RESPIRATORY Flashcards
1
Q
At what spine level does the trachea bifurcate
A
T4
2
Q
What is the lung segmentations after the bronchi divides
A
Lobar bronchi, segmental bronchi, terminal bronchioles, respiratory bronchi, alveolar ducts, sacs
3
Q
What are the main muscles of inspiration
A
Diaphragm and external intercostals
4
Q
what nerve supplies the diaphragm
A
the phrenic nerve - c3,4,5
5
Q
What are the fissures on the right lung called
A
The horizontal and oblique fissure
6
Q
how many fissures do the right and left lung have respectively?
A
2 and 1
7
Q
what is the left lung fissure(s) called
A
the oblique
8
Q
what are the pleural layers called
A
the parietal and visceral. visceral is on the organ side and parietal is on the outside
9
Q
What are the structures in the upper airways
A
Nasal passage, larynx, trachea, lobar bronchi down to terminal bronchi
10
Q
what are the structures in the lower airway
A
respiratory bronchioles to alveolar sacs
11
Q
what is respiratory epithelium
A
Pseudostratified ciliated columnar epithelium with interspersed goblet cells
12
Q
What is the mechanics of inspiration
A
Phrenic causes diaphragm to contract and it moves down, as well as external intercostals contracting. this increases the thoracic pressure and lowers the pressure. the chest wall and ribs move up and out and the oxygen moves in down the pressure gradient
13
Q
what are the muscles of forced inspiration
A
the sternocleidomastoid, the serratus anterior and the latissimus dorsi
14
Q
what happens during expiration
A
it is normally a passive process, there is decreased phrenic input to the diaphragm and external intercostals which causes them to relax. this causes a decrease in volume and an increase in pressure in the thorax. the alveoli compress and the air passively moves down the gradient
15
Q
what are the accessory muscles for forced expiration
A
the internal intercostals and the abdominal muscles
16
Q
what is the transpulmonary pressure
A
the difference between the alveolar and interpleural pressure, normally about 4mmHg
17
Q
what happens if the transpulmonary pressure is 0mmHg
A
you would get a pneumothorax
18
Q
what are the two main respiratory centers in the brain
A
the pontine and medullary centers
19
Q
what are the pontine centers of respiration and what is their function
A
the apneustic center which fine tunes the inspiratory stimulus and acts on the DRG to cause inspiration
the pneumotaxic center is involved in the smoothing the transition to expiration and acts on the VRG
20
Q
What are the medullary centers of respiration
A
the VRG (ventral respiratory group) and the DRG (dorsal respiratory group)
21
Q
what are the different types of receptor found in the lungs
A
Slow adapting stretch receptors, rapid adapting stretch receptors, J receptors and chemoreceptors
22
Q
What is the function of slow adapting stretch receptors
A
they respond to distension and end inspiration to prevent overstretch of the lungs
23
Q
what is the function of rapid adapting stretch receptors
A
they are between the airway epithelium and they respond to irritants - bronchoconstriction
24
Q
what is the function of J receptors
A
the are across the capillary wall and respond to an increase in lung pressure due to a build up of fluid. they will increase the respiratory rate to induce rapid shallow breathing
25
where are peripheral chemoreceptors found?
