Animal Physiology - Exam 1 Flashcards
1
Q
All invertebrates are __________.
A
ectotherms
2
Q
Ectotherm body temperature and metabolic rate are ____________ correlated.
A
positively
3
Q
Endotherm body temperature is relatively constant except for ______
A
when the environmental temperature is low, then metabolic rate will be high. (engaging homeostatic regulation)
4
Q
Homeostasis
A
The tendency of organisms to maintain a relatively constant internal environment despite variable external conditions
5
Q
Between a fish and the external environment, which has a greater fluctuation of oxygen concentration over time?
A
External environment
6
Q
Homeostatic loop
A
way of controlling systems via feedback
7
Q
Set point
A
the point at which homeostasis is set
8
Q
The _______ feedback loop is the most common and it’s purpose is to _______ the variable ____ the setpoint.
A
Negative; return: to (restores homeostasis)
9
Q
The _______ feedback loop is rare but effective and it’s purpose is to ________ the variable ____ the setpoint
A
positive; move; away from (disrupts homeostasis, establishes new setpoint or dynamic biological action)
10
Q
_______: a collection of specialized cells of the same type that come together to function and focus on common cellular activity on a _______ scale.
A
Tissues; smaller
11
Q
_______: are made of multiple tissues coming together and work on a _______ scale
A
organs; larger
12
Q
________: series of connected but individual organs are coming together for a larger function
A
organ systems (ie: digestive)
13
Q
Organ systems involved in control are:
A
nervous, endocrine
14
Q
Organ systems involved in support and movement:
A
skeletal, muscular
15
Q
_______ and ______ are other functions of organ systems
A
maintenance; reproduction
16
Q
Body systems are _________
A
integrated
17
Q
What are the components of body fluid?
A
- intracellular fluid (ICF)
- extracellular fluid (ECF)
- in a dynamic state
18
Q
Intracellular fluid?
A
- is 40% of body weight
- is the fluid inside the cytoplasm of cells
19
Q
Extracellular fluid?
A
- is 20% of body weight
- is composed of blood plasma and interstitial fluid
20
Q
Interstitial fluid?
A
- 15% of body weight
- is the fluid between the cells and the blood vessels
21
Q
What does it mean that body fluid is in a dynamic state?
A
the 3 types of fluid (intracellular, interstitial, blood plasma) are in constant exchange
22
Q
Adaptation
A
Evolution through natural selection which leads the organism to match the demands of its environment physiologically, anatomically and behaviorally - irreversible. (populations evolve, not individuals)
23
Q
Acclimatization
A
persistent spectrum of changes due to prolonged exposure to naturally occurring environmental conditions - is reversible.
24
Q
Acclimation
A
persistent spectrum of changes because of a long exposure to experimentally-induced environmental conditions - is reversible. (only 1 variable changed, temp?)
25
Variables with relative stability?
- temperature (endotherms!)
- [O2] [CO2]
- ECF volume and pressure
- nutrients
- waste products
- water, salts
- pH
- fertility
26
________ conform within the environmental temperature
ectotherms
27
line of conformity
a 1:1 relationship between variables
28
Zone of stability
where homeostasis is maintained
29
What can thermal classification of animals be based on?
- source of body heat
- nature of their body temperature (Tb) relative to the environment (Te)
30
ectotherms
obtain heat from the external environment
31
endotherms
produce heat metabolically or actively radiate heat
32
heterotherms
show characteristics of both an ectotherm and an endotherm
33
Poikilotherms
variable internal body temperatures that fall within a wide range of environmental temperatures; also wide homeostatic range for body temperatures.
34
Homeotherms
maintain constant body temperatures with narrow homeostatic range for body temperature.
35
Heterotherms
can switch between homeo- and poikilotherm
36
Homeostatic range
the range between low and high body temperature levels - the normal range that sustains life
37
Some major differences between ecto- and endotherms
- resting metabolic rate (endotherms ^ @low temp)
- total energy expenditure at rest
- response to changes in temperature
38
A(n) _________ increases its metabolic rate to maintain its body temperature in cold conditions
endotherm
39
Between endo- and ectotherms, which type spends more metabolic energy?
Endotherms across almost all temperatures.
40
What is true for endo-, ecto-, and heterotherms?
they can use behavior to influence body temperature and metabolic rate
41
Examples of behavioral thermoregulation
- a lizard maintaining a specific body temperature in the day and night by its location
- an elephant splashing water over itself to release heat faster
42
_________ metabolic rate _______ with increasing body size
unscaled; increases
43
Metabolic rate =
0.1M^(3/4)
44
Mass vs. metabolic rate graph is a ______ _______, which means:
biological truism; the relationship stays constant across organisms in species
45
_____ -specific metabolic rates are highest in _____ endotherms
Mass; small
46
A mouse will...in comparison to an elephant
burn through energy more quickly to maintain temperature. It is losing heat every second
47
What is the significance of being able to fly?
