Animal Physiology Exam 3 Flashcards
1
Q
All water compounds contain what?
A
dissolved salts, gases, and organic compounds
2
Q
What is physiologically important?
A
Temperature and water compounds
3
Q
Body fluids account for how much of body weight?
A
60%
4
Q
What are the 3 major body fluid compartments?
A
(1) intracellular
(2) interstitial
(3) blood plasma
5
Q
Which body fluid compartments have similar ionic compositions?
A
blood plasma & interstitial fluids
6
Q
Which body fluid compartment usually has very different Na, K, etc.. compositions?
A
intracellular fluids
7
Q
Osmoregulation
A
regulation of water & ion balance
8
Q
Ionic regulation
A
adjusting particular ionic concentrations
9
Q
Excretion
A
elimination of metabolic wastes
10
Q
body fluids are what?
A
dilute saline solutions
11
Q
Excretion & osmoregulation are managed by the same what?
A
organs
12
Q
Optimal function requires hydration state & [solute] to be what?
A
maintained within relatively narrow limits
13
Q
What the main problem in terms of water and ion balance?
A
proper internal conditions almost always very different from environmental conditions
14
Q
What is necessary to maintain water and ion balance?
A
regulatory mechanisms
15
Q
Osmolarity
A
measure of the solute concentration of a solution; depends on # of dissolved particles
16
Q
Hyperosmotic
A
[body fluids] > environment
17
Q
Isosmotic
A
[solute] of body fluids = environment
18
Q
Hyposmotic
A
[body fluids] < environment
19
Q
Most marine inverts are what?
A
Osmoconformers; isosmotic with seawater; but they often regulate certain solute concentration to some extent
20
Q
Freshwater animals are all what?
A
osmoregulators
21
Q
Freshwater animals maintain what?
A
hyperosmotic body fluids
22
Q
Marine vertebrates are almost always what?
A
hyposmotic osmoregulators
23
Q
Terrestrial environments vary greatly in what?
A
temperature & humidity
24
Q
U/P ratio
A
index of action of the kidneys in osmotic regulation
25
isosmotic urine
U/P = 1; e.g. seabirds
26
Hyposmotic urine
U/P < 1; e.g. freshwater organisms
27
Hyperosmotic urine
U/P > 1; e.g. terrestrial mammals, insects, marine mammals
28
What are the 3 sources of water?
drinking water, dietary water, metabolic water
29
Dietary water
preformed water in plant & animal tissues
30
Desert mammals gain water from where?
dietary &/or metabolic
31
How do kangaroo rats compare to lab rats?
Kangaroo rats retain more water because they lose less water through their wastes (feces & urine)
32
What does a freshwater animal's blood plasma composition look like compared to a river?
higher ion concentrations and higher osmotic pressure
33
Freshwater animals are what compared to ambient water?
hyperosmotic
34
Freshwater animals gain and lose what from gills?
Gain: water, Na+, Cl-
Lose: salt
35
Freshwater animals gain what from food?
salt (ions) & water (don't drink)
36
Freshwater lose what from feces?
salt & water; large amounts of urine, very hyposmotic to plasma
37
What structure is on lobsters that dilutes urine?
corpious
38
Freshwater animals have dilute what?
blood plasma & urine
39
Bicarbonate ions and protons are actively (require ATP) exchanged for what in the gills of Freshwater fish?
Cl- and Na+
40
Marine water animals are what to seawater?
isosmotic
41
Hagfish are what?
Marine, stenohaline, osmoconformers & isosmotic
42
Hagfish have to influx or efflux of what?
water
43
Hagfish undergo what kind of regulation like marine invertebrates?
ionic regulation
44
Marine teleost gain and lose what from gills?
Gain: salt
Lose: water, Cl- (active) & Na+ (passive or active)
45
Marine teleost lose what from feces & urine?
Salts and water; small amounts of urine; nearly isosmotic to plasma, rich in Mg 2+ & SO4 2-
46
Marine teleost gain what from food & seawater?
salts & water
47
Whats the problem for osmoregulating marine air breathing vertebrates?
high salt load; Receive high salt from food and drink
48
What the solution to marine air breathing vertebrate osmoregulators problem?
