Chapter 1 - Animals and Environments Flashcards
Why is physiology important to humans?
Key discipline for understanding the fundamental biology of all animals, human health and disease, the health and disease of nonhuman animals of importance to human affairs.
What is physiology?
The study of animal function - “how animals work”
Three examples of physiology at three different levels of organization
Evolution - salmon species differ genetically and the differences increase as the distance between them increases.
Chemistry and physics - animals adhere to the laws of chem and physics, and sometimes take advantage of them; Salmon ATP, extracted from organic molecules is sent to muscles which contract and exert biomechanical forces on the water which propel them through the water.
Ecology - when the fluid environment of salmon changes from salt to freshwater their ion pumps switch from pumping ions inward in freshwater to pumping them outward in seawater.
Distinguish the mechanism of a physiological trait from its evolutionary origin (adaptive significance)
Current mechanisms are products of evolution. Light flashes of fire flies function to attract males. Firefly luciferin reacts with ATP to produce luciferin-AMP which reacts with oxygen to emit light. The mechanism is adaptive and the adaptive significance is mate attraction.
Mechanistic physiology
Approach to studying physiology that focuses on mechanisms
evolutionary physiology
approach of study that focuses on evolutionary origins
Comparative physiology
Synthetic study that compares the ways that various animals carry out similar functions
environmental physiology
approach that studies how animals respond physiologically to their environmental challenges and conditions
Mechanism of homeostasis
(internal condition that’s being maintained) - “the coordinated physiological processes which maintain most of the constant states in the organism.”
-maintaining internal constancy
mechanism of negative feedback
(mechanism that permits/maintains homeostasis) - the system opposes deviation of the controlled variable from the set point; synonymous to homeostasis.
conformity
An animal that permits its internal and external environment to be equal. Failure of homeostasis, failure to respond.
regulators
Maintain an internal environment separate form their external environment.
Acute changes
short term changes that individual’s exhibit soon after their environments have changed.
Chronic changes
(acclimation/phenotypic plasticity) - long term changes that individual’s display after they’ve been in a new environment for days, weeks, months.
evolutionary changes
changes that occur by alteration of gene frequencies over the course of multiple generations in pops in a new environment
Three environmental factors that influence physiology w/ examples
Temperature - too low/high animals cannot function and die
Air - in high elevation, air availability is limited. Limits metabolic energy cannot respirate.
Water - in deep water, metabolic energy is limited , cannot respirate.
How does an animal’s body size affects its physiological processes?
Scaling - the size of an animal affects many traits. The larger an animal is, the longer their gestation time will be.
Comparative method
Approach for examining evolutionary processes - seeks to identify adaptive traits by comparing how a particular function is carried out by related and unrelated species.
Lab experiments
approach for examining evolutionary processes - changes in gene frequencies can be studied
study of genetic structures
approach for examining evolutionary processes - clines are a progressive change in allele frequencies or gene controlled phenotype frequencies along an environmental gradient.
phylogenetic reconstruction
approach for examining evolutionary processes - making family trees based on molecular genetic data
adaptive significance
the reason why the trait is an asset; why natural selection favored the evolution of the trait.
Pleiotropy
control of an allele of a single gene of two or more distinct and unrelated traits
genetic drift
processes in which chance assumes a preeminent role in altering gene frequencies
Why do animals eat all the time?
- Energy is needed to combat entropy
- Animals continuously breakdown and rebuild tissues and need new material for that
Animals are structurally dynamic
- Organization of atom’s define the animal, but the atom’s are always changing and being replaced.
Marine invertebrates
have body fluids near the salt concentration of sea water and do not need to regulate
Freshwater animals
tend to gain water osmotically, which dilutes their body fluids, and must use energy to pump it out
Terrestrial animals
tent to lose water, must use mechanisms to maintain water
marine animals
subject to water loss if they have terrestrial or freshwater ancestry