A bird can find new niches to hunt/mate/live instead of being constrained to travel on foot like a t-rex
48
freshwater aquatic invertebrates are important...(hint: relates to pH)
bioindicators of environmental health
49
The _____ is very sensitive to acidic conditions, this organism will tell us early of a change in _____.
midge; pH
50
At rest, what is the extracellular and intracellular concentration of potassium. This favors...
5 mM; 148 mM; efflux from the cell
51
At rest, what is the extracellular and intracellular concentration of sodium, this favors..
142 mM; 10mM; influx into the cell
52
At rest, calcium concentration favors ______.
influx
53
At rest, Chloride concentration favors _______.
influx
54
How to calculate change in concentration
the difference in concentration:
out-in across the membrane for a specific ion/solute
55
electrochemical equilibrium influenced by
- degree of membrane permeability to ions and water
- membrane impermeability to large charged molecules (ex: anions)
56
What will happen if impermeable anions (A-) are added to one side of the membrane
- the electrochemical equilibrium of each ion species changes.
- There will be more negatively charged ions on the outside of the cell.
57
The inside of the cell is generally _____, so K+ movement is _______.
negative; restricted to keep negative charges from being too great
58
Partition coefficient is measured by
K = [solute] lipid/ [solute] water
59
If K is high, what does it mean?
The solute is more permeable across the cell membrane
60
Partition coefficient measures
the membrane permeability of a non-electrolyte based on if it can cross a membrane (dissolve and diffuse)
61
Permeability constant across a membrane is directly related to
K, so P is dependent on K.
62
Dm is
diffusion coefficient of solute (rate of diffusion substance through membrane)
63
x is
diffusion distance
64
If x is high, P will be
low
65
If P is high, K is
high
66
if Dm is high, P will be
high
67
Fick's diffusion equation is
J = dQs/dt, the rate of diffusion by the quantity [Q] of solute [s] diffusing per unit time
68
Fick's law is
Diffusion rate (J) is directly proportional to change in concentration gradient (deltaC s) x total diffusional surface area (SA) x solubility of substance (S s) / diffusion distance (X) x the sqrt of molecular weight (MW s)
69
If MW goes up, J will
go down (inversely related)
70
if deltaC s goes up, J will
go up (deltaC s = concentration gradient of substance; difference between C1 and C2 across the membrane) (directly related)
71
if A goes up, J will
go up (directly related)
72
If X goes up, J will
go down (inversely related) (X = diffusion distance or membrane thickness)
73
If S s goes down, J will go
down (S s = solubility of the substance, molecule or ion)
74
If J goes down, what will happen to each component
sqrt of MW up, X up, SA down, S s down, deltaC s down
75
Osmosis
the movement of water through a semipermeable membrane from a less concentrated to a more concentrated solution
76
Solutes exert ________ ______: a force that _____ water _____ the cell, based on ____ ___
osmotic pressure; draws; into; concentration differences
77
fluid exerts ______ ______: a force that _____ water _____ the cell, based on _____ ______.
hydrostatic pressure; pushes; out of; pressure differences
78
Hydrostatic force
the force exerted by the fluid per unit area of the contact surface
79
What does [A-] mean when looking at it with other concentrations
the molar equivalent of negative charges carried by other molecules and ions
80
Donnan equilibrium
when the ion concentration is equal between the inside and outside of the cell
81
T/F: the cell is in Donnan equilibrium
False, the charges must be unequal to balance other charges present in the cell.
82
Living cells are at a _____ _____, not equilibrium because energy is ________ for maintenance
steady state; required
83
Cells ______ regulate their intracellular volume
dynamically
84
What will happen if Na+ levels are not maintained at equilibrium because of some metabolic inhibitor added
the cell will no longer be able to pump Na+ out, this means that water will influx via osmotic pressure which increases cell volume and eventually this will cause the cell to burst
85
Leaky membrane channels are
always open
86
An example of a resting channel
a resting K+ channel is always open, so K+ is constantly lost
87
Gated membrane channels are
open only under specific conditions
88
A voltage-gated channel is
a channel that opens (briefly) in response to change in the membrane potential (in volts)
89
A ligand-gated channel is
a channel that opens (closes) in response to a specific extracellular neurotransmitter
90
A signal-gated channel
a channel that opens (closes) in response to a specific intracellular molecule
91
A mechanically-gated channel
a channel that opens when there is applied pressure from the environment
92
What transports polar molecules (like glucose/amino acids) across membranes
Carriers
93
Carriers are _____ ______ that possess a _____ _____ for the molecules or ions being transported. This is NOT a ______.
specific proteins; binding site; channel
94
Carriers can be ________ because there is a ______ amount in the cell membrane
saturated; limited
95
Uniporters
can only flux one molecule or ion
96
Coupled transporters
flux of more than one molecule/ion: symporter or antiporter
97
symporters
unidirectional
98
antiporters
bidirectional (both molecules/ions must be present to work)
99
Uniporters, symporters and antiporters are(hint: type of transport)
types of facilitated transport because there is a protein present
100
Passive diffusion through a membrane looks like what on a graph?
a straight, positive linear line that changes in height of slope based on membrane permeability
101
Passive transport through channels looks like what on a graph?
a straight, positive linear line that levels at close to end of the height of extracellular concentration of the substrate
102
Carrier-mediated transport (passive or active) looks like
A straight, positive linear line that levels out much faster, which tells us that there are a limited number of carriers available in the membrane and they will be become saturated at a certain point
103
Vmax is
when the rate of diffusion reaches its maximum
104
Channels are
selective for their ions
105
An ion with a large radius has a
low strength of hydration shield
106
channels are selective based on
- size of the ion (must be the right size to remove H2O molecules attached-takes energy to remove H2O)
- charge of the ion (to cause conformational change when it binds to the carbonyl on the a-helices in the channel)
107
A channel/carrier reduces energy of activation (deltaG) for diffusion with:
- creating a aqueous (hydrophobic) environment within the membrane for the solute
- promotion of dehydration (loss of H2O) with the solute binding to the amino acid side chains (helps ion pass through narrow channel IF right size)
108
An ion with a small radius, like Na+, has a
stronger hydration shield
109
Epithelial tissues are
- semi-permeable tissue
- a selective barrier between outside environment and inside of body
- composed of sheets of epithelial cells connected via tight junctions
- line cavities + hollow organs (like small intestines)
110
Epithelial tissues do form _____ which affects the _______/________ of _________, ________ and _____
barriers; transport/movement; water, solutes; cells
111
What part of the digestive system has the most carriers?
the small intestines
112
_______ _____ facilitate regulation of substance flux across body compartments
epithelial tissues
113
The _____ ______ in epithelial cells limit __________ path
tight junctions; paracellular
114
_________ path of ______/________ substances is ________ by the type of transporters in the membranes of the cells
transcellular; ionic/hydrophobic; regulated
115
In what direction does current in (frog) skin move?
+ to -
116
What is an example of charge moving transcellularly
Na+ passively and slowly moves into a cell from the external environment, this means through the active transport pump (ATP), cells will be pushing Na+ out the epithelial cell into the interior of the body. This allows for net movement of sodium into the body.
117
transcellular movement/path
when there is selective transport through the cell. Occur through membrane-bound proteins on the cell.
118
paracellular movement/path
where substances move through the space between two cells. Depends on how tight the junctions are.
119
Active transport
requires energy to move substances against an electrochemical gradient
120
Active transport can be in ______ directions and it can transport _____ molecule (s)/ion (s)
either or both; one or more
121
________ active transport ______ direct participation of ______
primary; requires; ATP
122
_________ active transport (_________): energy comes from a _______ __________ gradient that is established by:
secondary; cotransport; ion concentration; primary active transport
123
What is the most important protein in physiology
the Na+-K+ ATPase transporter
124
T/F: the Na+-K+ pump is found in all animal cells
true
125
T/F: the Na+-K+ pump is a symporter
False, an antiporter
126
what role does Na/K ATPase play in Na+ ion gradient in the cell?
balances rate of active transport of Na+ with Na+ leak
127
What happens to Na/K ATPase if the cell is metabolically blocked
it is inhibited
128
The potent neurotoxin on the newt's skin is
tetrodotoxin
129
the Na+/K+ pump facilitates ________ separation of cell membrane. it also _______ different [__] and [___] across the plasma membrane
charge; restores; K+; Na+
130
Once ______ ______ ______ uses _____ to create ion gradients; other _______ can then be transported ________ with the ion, _______ the _______ concentration gradient
primary active transport; ATP; substrates; secondarily; AGAINST; substrate's
131
Co-transport with Na+ renders:
substrate transport against its concentration gradient energetically favorable
132
T/F: other solutes can drive secondary active transport
True
133
Neurons are _____ cells
excitable
134
_______/_______ potentials are present and can ______ changes in cellular activity
electrical; chemical; enable
135
Application of ______ _____ to any cell will affect its activity
electrical stimulation
136
the receiving end of the neuron contains
the dendrites
137
where does the 1st change in membrane charge occur?