Kidney & extrarenal salt glands
49
Kidney
excretes hyperosmotic urine (relative to body fluids) in birds and mammals
50
Extrarenal salt glands
produce highly concentrated fluid containing mainly NaCl; intermittent function in response to high salt loads; e.g. birds, sea turtles
51
What is the advantage of living in a terrestrial environment? disadvantage?
advantage: abundant oxygen
disadvantage: major water loss
52
What two groups have successfully invaded land?
arthropods & vertebrates
53
Some groups who live in terrestrial environments have to exploit what?
moist environments
54
What is the key to reducing water loss on land?
integumentary permeability; high resistance (thick skin)
55
Rate of water loss equation
J = K x (WVPi - WVPo) / X
56
What contributes to decreased permeability of the integument?
Thin layers, increasing temperature (transition temperature), lipid composition
57
Lipids undergo what as temperature increases?
phase changes, which leads to more water loss
58
Transition temperature
temperature at which water loss increases drastically rather than gradually
59
Variation in lipid composition exists among what?
population of single species & related species
60
Organisms that use what is at a major disadvantage in terms of respiratory water loss?
cutaneous respiration
61
Mammals, birds & reptiles control respiratory water loss via what?
regulating breathing movements
62
Insects open & close what?
spiracles to tracheal system
63
How is water conserved by cooling exhalant air done?
countercurrent mechanism in the nasal passage
64
Total respiratory water loss is dependent on what?
body size and phylogeny
65
Smaller organisms have what in terms of water loss?
greater evaporative water loss
66
Osmoregulation of earthworms
- lose water via evaporation through skin
- live in damp soil
- osmoregulate like freshwater animals
67
Osmoregulation of amphibians
- lose water via evaporation
- in water, osmoregulate like freshwater animals
- must live near or in water/humid air
- skin is main osmoregulatory organ
- actively pump in Na & Cl follows passively
- lots of urine
68
Osmoregulation of desert frogs
- live underground during drought
- explosively breed after rainfall
- some australian frogs: store 30% water as dilute urine in bladder; [Urea] is high
69
Stenohaline
survive in only narrow range of salinities
70
Euryhaline
survive across broad range of salinities
71
Osmoconformers
permit blood osmotic pressure to match ambient osmotic pressure
72
Osmoregulators
maintain relatively stable osmotic pressure despite ambient variation
73
What are the salinity trends in estuaries?
higher salinity closer to sea; brackish water animals typically euryhaline
74
What are the two types of osmotic regulation?
hyper-isosmotic & Hyper-hyposmotic
75
hyper-isosmotic
regulate at low water concentration, isosmotic at high water concentration
76
hyper-hyposmotic
regulate at low and high water concentrations
77
Frogs and toads have high water loss because of what?
low skin resistance
78
Some frogs and toads have what? Or secrete what?
impermeable or secrete a waxy substance to increase resistance
79
Some frogs and toads excrete what?
Uric acid
80
How does Urea compare to Uric acid?
-urea at high concentrations is toxic & must be highly diluted
- Uric acid is not as toxic & reduces excretory water loss
81
Lower elevations are typically?
warmer & drier (high VPD)
82
If salamanders are acclimated to cool conditions & exposed to high VPD then what occurs?
water loss increases
83
If salamanders are acclimated to cool conditions & exposed to warmer environment then what occurs?
lose less water
84
heat loss equals what?
heat gain
85
Body temperature depends on what?
heat exchange with environment
86
Animals obey the laws of what?
thermodynamics
87
What is the 2nd law of thermodynamics?
in an isolated system, change is always towards disorder; energy from outside (an open system) is necessary to maintain order
88
Why must animals consume energy?
because energy is lost when moved through system
89
Energy enters an animal's body as what?
chemical energy
90
Energy leaves an animals body as what?
heat, chemical energy or external work
91
Absorbed chemical energy is used to perform what three major types of physiological work inside the body?
1) biosynthesis
2) maintenance
3) generation of external work
92
Metabolic rate
quantity of energy used per unit time
93
Aerobic
oxidative metabolism of food into ATP
94
oxidative metabolism
Chemical bonds of glucose (generally) broken to produce energy; requires oxygen; e.g. cellular respiration
95
Anaerobic
ATP production without oxidative metabolism; e.g. glycolysis
96
Anaerobic is faster but...
less efficient; makes less ATP
97
How is metabolic rate calculated?
direct calorimetry or indirect calorimetry
98
Why is metabolic rate important?
