What is anatomy?
the study of the biological form of an organism (ex: wings, beaks)
What is physiology?
the study of biological functions an organism performs (ex: digestion)
What is homeostasis?
the maintenance of a “steady” state or internal balance regardless of external environment
What must be regulated to maintain homeostasis?
body temperature, blood pH, glucose concentration, etc.
What does homeostasis require?
What is the importance of homeostasis?
helps to sustain life in extreme environment
(NEGATIVE FEEDBACK LOOP DIAGRAM - LABEL)
What are the 4 physical processes of heat exchange with the environment?
radiation, evaporation, convection, conduction
What is the term to describe the emission of electromagnetic waves by all objects warmer than absolute zero?
What heat exchange processes does a lizard depend on?
What does evaporation do to heat on the body?
removes it (thus cooling the body)
What is the difference between convection and conduction?
conduction transfers heat between molecules of objects in direct contact with each other whereas convection involves the movement of warm fluid to or from the surface of an object
What is the term to describe the rate at which animals need to acquire food?
How can temperature affect tissues?
it can affect:
- performance of proteins
- rates of biophysical processes (diffusion, osmosis)
- rates of biochemical reactions
- viscous properties of membranes
How does temperature affect the performance of proteins?
it can denature them - which prevents enzymes from functioning properly
How do warm vs. cold temperatures affect membranes?
warm temperatures cause membranes to become more fluid while cold causes them to become more rigid and less permeable
What are some ways in which animals deal with cold winter temperatures?
physical adaptations such as fur and behavioural adaptations such as migration
How do animals avoid freezing?
- migrate to warmer climate
- move to insulated environment (underground or underwater)
- lower body temperature to slow metabolic rate (hibernation)
How do antifreeze proteins work?
adsorb small ice crystals; preventing the growht of large crystals
What are some components of tissue antifreeze?
carbohydrates (ethylene glycol, glycerol, glucose), electrolytes (Na+, Cl-)
Why is it bad if water freeezes in a tissue?
it expands and forms sharp crystals
How do some animals tolerate freezing?
survive by freezing solid
Why is it important to maintain body temperature?
to survive - organisms are specialized for different temperatures (specialized proteins and membrane composition)
What is the difference between poikilotherms (ecotherms) and endotherms?
poikilotherms have no internal regulation of body temperature so they occupy environments of chosen temperature, whereas endotherms warm their tissues with metabolic heat
What are 3 ways in which endotherms can regulate their body temperatures?
- adjust insulation
- change rate of blood flow in vessels to skin
- change posture
How might an endotherm adjust its insulation?
erect or compress its feathers/fur
What is the difference between vasodialation and vasoconstriction?
vasodialation increases blood vessel surface area to dissipate heat; vasoconstriction closes in vessels to retain heat in core
How can an endotherm use its posture to retain heat? to dissipate heat?
- tuck in/hunch over to retain heat (smaller surface area)
- extend limbs to dissipate heat (larger surface area)
How does the body generate heat when it is below thermal neutral zone (TNZ)?
shivering and brown fat
What is shivering?
unsynchronized contraction of adjacent muscle units (produces no useful work - ATP bond energy dissipated as heat)
What part of the body is responsible for coordinating heat generation?
What is special about brown fat?
contains a lot of mitochrondria that help break down fatty acids and generate heat in doing so (little furnaces)
What takes up 1-3% of fat mass?
How do blood vessels perform heat exchange?
counter-current exchange - transfer heat between blood flowing in opposite directions
What is osmoregulation?
maintenance of osmolarity (water-solute content) of body fluids)
What is the term to describe the sum of concentration of dissolved substances?
What is osmotic pressure?
pressure from flow of water through semipermeable membrane separating solutions with different solute concentrations
In what direction does water flow?
from an area of high concentration to low
How is the osmolarity of marine invertebrates and hagfish related to that of salt water?
Why is it hard for fish to enter environments with different osmotic pressure?
it causes them huge osmotic stress
What benefit does the ability to osmoregulate give?
can inhabit different areas - invade new environments
What is produced by refining a filtrate that is derived from body fluids?
What are the 4 key functions of most excretory systems?
filtration, reabsorption, secretion, and excretion
What is filtration?
pressure-filtering of body fluids
What is reabsorption?
reclaiming valuable solutes
What is secretion?
adding toxins and other solutes from the body fluids to the filtrate
What is the importance of secretion?
gets rid of toxins
What is the term to describe the removal of filtrate from a system?
What does urine allow organisms to do?
gain or lose excess water (necessary if living in a specific osmotic environment)
What is the least toxic nitrogenous waste?
What is the most toxic nitrogenous waste?
How does the toxicity of urea relate to that of ammonia and uric acid?
less toxic than ammonia; more toxic than uric acid
Order urea, uric acid, and ammonia from least to most expensive
ammonia, urea, uric acid
What type of environment is ammonia good in and why?
aquatic environment (takes a lot of water to dilute) - diffuses across gills
What nitrogenous waste takes the least water to dilute?
What is the relationship between the tendency to lose water to the environment and the amount/concentration of urine produced?
more water loss, smaller volume of urine, urine concentration slightly less than body fluids
What happens to freshwater fish in their environment?
tend to gain water
What tends to happen to the body water in terrestrial vertebrates?
tends to be lost to air
Order marine fish, freshwater fish, and terrestrial vertebrates from least to most volume of urine produced
marine fish, terrestrial vertebrates, freshwater fish
How do marine mammals drink sea water?
have very efficient kidneys that excrete the excess salt
How do marine birds and reptile get rid of salt after drinking sea water?
salt glands excrete the salt through countercurrent exchange
How do terrestrial animals conserve water?
special adaptations to absorb water, waterproof skin, etc.
What type of environment do marine fish live in?
What are the layers of (WATERPROOF?) skin, in order from exterior to interior?
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
What makes up the stratum corneum?
dead cells with lipids and/or keratin inside and between cells
What are some adaptations that desert mammals have to balance water?
- drink little or no water
- obtain water from food
- produce more concentrated urine
What is the primary function of urine?