Homeostasis

Question 1

Feedback Systems (Loops)

Answer 1

Are a cycle of events in which the internal environment is:

Monitored
Evaluated
Changed 
Re-Monitored
Re-Evaluated

Question 2

Controlled Condition

Answer 2

The variable being monitored

Question 3

Stimulus

Answer 3

Whatever disrupts/changes the controlled condition (external or internal)

Question 4

Components of a Feedback System/Loop

Answer 4

A sensor/receptor
Transmission pathways
A control centre
An effector

Question 5

Sensor/Receptor

Answer 5

A structure that monitors changes in a controlled condition.

Detects chemical, electrical, mechanical changes

Sends info to the control centres

Question 6

Homeostasis

Answer 6

The condition of balance in the body’s internal environment due to the constant interaction of the body’s many internal regulatory processes.

Question 7

Transmission Pathways

Answer 7

The nervous and blood vessel pathways (as well as their signalling molecules)
Relay messages between (a) the sensor/receptor and the control centre and (b) the control centre and the effector

Question 8

Control Centre

Answer 8

Comprised of the nervous and endocrine systems.
Sets the range of values within which the controlled condition should be maintained.
Evaluates and compares the input received from the sensor/receptor against set range.
Determines the body’s responses to the change in controlled condition
Sends commands to the effector

Question 9

Effector

Answer 9

Structures that ultimately produces the response to a given stimulus.
Receives the commands from control centre.
Produces the response that will change the controlled condition.

Question 10

Negative Feedback System

Answer 10

Function to reverse changes in the internal environment.
Respond to a disturbance by moving the controlled condition back towards the initial set range.
Very Stable
Predominant system

Question 11

Positive Feedback Systems

Answer 11

Function to strengthen changes in the internal environment.
Respond to a disturbance by moving the controlled condition farther from the initial set range.
There is some mechanism that shuts down the response.
Inherently unstable.
Uncommon.

Question 12

Implications of Homeostatic Imbalances/Dysfunction

Answer 12

Body can change the parameters within which it is acceptable to function.

Adaptation: the adjustment of an organism to its environment.

Compensation: the adjustment of an organism to counterbalance a defect.

If homeostasis is mildly affected, you may not notice it (mild symptoms)

If homeostasis is moderately affected, disease states can occur.

If homeostasis is severely affected, death is possible.