Module 1: Basic Principles, Body Temperature, and Thermoregulation

Question 1

What is Physiology?

Answer 1

functional: biological study of the functions of living organisms and their parts.
operational: the study of how cells interact with their environment to obtain the things required for life

Question 2

What are the basic principles of physiology?

Answer 2

ALL LIFE IS:
1) Aquatic
2) Compartmentalized
3) Deals with same fundamental problems
4) Constrained by laws of physics and chemistry
5) Can tolerate only a limited range of conditions

Question 3

Is Aquatic

Answer 3

Body fluids of all animals have the same general composition: water, salts, biochemical substances

Question 4

Is Compartmentalized

Answer 4

Separation of substances in different compartments:
-ICF: inside cells
-ECF: outside cells

Question 5

Same Fundamental Problems

Answer 5

Need to reproduce, deal with temperature, need energy to survive

Question 6

Metabolic Rate

Answer 6

the amount of energy an animal uses in a unit amount of time

Question 7

Constrained by laws of physics and chemistry

Answer 7

Ohm’s law, boyles law, etc.
Physical environment governs what a cell can and cannot do

Question 8

Size Principle

Answer 8

As radius gets bigger, sa/v gets smaller.
smaller sa/v = surface area for exchange decreases, ex: large animal has less heat leave body due to smaller sa/v ratio

Question 9

Can tolerate limited range of conditions

Answer 9

maintaining homeostasis - salts, water, oxygen, ect

Question 10

Sensor

Answer 10

measures some aspect of the internal environment (temp)

Question 11

integrator

Answer 11

compares the sensor measurement to a reference value (set point)

Question 12

effector

Answer 12

output of the system that changes the internal environment (increases temp)

Question 13

Thermal Budget

Answer 13

balance between heat input and output in maintaining optimal body temperature

Question 14

Principles of Heat Transfer

Answer 14

Conduction
Convection
Evaporation
Radiation

Question 15

Conduction

Answer 15

heat transfer through physical contact, can be influenced by temp gradient, surface area, length between objects, ect

Question 16

Vasoconstriction

Answer 16

tightening of blood vessels to avoid temp from getting to cold

Question 17

Vasodilation

Answer 17

widening of vessels to avoid temp from getting to hot (exercise)

Question 18

Convection

Answer 18

Environmental medium (air or water) moves over the body surface

Question 19

Radiation

Answer 19

transfer of heat through space by electromagnetic radiation

Question 20

Evaporation

Answer 20

Transformation of water to vapor

Question 21

Which type of heat transfer is not a mechanism for heat gain in a thermal budget?

Answer 21

Evaporation

Question 22

What is counter-current exchange?

Answer 22

When heat from blood in the arteries (away from heart) is transferred to the veins (towards heart), warming the venous blood, and maintains core body temperature in the cold. It is a small driving force, less heat loss

Question 23

Organization in biological systems

Answer 23

Cellular Level
Tissue Level
Organ Level
System Level

Question 24

Cellular Respiration and its two types

Answer 24

Refers to cells breaking down glucose, aerobic and anerobic metabolism

Question 25

Which metabolism is more efficient?

Answer 25

Aerobic Metabolism is more efficient because it produces more atp and also produces co2 which is important and used as a buffer

Question 26

Sodium

Answer 26

ECF: Hi
ICF: Low

Question 27

Potassium

Answer 27

ECF: Low
ICF: Hi

Question 28

Calcium

Answer 28

ECF: Low
ICF: Very Low

Question 29

Transport Equation for Conduction

Answer 29

ease of movement times driving force (difference in temperatures)
ease of movement: thermal conductivity, multiplied by surface area, divided by length

Question 30

What are the two major strategies for thermoregulation?

Answer 30

Ectothermy and Endothermy

Question 31

What is the relationship between an ectotherm’s body temperature to the environment, compared to an endotherm?

Answer 31

an ectotherm’s body temp is proportional to that of ambient temp (increases as amb increases)

an endotherms body temp is independent, and remains constant over wide range of amb temps

Question 32

Relationship between MR and AMB temp for Ectotherms

Answer 32

increases exponentially, at lower temp mr is lower and at higher temp mr is higher/ Optimal MR is in the middle

Question 33

Relationship between body temp and ambient temp

Answer 33

Body temp remains relatively constant through many ambient temps, there will be a driving force for heat loss or heat gain
Endotherm has to either conserve heat or dissipate heat

Question 34

Relationship btwn MR and Tamb for Endotherms

Answer 34

Body temp relatively constant
MR increases as Tamb decreases
Thermoneutral zone: range of tamb where an organism can thermoregulate without having to increase MR
As Tamb gets higher, MR Increases, sweating requires energy