1.4 Flashcards
1
Q
Which ribs are the true ribs and why?
A
1-7
Because they attach to the sternum via their own costal cartilage
2
Q
Which ribs are the false ribs?
A
8-12
Because they attach to sternum via fused costal cartilage of rib 7
3
Q
Out of the false ribs, which ribs are known as floating ribs?
A
11 and 12 because they do not attach to sterum
4
Q
Name the 3 parts that make up the sternum.
A
Manubrium
Body
Xiphoid
5
Q
On CXR, are the posterior or anterior bits of the ribs more horizontal?
A
Posterior
The anterior part looks curved downwards slightly and they aren’t seen as clearly as the back bits
6
Q
From deep to superficial, list the muscles of the ribs and include where the neurovascular bundle lies.
A
(parietal pleura) Innermost intercostals - Neurovascular bundle Inner intercostal muscles External intercostal muscles
7
Q
Which intercostal muscles are used in expiration?
A
Inner intercostal muscles
8
Q
Which intercostal muscles are used in inspiration?
A
External intercostal muscles
9
Q
What movement does the contraction of the 3 different intercostal muscles do?
A
The contraction of the external intercostal muscles causes an elevation of the ribs (inspiratory breathing muscles) whereas both the internal and innermost intercostal muscles lower the ribs (expiratory breathing muscles)
10
Q
Name the accessory muscles of respiration
A
Sternocleidomastoid
Scalene
Trapezius
Rectus abdominus
11
Q
Name the primary muscles of respiration
A
Inspiration: external intercostals, diaphragm
Expiration: internal intercostals, intercostalis intimi, subcostals
The muscles of inspiration elevate the ribs and sternum, and the muscles of expiration depress them.
12
Q
List the accessory muscles of inspiration..
A
Accessory inspiratory muscles:
- Sternocleidomastoid,
- Scalenus anterior medius, and posterior
- Pectoralis major and minor
13
Q
List the accessory muscles of expiration.
A
Accessory expiratory muscles:
- Abdominal muscles: rectus abdominis (especially), external oblique, internal oblique and transversus abdominis
14
Q
Innervation of the diaphragm
A
R and L phrenic nerve (C3-5)
15
Q
Name the structures that pass through the gaps of the diaphragm.
A
T8 = IVC and R phrenic nerve
T10 = Oesophagus and vagus nerves (R+L)
T12 = Aorta, azygous vein and thoracic duct
16
Q
As you move posteriorly, which direction does the diagram also move?
A
Inferiorly
17
Q
From top to bottom, how are the structure within the neurovascular bundle of the ribs relative to one another?
A
VAN - from superior to inferior
- Vein
- Artery
- Nerve
18
Q
Which arteries supply the neurovascular bundle of the ribs?
A
An anastomosis of the anterior and posterior intercostal arteries
19
Q
Where is the anterior intercostal artery derived from?
A
Internal thoracic artery (from subclavian)
20
Q
Where is the posterior intercostal artery derived from?
A
Thoracic aorta
21
Q
Where does the ribcage drain?
A
Drain into azygous and internal thoracic veins
22
Q
Is the horizontal fissure of the right lung superior or inferior to the oblique fissure?
A
Superior
23
Q
Which fissure separates the inferior lobe from the superior lobe of the right lung?
A
Oblique fissue
24
Q
Which fissure separates the inferior lobe from the middle lobe of the right lung?
A
Horizontal fissue
25
Which fissure separates the superior lobe from the middle lobe of the right lung?
Oblique fissue
26
What happens to the parietal and visceral pleura at the hilum of lungs?
They meet
They are continuous with one another with pleural fluid in the potential space between them
27
Most of the anterior lobe of the chest is formed by which lung lobe?
Superior on L side
Superior (majority) and middle on R side
28
Most of the posterior lobe of the chest is formed by which lung lobe?
Inferior lobes
29
The tracheal bifurcates at which vertebral level?
T4/5 (at carina)
30
Which airway division has the highest density of smooth muscle?
What does this allow?
Bronchioles
Therefore allows regulation over airway diameter and resistance
31
Name given to last part of the conducting system.
Terminal bronchioles (gaseous exchange doesn't happen until the respiratory bronchioles which have thinner walls)
32
Blood supply to lungs comes from which arteries?
Bronchial arteries - supply the conducting airways
Pulmonary arteries have deoxygenated blood going to respiratory zone in lungs for oxygenation and waste gas removal
33
How does lymph drain in lungs?
From plerua to hila then up towards neck
34
Name the 4 things found at hila
Pulmonary veins
Pulmonary artery
Lymphatics
Bronchi
35
How do the pulmonary artery and bronchi lie relative to one another in general, at the hila?
Pul artery superiorly
| Bronchi posteriorly
36
Describe the respiratory epithelium
Pseudostratified columnar, ciliated (motile cilia usually which waft stuff up)
With mucus glands formed of goblet cell
37
How does the respiratory epithelium change in response to smoke?
Undergoes metaplasia and becomes squamous epithelium
This can then undergo malignant change and this will lead to squamous cell carcino
38
Which type pneumocytes are more abundant?
Type 1 (not the surfactant secreting type 2)
39
How are the basement membranes of the type 1 pneumocytes and pulmonary capillary endothelial cells related?
The basement membrane of both cell types are fused together to give shortest diffusion barrier possible
40
Epithelium of nose and nasal septum (upper airways)
Initially keratinised then respiratory epithelium
41
Which bones and cartilage form the septum?
The nasal septum is composed of 5 structures:
- perpendicular plate of ethmoid bone
- vomer bone
- septal nasal cartilage
- crest of the maxillary bone
- crest of the palatine bone
42
How many paranasal air sinuses are there?
8 in total (4 paired)
43
Name the air sinuses and state their function
Frontal x2
Ethmoidal x2 (more like a bunch of tiny sinuses)
Maxillary x2
Sphenoidal x2
Make skull lighter, vocalisation
44
Via what do air sinuses drain into nasal meatuses?
Ostia
45
Name the 5 key vessels of the nasal septum.
```
Anterior ethmoidal arteries
Posterior ethmoidal a.
Sphenopalatine a.
Greater palatine a.
Superior labial a.
```
They anastomosis at little's area (Kiesselbach's plexus)
46
What is the pharynx above soft palate known as?
- Nasopharynx
- Oropharynx
- Laryngopharynx
Nasopharynx
47
What is the pharynx between soft palate and hyoid bone known as?
- Nasopharynx
- Oropharynx
- Laryngopharynx
Oropharynx
48
What is the pharynx behind the larynx (from epiglottis to C5 (cricoid)) known as?
- Nasopharynx
- Oropharynx
- Laryngopharynx
Laryngopharynnx
49
Sequential nasopharyngeal contraction of the constrictor muscles of the pharynx is important in which reflex?
Swallowing - closes soft palate
50
Which structure joins the nasopharynx to the middle ear?
Eustachian tube (aka pharyngotympanic tubule)
51
The pharynx is a key site of lymphatic tissue. Name them.
```
Pharyngeal tonsils (adenoids)
Palatine tonsils
```
52
Describe the pharynx gag reflex
Stimulated by touching the posterior pharyngeal wall
Sends nerve impulses along CN IX (glossopharyngeal afferents)
Reach brainstem and activate bilateral vagal efferents
Via vagus nerve (CN X) pharyngeal contraction occurs along with elevation of soft palate and uvula
53
List the key structures of the larynx
- Hyoid bone (sesamoid)
- [Thyrohyoid membrane]
- Thyroid cartilage (adam's apple in men)
- [Cricothyroid membrane]
- Cricoid cartilage (posterior part wider than anterior part)
- Arytenoid cartilages (sit on cricoid cartilage)
- Cuneiform and corniculate cartilages(even smaller than arytenoid)
54
Which sesamoid bone sits superiorly to the thyroid cartilage?
Hyoid bone
55
Where does the frontal and maxillary sinuses drain?
a. Middle meatus
b. Sphenoethmoidal recess
c. Superior meatus
d. Inferior meatus
Frontal sinuses = middle meatus
Maxillary sinuses = middle meatus, largest sinus
56
Where does the anterior and middle ethmoidal sinuses drain?
a. Middle meatus
b. Sphenoethmoidal recess
c. Superior meatus
d. Inferior meatus
Middle meatus
57
Where does the sphenoidal sinuses drain?
a. Middle meatus
b. Sphenoethmoidal recess
c. Superior meatus
d. Inferior meatus
Spheno-ethmoidal recess
58
Where does the anterior and middle ethmoidal sinuses drain?
a. Middle meatus
b. Sphenoethmoidal recess
c. Superior meatus
d. Inferior meatus
Superior meatus
59
Where are tubes passed in the nose?
Widest part of nasal cavity = Inferior nasal meatus – therefore we pass tubes through this area.
60
Major artery to nose?
Sphenopalatine artery
61
There are 9 cartilages total that make up larynx.
Name the unpaired cartilages (bigger than paired cartilages).
o Thyroid (adam’s apple)
o Epiglottis
o Cricoid: round like a signet ring, more prominent at the back
62
There are 9 cartilages total that make up larynx.
Name the paired cartilages (2 of each).
o Arytenoid – adduct the vocal cords
o Cuneiform
o Corniculate
63
What do these organs have in common?
- Stomach
- Liver
- Spleen
- Jejunum, Ileum & 1st 2cm of duodenum
- Transverse & sigmoid colon
- Appendix
- Upper 3rd of rectum
- Tail of pancreas
They are intraperitoneal organs: completely covered in visceral peritoneum, anteriorly & posteriorly
64
List retroperitoneal organs: covered by peritoneum on anterior surface (SAD PUCKER)
- Suprarenal glands (adrenal)
- Aorta/ IVC
- Duodenum except 1st (superior) section 2cm
- Pancreas except tail
- Ureters
- Colon (ascending & descending)
- Kidneys
- oEsophagus
- Rectum
65
Is the laryngeal inlet open or shut when breathing/speaking?
Open
It's closed for swallowing
66
Which muscles are involved in laryngeal elevation (which is needed for closure of epiglottis)?
Suprahyoid muscles
67
The top edge of the cricothyroid membrane attaches to arytenoid cartilage to form which important structures?
True vocal cords
68
Action of vocalis and thyroarytenoid muscles.
Loosen or tighten vocal cords
69
Which arteries supply the larynx?
Superior and inferior laryngeal arteries
70
Motor nerve supply to larynx
Almost entirely from the recurrent laryngeal nerve (branch of vagus nerve)
Except cricothyroid (external superior laryngeal nerve)
71
Damage to recurrent laryngeal nerve can lead to palse of which muscles?
Intrinsic muscles of the larynx and change voice
72
Sensory nerve supply to larynx
Above cords = superior laryngeal n.
| Below cords = recurrent laryngeal n.
73
Which structure closes the laryngeal inlet?
Epiglottis
74
Afferent and efferent nerves involved in gag reflex
Glossopharyngeal afferent
| Vagal efferents
75
Name given to volume of air left in the lungs after normal expiration?
Functional residual capacity (not same as residual volume which is volume of air left in lungs after maximal expiration)
76
What is the physiological dead space in terms of ventilation?
Areas of the respiratory tract with gaseous movement but no gaseous exchange occurring.
E.g. conducting airways (trachea, bronchi, bronchioles (except terminal bronchioles)
Alveolar dead space is pathological because there should be gaseous exchange in gaseous exchange zones
77
Is pleural pressure always negative or positive?
Always negative
Because lung has an elastic inward recoil and chest has elastic outward recoil so they recoil against each other and generate a negative pressure which lower than atmospheric pressure
So air flows in
78
Is the pleural pressure more negative during inspiration or expiration? Why?
Inspiration
Because as you breath in the chest expands and pulls out and pulls the lungs outwards and downwards along with it (imagine a vacuum like suction)
79
What does decreased elasticity of respiratory structures do to compliance?
Decreases compliance
Compliance is also affected by alveolar surface tension
80
Define elasticity
Resistance to deformation
81
Role of surfactant
Detergent that decreases surface tension in alveoli which reduces collapsing radial forces (that would cause lung (alveolar) collapse of unopposed)
It INCREASES lung compliance and makes it easier for lungs to expand
82
Where in the airways is resistance greater?
Large airways - resistance greater because of low total cross-sectional area and due to turbulent air flow within the large lumen (diameter), higher velocity of air flow and branching causing high resistance
Trachea, bronchi and larger bronchioles
83
How is bronchial diameter controlled?
Bronchoconstriction via parasympathetic autonomic NS (vagus) and via low airway CO2, leukotrienes, distamine, bradykinin
Bronchodilation via sympathetic (beta-2-adrenoreceptor ligation)
84
What causes bronchoconstriction (contraction of bronchial smooth muscle)?
```
Low airway CO2
Leukotrienes, histamine, bradykinin
Vagus nerve stimulation
Increased mucus
Some rest tone
```
85
What is salbutamol an example of?
B2-adrenoreceptor agonist used for bronchodilation in asthma and COPD (obstructive airways diseases)
86
Limitation to air flow from exciting alveoli causes restrictive or obstructive airway disease?
Obstructive
During expiration pressure is highest in alveoli and lowest at mouth so should go towards mouth but when airway obstructed (at large airways) the airway pressure drops at site of constriction so air doesn't want to flow out
Causes a wheeze
87
COPD causes expiratory limitation due to increased or decreased resistance?
Increased
88
Are O2 and CO2 diffusion or perfusion limited gases?
Perfusion - less than half way along the pulmonary capillary the oxygen and carbon dioxide in the blood and alveoli are at equilibrium so gaseous exchange doesn't occur anymore
CO is diffusion limited
89
Why is equilibrium achieved during gaseous exchange in alveoli/pulmonary capillaries very quickly for O2 and CO2 but slowly for CO?
O2 and CO2 have low solubility and no binding in blood so readily move in and out of pulmonary capillaries - they exert high partial pressure in blood
CO is highly soluble in blood and has high haemoglobin affinity (and other proteins) so it binds really strongly and doesn't except a high partial pressure in blood
90
When inspired O2 levels are low, will oxygen be perfusion or diffusion limited?
Diffusion limited because O2 won't reach equilibrium within capillary and alveoli
91
How does anaemia affect blood oxygen content?
Lack of haemoglobin leads to less blood oxygen content although the haemoglobin saturation can be 100%
Tissues get a normal proportion of oxygen delivery because the O2 partial pressures and Hb saturation curve maintains sigmoidal shape
92
In which state is most of CO2 carried in blood?
HCO3- (bicarbonate) using carbonic anhydrase
93
What is the Bohr effect?
Reduced Hb affinity for oxygen due to increased CO2
| so in high CO2 environments (respiring tissues) oxygen dissociates from haemoglobin more readily
94
Does O2 of CO2 diffuse more easily?
CO2 - but both are perfusion limited gases (normally)
95
What does reducing the CO2 partial pressure do to O2 partial pressure?
Increases it
96
Respiratory failure is defined as:
1. PaCO2 <8 kPa
2. PaO2 <8 kPa
3. PaO2 >8 kPa
4. PaCO2 >8kPa
2. PaO2 <8 kPa
| 10. 5 to 13.5 kPa is normal
97
Type 1 respiratory failure is defined as:
1. PaCO2 <6kPa
2. PaCO2 >6 kPa
3. PaO2 >8 kPa
1. PaCO2 <6kPa
Respiratory failure with normal or low CO2
(5.1 to 5.6 kPa is normal)
98
Type 1 respiratory failure is defined as:
1. PaCO2 <6kPa
2. PaCO2 >6 kPa
3. PaO2 >8 kPa
2. PaCO2 >6 kPa
Respiratory failure with a raised CO2
99
Normal oxygen partial pressure?
Partial pressure of oxygen (PaO2): 75 to 100 mm Hg (10.5 to 13.5 kPa)
100
Normal carbon dioxide partial pressure?
Partial pressure of carbon dioxide (PaCO2): 38 to 42 mm Hg (5.1 to 5.6 kPa)
101
Is type 1 or type 2 respiratory failure usually do to a failure of ventilation?
Type 2
102
Hypercapnia and hypoxia is known as what type respiratory failure?
Type 2
103
Hypoxia without hypercapnia is known as what type respiratory failure?
Type 1
104
Is ventilation and perfusion greater (better) at the base or towards apex of lung?
Base
Perfusion more greater than ventilation great at base
105
What is V/Q ratio?
Ventilation-perfusion ratio
106
What is normal V/Q?
0.8
107
What would the V/Q be in an area that is perfused but not ventilated?
Cause: R to L shunt
E.g. Pneumonia, COPD
```
Perfusion = Q = 1
Ventilation = V = 0
```
0/1 = 0
108
What would the V/Q be in an area that is ventilated but not perfused?
Cause = alveolar dead space
E.g. pulmonary embolism
```
Perfusion = Q = 0
Ventilation = V = 1
```
1/0 = undefined or infinity
109
In unventilated areas (e.g. pneumonia), in the airway PaO2 is low, the airway PaCO2 high which leads to a lower pH.
How does the pulmonary vasculature and bronchial smooth muscle try to correct this ventilation-perfusion mismatch?
Low pH (respiratory acidosis) acts on pulmonary vasculature to cause vasoconstriction to decrease perfusion
Also bronchodilation occurs to increase ventilation
110
In COPD patients get chronic hypoxia. What does this do to pulmonary vasculature?
Chronic pulmonary vasoconstriction which increases R heart pressure and the heart work --> eventually can lead to cor pulmonale
111
Which type respiratory failure would cause a respiratory acidosis and which will cause an alkalosis?
Type 1 = resp alkalosis
Type 2 - resp acidosis
112
The base of lung receives relative more ventilation or perfusion?
Perfusion
113
Does phrenic nerve activity mediate inspiration or expiration?
Inspiration
Expiration is a passive process usually but active expiration (forced) is mediated by internal intercostal nerve activity
114
Which receptors mediate breathing?
Central chemoreceptors
115
When CO2 increases why does blood become more acidic?
CO2 combines with H2O to form bicarbonate and H+
Increased proton level lowers pH
116
Why don't the central chemoreceptors respond to changes in pH?
Because H+ cannot cross blood brain barrier but CO2 can so central chemoreceptors respond to CO2 changes only
117
In chronic hypercapnia, how does the metabolic system buffer the acidic CSF?
Slowly exports bicarbonate from blood in to of CSF in exchange for chloride.
HCO3- binds to H+ and eventually forms water and CO2
CO2 can diffuse out of CSF
118
Where are peripheral chemoreceptors found?
```
Carotid body (IX)
Aortic body (X)
```
119
What do are peripheral chemoreceptors respond to?
Changes in PCO2, PO2 (key role), pH
They are sensitive to pH change not just from respiratory acidosis/alkalosis but also metabolic acidosis and alkalosis
120
How is exercise detected by the body?
Receptors in joints (joint receptors)
| Receptors in muscles (metaboreceptors)
121
Central chemoreceptors respond to low CSF pH do to raised what?
Arterial CO2
122
Peripheral chemoreceptors mainly respond to?
Arterial O2 and metabolic acidosis
123
Aerobic exercise causes hyperpnoea. Does it change arterial blood gases?
No
