Module 1

Question 1

Define Physiology:

Answer 1

The study of the normal functioning of a living organism and its component parts, including all its physical and chemical processes.

Question 2

What are emergent properties?

Answer 2

Properties of a complex, non-linear system that cannot be explained by knowledge of its parts.

Question 3

List the levels of organization in physiology:

Answer 3

Molecules < Cells < Tissue < Organs < Organ System

Question 4

Distinguish between function and mechanism. What does physiology favour?

Answer 4

Function: ‘Why’ or a teleological approach
Mechanism: ‘How’ or a mechanistic approach
Physiology favours a mechanistic approach.

Question 5

Define Homeostasis:

Answer 5

Maintaining a stable internal environment despite external changes. Homeostasis does not mean equilibrium, rather it is in a dynamic steady state or a stable disequilibrium.

Question 6

Give examples of external changes and internal changes:

Answer 6

External change: toxic chemicals, physical trauma, foreign invaders
Internal change: abnormal cell growth, autoimmune disorders, genetic disorders

Question 7

What is Pathophysiological state:

Answer 7

Occurs when compensation fails and results in a state of sickness.

Question 8

What is considered the internal environment of the body?

Answer 8

Extracellular fluid: the buffer between cells and the external environment

Question 9

Define dynamic steady state:

Answer 9

Movement of materials back and forth with a substance with no net movement within the substance.

Question 10

Define the law of mass balance:

Answer 10

The amount of a substance in the body is to remain constant. Any gain must be offset by an equal loss.

Question 11

Draw the basic layout of control systems.

Answer 11

Input signal → Integrating center → Output signal → Response

Question 12

Describe the difference between local control and reflex control.

Answer 12

Local control: restricted to the tissues or cells involved.

Reflex control: Changes widespread throughout body (systemic) and uses more complex control systems to maintain homeostasis. It is any long-distance pathway that uses the nervous, endocrine system, or both. It has an acceptable set point and can be antagonistic.

It contains two partsfl the response loop and the feedback loop (which modulates the response loop and feeds back to ultimately influence the input).

Question 13

Describe the three types of feedback loops:

Answer 13

1. Negative feedback loop: a pathway in which the response opposes or removes the signal. It stabilizes a system, is homeostatic, can restore the initial state.
2. Positive feedback loop: reinforces the stimulus to drive the system away from a normal value rather than decreasing or removing it. It is not homeostatic. Requires intervention or event outside the loop to cease the response.
3. Feedforward control: a few reflexes have evolved to allow the body to predict that a change is about to occur.

Question 14

Define biorhythms:

Answer 14

Variables that change predictably and create repeating patterns or cycles of changes.
Can vary within an individual over time.