- determines how much food an organism needs
- provides quantitative measure of the total activity of all physiological mechanisms
99
Direct calorimetry
directly measuring the rate of heat loss from an animals body; Lavoisier's experiment
100
Latent heat of fusion
energy necessary to change from solid to liquid
101
Lavoisier's experiment
- surrounded the animal with an ice-filled jacket to measure heat production
- enclosed the apparatus in an outer ice-filled jacket to intercept environmental heat
- Ice melted by the animal yielded liquid water for measurement
102
Indirect calorimetry
measuring gas exchange to obtain metabolic rate
103
What is measured in gas exchange?
O2 consumption & CO2 production
104
Why does measuring gas exchange (indirect calorimetry) work?
when Glucose is oxidized at a fixed proportion of O2 is used and CO2 produced; thus, heat production can be measured from gas exchange
105
6O2 equals what in heat?
2820 kJ
106
Is measuring gas exchange always accurate?
no
107
Respiratory quotient (RQ)
respiratory exchange ratio; a method of determining what food is being metabolized
108
RQ ratio of carbs
1
109
RQ ratio of lipids
.71
110
RQ ratio of proteins
.83
111
Basal metabolic rate (BMR)
minimum metabolic required for maintenance
112
BMR is measured during/in?
post-absorptive state, at rest, at specified temperature (thermo-neutral zone)
113
BMR is called what in ectotherms?
Standard metabolic rate (SMR)
114
Activity metabolism
increased activity results in increased aerobic metabolism up to a point (maximal metabolic rate)
115
Aerobic capacity
point at which metabolism can be supported aerobically
116
If metabolism supersedes aerobic capacity then it can be supported by what?
anaerobic metabolism (comes with consequences)
117
Aerobic scope
MMR - BMR
118
Factorial scope
MMR/BMR; generally about 10 for vertebrates
119
Aerobic scope in generally higher for what?
active animals
120
Endotherms aerobic maximum metabolic rate is generally what compared to ectotherms?
10x greater
121
Temperature effects aerobic scope for activity in what?
ectotherms
122
The maximal capacity for activity for ectotherms occurs at what?
temperatures near those experienced in nature
123
What largely effects metabolic rate?
physical activity & environmental temperature
124
What has a minor effect on metabolic rate?
ingestion of a meal, body size, gender, age, environmental oxygen levels, hormonal status, time of day, salinity
125
What effects BMR?
age, sex, circadian phase, season, digestive state, phylogeny, body size, temperature (ectotherms), habits & habitat
126
Circadian phase effects on BMR
BMR higher during active phase than resting
127
Digestive state effects on BMR
energy is required for digestion; increased metabolic rate due to digestive processes (specific dynamic action [SDA])
128
Digestive state effect on BMR differs based on what?
type & size of food ingested; greatest change for proteins (up 20-30%)
129
Its important to measure BMR in animals in what state?
post-absorptive state
130
phylogeny effects on BMR
varies among vertebrate classes and between other taxonomic groups
131
habits & habitats effects on BMR
Varies depending on food habits & habitat
- Habitat e.g. tropical species of birds & salamanders have a lower BMR than temperate species
- Habits e.g. mammalian carnivores BMR is higher
132
BMR may vary among populations inhabiting different environments at what?
different times of the year
- e.g. Fence lizards in NJ have higher BMR than lizards in SC during the summer, but not during the spring or fall
133
Metabolic rate and body size is expressed in what two ways?
1) whole-animal
2) mass-specific
134
Why is the slope of metabolic rate & weight less than 1?
Theres a compromise between size and SA; as body mass increases the SA: BM ratio decreases
135
Anaerobic scope
the maximal rate of lactate production by glycolysis during activity minus resting lactate production
136
Anaerobic metabolism cannot what?
be sustained long
137
Build up of lactate in tissues is what?
deleterious to enzyme & muscle function & has negative impacts on hemoglobin loading capacity in the blood
138
Anaerobic scope tends to be larger in animals that what?
use rapid bursts of energy (rapid burst of locomotion)
139
Activity increases what?
Metabolic rate to the max metabolic rate
140
Max metabolic rate varies with what?
temperature & body mass
141
Sustained locomotion may be required for what?
escape, foraging, defense, mating, courtship
142
Initial stages of activity or burst of activity use what?
anaerobic energy
143
Long-term activity must occur within what?
aerobic limits
144
Maximum metabolic rate sets what?
limits on sustained activity & behaviors
145
How is locomotive energetics measured?
by quantifying O2 consumption at a steady rate
146
While walking or running what increases linearly with speed?
