Unifying Concepts in Physiology and Homeostasis

Question 1

Physiological processes obey the laws of __ & ___.

Answer 1

Physics and chemistry.

Question 2

How does temperature effect physiological processes?

Answer 2

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.

Question 3

What is Q10 [reference to temperature and reaction rates]?

Answer 3

The rate of reaction at a certain temperature over the rate of reaction at that temperature minus 10 degrees.

Question 4

Why does temperature raise the rate of reaction?

Answer 4

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.

Question 5

Define Metabolism

Answer 5

The sum of all chemical reactions that occur in a body system.

Question 6

What can be used to calculate metabolism?

Answer 6

The rate of oxygen consumption in ‘per gram of body weight/hour’.

Question 7

What do electrical laws describe?

Answer 7

The membrane function of all cells, including excitable cells.

Question 8

What is Electric Potential?

Answer 8

The difference in electrical charge between the external and internal charge of the cells.
Very important in carrying out functions.

Question 9

How do neurons and muscle cells carry out their functions?

Answer 9

By generating electricity through moving and transporting ions outside the body.

Question 10

True or False: Body size has no affect on physiological process.

Answer 10

False, body size does have an affect on many physiological processes.
Examples: the greater the body mass, the lower the metabolic rate.

Question 11

Key Concept: Surface area/volume ratio, in relation to animal size.

Answer 11

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.

Question 12

SA/V is important in physiology because some properties vary in relation to ___ and ____.

Answer 12

The volume and surface area.

Question 13

Almost all the physiological changes that occur within a body deal with the ___.

Answer 13

Body mass, a function of volume. Example: heat production.

Question 14

Almost all the changes that deal with the internal and external functions deal with ___.

Answer 14

Surface area. Example: heat dissipation.

Question 15

___ animals are more efficient in maintaining body temperature because of a lower SA/V.

Answer 15

Large animals; less heat loss, lower metabolic rate.

Question 16

Large animals require ___ ___ ti enhance exchange with the environment.

Answer 16

Structural adaptations, the lower SA/V brings a challenge with exchanging material with the environment.

Question 17

__ __ with simple body construction have enough surface area to meet their cell’s needs.

Answer 17

Small animals. When the SA/V reaches a point, a simple exchange like diffusion is not enough.

Question 18

The physiological phenotype is a product of the ___ and the ___.

Answer 18

Genotype and the environment.

Question 19

What is phenotypic plasticity?

Answer 19

A phenotypic change without a change in the genotype. The change is due to the environment, and reverses when possible.

Question 20

What does acclimation result in?

Answer 20

A reversible phenotypic change due to short-term changes in the environment.

Question 21

What are two ways animals respond to environmental change?

Answer 21

Long term = evolutionary adaptations

Short term = acclimation and homeostasis

Question 22

What are evolutionary changes resulting from water, regarding movement?

Answer 22

Water is more viscous, which affects movement. Since it is more dense than air, animals develop stream-like body shapes to reduce draft.

Question 23

What are evolutionary changes resulting from water, regarding low light penetration?

Answer 23

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.

Question 24

What evolutionary changes result from water, regarding the change in solute concentrations?

Answer 24

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.

Question 25

What evolutionary changes result from water, regarding low oxygen solubility?

Answer 25

Affecting respiration, oxygen is not very soluble in water so adaptations are needed to extract oxygen from water more efficiently.

Question 26

What evolutionary changes result from air, regarding movement?

Answer 26

Less vicious, more restricted by gravitational force. Vertebrates have strong skeletal structure, wings needed for flying.

Question 27

What evolutionary changes result from air, regarding moisture?

Answer 27

Very dry, affecting osmoregulation. Desiccation is a problem, thick skin helps to maintain water balance in body.

Question 28

What three things do animals generally do?

Answer 28

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

Question 29

Effects of external environmental change are reduced by what?

Answer 29

By maintaining a stable internal bodily environment, homeostasis.

Question 30

Define homeostasis.

Answer 30

A general term to describe the physiological processes that maintain internal stability.

Question 31

What are the two major strategies used to deal with environmental variables?

Answer 31

Conformity and regulation.

Question 32

What are conformers?

Answer 32

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.

Question 33

What are regulators?

Answer 33

Animals that maintain physiology different from their environment. Variations occur in a very narrow range. Energetically expensive.