Homeostasis

Question 1

As fat percentage in the body increases what happens to the percentage of water in the body ?

Answer 1

As fat percentage increases the percentage of water decreases

Question 2

What is the formula of the dilution principle ?

Answer 2

V = M/C

Question 3

What must be considered when measuring a body fluid compartment ?

Answer 3

The nature of the substance and which compartment you wish to measure

Question 4

What is the only body fluid that can be sampled directly ?

Answer 4

Plasma and components of plasma such as ECF and TBW

Question 5

How is plasma volume measured ?

Answer 5

Radioactive labels attached to plasma proteins as plasma proteins cannot cross the capillary wall

Question 6

How is extracellular volume measured ?

Answer 6

With a substance that can cross the capillary walls but not the cell membrane such as sucrose, insulin or large ions

Question 7

How is total body water (TBW) measured ?

Answer 7

Loading dose of heavy water (D20)

Question 8

What is negative feedback ?

Answer 8

It switches off compensatory mechanisms such as shivering, once the body temp has risen the shivering will stop due to negative feedback.
It will restore the regulated variable after displacement but cannot prevent it.

Question 9

What is feed forward control ?

Answer 9

This system will detect change in the body before the negative feedback system, it pre-empts change.

Question 10

What is positive feedback ?

Answer 10

Where an initial disturbance leads to an even greater disturbance, heavily associated with pathology.