Quiz 1 Flashcards
1
Q
Physiology
A
- how things work
- the biological study of the functions of living organisms and their parts
- the study of how cells interact with their environment to obtain the things required for life (vital substances ex. water, salts, oxygen, nutrients, heat)
2
Q
external environment
A
- outside of the organism
- barrier between internal and external is the skin/integument
- cells interact through exchange processes
- organisms interact with external through exchange systems
3
Q
exchange systems
A
- any system that allows for the exchange of material (vital substances) from external environment to internal environment or internal environment to external environment
- ex. respiratory system (O2/CO2), digestive system (nutrients/H2O), urinary system (excretion/H2O), circulatory system (distribution)
4
Q
organization of complex biological organisms
A
- cellular level- (four general cell types)- epithelial, connective tissue, nerve, muscle
- tissue level- (groups of cells with common structure and function) ex. muscle tissue
- organ level- (organization of different tissues to perform specific functions) ex. heart
- system level- (several organs organized carry out major body functions) ex. cardiovascular system
5
Q
basic principles
A
- all life is:
- aquatic
- compartmentalized
- deals with same fundamental problems
- constrained by laws of physics and chemistry
- can tolerate only a limited range of conditions
6
Q
All life is aquatic
A
- body fluids of all animals have the same general composition
- H2O and salts (very much like sea water)
- water is the major component and is 75% of body weight and 99% of all molecules (in humans)
- salts (simple inorganic substances)- .75% of molecules are salts (Na+, K+,Cl-)
- biochemical substances (proteins, nucleic acids, etc.)- .35% of molecules
- all life is maintaining an internal aquatic environment for the cells (cells are aquatic)
7
Q
all life is compartmentalized
A
- separation of substances in different compartments
- the cell- the basic unit (compartment)
- the major fluid compartments inside organisms:
- intracellular fluid (ICF)- inside of cells
- extracellular fluid (ECF)- outside of cells
- interstitial fluid- ECF that is not in the circulatory system
- plasma- liquid portion of blood (ECF)
8
Q
Sodium
A
- high concentration in ECF
- low concentration in ICF
9
Q
Potassium
A
- low concentration in ECF
- high concentration in ICF
10
Q
Calcium
A
- low concentration in ECF
- very low concentration in ICF
- a lot of energy is being expended to achieve this -> this is bc Ca is very important to the cell
11
Q
asymmetries between compartments are essential for physiological processes
A
- a fundamental challenge for all organisms is how to maintain asymmetry
- cells expend energy to maintains these asymmetries
- hard to transport substances selectively between compartments -> requires energy and trade offs
- trade offs- lose H2O during respiration, lose H2O during thermoregulation
12
Q
all life deals with the same fundamental problems
A
- many animals have solved fundamental problems in interesting ways
- can gain unique and distinctive insights by looking at different animals
- comparative physiology
- all life requires the input of energy
- life is energetically unfavorable (need energy to survive)
- > every organisms has asymmetries and compartments that require energy in order to maintain
- another ex. reproduction which requires energy
13
Q
Adenosine triphosphate (ATP)
A
- principal form of energy used by cells
- hydrolyzes ATP to ADP which allows us to do cellular work
- food energy is required to make ATP
- ATP is made during cellular respiration (mainly from glucose)
- glucose is broken down aerobically (oxygen)- CO2 + H2O + 38 ATP -> more efficient, and anaerobic (no oxygen)- lactic acid + 2 ATP -> faster
- aerobic metabolism is more efficient
- oxygen intake can be measured and predict how much energy an organism is making and expending
- aerobic metabolism allows of animals living in dry environment to produce H2O
14
Q
metabolic rate (MR)
A
- the amount of energy an animal uses in a unit amount of time
- measured as O2 consumption in units of calories or kilocalories (1000 cal)- because O2 is proportionate with the amount of ATP is needs to generate and expend
- sum of all energy requiring biochemical reactions:
- basal metabolic rate
- movement
- heat production
- anabolic pathways (building biomass)
- MR is not constant and is never zero
- higher the MR higher the heat produced
15
Q
all life is constrained by the laws of physics and chemistry
A
- ohm’s law
- boyles law
- ideal gas law
- gravity
