Intro Physiology And Homeostasis

Question 1

What is the definition of Physiology

Answer 1

The study of the normal functioning of a living organism and its component parts

Question 2

Physiology is an integrative science and closely tied to:

Answer 2

Anatomy; the structure of a cell, tissue, or organ must provide a physical basis

Question 3

Smallest unit of structure capable of carrying out life processes?

Answer 3

Cells

Question 4

Collection of cells carrying out related functions?

Answer 4

Tissue

Question 5

Formation of tissues into a structural and functional unit?

Answer 5

Organ

Question 6

Integrated groups of organs?

Answer 6

Organ System

Question 7

What are properties of a complex system that cannot be explained by a knowledge of a systems individual components?

Answer 7

Emergent Properties

Question 8

What do emergent properties result from?

Answer 8

Complex, nonlinear interactions of the systems different components

Question 9

Which physiologists take a teleological approach

Answer 9

Function or “why”

Question 10

Which physiologists take a mechanistic approach?

Answer 10

the mechanism or “how”

Question 11

What is Homeostasis

Answer 11

The ability to maintain a relatively stable internal environment despite exposure to external variability

Question 12

What are humans normal internal body temperature?

Answer 12

Around 37 degrees Celsius

Question 13

Homeo=
Homo=
Stasis=

Answer 13

Like or similar (range of values)
Same
Condition (not a static state)

Question 14

Examples of External change in Homeostasis

Answer 14

Exposure to;
Toxic chemicals
Physical trauma
Foreign invaders
-these all throw off homeostasis

Question 15

Examples of Internal change in homeostasis

Answer 15

Inside the body;
Abnormal cell growth
Autoimmune disorders
Genetic disorders
-caused by abnormal functioning proteins

Question 16

Are cells tolerant or not to changes in their surroundings?

Answer 16

Not tolerant, they are fragile and this is why we need homeostasis

Question 17

What is Extracellular Fluid

Answer 17

A fluid that surrounds cells, is a buffer between cells and the external environment

Question 18

What law is: if the amount of a substance in the body is to remain constant, any gain must be offset by an equal loss?

Answer 18

Law of Mass Balance
-input needs to match output, vice versa

Question 19

Differences between ECF and ICF

Answer 19

ECF is relatively easily to monitor (plasma), while ICF is hard

Question 20

How does the body maintain homeostasis

Answer 20

It monitors certain key functions/ variables by controlling bisystems that kick in when values deviate

Question 21

Control System Steps:

Answer 21

Input signal, Integrating centre, Output signal, Response

Question 22

What is Local Control

Answer 22

-restricted to tissues or cells involved
Active cells create reduced O2 levels in tissue
-too much oxygen= lower levels
-input signal causes decrease in oxygen

Question 23

For anything variable in the body that remains constant, when there is an increase in this variable there must be an equal removal: this is best defined as;

Answer 23

Mass Balance

Question 24

What is Reflex Control

Answer 24

-uses long distance signalling

-uses more complex control systems to maintain homeostasis -e.g. blood pressure
-any long distance pathway that uses the nervous, endocrine system, or both
Negative/ Positive feedback, Feedforward control

Question 25

Facts of Negative Feedback Loops

Answer 25

-a pathway in which the response opposes or removes the stimulus signal
-can’t prevent, but reacts
-stabilizes a system, is homeostatic

Question 26

Baroreceptor reflex: Reflex Control system example

Answer 26

Stimulus: stretch of artery wall due to increased pressure
Sensor: baroreceptor
Input signal: mechanical stretch
Integrating centre: medulla
Output signal: signals sent toward target tissues
Target: heart and peripheral arterioles
Response: reduced HR, SV, peripheral dialation

Question 27

info on Positive Feedback Loops

Answer 27

-NOT homeostatic
-reinforce stimulus to drive system AWAY from normal value
-needs intervention or event outside of loop to stop response
Ex) uterine contractions

Question 28

Feedforward Control

Answer 28

-a few reflexes have evolved that allow the body to predict a change is about to occur
-body anticipates change and prepares for it
Ex) horse starts breathing heavy before a race