Lecture 1: Body Fluid Compartments Flashcards
Why do we sweat when we exercise?
Because our muscle are not efficient in doing work and generate heat, which is dissipated as sweat evaporates off the skin,
What is the best fluid to replace sweat?
Sweat itself
What happens at 2% body weight fluid loss? How many liters of sweat does that represent?
Impaired performance 1.5 L
What happens at 4% body weight fluid loss? How many liters of sweat does that represent?
Decreased capacity for muscular work (capacity to do work) 3 L
What happens at 5% body weight fluid loss? How many liters of sweat does that represent?
Heat exhaustion 3.5 L
What happens at 7% body weight fluid loss? How many liters of sweat does that represent?
Hallucinations 5 L
What happens at 10% body weight fluid loss? How many liters of sweat does that represent?
Circulatory system collapse/Heat stroke 7 L
What were unicellular organisms not capable of doing?
They had no way of regulating themselves if the environment is not right
What body compartment do cells bathe in?
Milieu interieur
What is another name for the milieu interieur?
Interstitial fluid
Who coined the term milieu interieur?
Claude Bernard
Through what do nutrients arrive at the capillary bed?
Arterioles
Through what do metabolites leave at the capillary bed?
Venules
Role of circulatory system? Made of which two parts?
To “pump” and circulate nutrients to the cells and take waste products away Heart and vasculature
Role of respiratory system?
To deliver O2 and excrete CO2
Role of gastrointestinal system?
To take in nutrients and break them down to be able to utilize them and then eliminate what we don’t need
Role of renal/urinary system?
To monitor and regulate all of the electrolytes in the body
What is an electrolyte?
A substance (as sodium or calcium) that is an ion in the body regulating the flow of nutrients into and waste products out of cells
Role of musculoskeletal system?
To physically obtain whatever nutrients we need
What are the two physiological systems that regulate our vital functions?
The nervous (PNS/CNS) and endocrine systems
Role of immune system?
To defend our body from pathogens
Is the reproductive system a physiological system? Why?
No because its purpose is to protect the species as a whole not homeostasis of an individual organism
What is the definition of homeostasis?
The process by which the body maintains constancy in internal function in the face of changes in the external environment
How does our % total body water change from birth to adulthood?
It decreases
What is the % TBW of an adult?
58-60%
What is the % TBW of an obese adult?
40-50%
What is the % TBW of an emaciated adult?
70-75%
Why do fat people have a lower % TBW than skinny people?
Fat cells have less water!
Is there a difference in % TBW between men and women? Why?
Yes, women tend to have less TBW than men because they contain more subcutaneous adipose tissue in their bodies.
Is there more water inside or outside cells? What are the exact ratios?
Inside
2/3 inside and 1/3 outside