VO2 (metabolic rate); increases to VO2 max
147
Maximal aerobic speed
speed at which VO2 (max)
148
Lower speeds can be sustained for what?
longer (aerobic reliant)
149
Y-intercept
Metabolic rate at 0 speed
150
Why is metabolic Rate at zero speed higher than BMR?
posture
151
Net cost of transport (COT)
- slope of line from zero speed to max aerobic speed
- amount of energy required to travel a distance (independent of time & speed)
152
Total cost of transport
VO2 (MR) at x speed/ x speed
- highly speed dependent
153
As speed increases what decreases with distance?
energy
154
Most economical transport is achieved when moving close to what?
maximal aerobic speed
155
In mechanical vehicles what increases exponentially?
power
156
linear increase of aerobic input with speed may what?
be unexpected
157
COT total equation
metabolic rate / speed
158
Animals naturally change what that has the lowest energy expenditure at a given speed?
gait
159
A linear function approximates what about VO2?
Its maintained across a range of speeds
160
What differs in metabolic capacities and locomotor capacities?
endotherms and ectotherms
161
What is similar between endotherms and ectotherms in terms of energy?
net cost of transport; similar speeds require similar energy inputs
162
Ectotherms reach what at lower speeds?
aerobic limits
163
Ectotherms have what?
lower maximal aerobic speeds (MAS)
164
Endoderms can engage in what?
broader range of locomotory activities than ectotherms; correlated with greater aerobic scope
165
Energy cost of locomotion does not what?
increase proportionately with body mass; instead mass ^ .7
166
On a mass specific basis, the cost of moving a unit of mass is what for larger animals?
less; mass ^ -.3
167
Smaller animals require what?
more energy to move
168
energy increases as what? why?
size decreases; large animals move faster
169
Lower body temperatures do what?
conserve energy (low MR), BUT aerobically sustainable behaviors are limited
170
Higher body temperatures allow what?
more behaviors, BUT with more energy
171
minimal cost of transport is what at low and high body temperatures?
similar
172
An animal with high body temperature may reduce transport cost by what?
traveling faster
173
Why is temperature important?
1) species distribution
2) Metabolism & rate of O2 consumption
3) hatching time & food distribution
174
How does increasing temperature effect metabolism and rate of O2 consumption?
aerobic scope decreased; MMR decreased & BMR increased
175
What are the two main thermal strategies?
tolerance and regulation
176
Physiological regulation
- redirect blood flow for increased heat gain/ loss
- vasodilation & vasoconstriction
177
Behavioral thermoregulation
reposition body relative to heat source
178
thermoregulators
maintain a particular mean or variance of body temperature using neural mechanisms (hypothalamus) to sense & respond to the environment
179
Early studies of thermoregulation focused on what?
relationship between ambient (air) temperature and body temperature
180
Perfect thermoregulator
no body temperature change with air temperature change
181
Perfect thermorconformer
body temperature equals air temperature
182
What was the pitfall of early studies?
water-filled beer cans seemed to have thermoregulated in Heath's experiment; In actuality the physical properties of the can differed from those of air, making it appear as though the can thermoregulated
183
What did the lizard skin mold experiment show?
showed more temperature tolerance to a wider range of temperatures in models than in real lizards
184
What is the acute effect of temperature on metabolic rate equation?
Q10 = R(t) / R(t-10)
185
In ectotherms/poikilotherms, Q10 is what?
2-3
186
What is a chronic response to metabolic rate?
Acclimation; blunts response to changes in temperature
187
What cellular/biochemical mechanisms drive acclimation?
abundance of mitochondria/unit muscle & activity of cytochrome oxidase per mitochondrial protein
188
Thermal performance curves assess what?
the physiological benefits of selecting a particular body temperature
189
What is the ecological relevance of physiological variance?
physiological performance measurements should be "whole animal" measurements that correlate with fitness
190
What are examples of physiological performance correlating with fitness?
growth rates, digestive efficiency, predator avoidance, disease resistance, acceleration, metabolic scope, rate of egg production, etc.
191
Most physiological systems are maximized at what?
intermediate body temperatures (thermal sensitivity)
192
What are three descriptive measures of thermal sensitivity?
1) thermal Optimum (Topt)
2) thermal performance breadth (TPB)
3) tolerance range
193
Thermal Optimum
temperature at which performance is maximized
194
Thermal performance breadth
range of temps over which performance is some % of maximum
195
Tolerance Range
temperatures beyond which physiological function ceases at (CT min and CT max)
196
Ecological decline occurs at what compared to acute stress?
milder temperatures
197
Why are animals impaired at temperatures with the pejus range?
oxygen and capacity limitation of thermal tolerance
198
Why does temperature matter to organisms?
