Respiritory Flashcards
(92 cards)
1
Q
What is the overall role of the respiratory system?
A
To ensure the correct amounts oxygen is taken up and the right amounts of carbon dioxide are removed.
2
Q
What are the assumptions of an ideal gas?
A
- Particles are so small as to be continuous and smooth in nature.
- Molecules are in random, rapid and constant motion.
- All particles have the same mass.
- The volumes of the gas in negligible compared to their container.
- All collisions are elastic.
- No forces act except upon collision.
- Classical dynamics is assumed.
- Ek depends only on temperature
- time of collision is negligible.
3
Q
How does a gas exert pressure on it’s container?
A
Consider a particle travelling at velocity V, Mass M, against a wall in a square container length X.
P=F/A
P=F/X^2
F=NM(V^2)/3L
4
Q
How does temp affect particle speed?
A
Ek for a particle=3TB/2
T for the entire gas=2Ek/3NB
5
Q
Define Boyle’s law
A
Pressure is inversely proportional to volume
6
Q
Define Charles’s Law
A
Ek is proportional to T
7
Q
Define the Universal gas law
A
PV=nRT
8
Q
What is standard pressure
A
101.1kPa
9
Q
What is meant by the term partial pressure?
A
2 or more gases can be combined in the same container and can all exert a pressure but it won’t be the entire pressure of the system. It’s a quantitative measurement of how much pressure each gas is providing in the system.
10
Q
How is a partial pressure calculated for gas A that forms 10% of a gas composition of a pressure system at 100kPa?
A
10kPa.
11
Q
what is the saturated vapour pressure of water at 37 degrees C?
A
6.28kPa. Dependent only on temperature.
12
Q
How do gases exert pressure when in water?
A
Known as tension. This is the same as if the water is not present. Tension is a measure of how much the gas wants to leave the water.
13
Q
How is total gas content calculated in water?
A
content=Reacted gas + dissolved gas
14
Q
how many alveoli are there?
A
300 million
15
Q
What are the major divisions of the airways?
A
Conducting airways Trachea 2 Bronchi Lobar Bronchi (one to each lobe) Segmental to sub segmental bronchioles (lack cartilage) 200000 terminal bronchioles Respiratory airways Respiratory bronchioles alveolar ducts alveolar sacs
16
Q
Describe ventilation perfusion matching
A
V/Q ideally =0.8
There is where the lungs are able to direct blood flow to where 0.8 is achieved. This is through the process of gravity i.e at the base of the lung having more pressure and also hypoxic pulmonary vasoconstriction.
17
Q
Define ventilation
A
Resp rate x tidal volume
18
Q
What are the superficial landmarks of the external nose?
A
Root, bridge, tip, septum, nostril, wing
19
Q
Where does the nasal cavity extend from?
A
nostrils to posterior nares
20
Q
What separates the two nasal cavities?
A
nasal septum
21
Q
What is on the lateral wall of the nasal cavity?
A
3 turbinate (superior middle and inferior) and 3 meatus (superior middle and inferior)
22
Q
What are the major functions of the nose? What features enable this?
A
filter- hairs, cilia and mucus
humidify- watery nasal secretions evaporate
warm air- vessels just below epithelium
mix air- tubinates
olfaction,
receives local secretions from the sinuses and nasolacrimal duct.
23
Q
What is the lining of the nasal cavity?
A
Pseudo stratified columnar ciliated epithelium
24
Q
What are the 4 paranasal sinuses?
A
Frontal, maxillary, sphenoid, ethmoid
25
what is the epithelium in the paranasal sinuses?
pseudo stratified
26
where do the secretions of the paranasal sinuses drain into?
the nasal cavity
27
what are the main theories of the purpose of the paranasal sinuses?
Extension of nasal cavity, lightening weight of the skill, buffer for trauma, insulation for eyes.
28
What are the 3 parts of the pharynx?
Naso...
Oro....
Laryngo....
29
What are the key features of the nasopharynx?
extends from the base of the skull to the upper surface of the soft palate.
Always patent
Communicates with the middle ear via the eustachian tube.
Contains the adenoids
Anteriorly it communicates with the choanae of the nasal cavities.
30
What are the key features of the Oropharynx?
Extends from the uvula to the level of the hyoid bone. Opens into to mouth via the isthmus faucium.
Lateral wall is the palantine tonsil.
Lined by stratified squamous epithelium
31
What are the key features of the laryngo pharynx?
Caudal part of the pharynx
Superior boundary is the hyoid bone.
Inferiorly is the junction between the resp tract and oesophagus.
32
Describe the key features of the larynx and it's function
Important in air movement in and out of lungs. Fully patent in breathing, partially in speech, only in the final part of coughing and never in swallowing. It is at the level of C3-6 in adults and connects the inferior pharynx to the trachea. It extends from the tip of the epiglottis to the inferior border of the cricoid cartilage. Sound is generated in the larynx through vibration of the vocal cords in the glottis.Tension is induced by movement of the intrinsic muscles of the larynx.
