by simple diffusion
(able to cross membrane)
249
what in the cell determines what hormones it can make
enzymes in the cell
250
what are 4 examples of steroid hormones
cortisol, aldosterone, estrogen, testosterone
251
where are steroid hormones made
in only a few organs
(adrenal gland, gonads)
252
do steroid hormones have a longer or shorter half life compared to peptide hormones
longer
253
what do steroid hormones carry
proteins
254
what kind of receptor do steroid hormones use
cytoplasmic or nuclear
(outside nucleus)
255
what kinds of effects do steroid hormones have
slow, longer-lasting effects
(gene expression)
256
what is the law of mass action
there is a constant bound:unbound ratio; as the unbound hormone leaves the blood more unbinds from the protein carrier
257
what are amine hormones derived from
tryptophan or tyrosine
258
what do the characteristics (peptide or steroid like) of an amine hormone dependent on
solubility
259
what is the tryptophan derived hormone
melatonin
260
is melatonin lipophilic or lipophobic
lipophilic
261
what are the two subtypes of tyrosine derived hormones
catecholamines and thyroid hormones
262
are catecholamines lipophilic or lipophobic
lipophobic
263
are thyroid hormones lipophilic or lipophobic
lipophilic
264
what are the three catecholamines
dopamine
norepinephrine
epinephrine
265
what is the difference between a paracrine signal and a hormone
paracrine signals have a shorter half life and do not effect long distance
266
what is the basic pathway of an endocrine reflex pathway
stimulus --> sensor --> input --> integrating center --> output --> effector --> physiological response
267
what happens in a simple endocrine pathway
endocrine cell directly senses stimulus, integrates, and responds by secreting hormone
268
what are two examples of simple endocrine pathways
pancreas (insulin and glucagon)
parathyroid glands (parathyroid hormone PTH)
269
what happens in a complex endocrine pathway
endocrine cells evaluate 3 input signals when "deciding" whether and how much insulin to secrete
270
what is an example of a complex endocrine pathway
insulin (pancreatic endocrine cells evaluate the input signals)
271
what is the pituitary gland actually composed of
two fused glands
272
what are the two segments of the pituitary gland
posterior and anterior pituitary
273
what is the posterior pituitary made of
nervous tissue (extension of hypothalamus)
274
what are the two hormones that the posterior pituitary secrete
vasopressin and oxytocin
275
what is the function of vasopressin
water balance in kidneys
276
what is the function of oxytocin
uterine contractions
277
what is the anterior pituitary made of
epithelial tissue
278
what does the anterior pituitary secrete
6 tropic hormones
279
what are the six tropic hormones that the anterior pituitary secretes
1. luteinizing hormone (LH)
2. follicle stimulating hormone (FSH)
3. prolactin
4. thyrotropin or thyroid stimulating hormone (TSH)
5. growth hormone (GH)
6. corticotropin or adrenocorticotropic hormone (ACTH)
280
what are the two gonadotropin hormones
LH and FSH
281
what is the purpose of the gonadotropin hormones
reproduction and metabolism
282
what is the purpose of prolactin
milk production
283
what is the purpose of TSH
development and metabolism
284
what is the purpose of growth hormone
growth and metabolism
285
what is the purpose of ACTH
stress and metabolism
286
what do hypothalamic neurons secrete
releasing hormones (RH) that increase secretion of hormones by the anterior pituitary
287
how are hypothalamic neurons connected to the anterior pituitary
a portal system to avoid dilution
288
what releasing hormone (RH) releases LH and FSH
gonadotropin RH (GnRH)
289
what RH inhibits the release of prolactin
dopamine
290
what RH is used to release TSH
thyrotropin RH (TRH)
291
what RH is used to release GH
growth hormone RH (GHRH)
292
what RH is used to release ACTH
corticotropin RH (CRH)
293
what are the three integrating centers of the hypothalamic-pituitary (HP) axes
hypothalamus
anterior pituitary
peripheral endocrine gland
294
what is HPG
hypothalamic-pituitary-gonadal axis
295
what is the pathway to release sex hormones
GnRH --> LH/FSH --> sex hormones
296
what is HPT
hypothalamic-pituitary-thyroid axis
297
what is the pathway to release thyroid hormones
TRH --> TSH --> thyroid hormones
298
what is the HPA
hypothalamic-pituitary-adrenal axis
299
what is the pathway to release cortisol
CRH --> ACTH --> cortisol
300
why is cortisol essential for life
it prevents hypoglycemia
301
what is the long loop feedback loop
peripheral gland secretion inhibits secretion by hypothalamus and anterior pituitary
302
what is the short loop feedback loop
anterior pituitary secretion inhibits secretion by hypothalamus
303
what kind of feedback loops are the long and short feedback loops
negative feedback
304
what is synergism
the combined effect of the hormones is greater than additive
305
what is permissiveness
the hormone has no effect by itself, but is necessary for another hormone's full effect
306
what is antagonism
two hormones have opposing effects
307
what is hypersecretion
hormone excess
308
what are examples of hypersecretion
tumors/cancer and autoimmune disease
309
what is hyposecretion
hormone deficiency
310
what are causes of hyposecretion
decreased synthesis or atrophy of a gland
311
what is the third pattern of endocrine pathology that causes changes in receptors or 2nd messenger pathways
abnormal responsiveness of target tissues to the hormone
312
what is primary pathology in HP axes
dysfunction of peripheral endocrine gland
313
what is secondary pathology in HP axes
dysfunction of pituitary gland
314
what is tertiary pathology in HP axes
dysfunction of hypothalamus
