Homeostasis- Lecture 1

Question 1

Define the term “homeostasis” and explain how it differs from “steady state”?

Answer 1

Homeostasis refers to the maintenance of a CONSTANT and NORMAL internal state.

Steady state does also refer to a constant state, yet it usually refers to an elevated state whereby a plateau has been reached at abnormal levels.
eg: HR at maximal exercise

Question 2

Cite an example of a homeostatic control system within the body?
What are the main parts of a control system?

“SCE”

Answer 2

The cardiovascular system
SENSOR, CENTRE, EFFECTOR

eg: temp moves above 37, stimulus changes internal conditions and informs the brain, sensor picks this up, leading to the control centre causing sweat glands to secrete ect through the effector.

Question 3

Explain the role of the sensor, integrating centre and effector?

Answer 3

Sensor- picks up response of stimulus and signals the integrating sensor of a disturbance.
Integrating centre- used to signal the effector of the disturbance, initiates response
Effector- responsible for a change back to normal , correcting disturbance and removing stimulus through negative feedback

Question 4

Define the term negative feedback in relation to a biological system?

Answer 4

When the actions of a biological system REVERSE changes to the body’s natural state, moving back to a state of equilibrium.

Question 5

Discuss the concept of gain associated with a biological control centre?

Answer 5

Gain= ability/ capacity to maintain homeostatic control
Large gain= high capacity
Small gain= low capacity