In men they are slightly longer but both are pearly white in colour.
33
What is the significance of the recurrent laryngeal's path?
It passes down into the chest loops under aortic arch and on right under the subclavian and then back up to the larynx except the cricothyroid muscle which is by the superior laryngeal nerve. This means any abnormality arising in the mediastinum could cause a nerve lesion affecting vocal ability.
34
What two places are common for URTIs to spread to?
Sinuses and middle ear
35
What disorders could cause resp issues to arise in the larynx?
Oedema from infections or anaphylaxis.
Tumors
Aspiration
Bilateral vocal cord paralysis leading to aspiration.
36
What disorders could cause resp issues to arise in the pharynx?
Unconscious relaxation of the tongue which can fall back obstructing the airway.
Sleep apnoea.
37
What disorders could cause resp issues to arise in the nose?
Nasal polyps which leads to mouth breathing dropping humidification of air.
38
What are the two parts of the respiratory tract in terms of function?
Conducting portion and respiratory portion.
39
Describe the lobes of the lungs.
Right- superior (Horizontal) middle (oblique) inferior
| Left- Superior (oblique) Inferior
40
What makes up the respiratory portion?
Resp bronchioles, Alveolar ducts, alveoli
41
Where does the conducting portion of the resp tract extend from?
Nasal cavity--> terminal bronchioles.
42
Where does the intrapulmonary portion of the resp tract extend from?
Secondary bronchi --> alveoli
43
How does the epithelium change throughout the resp tract?
Pseudo stratified ciliated (nasal cavity to bronchioles)
Simple columnar with cillia and clara cells but no goblet cells. (terminal bronchioles)
Simple cuboidal (resp bronchioles and alveolar ducts)
Alveoli- simple squamous and septal cells
44
Where are the olfactory mucosa? and what are the key features of?
Posterior and superior in the nasal fossa. Tall pseudostratified epithelium and no mucus secreting cells. Non motile cillia and contains many olfactory cells which come together to become olfactory nerves.
45
Why does air flow alternate between each nostril?
Due to changes in the swelling of the venous plexuses every 20-30 minutes.
46
When does there cease to be cartilage in the resp tract?
at the bronchioles
47
What keeps the bronchioles patent?
The surrounding alveoli.
48
What is the role of type 2 pneumocytes?
Secrete surfactant
49
Describe emphysema
Destruction of elastin in the alveoli leads to a reduction in patency of the bronchioles. This can be due to an inappropriate level of trypsin alpha 1 antitrypsin deficiency or smoking
50
What factors affect diffusion?
```
Ek of the particle
Size of the particle
dynamic viscosity
area over which it's occurring
Physical barriers
```
51
What is the mixed venous blood oxygen and carbon dioxide tension?
What are the normal partial pressures of oxygen and carbon dioxide in alveolar air?
consequence?
O2-6
CO2-6.5
O2-13.3
CO2-5.3
Causes Gas to pass down it's concentration gradient. IN this case Oxygen from the gas into the blood and vice versa for carbon dioxide.
52
Describe the path that an oxygen molecule has to take to get from the lungs to Hb
Diffusion through the gas
Diffusion through the epithelial cell of the alveolus
Tissue fluid
endothelial cell of capollary
PLasma
Red cell membrane
gas, 5 cell membranes, 2 layers of tissue fluid
53
What is the major factor that determines rate of gaseous diffusion between gases in gas?
the mass of the particles. Therefore in the lungs carbon dioxide diffuses slower than oxygen.
54
What is the major factor that determines rate of gaseous diffusion between gases in liquid?
Solubility
55
What has the fastest overall rate of diffusion between oxygen and carbon dioxide?
Carbon Dioxide therefore oxygen is limiting
56
How long does Hb need to be in the lungs before it gets saturated with oxygen? consequences?
0.5 seconds
| Even upon exercise this is not exceeded and so gas diffusion is not limiting assuming lungs are functioning.
57
What is the consequence of alveoli being in Equilibrium with their surrounding capillaries?
The gas partial pressures of the alveoli are the same as the arterial gas measurements.
58
How is ventilation measured?
Using a spirometer
59
Define tidal volume
VOlume breathed in and out with each breath
60
Define inspiratory reserve volume
Extra volume that can be breathed in over that at rest
61
Define expiratory reserve volume
Extra volume that can be breathed out over that at rest
62
Define residual volume
VOlume left in lungs at maximal expiration
63
How is residual volume measured?
Using a helium dilution
64
Define vital capacity
maz in to max out and is typically about 5L.
65
Define inspiratory capacity
Biggest inhalation possible from resting expiratory level and is typically 3L
66
Define functional residal capacity
Volume of air in lungs at resting expiratory capacity which is typically 2L. (equal to residual volume + expiratory reserve).
67
Define ventilation rate
Amount of air moved into and out of lungs per minute.
| Volume of breath X No of breaths.
