Physiology Flashcards
How does water enter an animal’s system
1) Preformed water (food and drink)
2) Metabolic water production
How do electrolytes enter an animal’s system
1) Preformed water (food and drink)
How does water leave an animal’s system
1) Respiration
2) Cutaneous water loss
3) Feces
4) Urine
How do electrolytes leave an animal’s system
1) Feces
2) Urine
How do freshwater fish osmoregulate?
1) They are hyperosmotic
2) They are at risk of hypervolemia and hyponatremia
3) They produce dilute urine
4) They uptake electrolytes in the gills
How do marine fish osmoregulate?
1) They are hypoosmotic
2) They are at risk of hypovolemia and hypernatremia
3) They actively drink seawater
4) They produce concentrated urine
5) They excrete electrolytes through chloride cells in the gills
How do elasmobranchs osmoregulate?
1) They have TMAO and urea in their blood which increases blood osmolality
2) Therefore, they are hyperosmotic
2) They are at risk of hypervolemia and hyponatremia
3) Concentration of saltwater is higher in water than in their blood which is why they need a rectal salt gland
How do marine reptiles osmoregulate?
1) They produce uric acid which, although requires a lot of water, allows some urine to pass backwards into the hindgut for water resorption
2) They have a salt gland that allows them to drink sea water while maintaining osmotic balance.
How do marine birds osmoregulate?
1) They produce uric acid which, although requires a lot of water, allows some urine to pass backwards into the hindgut for water resorption
2) They have a salt gland that allows them to drink sea water while maintaining osmotic balance.
How do marine mammals osmoregulate?
1) Very concentrated urine (reniculate kidney)
2) Apneustic breathing
3) Nasal turbinates
4) Lipid rich diet
5) Lipid-dense milk (when lactating)
Nitrogenous waste in different organisms
1) Ammonia = most aquatic animals (fish)
2) Urea = mammals, most amphibians, sharks
3) Uric acid = birds, insects, reptiles
Which marine mammals drink seawater?
1) Sea otters, common bottlenose dolphin, hooded seal, harp seal (while feeding)
2) Galapagos fur seal, short-beaked common dolphin, and short-finned pilot whale while fasting
Surface area scaling
Volume ^2/3
Mass ^ 1
Length^2
Volume
Length^3
Mass ^ 1
Fundamental variables of scaling relationships and derived variables
1) Mass
2) Length
3) Time
Derived
1) Density
2) Velocity
3) Acceleration
4) Force
5) Stress
6) Work
7) Power
8) Mass specific power
9) Biomass density
10) Production
11) Productivity
Equation for scaling of body mass
Y=aMsub(b)^b
a = proportionality constant
b = mass exponent
In log form:
log(Y) = log(a) +b*log(Msub(b))
Things that scale with body mass
1) Blood volume of mammals
2) Lung volume of mammals
3) Resting metabolic rate: Mass^.75
3) Mass-specific metabolic rate: Mass^-.25
4) VO2max: Mass^.75 (.81)
5) Specific net transport cost ^-.25
Scaling of metabolic rate
1) Total Metabolic Rate: Mass^.75
2) Mass-Specific Metabolic Rate: Mass^-.25
Environmental implications of scaling of metabolic rate
1) Small mammals degrade more energy per unit mass than large mammals
2) Therefore, a given energy supply will run
out more quickly for small animals
3) Or, looked at per unit time, a given energy supply will support a much smaller biomass of mice than of large moose or elephants
4) So larger species are better at getting and using energy than smaller species from similar taxa (better competitors)
Oxygen consumption and locomotion
1) For running animals on land, oxygen consumption increases with speed of running and the slope of this line is greater for small animals
2) Cost of travel is smaller for larger animals (relatively)
3) But minimum total cost of transport increases with increasing body size
Environmental implications of locomotory scaling
1) Informs optimal foraging theory
2) Using maximum and average speeds for animals of a given body size allows us to estimate range over which they can operate as the distance from a central point like a nest.
3) Has implications for territory size and habitat quality
4) For any given migration time, flying animals will be able to complete a much longer distance than walkers or swimmers of similar size, so to achieve the same distance in the same time, walkers or swimmers would have to be much larger.
Mammalian Dive Response
1) Breathing ceases
2) Bradycardia
3) Blood flow to peripheral tissues and organs reduced
Diving metabolism
1) Hypometabolism: thought to be related to anaerobic metabolism (ATP produced without oxygen, but only 2 ATP produced per molecule of glucose, lactic acid is byproduct)
2) Aerobic metabolism (38 ATP produced per molecule of glucose)
Challenges of Diving
1) HPNS (most animals do not dive deep enough to experience this)
2) Collapse/compression of air spaces (surfactant)
3) Oxygen toxicity, nitrogen narcosis, and decompression sickness (breathhold dive and collapse lungs)
4) Foraging without breathing (Bradycardia, hypoxia resistance)