- kinetic & potential energy
- intertia, momentum, velocity, & drag
- physical environment governs what cells can and cannot accomplish
- cells can utilize these laws to their advantage ex. signaling
16
Q
size principle- relationship between surface area and volume
A
- size of animal matters
- ex. of how life is constrained by the laws of physics and chemistry
- as the radius gets bigger, the SA/V ratio gets smaller and relative surface area for exchange decreases
- therefore, a larger animal will lose more heat to the environment than the smaller animal bc it has more SA -> but the larger animal will have more cells (volume) to generate more heat
- the smaller animals is losing more heat in proportion to the heat it is able to generate bc it has a smaller SA to V ratio
- large animal- low heat exchange and good heat retention
- small animal- high heat exchange and poor heat retention -> gets hotter and colder faster
17
Q
All life can tolerate only a limited range of conditions
A
- referring to the internal environment*
- salts, H2O, O2, CO2, nutrients, waste elimination, temperature, pH
- the process of maintaining these conditions within tolerable ranges is called homeostasis
- homeostasis- maintenance of a relatively constant internal environment- requires cell-to-cell communication (nervous system, hormonal system, intrinsic system) and requires negative feedback
18
Q
Feedback systems
A
- all feedback systems have the following components:
- sensor- measures some aspect of the internal environment (ex. temp)
- integrator- compares the sensor measurement to a reference value (set point) (ex. normal temp)
- effector- the output of the system that changes the internal environment (ex. increases temp)
- ex. sensor detects temp -> integrator compares temp to set point -> decides its too warm -> effector lowers the temp
- a decrease in the sensor measurement has the same effect on the output of the system as an increase in the set point
19
Q
negative feedback
A
- response is opposite to the stimulus
- maintains the set point
- effector counteracts (is opposite to) the initial sensor stimulus
- critical for maintaining homeostasis
20
Q
positive feedback
A
- the effector increases the initial sensor stimulus
- leads to rapid change
- an increase in temperature measured by the sensor results in the effector causing a further increase in temperature
- ex. giving birth, blood clotting, fever, *action potential- depolarization of the cell leads to more depolarization
21
Q
physiological ecology
A
- the organisms relationship to its physiochemical environment
- goal- understand how organisms use the basic law of physics and chemistry to meet their biological needs and solve basic physiological problems
- essence of comparative physiology- how different organisms solve the same problems with different environments
1. body temperature and temperature regulation
2. water and ion balance
22
Q
Energy utilization
A
- inject macromolecules
- break down into energy (ATP)
- cellular work, biosynthesis, external work
- all of these processes produce heat bc they are inefficient (some energy is lost to heat)
- *energy utilization is a source of heat (endogenous)
23
Q
Nitrogenous wastes
A
- ingested foods include proteins, carbohydrates, and fats
- the end products of ingested food are typically CO2 and metabolic H2O
- Metabolic breakdown of proteins also produces ammonia (NH3) (nitrogenous wastes)
- nitrogenous wastes are: salvaged for amino acid synthesis, excreted (high levels of ammonia are lethal), and in some animals, converted to less toxic forms of nitrogen (urea, uric acid)
- *trade offs: it takes energy to convert nitrogen, water must be sacrificed in order to excrete nitrogen
24
Q
Conversion of nitrogen trade offs
A
- leaving it be- no energy required, requires a lot of water to eliminate (.5 L per g of nitrogen), ammonotelic
- urea- less toxic (can be stored), requires energy, requires .05L of water per g, ureotelic
- uric acid- requires little water to eliminate, requires energy, .001L of water per g, uricotelic
- aquatic animals are commonly ammonotelic, mammals and marine mammals are ureotelic, birds are uricotelic
- ammonia > urea > uric acid -> solubility
25
Q
Heat
A
heat is kinetic energy (molecular motion)
26
Q
temperature
A
- an index of molecular motion (average kinetic energy)
- Hot- high heat content, high energy content, high molecules motion, high temperature
- Cold- low heat content, low energy content, low molecular motion, low temperature
27
Q
endogeneous heat
A
heat originating from the organism
-comes as a by product from chemical processes (biosynthesis, etc.)
