Flashcards in Unifying Concepts in Physiology and Homeostasis Deck (33):
Physiological processes obey the laws of __ & ___.
Physics and chemistry.
How does temperature effect physiological processes?
The rate of reaction increases with temperature.
Most biological reactions and physiological processes fall between doubling and tripling their rates with a ten degree rise in temperature.
What is Q10 [reference to temperature and reaction rates]?
The rate of reaction at a certain temperature over the rate of reaction at that temperature minus 10 degrees.
Why does temperature raise the rate of reaction?
There is an increase in thermal energy and therefore an increase in kinetic energy, bringing the reacting molecules closer together more frequently; raising the rate of reaction.
The sum of all chemical reactions that occur in a body system.
What can be used to calculate metabolism?
The rate of oxygen consumption in 'per gram of body weight/hour'.
What do electrical laws describe?
The membrane function of all cells, including excitable cells.
What is Electric Potential?
The difference in electrical charge between the external and internal charge of the cells.
Very important in carrying out functions.
How do neurons and muscle cells carry out their functions?
By generating electricity through moving and transporting ions outside the body.
True or False: Body size has no affect on physiological process.
False, body size does have an affect on many physiological processes.
Examples: the greater the body mass, the lower the metabolic rate.
Key Concept: Surface area/volume ratio, in relation to animal size.
The SA/V will be greater in smaller compared to larger animals. The rate of increase of volume is by a power of three while the rate of increase of surface area is two.
SA/V is important in physiology because some properties vary in relation to ___ and ____.
The volume and surface area.
Almost all the physiological changes that occur within a body deal with the ___.
Body mass, a function of volume. Example: heat production.
Almost all the changes that deal with the internal and external functions deal with ___.
Surface area. Example: heat dissipation.
___ animals are more efficient in maintaining body temperature because of a lower SA/V.
Large animals; less heat loss, lower metabolic rate.
Large animals require ___ ___ ti enhance exchange with the environment.
Structural adaptations, the lower SA/V brings a challenge with exchanging material with the environment.
__ __ with simple body construction have enough surface area to meet their cell's needs.
Small animals. When the SA/V reaches a point, a simple exchange like diffusion is not enough.
The physiological phenotype is a product of the ___ and the ___.
Genotype and the environment.
What is phenotypic plasticity?
A phenotypic change without a change in the genotype. The change is due to the environment, and reverses when possible.
What does acclimation result in?
A reversible phenotypic change due to short-term changes in the environment.
What are two ways animals respond to environmental change?
Long term = evolutionary adaptations
Short term = acclimation and homeostasis
What are evolutionary changes resulting from water, regarding movement?
Water is more viscous, which affects movement. Since it is more dense than air, animals develop stream-like body shapes to reduce draft.
What are evolutionary changes resulting from water, regarding low light penetration?
It affects the sensory systems, and animals need structural and functional adaptations to sense their environment. Some adaptations include the lateral line that allows movement detection in water, or adaptations to detect changes in electrical signals.
What evolutionary changes result from water, regarding the change in solute concentrations?
Affecting osmoregulation, fresh water fish have more salt in their blood compared to the water; they need adaptations to combat the loss of salt due to diffusion.
What evolutionary changes result from water, regarding low oxygen solubility?
Affecting respiration, oxygen is not very soluble in water so adaptations are needed to extract oxygen from water more efficiently.
What evolutionary changes result from air, regarding movement?
Less vicious, more restricted by gravitational force. Vertebrates have strong skeletal structure, wings needed for flying.
What evolutionary changes result from air, regarding moisture?
Very dry, affecting osmoregulation. Desiccation is a problem, thick skin helps to maintain water balance in body.
What three things do animals generally do?
1. Live in a constantly changing environment
2. Respond favourably to changes in order to survive
3. Use physiological and behavioural responses to minimize disruptive effects of change
Effects of external environmental change are reduced by what?
By maintaining a stable internal bodily environment, homeostasis.
A general term to describe the physiological processes that maintain internal stability.
What are the two major strategies used to deal with environmental variables?
Conformity and regulation.
What are conformers?
Animals that allow physiology to fluctuate with the environment. A change in temperature means that they will allow their body to follow suit. Not energetically expensive.