in the aortic arch and in the carotid sinus (bifurcation)
26
what does the peripheral chemoreceptors detect
they detect changes in pressure of oxygen (activated about 60% saturation) and also H+ ion concentration
27
where are the central chemoreceptors found
in the medulla
28
what do the central chemoreceptors detect
they look at the partial pressure of carbon dioxide, very important for the respiratory drive
29
how to peripheral chemoreceptors detect carbon dioxide
carbon dioxide crosses the blood brain barrier and reacts with water. this becomes H2CO3. this then dissociates into HCO3- and H+ which is then detected by the chemoreceptors
30
where is more perfused, top or bottom of the lung
the bottom of the lung, due to gravity. this means the V/Q is lower at the bottom of the lung
31
what is a dead space in the lungs
when there is ventilation but not perfusion, which causes a HIGH V/Q
32
what is a shunt in the lungs
when there is no ventilation but there is perfusion. there is a low V/Q value here
33
what happens when there is a dead space in the lungs
there is local bronchoconstriction which causes air to be diverted to areas which are better perfused
34
what happens when there is a shunt in the lungs
there is hypoxic pulmonary vasoconstriction, blood is directed to better ventilated areas
35
what happens if the oxygen dissociation curve moves to the right
it means that there is a lower affinity and therefore a higher level of dissociation
36
what happens if the oxygen dissociation curve moves to the left
the more left then the higher affinity and the more binding
37
what factors may cause a left shift of the oxygen dissociation curve
higher pH, decrease in CO2, lower temperature and lower DPG. also carbon monoxide and foetal haemoglobin
38
what causes the oxygen dissociation curve to move to the right
low pH, increased CO2, increase in temperature and increase DPG
39
how is carbon dioxide transported in the blood
dissolved in the plasma (10%), bound to hemoglobin in the form of carbaminohemoglobin (23%), and as HCO3- (65%)
40
What does hypoventilation cause
increase CO2, increase H+, induce respiratory acidosis
41
what does hyperventilation cause
decrease in CO2, therefore decrease hydrogen and causes respiratory alkalosis
42
what is the carbonic acid equation
CO2 + H2O - (carbonic anhydrase) - H2CO3 - H+ + HCO3-
43
What is Daltons equation
PT = ppA + ppB + ppC etc
| pressure exerted by mixture of gases are equal to the pressure of the equal parts
44
what is boyle's law
P1V1 = P2V2
| P proportional to V
45
what is henrys law
volume of gas dissolved in a liquid depends on the partial pressure and solubility of it
46
What is Ohms law
V=IR
| pressure = flow X resistance
47
what is the alveolar gas equation
PAO2 = PiO2 - PaCO2/R
| where R=0.8
48
what is Laplace's law
P = 2T/R
| alveoli pressure depends on the surface tension and radius. On alveoli its reduced by surfactant
49
what is compliance
greater compliance means the greater ability for the lungs to expand. it is dependent on surface tension and elasticity of the lung
50
what are the most common causes of hypoxia
hypoventilation increasing PaCO2, diffusion impairment (thickening of a membrane), shunt and V/Q mismatch
51
what is type 1 respiratory failure
low/normal PaCO2, low PaCo2
52
what is type 2 respiratory failure
low PaO2, high PaCO2
53
what is the laryngopharynx
hyaloid and then cricoid cartilage. the epiglottis is elastic
54
how many vocal cords do you have
you have two vocal cords and one false set of vocal cords
55
what epithelium is in the epiglottis
upper part is stratified squamous and lower is respiratory epithelium
56
what is the anatomical and physiological dead space
the anatomical dead space is the air in the conducting zone. the physiological dead space is the anatomical plus the alveoli dead space
57
what is FEV1
it is the forced expiratory volume in one second
58
what happens when you have airway obstruction
FEV1 is reduced more than the FVC. the FEV1/FVC ratio is less than 0.7. this occurs in COPD and asthma
59
what happens in airway restriction
both the FEV1 and FVC is reduced equally. the ratio is normal. this occurs in pulmonary fibrosis and muscular failure
60
how do airways constrict
parasympathetic - Ach binds to the M3 muscarinic receptors and causes bronchoconstriction
61
what causes airways to dilate
adrenaline and noradrenaline binds to B2 adrenoreceptors and causes dilation
62
what is type 1 hypersensitivity
IgE - hay fever
63
what is type 2 hypersensitivity
autoimmune, IgG mediated
64
what causes type 3 hypersensitivity
the complement system and immune complex formation. hypersensitivity pneumonitis
65
what is type 4 hypersensitivity
T cell mediated in the form of granulomas. sarcoidosis
66
what causes anaphylaxis
the first exposure causes IgE to be sensitized and presentation of past cells. the second time IgE binds to a high affinity receptor on mast cells which then degranulates releasing histamine and tryptase. this causes low blood pressure, difficulty breathing and swelling of upper airway
67
what is the fetal lung circulation
the lungs are not used in utero, as there is high pressure. there is the ductus venosus to the inferior vena cava, the foramen ovale allows for shunting between the right and left side of the heart
68
what happens during the first breath
the fluid in the lungs is expelled, the pressure drops and the lungs open, the pulmonary circulation takes over and the foramen ovale closes
69
how does aging affect the lung
decreased chest compliance, thorax changes shape (increased curvature), decreased respiratory muscle strength, decrease in elastic recoil, impaired gas exchange, impaired immunity
70
describe the bronchiole circulation
there is a thick wall, there is pressure of 120/80.