1) affects rate of tissue processes
2) affects the molecular conformation & thus, the functional state of molecules
3) Enzyme substrate affinity & temperature (thermal adaption) affinity decreases as temperature increases
4) Homeoviscous adaptation
199
Temperature varies both what?
spatially & temporally
200
Tolerance to high temperatures is measured using what?
CT max & LD50
201
LD50
maintain animals at various constant temperatures; body temperature @ which 50% of animals die
202
CTmax
subject animals to slowly increasing temperatures; body temperature when animals are incapable of removing themselves from the situation
203
thermal sensitivity allows what?
predictions of performance with spatial and temporal variation in temperature
204
Animal max temp
50C
205
plant max temp
75C
206
bacterial max temp
1000C
207
Highest terrestrial animal temperature
desert ant; higher than 45C
208
Species differences are reflect in aspects of what? e.g.?
ecology; e.g. latitude, habitat selection
209
Some terrestrial animals normally live close to what?
their CTM
210
Aquatic/marine animals generally have what?
lower maximal lethal temperature
211
Often CTmax is tightly correlated with what?
breakdown of critical physiological processes
212
What is reduced at higher temperatures?
O2 binding affinity
213
What is a cause of death at high body temperatures?
Insufficient oxygen (hypoxia)
214
Hypoxia
high temperatures cause mismatch between oxygen demand and oxygen supply
215
Hypoxia leads to what?
1) reliance on anaerobic pathway
2) depletion or accumulation of secondary metabolites
3) protein inactivation
216
First defense to high, non-lethal temperatures is what?
behavioral
217
what is the molecular response to high temperatures?
Heat-shock proteins (hsps)
218
Heat shock proteins
molecular chaperones: facilitate successful folding, assembly, and secretion of proteins
219
Hsps in animals cells can help prevent what?
stress-induced denaturation
220
Hsps are induced by what?
acute non-lethal temperatures
221
downsides to Hsps?
energetically expensive & have detrimental effects
222
There is a fitness cost to having high levels of functional hsps during what?
low heat stress
223
The ability to induce hsps is advantageous during what?
moderate to high heat stress
224
Shallow terrestrial anurans are what?
freeze tolerant
225
Terrestrial burrowers or aquatic anurans are what?
not freeze tolerant
226
Supercooling point
process of cooling a liquid or gas below its freezing point without it becoming solid
227
What percentage of total body water as ice can an anuran tolerate?
65-70%
228
What aspects of anurans helps them be freeze tolerant?
Low molecular weight carbohydrates (glucose & glycerol) which function as anti-freeze & cryoprotectants
229
Liver glycogen is a source of what?
glucose
230
Chorus frogs accumulated what while the toads did not?
glucose
231
glucose accumulation is associated with what?
higher liver phosphorylase activity in frogs
232
development of freezing tolerance likely associated with increase in what?
glycogen phosphorylase activity
233
Endotherms problem in the cold?
Favorable conditions in summer, but deteriorates in winter
234
birds respond to the cold in what two ways?
1) migration
2) permanent residency
235
what are the three types of adjustments?
physical, physiological, behavioral
236
Physical adjustments
feathers, subcutaneous fat, regional hypothermia & peripheral circulation
237
peripheral vasoconstriction
shunts blood away from body surface
238
countercurrent heat exchange
closely opposed vessels allow heat exchange to keep warm blood near core
239
Changes in what can lead to increase heat loss?
peripheral circulation
240
Some birds increase what in winter?
BMR
241
Increased BMR likely associated with what?
cost of maintaining metabolic machinery
242
Summit MR correlated with shivering endurance provides what?
higher total capacity for heat production
243
Shivering increases what?
thermogenic capacity
244
What are the two options that increase Msum in winter?
1) enhanced fat catabolism capacities
2) bigger muscles for shivering
245
citrate synthase
important enzyme in cellular respiration
246
increased citrate synthase activity increases what?
cellular aerobic capacity
247
Fatty acid binding protein (FABP)
makes fat available for catabolism
248
Myostatin
potent endocrine inhibitor of muscle growth in mammals
249
Msum & cold tolerance what in winter?
increases
250
Pectoralis muscle mass what in winter?
increases
251
Myostatin and TLL-1 gene expression what in winter?
decrease
