Homeostasis

Question 1

Define Homeostasis

Answer 1

maintaining relatively similar and constant internal environment

body systems function optimally and produce energy.

Question 2

What type of change results in a homeostatic response.

Answer 2

Internal and External

changes internal environment and loss of homeostasis

Question 3

Explain the importance homeostasis

Answer 3

body systems not very tolerant to change in internal environment or any imbalances

allows for optimal environment for body systems to function and produce energy efficiently

Question 4

Describe the principles behind negative feedback control systems.

Answer 4

1. When a condition that is regulated through homeostasis is sensed to have shifted from normal range, a signal is produced that triggers response
2. response corrects original disturbance and brings regulated condition back within normal range

Question 5

What size of response is triggered in negative feedback.

Answer 5

directly proportional to size of disturbance, i.e. bigger disturbance, bigger response

Question 6

Explain what is meant by feed forward control.

Answer 6

additional receptors allow for body systems to anticipate change in internal condition and activate earlier response.

Question 7

Give an example to feed forward control.

Answer 7

• when a person is loosing fluids, kidneys will detect increase in the body fluid concentration
• will pre empt a state of dehydration.
• does this by producing smaller volumes of urine, producing more concentrated urine which will conserve water.

Question 8

Explain a positive feedback mechanism.

Answer 8

1. occurs when disruption leads to imbalance of internal environment
2. imbalance then leads to a response
3. response amplifies initial disturbance leading to greater imbalance.

Question 9

Identify the different body fluid compartments.

Answer 9

1. Intracellular Fluids (within cell)
2. Interstitial Fluids (outside cell)
3. Plasma (fluid component ofblood)

Question 10

Explain the importance of the nature of barriers which separate body compartments.

Answer 10

allow for free movement of water across different compartments
selectively permeable and can prevent movement of any unwanted molecules across different membrane compartments.

Question 11

Why is water balance important.

Answer 11

water affects concentration of everything else in the body and thus water balance must be homeostatic-ally controlled.
average daily water balance in an adult male is thermoneutral.

Question 12

Define the dilution principle.

Answer 12

volume of body fluid equals mass of component in fluid, dived by concentration of that component in the fluid.

V = M/C

Question 13

Describe the use of the dilution principle in the measurement of body fluid compartments.

Answer 13