28
Q
Thermal budget
A
- energy sources vs ways energy leaves the animal
- in and out should be equal
- heat can transfer through: conduction, convection, evaporation, radiation
29
Q
Heat transfer: Conduction*
A
- heat transfer through physical contact (solids, liquids)
- T1=T2- no net transfer
- T2>T1- net flow from T2 to T1
- T1>T2- net flow from T1 to T2
- factors that influence heat conduction:
- temperature gradient is driving force
- surface area of contact influences ease of movement
- length between objects influences ease of movement (thickness)
- composition of interface influences ease of movement (thermal conductivity ex. metal)
30
Q
transport equation
A
dQ/dt= K*A/l * (T2-T1)
- dQ/dt- net rate at which heat is moving (flow of heat)
- K*A/l- ease of movement
- (T2-T1)- difference in temp, driving force
- A- surface area
- l- length between objects
- K- thermal conductivity
31
Q
Exchange of heat between blood and environment
A
- heat from blood through interstitial fluid and skin to the air
- SA of skin and vessels
- l- space between blood and air
- K- basically water
- vasodilation- enlargement of vessels make them closer to the skin and makes flow of heat easier and larger (decreases l)
- vasocontriction- vice versa
- > passive process
- > increase heat exchange
32
Q
Heat transfer- convection
A
- occurs when environmental medium (air or water) moves over the body surface
- modified version of conduction (slower)
- transfer equation essentially the same as for conduction
1. free convection- environmental medium not mechanically moved (passive movement (hot air rises, convective currents))
2. forced convection- environmental medium physically moved
33
Q
free convection
A
- boundary layers- form when there is little or no forced movement of environmental medium
- decreased driving force for heat exchange
- because of boundary layers body senses environmental temperature as 35, not 20 degrees
34
Q
forced convection
A
- physical movement of environmental medium disrupts boundary layers
- without boundary layers, body senses true environment temperature of 20 degrees (wind chill)
- turning on a fan, breeze, running
- good on a hot day bad on a cold day
35
Q
Heat transfer: evaporation
A
- transformation of water from liquid to vapor (gas)
- requires energy cools down environment
- 1g H2O -> 580 cal (heat of vaporization)
- evaporative cooling- when water moves from liquid phase to vapor phase, it absorbs energy from the body surface -> cooling
- takes heat from body to go from liquid to vapor
- does not relate to the heat equation
- sweating, panting
36
Q
Heat transfer: radiation
A
- without contact
- longer wavelength- less energy
- anything that has heat sends out electromagnetic radiation
- can be absorbed or reflected back into the environment
- night vision goggles pick up on heat
37
Q
Heat in
A
- heat gain from ext. env.
- conduction
- convection
- radiation
- endogeneous heat prod.- comes from chemcial processes
- metabolic rate
38
Q
heat out
A
- heat loss to ext. env.
- conduction
- convection
- radiation
- evaporation
39
Q
counter-current exchange
A
-flow on one side is opposite to the flow on the other side -> maximize heat transfer
Bird on ice ex.
