Homeostasis 1 & 2

Question 1

What is homeostasis?

Answer 1

Maintaining similar conditions constantly in the internal environment so all processes can work optimally.

Question 2

Why is homeostasis important?

Answer 2

Homeostasis is fundamental to life. Disruption of homeostasis leads to disease. When an internal change is detected the organ will try to compensate. If compensation fails, disease occurs it is successful homeostasis is achieved.

Question 3

What is the equation of life?

Answer 3

Nutrients + O2 —> energy (ATP) + waste (inc CO2)

Question 4

3 homeostasis control systems

Answer 4

Negative feedback
most common)
Normal process, restores the regulated condition after disturbance. Self limiting as the response stops the trigger (trigger that started the response is removed)

Positive feedback
Uncommon in control system but does occur and is crucial when it does (action potentials in nerve cells). Can lead to further disturbance as causes a chain reaction of more trigger/response. Can lead to disease

Feedforward
Predicts and prevents disturbance to homeostasis before it happens.

Question 5

What are the different body fluid compartments?

Answer 5

Plasma
Intersitital fluid
Extracellular fluid

Question 6

Briefly explain the fluid composition of ICF and ECF.
How is water distributed in the body?

Answer 6

Intracellular fluid (ICF) has a very different composition to extracellular fluid (ECF) because of the selective permeability of the cell membrane.
Plasma fluid (dynamic component of the ECF) and interstitial fluid composition is similar, only proteins and blood cells can’t move through the blood capillary walls.

Water distribution
ICF = 2/3
ECF = 1/3