in the dendrites
138
what is part of integration in a neuron?
dendrites to the axon hillock
139
what is part of the spike initiation in a neuron?
the axon hillock
140
what is part of the impulse conduction of the neuron?
the axon (myelin sheath) until the axon terminals
141
the axon terminals are involved in:
transmitter secretion/release
142
Dendrite to the end of myelin sheath is:
electrical signals
143
axon terminals convert into
chemical signals
144
Neurons ________ to form ______ (simple or complex) to _______ signals throughout body
connected; circuits; transmit
145
neurons are
conductive
can be stimulated with a completed circuit and a stimulus
146
The cell's membrane potential is denoted by:
the type of charge that is lining up next to the membrane. On the outside, positive charges are gathering, on the inside, negative charges are gathering
147
Voltage difference (Vm) is _____ _____ across the membrane
relatively stable and negative
148
another name for this relatively stable voltage reflecting cell's inactive state is:
the resting potential
149
Vm quantitatively dependent on:
- different ion concentrations inside and outside the cell
- selective permeability of ion channels
150
What will happen across a cell membrane only permeable to K+ if K+ concentrations are equal?
there will be no net current (=movement)
151
with _______ concentration, ____+ current (_____) formed
unequal; K; flux
152
Loss of + charge across membrane?
- charge inequity across membrane that creates electromotive force (emf) opposite conc. gradient
153
large enough emf?
K+ movement stops, with unequal concentrations still and equilibrium potential (mV) established for K+
- this is when the electrical gradient and concentration gradient are equal in magnitude
154
What is the equation for the equilibrium potential for a specific ion?
E ion = 58 or 62/Z times log ([ion]out/[ion]in)
155
58 in nernst is
room temp
156
62 in nernst is
body temp
157
T/F: the membrane is equally permeable to all ion species
False
158
T/F: nernst does take permeability into account
False
159
What will happen if there is high K+ concentration outside the cell
diffusion will decrease
K+ will begin to influx
this is not normal cell behavior
160
What does the Goldman equation take into account?
It takes into account the permeability of each ion in addition to each ions deltaC
161
What is the Goldman equation
Em (membrane potential) = 58 or 62 times log (PK+ [K+]out/PK+[K+]in) + (PNa+[Na+]out/PNa+[Na+]in) + (PCl-[Cl-]in/PCl-[Cl-]out)
162
PK+ at rest?
100
163
PNa+ at rest?
3
164
PCl- at rest?
10
165
At cell birth, what is the cells membrane potential?
the cells membrane potential is very negative and it will attract K+ because it is already losing K+ through passive diffusion
166
What happens if a cell is too negative?
it will resist work
167
The cell is continually losing ______ charged ions, __+, which generates a ________ charged internal electrical gradient
positively; K+; negatively
168
what other ion can move through leaky K+ channels down it's own electrochemical gradient to help offset the highly negative intercellular charge
Na+
169
Voltage is equal to
current times resistance
170
Passive electrical response
a shift in membrane potential produced when an electrical current is applied to and flows across the cell membrane
- slow, smooth changes
171
What is happening in the membrane during passive electrical responses
- no ion channels open or close
- ionic current occurring through K+ channels (static)
- resting K+ channels always open in the membrane
172
hyperpolarize
cell's potential becomes more negative relative to resting
173
depolarize
cell's potential becomes more positive relative to resting
174
Current moving upward is _____ ___ a cell
efflux out of
175
Current moving downward is ___ ___ a cell
influx into
176
The membrane operates as a ______ ______ to yield ______ membrane properties
simple; circuit; passive
177
Ic is
- Capacitative current as a stored potential across only phospholipids
- builds rapidly + 1st then discharges
178
Ir is
resistive current through ion channels only
- fewer channels than membrane SA so more limited
- can be rapid based on channel type
179
delta Vm is
membrane potential = change in current times resistance present
180
Resistance is ______ affected by membrane permeability
directly
181
Capacitors _____ charges
store
182
conductors _____charges
move
183
Membrane conductance is a measure of what
The movement of charge across the membrane
184
Conductance is _______ to permeability because it is determined by ______ and their _______
unequal; ions; concentration
185
Resistance (R) is equal to
1 over conductance (G)
- conductance and resistance are inversely related
186
High conductance yields a
weakly resistive membrane (can't store charge, very low potential)
187
Resistance _____ flow of current
hinders
188
increased delta C means _________ resistance
decreased
189
a small separation of charges across a membrane means
increased resistance
190
an increase Resistance means
a decreased cross-sectional area (# of open channels)
191
increased distance (x) traversed by current (membrane thickness) means
increased R
192