O2 causes vasoconstriction and hypoxia causes vasodilation. there is delivery of oxygen to the lung tissue.
there is redistribution of the blood
71
describe the pulmonary circulation
there are thin walls with a pressure of 25/8. oxygen causes vasodilation and hypoxia causes vasoconstriction. it picks up oxygen
72
what the pulse pressure
it is the difference between the systolic and diastolic pressure
73
what does Poiseuille's law relate to
resistance is inversely proportional to the radius^4
| there is a small decrease in radius leads to a large increase in vascular resistance
74
what does PEF stand for
peak expiratory flow
75
what is FEV1
it is the forced expiratory volume in one second
76
what is FVC
forced vital capacity - total expiratory volume that we have
77
what happens in lung obstruction
the FEV1/FVC is less than 0.7. this occurs when there is a block, in COPD and asthma.
there is a reduction of FEV1, but the FVC stays the same
78
what happens in lung restriction
the FVC is less than 0.8. there is a decreased expiratory volume (lung is filling less), this occurs in pulmonary fibrosis
79
what does IRV stand for
maximal inhalation excess of normal inspiration
80
what does ERV stand for
the maximal exhalation excess of normal
81
what does TV stand for
tidal volume - this is just normal breathing
82
what does RV stand for
residual volume
| this is the air left after maximal expiration
83
what is the VC
this is the maximal expiration after the maximal inhalation
| IRV + TV + ERV
84
what is IC
it is the maximal inspiration after tidal expiration
IRV + TV
inspiration capacity
85
what is FRC
it is the functional residual capacity - ERV + RV
| this is the air in the lungs left after normal expiration
86
what is TLC
this is the total lung capacity - IRV+TV+ERV+RV
87
what is the typical TLC volume
it is about 5 liters
88
what is the normal IRV volume
2000/2500 mls
89
what is the normal TV volume
500 mls
90
what is the normal ERV volume
1250 mls
91
what is the normal RV volume
1250 mls
92
what is the key mediator in the innate immunity
neutrophils (also macrophages are involved)
93
what happens during neutrophil activation
they identify a threat, they are activated by cytokines and adhere. they then move through gaps in the endothelial cell wall and move into the tissue. they then phagocytose bacteria as well as degranulating
94
what do CD8 cells do
they are cytotoxic T cells = they go to pathogens and puncture holes in the membrane through secreting perforin. the cells split due to uncontrolled osmolarity
95
what do CD4 cells do
these are T helper cells - activate other cells
96
what are the 5 classes of antibodies and what do they do
```
IgG, A, M, E and D
IgG - most abundant
IgA - in mucosa and breast milk
IgM - first in infection
IgE - anaphylaxis and allergy
IgD - not 100%
```
97
what are the non immune barriers in the lungs
the physical defenses: respiratory epithelium, mucus, coughing
98
what is type 1 sensitivity
type 1 is IgE mediated, it occurs in acute anaphylaxis. they bind to basophils and mast cells and causes degranulation. they release histamine and prostaglandins. this causes bronchoconstriction, vasodilation and the inflammatory response
99
what is hypersensitivity type 2
it is IgG and IgM mediated, which is a cytotoxic response. this occurs in Goodpasture's disease. this results in tissue damage and altered receptors
100
what is hypersensitivity type 3
this is IgG mediated and occurs in immune complex formation. this occurs in farmers lung, workers lung, pigeon lung
101
what is hypersensitivity type 4
this it T cell mediated, this causes a delayed response
102
what does parasympathetic stimulation do to airway tone
this causes bronchoconstriction, mediated by the vagus nerve. Ach acts on the M3 receptors
103
what does sympathetic stimulation do to airway tone
causes bronchodilation, which is mediated by the sympathetic chain. Nor stimulates adrenaline release from the adrenals. this acts on the B2 type receptors on the smooth muscle
104
