Animal Physiology - Exam 1 Flashcards
All invertebrates are __________.
ectotherms
Ectotherm body temperature and metabolic rate are ____________ correlated.
positively
Endotherm body temperature is relatively constant except for ______
when the environmental temperature is low, then metabolic rate will be high. (engaging homeostatic regulation)
Homeostasis
The tendency of organisms to maintain a relatively constant internal environment despite variable external conditions
Between a fish and the external environment, which has a greater fluctuation of oxygen concentration over time?
External environment
Homeostatic loop
way of controlling systems via feedback
Set point
the point at which homeostasis is set
The _______ feedback loop is the most common and it’s purpose is to _______ the variable ____ the setpoint.
Negative; return: to (restores homeostasis)
The _______ feedback loop is rare but effective and it’s purpose is to ________ the variable ____ the setpoint
positive; move; away from (disrupts homeostasis, establishes new setpoint or dynamic biological action)
_______: a collection of specialized cells of the same type that come together to function and focus on common cellular activity on a _______ scale.
Tissues; smaller
_______: are made of multiple tissues coming together and work on a _______ scale
organs; larger
________: series of connected but individual organs are coming together for a larger function
organ systems (ie: digestive)
Organ systems involved in control are:
nervous, endocrine
Organ systems involved in support and movement:
skeletal, muscular
_______ and ______ are other functions of organ systems
maintenance; reproduction
Body systems are _________
integrated
What are the components of body fluid?
- intracellular fluid (ICF)
- extracellular fluid (ECF)
- in a dynamic state
Intracellular fluid?
- is 40% of body weight
- is the fluid inside the cytoplasm of cells
Extracellular fluid?
- is 20% of body weight
- is composed of blood plasma and interstitial fluid
Interstitial fluid?
- 15% of body weight
- is the fluid between the cells and the blood vessels
What does it mean that body fluid is in a dynamic state?
the 3 types of fluid (intracellular, interstitial, blood plasma) are in constant exchange
Adaptation
Evolution through natural selection which leads the organism to match the demands of its environment physiologically, anatomically and behaviorally - irreversible. (populations evolve, not individuals)
Acclimatization
persistent spectrum of changes due to prolonged exposure to naturally occurring environmental conditions - is reversible.
Acclimation
persistent spectrum of changes because of a long exposure to experimentally-induced environmental conditions - is reversible. (only 1 variable changed, temp?)
Variables with relative stability?
- temperature (endotherms!)
- [O2] [CO2]
- ECF volume and pressure
- nutrients
- waste products
- water, salts
- pH
- fertility
________ conform within the environmental temperature
ectotherms
line of conformity
a 1:1 relationship between variables
Zone of stability
where homeostasis is maintained
What can thermal classification of animals be based on?
- source of body heat
- nature of their body temperature (Tb) relative to the environment (Te)
ectotherms
obtain heat from the external environment
endotherms
produce heat metabolically or actively radiate heat
heterotherms
show characteristics of both an ectotherm and an endotherm
Poikilotherms
variable internal body temperatures that fall within a wide range of environmental temperatures; also wide homeostatic range for body temperatures.
Homeotherms
maintain constant body temperatures with narrow homeostatic range for body temperature.
Heterotherms
can switch between homeo- and poikilotherm
Homeostatic range
the range between low and high body temperature levels - the normal range that sustains life
Some major differences between ecto- and endotherms
- resting metabolic rate (endotherms ^ @low temp)
- total energy expenditure at rest
- response to changes in temperature
A(n) _________ increases its metabolic rate to maintain its body temperature in cold conditions
endotherm
Between endo- and ectotherms, which type spends more metabolic energy?
Endotherms across almost all temperatures.
What is true for endo-, ecto-, and heterotherms?
they can use behavior to influence body temperature and metabolic rate
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
_________ metabolic rate _______ with increasing body size
unscaled; increases
Metabolic rate =
0.1M^(3/4)
Mass vs. metabolic rate graph is a ______ _______, which means:
biological truism; the relationship stays constant across organisms in species
_____ -specific metabolic rates are highest in _____ endotherms
Mass; small
A mouse will…in comparison to an elephant
burn through energy more quickly to maintain temperature. It is losing heat every second
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
freshwater aquatic invertebrates are important…(hint: relates to pH)
bioindicators of environmental health
The _____ is very sensitive to acidic conditions, this organism will tell us early of a change in _____.
midge; pH
At rest, what is the extracellular and intracellular concentration of potassium. This favors…
5 mM; 148 mM; efflux from the cell
At rest, what is the extracellular and intracellular concentration of sodium, this favors..
142 mM; 10mM; influx into the cell
At rest, calcium concentration favors ______.
influx
At rest, Chloride concentration favors _______.
influx
How to calculate change in concentration
the difference in concentration:
out-in across the membrane for a specific ion/solute
electrochemical equilibrium influenced by
- degree of membrane permeability to ions and water
- membrane impermeability to large charged molecules (ex: anions)
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.
The inside of the cell is generally _____, so K+ movement is _______.
negative; restricted to keep negative charges from being too great
Partition coefficient is measured by
K = [solute] lipid/ [solute] water
If K is high, what does it mean?
The solute is more permeable across the cell membrane
Partition coefficient measures
the membrane permeability of a non-electrolyte based on if it can cross a membrane (dissolve and diffuse)
Permeability constant across a membrane is directly related to
K, so P is dependent on K.
Dm is
diffusion coefficient of solute (rate of diffusion substance through membrane)
x is
diffusion distance
If x is high, P will be
low
If P is high, K is
high
if Dm is high, P will be
high
Fick’s diffusion equation is
J = dQs/dt, the rate of diffusion by the quantity [Q] of solute [s] diffusing per unit time
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)
If MW goes up, J will
go down (inversely related)
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)
if A goes up, J will
go up (directly related)
If X goes up, J will
go down (inversely related) (X = diffusion distance or membrane thickness)
If S s goes down, J will go
down (S s = solubility of the substance, molecule or ion)
If J goes down, what will happen to each component
sqrt of MW up, X up, SA down, S s down, deltaC s down
Osmosis
the movement of water through a semipermeable membrane from a less concentrated to a more concentrated solution
Solutes exert ________ ______: a force that _____ water _____ the cell, based on ____ ___
osmotic pressure; draws; into; concentration differences