Review posters 11/05/2016 Flashcards Preview

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Flashcards in Review posters 11/05/2016 Deck (32):
1

Pulmonary ventilation

Volume of air breathed in and out per minute
= TV x RR

2

Anatomical dead space

Not all the air inhaled reaches the alveoli for gas exchange. This air is unusable and is therefore known as anatomical dead space.

3

Alveolar ventilation

Volume of air exchanged between the alveoli and the atmosphere per minute
= (TV-anatomical dead space) x RR

4

Describe the ventilation and perfusion of the lung

Lung is less ventilated and perfused at the top.
Better ventilated and perfused at the bottom.

5

Alveolar dead space.

When an alveolus is well ventilated but not well perfused.

6

How would you go about increasing pulmonary ventilation?

Increasing TV or RR. Increasing depth of breathing (TV) is the most advantageous due to anatomical dead space.

7

What four factors influence the rate of gas exchange in the alveoli?

The thickness of the alveoli
The surface area of the alveoli
The diffusion co-efficient of oxygen and carbon dioxide
Partial pressure gradient

8

What is the diffusion co-efficient ?

The ability of a gas to dissolve in the membrane. Carbon dioxide has a much higher one that oxygen (20x)

9

Daltons law

The total pressure exerted by a gas is the sum of the partial pressures of each individual gas.

10

What is partial pressure of a gas?

The pressure that one gas in a mixture of gases would exert if it were the only gas present occupying the same volume

11

The equation to work out the partial pressure of oxygen in the alveoli is:

PaO2= PiO2- [PaCO2/0.8]

PaO2= the alveoli partial pressure of oxygen
PiO2= the partial pressure of inspired oxygen
PaCO2= the partial pressure of CO2 in the arteries
0.8= the respiratory exchange ratio

12

Ficks law

The amount of gas that moves across a sheet is proportional to the area but inversely proportional to its thickness.

13

What is the purpose of the membrane?

To form a boundary
Selectively permeable
Maintains difference in ion concentration
Controls entry of nutrients and exit of waste

14

Name the sorts of proteins you would find in the lipid bilayer?

Integral proteins (span the bilayer). These could be ion channels or carrier proteins
Peripheral proteins (sit on the outside of the membrane)
Glycoproteins- sugar attached to proteins on the outside of the membrane

15

Docking mannose receptors

Allow exocytosis

16

Describe the lipid bilayer

Fluid membrane made up of phospholipid molecules.
Each phospholipid molecule has a hydrophillic head and hydrophobic tail.
Cholesterol is present in the membrane and offers stability and fluidity.

17

What types of junctions can you get between cells?

Desmosomes
Gap junctions
Tight junctions

18

Describe the types of junctions you can get between cells

Desmosomes- adhering junctions. Anchor cells together in tissues prone to stretch e.g. skin, cardiac
Tight junctions- lateral borders of epithelial cells joined together.
Gap junctions- communicating junctions that allow movement of charged ions

19

Purpose of membrane carbohydrates

Self identity markers- different cells have different markers.

20

What are the factors important for a particle to be able to diffuse across a membrane

Lipid solubility
Size of the particle
Magnitude of the concentration gradient
Surface area
Diffusion distance

21

Diffusion

Movement of particles from a high concentration to a low concentration (passive process)

22

Osmosis

Net diffusion of water from a high concentration to a low concentration (passive process)

23

Name the two active processes that can transport particles across a membrane

Active transport
Facilitated diffusion

24

Facilitated diffusion

Movement of particles via a carrier/channel protein down their concentration gradient.

25

Active transport

Two types- secondary active transport and primary active transport

26

Primary active transport

Movement of the particle against its concentration gradient using energy derived from ATP

27

Secondary active transport

Ions are used to provide energy to drive a particle against its concentration gradient

28

The two types of secondary active transport

Antiport- ion moves in different direction to particle
Symport-ion moves in the same direction to particle

29

Importance of the sodium pottasium pump

Maintains intracellular concentrations of Na+ and K+
Regulates cell volume by controlling concentration
Provides energy for secondary active transport

30

Osmolarity

The amount of osmotically active substances present in a solution

31

Tonicity

The effect osmolarity has on cell volume

32

Three key things for carrier mediated transport

Specificity
Competition
Saturation