-arterial blood on its way down warms the venous blood going back up to the heart
-by the time the arterial blood is down to the feet it is already cool from warming the venous blood -> less driving force
-small driving force for heat exchange from foot to ice- minimal heat loss to environment
40
Q
Core Body temperature
A
- organisms priority is to maintain core temp
- humans- core T ~ 37C
- birds ~ 39
- extremedies matter less than core bc they can be heated on way back
41
Q
why regulate temp
A
- chemical reactions are temperature sensitive
- enzymes need a specific temp
- reaction rate of virtually every process in the body increases exponentially with temperature
- proteins denature at too high temps
42
Q
Ectothermy
A
- use of external heat to thermoregulate poikilotherms (older terminology = variable Tb)
- cold blooded
- all non vertebrate species (amphibians/reptiles/fishes/sharks)
- proportional- temp varies with environment
- MR varies with environment- at low temp they use less energy (slower), at high temp they use more energy (faster) -> it has a optimal MR and T
- rely of behavioral thermoregulation mainly
43
Q
endothermy
A
- use of internal heat (MR) to thermoregulate hemeotherms (older terminology= constant Tb)
- warm blooded
- birds/mammals
- tunas/dinosaurs
- energetically very costly
- independent- temp is constant and independent of environment (negative feedback)
- driving force between environment and body temp
- As environment get colder the MR increases to maintain temp and at high temp MR also increases bc sweating requires energy (backward J trend)
- utilizes endogenous heat protection in order to thermoregulate
44
Q
heterothermy
A
- use of both internal and external heat to thermoregulate
- temporal heterothermy
- regional heterothermy
45
Q
Thermo acclimation
A
- optimal and maximum critical temp can shift depending on season
- optimal MR doesnt change
46
Q
thermoneutral zone
A
- the range of ambient temperatures that thermoregulation does not need to rely on increasing MR
- thermoregulate without having to generate more heat:
- vasodilation, constriction
- behavioral mechanisms
47
Q
Advantages of being an ectotherm
A
- requires less energy
- can exploit a broader range of body sizes/shapes
- more efficient in producing biomass
48
Q
Ectotherms: require less energy
A
- endotherms require ~17x more energy
- more suited to variations in food supply
- can tolerate a less predictable environment
- do not need to produce endogenous heat
49
Q
Ectotherms: can exploit broader range of body sizes/shapes
A
- since body temp = environment there is freedom from heat conserving constraints
- ectotherms can function with much smaller body masses than endotherms
- greater length/diameter variability in ecotherms
50
Q
Ectotherms: more efficient in producing biomass
A
- ingested food/energy available for producing biomass rather than maintaining high body temp
- ex. reproduce more babies
51
Q
Behavioral Thermoregulation ex.
A
-selecting temperature by behavior
FISH
-place a goldfish in a tank with cold on one side and hot on the other
-first the goldfish will explore
-it will find its optimal temperature zone where metabolic rate is optimal
-selecting temperature by behavior
LIZARD
-the lizard will sit on rocks to increase its body temp and MR due to the ambient heat from the rock and sun (the lizard temp will be higher than the ambient temp bc the rock)
-the temperature fluxuates bc it leaves the rock to explore
-at night it burrows to minimize heat loss
52
Q
heliotherm
A
heat source is the sun
53
Q
thigmotherm
A
heat source is the substrate (earth) ex. rocks
54
Q
thermoaclimation
A
- animal cant navigate its environment in order to thermoregulate bc of seasonal extremes
- biochemical changes in the body
- maximum critical temp will change by season (higher in summer)
- biochemically changes to function better in the winter time
- selective synthesis of multiple forms of the same enzyme (produces different enzymes in different seasons) -> isoenzymes- have different optimal temperatures and function at different rates at different temperatures
55
Q
Acute response in ambient temperature
A
- temp drop -> rapid drop in MR (vice versa)
- fish becomes very slow
- what happen immediately when temp changes
- quick
56
Q
Chronic response in ambient temperature
A
- slow increase in MR
- curve is shifting left
- acclimation
- if we put a fish in cold water the acute response will be first but if you leave it there over time (weeks) MR will slowly increase (chronic response)
- shifting set of isozymes
57
Q
Thermoregulation in endotherms
A
- behavioral thermoregulation is always occurring
- in the thermoneutral zone there is physiological thermoregulation -> vasodilation- increase heat disapation when its warmer, vasocontriction- when its cooler
58
Q
Endotherms in the cold
A
- Increase their MR -> increases the heat production -> energetically costly
- thermogenesis- convert chemical energy into heat
- main sources of endogenous heat production: shivering and nonshivering thermogenesis
- change thermal conduction (regulated process):
- decreasing driving force- counter-current exchange mechanism in limbs and pulsatile blood flow to limbs
- decrease surface area- less heat loss (short ear, short limbs)
- increase size- smaller surface area/volume ratio
- increase insulation- fur
- avoidance- hibernation, torpor
