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Physiology > Homeostasis > Flashcards

Flashcards in Homeostasis Deck (15):
1

The term homeostasis is used in physiology to describe...

The maintenance of a relatively stable internal environment

2

Describe the steps in the response loop

Stimulus
Sensor/receptor
Afferent pathway
Integrating centre
Efferent pathway
Target/effector
Response

3

What systems can the integrating centre involve

The endocrine system
The neural system
Both at the same time

4

Describe positive feedback

It reinforces the feedback escalating the response.
An example is the widening of the cervix during child birth

5

Describe diffusion

The passive process of particles moving from where they are more concentrated to where they are less concentrated

6

Describe osmosis

Water moves across a plasma membrane where it is in higher concentration to where it is less concentrated. Can also be thought of moving from where solute concentration is lower to higher

7

Describe a hypertonic solution

A higher concentration of non-permeable solutes outside the cell than inside

8

Describe a hypotonic solution

A higher concentration of non-permeable solutes inside the cell than outside

9

Describe an isotonic solution

The concentration of non permeable solutes is the same inside and outside the cell

10

Osmolarity refers to

The concentration of both penetrating and non penetrating particles

11

Normal cell osmolarity is

300 mOsm

12

Tonicity refers to

The concentration of only the non penetrating particles

13

What particles can pass the cell membrane

Small uncharged lipid soluble particles such as water oxygen lipids and carbon dioxide

14

What can't pass through the cell membrane

Large, charged, lipid insoluble particles such as ions and proteins

15

What is Fick's law equation

Net rate of diffusion is equal to surface area of the cell times by concentration gradient times by membrane permeability all divided by membrane thickness