Mcgill - Physiology 209

Front 1

What was Aristotle's take on physiology?

Back 1

That good health was associated with a balance between multiple life sustaining forces.

Front 2

What did Hippocrates believe in?

Back 2

Healing power of nature.

Front 3

Who was Jean Fernel and what did he define physiology as?

Back 3

- French Physician
- Defined as the "natural" part of medicine.

Front 4

Define Physiology:

Back 4

The study of the normal functional activities in the healthy living organism.

Front 5

What is the fundamental principle of physiology?

Back 5

Functional activities are directed towards maintaining homeostasis.

Front 6

What did Claude Bernard study?

Back 6

The differences between the milieu interieur vs. the external environment.

Front 7

What is the idea of milieu interieur?

Back 7

- All cells are surrounded by their own environment.
- It comprises of the various body fluids.

Front 8

What did Walter Canon define?

Back 8

That HOMEOSTASIS was a state of dynamic constancy.

Front 9

Aspects of Body Fluids

Back 9

1. Volume
2. Distribution
3. Characteristics
4. Functions

Front 10

Body Water, is the medium in which...

Back 10

(i) Solutes are dissolved
(ii) Metabolic reactions take place

Front 11

What accounts for the large variation (45-75%) in water content in different individuals?

Back 11

BONE (25% Water) & FAT - adipose tissue (10% Water)
- The fatter an organism is the lower its body water percentage is.
- The heavier boned people are, the lower their body water percentage is.

Front 12

What would happen is water content was computed as a fraction of lean body mass?

Back 12

The differenced between individuals would become insignificant because you would be excluding fat. Would range between 70-75%.

Front 13

What are the standard values of the physiological reference individual?

Back 13

21 year old, 70 kg white male.

Front 14

What are the body water percentage trends for both males and females with respect to age.

Back 14

Females body water percentage decreases from birth due to an increase in fat. Males follows roughly the same trend however after puberty they gain body water %.

Front 15

What are the body water percentages of a female and a male at 1) Infancy, 2) puberty and 3) Old age

Back 15

1) 75% Each
2) F = ~50%, M = ~60%
3) F = ~45 %, M = ~50%

Front 16

How much body water is in the 70 kg male and the 60 kg female?

Back 16

Male = 42 L
Female = 30 L

Front 17

What comprises obligatory losses? How much water does it account for?

Back 17

1) Insensible losses (~1L) and urine/stoool loses (~0.5L).
2) Obligatory losses acount for ~ 1.5 L of water

Front 18

What accounts for facultative losses? How much water does it account for?

Back 18

1) Urine
2) Varies with in taking of fluids.

Front 19

Insensible Perspiration accounts for how much water loss? What are its components?

Back 19

a) It accounts for ~ 1L
b) Components:
- Pure Water
- Passive evaporation (No energy used)
- Entire skin surface
- Continuous

Front 20

What are the components to water losses from sweating?

Back 20

1. Electrolyte solution
2. Active secretion (energy used)
3. Sweat glands
4. Activated by heavy work or high temperature.

Front 21

Over a 24 hr period, what is the turnover of water in the adult?

Back 21

3-4% of body mass.

Front 22

Over a 24 hr period, what is the turnover of water in an infant?

Back 22

10% of body mass. More than adult because has less body fat therefore a higher water weight %.

Front 23

A constant body water volume under conditions of health helps maintain...

Back 23

1) a normal solute concentration
2) a normal blood volume and pressure
These two factors help maintain an adequate supply of oxygen to the tissues.

Front 24

How can a negative water balence occur?

Back 24

1. Reduced water intake
2. Excessive Loss from gut (chronic diarrhea/vomitting)
3. Excessive sweating (running at high temperatures)
4. Excessive loss in expired air (mountain climbers)
5. Excessive loss in urine (various diseases don't allow kidneys to cope)

Front 25

Factors of Water "Intoxication".

Back 25

1. Excessive Intake - very rare since the kidneys can process many liters of water/day
2. Renal Failure - kidneys are incapable of producing urine.

Front 26

What are the two major body water compartments?

Back 26

Two Major Compartments:
1. Intracellular Fluid (ICF) - 40% Body Mass, 2/3 of Body Water
2. Extracellular Fluid (ECF) - 20% Body Mass, 1/3 of Body Water

Front 27

What are the subdivisions of the ECF?

Back 27

Two Major Compartments:
1. Plasma
2. Interstitial Fluid (ISF)
Two Minor Compartments:
1. Lymph
2. Transcellular Fluid

Front 28

What is Plasma?

Back 28

Plasma is the fluid medium, in which blood cells are suspended.

Front 29

What are the components of Blood?

Back 29

55% Plasma
45% RBCs
<1% Buffy Layer = WBCs + Platelets

Front 30

What is the hematocrit (Ht)?

Back 30

The percentage of blood volume that is occupied by the Red Blood Cells. (~45%)
Ht = Packed Cell Volume
The hematocrit separates the plasma when the blood is centrifuged.

Front 31

What percentage of body water does the plasma and the ISF take up?

Back 31

5% - Plasma, 15% Interstitial Fluid

Front 32

What is interstitial fluid? Where is it found?

Back 32

It is the true "Milieu Interieur". It is the fluid that percolated between individual cells. All exchanges are made through ISF. Found between cells, blood, capillaries, external environment.