how would you threat breathing problems with bronchodilators
increase in sympathetic activity via M3 antagonist (IPA), or decrease parasympathetic activity via B2 agonists (salbutamol)
105
how do you calculate PAO2
PiO2 - PaCO2/R
106
how do you calculate PaO2
PAO2 - (A-aDO2)
| where aDO2 is the alveolar arterial concentration gradient - typically 1)
107
how do you calculate
PaCO2 = K CO2/VA (a =alveolar V=ventilation)
108
what are the typical pressures of CO2, O2 and pH values at sea level
```
PaCO2 = 4.5-6
PaO2 = 10.5-13.5
pH = 7.35-7.45
```
109
what happens to air at altitude
the higher up you go the more the atmospheric pressure falls. PiO2 falls but the FiO2 stays the same. the fraction of the oxygen stays the same (of inspired oxygen), but the pressure of inspired gas falls
110
what is the physiological response to altitude
hyperventilation will occur, as you want more O2 and less CO2
there is a decrease in PaCO2, increased minute ventilation increase in heart rate and increase in the blood pH
111
what pathology occurs at altitude
acute mountain sickness (headache and another symptom) - only treatment it descent
high altitude pulmonary oedema - this occurs in unacclimated people - need oxygen and decent
112
what three laws are important to know for depth
boyle's law - P1V1=P2V2
daltons law = Pr = PPa + PPb + PPc ...
henry's law = Vgas dissolved in a liquid at temperature is proportional to the partial pressure of gas
113
what pathology occurs at depth
decompression sickness = nitrogen is the most common. this is when you ascend to quickly for gas to be excreted so you get gas bubbles in the tissue
inert gas narcosis = you have excess nitrogen with less constituent gases you have, this can cause poisoning
CNS oxygen toxicity = CNS deprived of oxygen for so long that it becomes toxic
Arterial gas embolism = 15 minutes after surfacing
Pulmonary barotrauma = trauma to pulmonary vessels due to high pressure/stress on the vessels
114
what week does the lungs start developing
week 4
115
what do the lungs develop from
from the endoderm (forms epithelial cells) and the splanchnic mesoderm
116
what is the pseudoglandular phase of lung development
this occurs in week 5-16 where the right and left bronchi form terminal bronchioles
117
what occurs during the canalicular phase of lung development
this is week 16-26 when the terminal bronchioles go to respiratory bronchioles which each form a few alveolar ducts
118
what happens during the saccular phase of lung development
week 26 to 8 months - alveolar ducts grow sacs at the end of them making alveoli
119
what happens during the alveolar phase of lung development
8 months to birth - the alveoli mature
120
what are the three lung shunts in the embryo
the foramen ovale, the ductus venosus and the ductus arteriosus
121
how many unbiblical arteries are there and what is their function
there are two, and their role is to carry blood from the foetus to the mother
122
how many umbilical veins are there and what is its function
there is one and it carried blood from the mother to the foetus
123
what does the umbilical vein become after birth
the ligamentum teres
124
what does the ductus venosus become after birth
the ligamentum venosum
125
what does the ductus arteriosus become after birth
the ligamentum arteriosus
126
what happens to the foramen ovale after birth
it closes and becomes the fossa ovalis
127
what produces surfactant in the lungs
the type 2 pneumocytes
128
when does surfactant production begin
it starts being produced at 34 weeks
129
what does surfactant do
it keeps alveoli open, maintaining the pressure across them, and making it easier to breathe
130
what happens to surfactant when a baby is born premature
because you have a large increase in surfactant two weeks pre birth, if you are born before this the baby does not have the adequate levels of surfactant. in this case its harder to breathe, and may need support. the child can recover but it increases the chance of death
131
What is the term used to describe a malignant tumour of the pleural membranes?
Mesothelioma
132
what is defined as ‘the amount of air remaining in the lungs after normal quiet expiration’
Functional residual capacity
133
what nerve supplies voluntary motor function to the larynx
the vagus nerve
134
what nerve supplies the cricothyroid muscle (motor)
superior laryngeal nerve
135
what are the muscles that supply the vocal cords (except cricothyroid)
recurrent laryngeal nerve
136
what are the recurrent laryngeal nerve and superior laryngeal nerves a branch of
the vagus nerve
137
what supplies sensory innervation to the larynx above the vocal cords
the internal laryngeal nerve (branch of the superior laryngeal nerve)
138
what supplies sensory innervation to the larynx below the vocal cords
the recurrent laryngeal nerve
139
what conditions would normally lead to type 2 respiratory failure
chronic obstructive pulmonary disease
140
if you inhale a peanut where is it more likely to be lodged in the airway
the right main bronchus
141
where are the main peripheral chemoreceptors located
the carotid arteries and the aortic arch
142
Type 1 Respiratory Failure is characterised by arterial blood gas picture of....
low pO2 and low/normal pCO2
143
wat would normally lead to type 1 respiratory failure
a pulmonary embolism, ventilation perfusion mismatch, alveolar hypoventilation, diffusion problems, shint
144
Chronic Type 2 Respiratory Failure is characterised by arterial blood gas picture of .....
low pO2, high pCO2, normal-high HCO3
145
how is vital capacity calculated
Tidal volume + Inspired reserve volume + Expired reserve volume
146
what cells provides cilia for the mucociliary escalator
Columnar Epithelial Cells
147
what will contribute to causing bronchodilation
adrenaline binding to β 2 -receptors in the smooth muscle of the bronchioles and causing their relaxation.
148
what factors are related to bronconstiction
beta blockers, histamine, parasympathetic stimulation
149
Changes in which of these blood parameters stimulates carotid chemoreceptors
Oxygen, carbon dioxide and H+ ions
150
where does the recurrent laryngeal nerve divide from
the vagus nerve
151
what does the brachiocephalic trunk split into
the right common carotid and the right subclavian
152
what are the branches of the thoracic aorta
bronchia, mediastinal, oesophageal, pericardial, superior phrenic and intercostal/subcostal
153
what are the bones found in the thorax
the sternum, the ribs, the thoracic spine and the superior and inferior costal facets
154
what is the formation of typical ribs
the typical ribs consist of a head, neck and body. the head has two articular facets separated by a wedge of bone. the neck connects the head to the body, and the body is flat or curves
155
what are the atypical ribs
1, 2, 10, 11, 12
156
what are the rib articulations
the costotransverse joint - tubercle of rib and transverse costal facet of vertebra
costovertebral joint = head of the rib and the superior costal facet of the corresponding vertebra
157
what is the joint found between the vertebral bodies
there is intervertebral discs made up of fibrocartilage.
158
what are the ligaments which are found through out the spine
the anterior and posterior longitudinal ligaments
the ligamentum flavum
the interspinous ligament
the supraspinous ligament
159
what is the function of the hyoid bone
it holds up the tongue and holds up the jaw
160
what vertebral level is the hyoid bone found
C3
161
what are the major structures of the hyoid bone
body, greater and lesser horn
162
what muscles and ligaments attach to the hyoid bone
suprahyoid - digastric, stylohyoid, geniohyoid, mylohyoid
| infrahyoid - thyrohyoid, omohyoid and sternohyoid
163
what are the three main ligament attachments of the hyoid bone
the stylohyoid, the thyrohyoid and the hyoepiglottic
164
what are the three parts of the pharynx
nasopharynx, oropharynx and larygopharynx
165
what is contained in the oropharynx
1/3 of the tongue, lingual tonsils the palatine tonsils and the superior constrictor muscle
166
what does the laryngopharynx contain
middle and inferior pharyngeal constrictors
167
what are the muscles of the pharynx innervated by
innervated by the vagus except stylopharyngeus which is innervated by the glossopharyngeal nerve
168
what are the two main groups of muscles in the pharynx
superior, middle and inferior
169
what is the larynx
it is an organ located in the anterior neck, with the structure being primarily cartilaginous
170
what is the innervation to the larynx
receives sensory and motor innervation via branches of the vagus nerve
- recurrent laryngeal
- superior laryngeal nerve (to the cricothyroid)
171
what are the suprahyoid muscles
stylohyoid, digastric, mylohyoid, and the geniohyoid
172
what is the function of the stylohyoid
initiates swallowing by pulling the hyoid bone in a posterior and superior direction
173
what is the digastric muscle
it is comprised of two muscular bellies connected by a tendon, it depresses the mandible and elevates the hyoid bone
174
what is the mylohyoid
it elevates the hyoid bone and the flood of the mouth
175
what is the geniohyoid
it arises from the mandible and attaches to the hyoid bone, acts to depress the mandible and elevate the hyoid bone
176
what are the infrahyoid bones
the omohyoid, the sternohyoid the sternothyroid and the thyrohyoid
177
what is the omohyoid
arises from scapula and runs under the sternocleidomastoid. it attaches the superior belly by the tendon which is then anchored to the clavicle. it attaches to the hyoid bone
- depresses hyoid bone
178
what is the sternohyoid
sternum to hyoid bone
| - depresses hyoid bone
179
what is the sternothyroid muscle
sternum to thyroid cartilage
| - depresses the thyroid cartilage
180
what is the thyrohyoid muscle
attaches to hyoid bone arising from the thyroid cartilage
| - depresses the hyoid bone
181
what are the scalene muscles
three paired muscles - anterior, middle and posterior which are located in the lateral aspect of the neck
182
what is the function of the scalene muscles
they can act as accessory muscles in respiration and flex the neck
183
what structures pass between the anterior and middle scalene muscles
the brachial plexus and subclavian artery
184
what is the lung suspended from the mediastinum by
the lung root
185
what is the apex of the lung
the blunt superior end of the lung, it projects upwards above the level of the first rib and into the floor of the neck
186
what is the base of the lung
inferior surface of the lung, sits on diaphragm
187
what are the three surfaces of the lung
costal, medial and diaphragmatic
188
what are the three borders of the lung
edges - anterior, inferior and posterior
189
where is the anterior border of the lungs
it is formed by the convergence of the mediastinal and costal surfaces - on the left lung there is the cardiac notch
190
what is found in the lung root
bronchus, pulmonary artery, two pulmonary veins, bronchial vessels, pulmonary plexus nerves and lymphatic vessels
191
what is the blood supply for the tissue of the lungs
the bronchial arteries
192
what does the bronchial arteries supply
the bronchi, the lung roots, visceral pleura and the supporting lung tissues
193
what is the venous drainage of the lung tissue
via the bronchial veins
| - the right vein drains into the azygos vein while the left drains into the accessory hemiazygos vein
194
what are the nerves of the lungs derived from
the pulmonary plexuses
195
what is the parasympathetic supply of the lungs
derived from the vagus
196
what does parasympathetic simulation of the lungs cause
stimulates secretion from bronchial glands, contraction of the bronchial smooth muscle and vasodilation of the pulmonary vessels
197
what is the sympathetic nerve supply of the lungs from
derived from the sympathetic trunks
198
what does sympathetic stimulation of the lungs cause
stimulate relaxation of the bronchial smooth muscle and vasoconstriction of the pulmonary vessels
199
what is the visceral afferent fibres of the lung
they conduct pain impulses to the sensory ganglion of the vagus nerve
200
what is the lymphatic drainage of the lungs
the superficial and the deep
| - superficial drains lung parenchyma and deep drains structures of lung root
201
what week in embryology does surfactant production begin
at 34 weeks
202
what is the average TLC
6L
203
what occurs to FEV1 and FVC in airway obstruction
the FVC stays the same (or is slightly decreased) as you can still breath out fully it just takes much longer. You have a significantly reduced FEV1 (below 80%) and therefore in these patients there is a reduced FEV1/FVC ratio (below 0.7)
204
what causes airway obstruction
COPD - there is reduced airflow and an increased air trapping causing hyperinflation of the lungs
205
what happens in airway restriction with regards to FEV1 and FVC
there is an impaired compliance due to fibrosis. The FEV1 is either normal or reduced but not significantly. the FVC is significantly reduced. because of this the FEV1/FVC ratio is not as affected and is often still above 0.7
206
what is the normal FEV1/FVC
80% or above
