Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Semester 3: Respiratory > Session 3 > Flashcards

Session 3 Flashcards

1
Q

What is the ideal gas equation?

A

PV=nRT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Boyle’s law?

A

Pressure in a ga is inversely proportional to its volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the total partial pressure exerted in a mixture of gases equal to?

A

The sum of the partial pressure of the individual gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is composition of atmospheric air?

A 
20.9% = Oxygen
78% = Nitrogen
0.03% = CO2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How do gases diffuse in the body?

A

Down the partial pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens when gas molecules come into contact with body fluids?

A
  • Gas molecule will enter the fluid to dissolve

- The water molecules evaporate to enter air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the saturated vapour pressure at body temperature?

A

6.28 kPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens to inhaled air in the upper respiratory tract?

A

Saturated with water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does water vapour affect the partial pressure of other gases at 101 kPa?

A

101-6.28

The use the normal ratios

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When is the equilibrium of gases established in a fluid?

A

Rate of gas molecules entering water = rate of gas molecules leaving the water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is occurring at equilibrium of gas in fluid?

A

Partial pressure of the gas in the liquid = partial pressure gas in the air above it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Partial pressure is the same as the amount of dissolved gas. True/False. Why?

A

False

Amount of gas dissolved = Partial pressure X solubility coefficient of gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When is partial pressure established if there is a component of liquid that the gas reacts with?

A

Partial pressure is established after the gas reacts with component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens when oxygen encounters plasma?

A
  • Enters plasma and dissolves in it
  • Dissolved oxygen enter red blood cells to bind to Hb
  • Process continues till Hb fully saturated
  • After Hb is fully saturated, oxygen continues to dissolve until the equilibrium is established
  • At equilibrium pO2 of plasma=pO2 of alveolar air
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens to the dissolved oxygen in plasma when it encounters tissues?

A

It is available to diffuse into tissues and is replaced by the oxygen bound to haemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why does alveolar air equilibrate with the blood air?

A

The is constantly gas moving out and into the alveolus. Oxygen move into the blood stream constantly .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens to the atmospheric pressure and gases at high altitudes?

A
  • The atmospheric pressure is lower

- There are fewer molecules of gas.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens to pressure as you dive further into the sea?

A

The pressure increase dramatically

Pressure below sea level = Atmospheric pressure+weight of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is decompression sickness in divers?

A
  • Nitrogen moves from high pressure in the lungs into the blood during a dive
  • A slow return to the surface lets the nitrogen return to the lungs where it is breathed out
  • A quick return doesn’t give the nitrogen enough time to leave the blood so instead it can form painful bubbles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the features of oxygen binding?

A
  • Reaction has to be reversible
  • Oxygen must dissociate at the tissue to supply them
  • Oxygen combines reversibly
21
Q

What are 2 examples of oxygen binding pigments?

A
  • Haemoglobin: Tetramer to bind 4 oxygen molecules

- Myoglobin: binds 1 oxygen molecule

22
Q

What is myoglobin?

A
  • Pigment found in muscles

- Contains 1 subunit of haem

23
Q

Why is myoglobin not a good carrier of oxygen?

A

It will not give up oxygen at the tissues due having a high affinity for oxygen even at low partial pressure. It acts as a storage molecule that will give up oxygen if the oxygen in the tissue gets very low. Also acts as a pigment for the muscle giving it the red appearance

24
Q

What is the structure of haemoglobin?

A
  • Tetramer consisting of 2 alpha and 2 beta subunits
  • Each subunit has a haem group and a globin group
  • 4 oxygen molecules bind to each molecule of haemoglobin
25
Q

What are the forms of haemoglobin?

A
  • Low affinity T state

- High affinity R state

26
Q

What happens to haemoglobin when the pO2 is low?

A

The haemoglobin shift to the low affinity T state so it is harder for the first O2 molecule to bind

27
Q

What happens as each O2 molecules bind to the haemoglobin?

A

The molecule becomes more relaxed and the binding of the next O2 molecule is easier

28
Q

What is the shape of the haemoglobin dissociation curve?

A

Sigmoidal curve

29
Q

What are the features of the haemoglobin dissociation curve?

A
  • Saturation changes greatly over a narrow range

- Reaction is highly reversible and depends on pO2 levels

30
Q

What happens to the oxygen content and pO2 if the patient is anaemic?

A
  • pO2 is normal

- Oxygen content is much lower

31
Q

What is the oxygen content of blood when the haemoglobin is saturated (13.3 kPa)?

How would you work out the amount of oxygen given up?

A

-2.2 mmol/l if the Hb concentration is normal

Each haemoglobin bind 4 oxygen molecules
2.2X4 = 8.8 mmol/l

Amount of oxygen given up = ((100 - Saturation at Partial pressure in the site)/100) X 8.8

32
Q

What happens to the dissociating at tissue with a lower pO2 and the result of this on venous blood?

A
  • Increased dissociation

- Lower saturation of venous blood

33
Q

What is the saturation of haemoglobin in venous blood?

A

-Over half the oxygen is still bound

34
Q

Tissue pO2 drops to 0 kPa. True or False

A

It cannot fall beyond 3 kPa

35
Q

What is the adaptation of very metabolically active tissue to allow them to receive sfficnet oxygen?

A

Very high capillary density so that pO2 will fall lower due to decreased diffusion distance

36
Q

What is the Bohr effect?

A
  • pH affects the affinity of haemoglobin
  • Acid condition shifts dissociation curve to the tight
  • Lower pH promotes shift to the T state and higher ph promotes a shift to the R state
37
Q

Why is the Bohr effect beneficial to the metabolically active tissues?

A

-pH is lower in most metabolically active tissue so extra O2 is given up

38
Q

What is maximum unloading of oxygen?

A
  • Occurs in tissues where pO2 can fall to a low level
  • In conditions where increased metabolic activity results in more acidic environment and higher temperature
  • Under these conditions about 70% bound oxygen can be given up
39
Q

In extreme exercise , metabolism can increase 10x but the cardiac output only goes up by 5x. What supplies the tissues with oxygen?

A

Tissues have improved extraction of oxygen.

This is due to a umber of factors

40
Q

What is the function of 2,3 BPG?

A

Increased 2,3-BPG shift the Hb dissociation curve for O2 to the right
This allows more O2 to be given up to tissues because of a shift in the curve

41
Q

What is the result of carbon monoxide poisoning?

A
  • Reacts with Hb to form COHb
  • Increased affinity for unaffected subunits for O2
  • Therefore O2 is not given up at tissues
  • This is fatal if the HbCO is greater than 50%
42
Q

What is hypoxaemia?

A

Low pO2 in arterial blood

43
Q

What is hypoxia?

A

Low oxygen levels in the body and tissues

44
Q

What is cyanosis?

A
  • Bluish coloration due to unsaturated haemoglobin

- Can be peripheral due to poor local circulation or systemic due poorly saturated blood in systemic circulation

45
Q

Why is cyanosis difficult to detect sometimes?

A
  • Poor lighting

- Skin colouration

46
Q

What is pulse oximetry?

A
  • Detection of level of Hb saturation by detection of difference in absorption of light between oxygenated and deoxygenated Hb
  • It only detect the pulsatile arterial blood
  • Venous blood and blood in tissues is ignored
47
Q

What is the limitation of pulse oximetry?

A
  • It doesn’t say how much haemoglobin is present

- It will not detect anaemia but just how well saturated a person blood is

48
Q

Why does cyanosis appear blue?

A

-Deoxygentated haemoglobin is less red that oxygenated haemoglobin

Semester 3: Respiratory (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions