Respiratory Flashcards
(111 cards)
1
Q
What are the functions of the nose? (4)
A
Warming of inspired air
Humidification
Filteration
Defence
2
Q
What divides the nasal cavity into meatuses?
A
Conchae
3
Q
What are the functions of the paranasal sinuses? (2)
A
Warm & humidify air
Reduce the weight of the skull
4
Q
What are the 4 paranasal sinuses?
A
Frontal
Maxillary
Ethmoidal
Sphenoid
5
Q
What innervates the frontal sinus?
A
Ophthalmic branch of CNV
6
Q
Where does the maxillary sinus open into?
A
Middle meatus via hiatus semilunaris
7
Q
What does the sphenoid sinus drain into?
A
Sphenoethmoidal recess
8
Q
What do the pharyngeal constrictors do?
A
Contract sequentially to move food bolus down CNX
9
Q
What do the inner longitudinal muscles do?
A
Contract to shorten & widen pharynx
10
Q
What is the sensory innervation to the pharynx?
A
Naso - CNV2
Oro - CNIX
Laryngo - CNX
11
Q
What are the true vocal cords lined by?
A
Stratified squamous non-keratinising epithelium
12
Q
What are the 9 laryngeal cartilages?
A
Single:
epiglottis
thyroid
cricoid
Double:
cuneiform
coniculate
arytenoid
13
Q
What is the larynx innervated by?
A
CNX (everything’s bloody innervated by this)
14
Q
What does the carotid sheaf contain?
A
Common carotid artery
Internal jugular vein
Vagus nerve
15
Q
At what level is the thyroid gland?
A
C5-T1
16
Q
At what level is the carina?
A
Level of sternal angle
17
Q
What are the borders of the anterior triangle of the neck?
A
Superior - inferior border of mandible
Inferior -medial border of sternocleidomastoid
Medial - immaginare line down middle of neck
18
Q
What is the mucociliary elevator?
A
Combination of sweeping movements by the cilia & mucus to trap inhaled particles & move them out of the airways to be swallowed & destroyed
19
Q
What is the sensory innervation of the trachea?
A
Recurrent laryngeal nerve
20
Q
Which main bronchus is shorter, wider & more vertical?
A
Right
21
Q
Where are the Clara cells & what do they produce?
A
Bronchioles
Surfactant lipoprotein - prevents bronchioles from collapsing upon expiration
22
Q
What are the 3 cell types found in alveoli?
A
Type I pneumocytes
Type II pneumocytes
Alveolar macrophages
23
Q
What cells produce surfactant?
A
Type II pneumocytes
24
Q
What does surfactant do?
A
Helps overcome the initial part of inhaling by reducing surface tension
25
What are the 3 main openings in the diaphragm?
```
Oesophageal hiatus (oesophagus, CNX)
Aortic hiatus (aorta, thoracic duct, azygous vein)
Caval opening (IVC)
```
26
What does the phrenic nerve innervate?
```
3Ps (sensory)
Pericardium
Pleura
Peritoneum
& diaphragm (motor)
C345 keeps the diaphragm alive!
```
27
What do the azygous & hemiazygous veins drain?
Posterior walls of thorax & abdomen
28
Where does the azygous vein recieve blood from?
Ascending lumbar veins & right subcostal veins
29
What are the true ribs?
1-7
| Attached directly to sternum
30
What are the false ribs?
8-10
| Connected to the 7th rib by cartilage
31
What are the floating ribs?
11-12
| Not attached anteriorly
32
In which direction do the external intercostal muscles run?
Inferioanteriorly
33
What is the action of the internal intercostal muscles?
Depress ribcage
34
What is the action of the pectoralis major?
Flexion, adduction, rotates the humerus (medially)
35
What is the innervation of the pectoralis major?
Medial & lateral pectoral nerves
36
What is the main action of serratus anterior?
To rotate the scapula, raising the arm
37
What is the innervation of the serratus anterior
Long thoracic nerve
38
What do the subcostal muscles do?
The same as internal intercostals (depress ribcage)
39
What muscle is continuous with the transverses abdominis?
Transversus thoracis
40
What are the 2 parts of the lung pleura?
Visceral (inner)
| Parietal (outer)
41
How many lobes does each lung have?
L - 2
| R - 3
42
What are the fissures of the lung?
Oblique
| Horizontal
43
What is at the level of the sternal angle?
2nd rib
44
Describe the process of inspiration
1. Motor neurone of phrenic nerve causes diaphragm to contract & flatten
2. This increases the thoracic volume
3. The chest wall moves away from the lung surface, which moves the parietal pleura away from the visceral pleura slightly
4. Intrapleural pressure decreases, and transpulmonary pressure increases
5. Pressure strong enough to overcome elastic recoil > lungs expand
6. Volume of lungs increases > pressure decreases (Boyle's law)
7. When the pressure decreases below the atmospheric pressure, air is forced in
45
When do the neutrons in the dorsal respiratory group in the medullary respiratory centre fire?
During inspiration
46
What controls the basal rate of respiration?
The respiratory rhythm generator in the VRG of the medullary respiratory centre
47
What does the apneurstic centre do? (lower pons)
Fine tunes medullary inspiratory neuron output & helps terminate inspiration by inhibiting these neurons
48
What does the pneumotaxic centre do? (upper pons)
Smooths transition from inspiration to expiration
49
Where are the slowly adapting stretch receptors found, what are they stimulated by & what do they do?
Smooth muscle layer of airways
Stimulated by large lung inflation
Send afferent impulses to brain & inhibit medullary inspiratory neutrons in DRG
50
Where are the rapidly adapting stretch receptors found, what are they stimulated by & what do they do?
In between epithelial cells of airways
Stimulated by lung distension
Bronchoconstriction & an activity burst
51
What will a decrease in PO2 do?
Stimulate peripheral chemoreceptors
Impulses to medullary inspiratory neurons
Increase in ventilation rate
52
Give the dissociation equation involving CO2 & H2O
CO2 + H2O H2CO3 H+ + HCO3-
53
What are J receptors stimulated by?
Lie in capillaries/interstitium of lung
| Stimulated by increase in lung interstitial pressure, caused by collection of fluid in interstitium
54
What are the effects of the stimulation of J receptors?
Rapid breathing
Dry cough
Sensation of pressure in chest
Dyspnoea
55
Where is the apex of the lung? (surface anatomy)
2 finger widths (patient's fingers) above the clavicle
56
Lower margin of lungs are at what levels? (surface anatomy)
6, 8, 10
57
Where is the oblique fissure? (surface anatomy)
Along 6th rib
58
Where is the horizontal fissure? (surface anatomy)
Along 4th rib (only R)
59
What does a lower V/Q ratio mean?
Decreased ventilation in the area
Decrease in O2 content of arterial blood
Results in vasoconstriction of blood vessels to that area
60
What does a higher V/Q ratio mean?
Decreased perfusion in the area
Decrease in CO2 content of alveolar air
Results in bronchoconstriction of airways to that area
61
What are the 3 layers of the gas exchange pathway in the lungs?
Thin alveolar epithelial cells (usually type I pneumocytes)
Basement membrane
Capillary epithelium
62
What is the equation for percentage haemoglobin saturation?
O2 bound to Hb / maximum capacity of Hb to bind to O2
| x100
63
What is the oxygen-haemoglobin dissociation curve?
As PaO2 increases, SaO2 increases (saturation)
64
An increase in PCO2, H+, temperature & DPG will do what to the dissociation curve?
Shift it to the right
At any given PO2, increasing one of these factors will decrease haemoglobin saturation (more PO2 is needed for the same saturation)
65
What will happen to the affinity of haemoglobin to O2 when a tissue's metabolic activity increases?
It will decrease, delivering more O2 to the tissue
66
What is Dalton's law?
The total pressure of a mixture of gases is equal to the sum of each of the gases as if it were present alone
67
What is Boyle's law?
The volume of a container & the pressure within the container are inversely related
68
What is Henry's law?
The amount of gas dissolved in a liquid is directly proportional to the partial pressure of that gas above that liquid
Solubility is directly proportional to partial pressure
69
What is the alveolar gas equation?
PAO2 = PiO2 - PaO2/R
PAO2 - alveolar oxygen
PiO2 - inspired oxygen
PaO2 - arterial oxygen
R - respiratory quotient
70
What is Laplace's law?
The pressure within an alveolus is directly proportional to the surface tension & inversely proportional to the radius
71
What is the CO2 + H2O reaction catalysed by?
Carbonic anhydrase enzyme
| only present in erythrocytes
72
What is the chloride shift?
HCO3- moves out of erythrocytes via a transporter that exchanges them for a Cl-
73
Describe CO2 transport in the lungs
PCO2 is higher in the blood than in the alveolar space
CO2 diffuses into alveoli
Moves position of equilibrium to left
H+ + HCO3- combine to form H2CO3, which dissociates into CO2 + H2O
More CO2 can now diffuse out into alveoli
74
What does haemoglobin act as a buffer for?
H+ ions
75
What is the Henderson-Hasselbalch equation?
pH = pK + log( [A-] / [HA] )
76
What is hypoxia?
Deficiency of O2 at tissue levels
77
What are the causes of hypoxia?
Hypoxemia (reduced arterial PO2)
Anaemia
Ischaemic hypoxia (blood flow too low)
Histotoxic hypoxia (cell unable to utilise because of a toxic agent)
78
What is hypercapnia?
Increase in PCO2 in arterial blood
79
What are the causes of hypercapnia?
Hypoventilation
Lung disease
Inhaling too much CO2
80
Define respiratory failure
A condition in which there is insufficient gas exchange to maintain arterial O2 & CO2 levels
81
What is Type I respiratory failure?
Hypoxia but not hypercapnia
| PaO2 low, PaCO2 normal
82
What is Type I respiratory failure caused by?
```
Low atmospheric pressure
V/Q mismatch
Avelolar hypoventilation
Shunt in heart
Asthma
Pneumonia
```
83
What is Type II respiratory failure?
Hypoxia & hypercapnia
| Low PaO2, high PaCO2
84
What is Type II respiratory failure caused by?
Increased airways resistance (asthma, COPD)
Reduced breathing effort (brainstem lesions, obesity)
Decreased lung area
Neuromuscular conditions
Head injuries affecting respiratory centres in the brain
85
Define tidal volume (500ml)
Volume of air moved in & out of lungs during quiet breathing
86
Define inspiratory reserve volume (3000ml)
Volume of air that can be inspired in addition to inspiration of tidal volume
87
Define residual volume (1000ml)
Volume of air that cannot be expired from lungs
88
Define vital capacity (5000ml)
Total volume of air that can be moved in & out of the lungs
89
Define functional residual capacity (2500ml)
Volume of air that remains in lungs during quiet breathing
90
Define FEV1
Forced expiratory volume in 1 second of expiration
91
What is the difference between a blockage of the upper & lower airways?
Upper - choking
| Lower - obstructive lung disease
92
What are the differences between pulmonary and systemic circulation?
Pulmonary - thin vessel walls, minor muscularisation, lower pressure
Systemic - thicker walls, significant muscularisation
93
What are the 4 key changes in the ageing lung?
Chest wall compliance decreases
Respiratory muscle strength decreases
Elastic recoil decreases
Gas exchange becomes impaired
94
What are the 2 types of immunity?
Innate (requires no previous exposure)
| Adaptive (requires previous exposure, immunological response)
95
What are the 3 main antibodies/immunoglobulins in an immune response?
IgM - produced at beginning of infection
IgG - highly specific
IgE - allergic response
96
What are the 4 types of hypersensitivity?
| Gell & Coombs classification of inflammatory diseases
Type I - allergic, IgE
Type II - cytotoxic, IgG (attacks body's own cells)
Type III - complexes, IgG (complexes on joints causing local inflammation)
Type IV - delayed, T-cell mediated
97
Where is histamine released from and what does it cause?
Mast cells in a Type I reaction
| Causes inflammation, vasodilation, mucous secretion & smooth muscle contraction
98
What is the intrinsic tone of the airways controlled by?
Parasympathetic NS
| ACh acts on cholinergic receptors on smooth muscle & causes them to contract
99
What type of muscarinic cholinergic receptor is found in the smooth muscle of the airways?
M3
100
What does adrenaline do to the airways?
Causes bronco dilation by acting on B2 adrenergic receptors in the airways
101
What are the steps of coughing?
1. air inspired
2. epiglottis closes, vocal cords shut
3. abdominal & intercostal muscles contract forcefully
4. intrathoracic pressure increases, narrowing trachea
5. epiglottis & vocal cords open widely
6. air expired
102
What do alveolar macrophages arise from?
Monocytes (WBCs) that circle in the blood
103
What are the 6 main functions of a neutrophil in an innate immune mechanism?
1. identification of threat
2. activation
3. adhesion to the thread
4. migration/chemotaxis
5. phagocytosis
6. bacterial killing
104
What is the role of B-lymphocytes?
Produce & release immunoglobulins
Becomes a plasma cell when activated
Antibodies bind to antigens & help in phagocytosis
105
What is the role of T-lymphocytes?
Secrete cytokines
106
What is respiratory epithelium?
Pseudostratified columnar ciliated interspersed with mucus secreting goblet cells
107
Which structures are lined by respiratory epithelium?
```
Nose
Olfactory epithelium
Oropharynx
Larynx
Trachea
```
108
What are the true vocal cords lined by?
Stratified squamous non-keratinizing epithelium
109
What are the bronchioles lined by?
Simple cuboidal epithelium
110
What are the alveoli lined by?
Simple squamous epithelium
111
What are the 7 layers of gas exchange?
1) alveolar epithelium
2) tissue interstitiel
3) capillary endothelium
4) plasma layer
5) red blood cell membrane
6) rbc cytoplasm
7) Hb binding forces