68
Define Pulmonary ventilation rate and give parameters of variance
Tidal volume V resp rate
| 8L/min at rest -->80L/min during exercise
69
What is dead space? What are the two types?
Areas of the conducting system that air fills but then the air doesn't participate in the exchange of gases as it's the last air in and first air out and so is wasted.
Serial or anatomical: air ways (0.15L)
Disruptive: parts of the lung tissue that is damaged (0.02L)
Total of physiological dead space=0.17L
70
Define alveolar ventilation rate.
| What are the assumption of this?
The amount of air that actually reaches the alveoli.
(Ventilation volume- dead space volume)Resp rate.
Assumptions: All the dead space is filled with air.
71
What is the effect of changing breathing patterns as proportions of intake used for gaseous exchange?
(Tidal volume/Dead space)= proportion of useful air.
| As tidal volume drops i.e in shallow breathing then proportion of useful air drops off.
72
What is the draw back of slow deep breathing?
It requires a larger amount of effort to maintain so the body usually compromises and breathes slightly shallower.
73
Describe the structure of the bony thorax
Narrowest inferiorly, it consists of the thoracic ribs, vertebrae sternum, manubrium and xiphoid process.
Costal margins extend down from the sternum allowing the lower false ribs to communicate.
It protects the lungs, stomach, liver and heart. the cavity it creates is subdivided into the mediastinum and the left and right pulmonary cavities.
74
Describe the features of a typical rib and what ribs are typical and non typical
Ribs 3-9 are typical.
Each has a head with 2 facets separated by a crest. One for the vertebrae above and one at it's level.
Each has a neck and upon which there is a tubercle which allows attachment for the transverse process and the costotransverse ligament.
The costal angle is the point of greatest curvature where is points anterolateral. Along the body is the costal groove which allows for the costal neurovasculature to have a degree of protection.
The other 4 ribs are atypical.
75
Describe a typical thoracic vertabrae
Independant, bilateral costal facets on the bodies and costal facets on the transverse processes. Long inferiorly slanting spinous process.
76
Describe the arrangement of the intercostal muscles and the structures immediately surrounding them,
External; slant anterior-inferiorly.
internal
Neurovasculature in groove
innermost
77
Describe the axis of movements of the ribs
in the upper ribs they move forwards. this is due to them being angled inferiorly so as they are raised it pushes out the sternum. The lower ribs move outwards in the bucket handle effect
78
Describe the origin of the costal nerves and what they innervate.
from T1-12
from the anterior rami of the thoracic mixed spinal nerve.
Supplies the intercostal muscles, the parietal pleura and the overlying skin.
79
Describe the arterial supply to the intercostals
Posterior intercostal artery comes from Aorta. Anterior intercostal artery comes from the internal thoracic artery. They anastomose laterally.
80
Describe the nervous innervation to the costal region
Leaves the spinal cord. Anterior branch splits into muscular branch and the main nerve. A lateral and anterior cutaneous branch pierces the tissue to the dermis at the lateral and anterior respectively.
81
What muscle is the largest contributor in inspiration?
| What are the key features of?
```
Diaphragm.
3 openings
T8- Vena cava
T10- oesophagus
T12- aortic
Innervated by the phrenic nerve (345) which supplies motor to diaphragm and sensory to;
-Diaphragm
```
82
What is the action of the phrenic nerve?
Innervated by the phrenic nerve (345) which supplies motor to diaphragm and sensory to;
- Diaphragm
- Mediastinal part of parietal pleura
- Diaphragmatic part of parietal pleura
83
Describe the movements of the thoracic cage in respiration
Inspiration.
Active, elevation of ribs by external.IC and contraction of diaphragm.
Expiration
passive in gentle respiration due to elastic recoil
Utilises internal and innermost IC muscles in more strenuous exercise.
84
Describe the pleural cavity
The pleural cavity of formed from the parietal and visceral layers. They have a greater volume than the lung and the costodiaphragmatic recess is a result of this.
85
Describe the pleura of the lungs
Parietal and visceral layers are both continuous at the hilum and form the potential space that is the pleural cavity.
Low friction as well lubricated and forms a good seal due to its high surface tension. This allows the expansion of the thorax to pull out the lung tissue as well.
86
What are pleural lines of reflection?
Sharp continuations of the sternal lines occurring where the costal pleura become continuous with diaphragmatic pleura inferiorly.
87
What level does the trachea diverge into 2 bronchi?
At the carina , T4/5
88
What are the differences between the right and left bronchi?
Left is less steep and longer
89
What levels are the lobes at?
Oblique- From T2--> 6th costal cartilage
| Horizontal from oblique along 4th costal cartilage
90
What lobes are in each lung?
```
Left
Superior (and lingula)
Inferior
Right
Superior
middle
Inferior
```
91
What supplies a bronchopulomary segment
a segmental bronchus
92
Describe the hilum of the lungs.
Contains a bronchus (distinctive due to cartilage)
Pulmonary arteries
Pulmonary vein (usually only one)
