Frank's Small Lungs Flashcards
What is the costodiaphragmatic recess?
The narrow gap between periphery of diaphragm and chest wall
What is residual volume?
The volume left in the lungs after the maximum breath out
What are well defined airways of the lung at the margin on a CT a sign of?
Pulmonary fibrosis
Where is myoglobin found?
In muscle
What is expiratory reserve volume?
The difference in volume between a full breath in and a normal breath out
What kind of joint are costochondral joints?
Synovial
When does lung compliance decrease in a healthy lung?
At low and high volumes
What anti-infection substances does mucus contain?
IgA, lysozyme and anti-trypsins
What bounds the thoracic space laterally?
The ribs
What is the relationship between temperature and solubility when gases dissolve in fluid?
The solubility of gas decreases with a rise in temperature (for example, gets more humid in hotter weather)
What bounds the thoracic space anteriorly?
The sternum
What is the posterior limit of the nasal cavities?
Nasopharynx
Where does pleura change from parietal to viscera pleura?
At the main bronchi
Why does haemoglobin release O2 when it reaches the tissues?
Lower PO2, higher temperature, high CO2 and acid levels decreasing affinity of haemoglobin for O2
How many lobes does the right lung have?
3
What does interstitial lung disease refer do?
Abnormal material between the airways
Does change partial pressure or concentration cause movement of gas?
Partial pressure
Where do costalchrondral joints arise from?
Ribs 8-10
Is normal breathing effort dependent or independent?
Effort dependent as inter pleural pressure is negative throughout
Which are the false ribs?
8-12
What forms the costal margin?
Anterior, inferior limit of the rib cage
What feature is typical of all thoracic vertebrae?
A transverse process
Where does pleura change from visceral to parietal?
At the main bronchi
What is happening when crackles are heard on listening to the lungs via stethoscope?
Airways are collapsing in expiration and snapping back open as pressure equalises in inspiration. Fineness or coarseness of crackle corresponds to size of the airway.
Which dermatome supplies the nipple?
T4
What O2 saturation is a sign of cyanosis?
85-90%
Where does the neurovascular bundle lie?
On the interior aspect of the rib
When will breathing 100% O2 or hyperventilation help a patient?
If they are at high altitude (breathing low PO2) or hypoxic
Where is mixed venous blood taken from?
The pulmonary artery, it is the best ‘average’
What is Dalton’s law?
The partial pressure of gas in a mixture is the pressure it would exert if it occupied the volume alone. It is expressed as fractional concentration (FO2) x barometric pressure (atm)
What is dynamic compliance?
Compliance of lung at any time during air movement
What kind of joint is the 1st sternocostal joint?
Primary cartilaginous
What do aryepiglottic muscles form?
A sphincter of the airways
Which ribs are atypical?
1st, 2nd, 11th 12th and occasionally 10th
How many segments does each lung have?
8-10
Where do internal intercostal arteries arise from?
Subclavian arteries
How does fibrosis affect elastic recoil?
Increases it
Where do anterior rami of the thoracic spinal nerves supply?
Intrinsic muscles of the chest and associated skin
What happens during pnemothorax?
If there is a breach of parietal pleura, air will rush into the inter pleural space ,as it usually has negative pressure, which causes an uncoupling of the lung from the chest wall often called collapsed lung as lung is unable to inflate properly
What is the blood supply of the anterior thoracic wall?
Anterior intercostal arteries from the internal thoracic arteries
What is PCO2 of atmospheric air?
0 kPa
What are intercostal nerves in relation to thoracic spinal nerves?
The anterior rami
Which dermatome supplies the anterior superior part of the chest?
C4
How far does the diaphragm descend in inspiration?
6 cm
What is the Haldane effect?
At any given PO2, the quantity of CO2 carried is greater in deoxygenated blood than oxygenated blood. This is because Hb forms carbamino compounds more easily, and is a better buffer when deoxygenated.
Where do internal thoracic arteries arise from?
Subclavian arteries
What passes through the thoracic inlet?
Common carotid artery, oesophagus, trachea and internal jugular vein
What is resting tidal volume?
Volume drawn in for normal breath
How does HCO3- move out of haemoglobin?
Out of cell down concentration gradient and exchanged for Cl- using HCO3-/Cl- antiporter
Where are the blood vessels and nerves and how are they arranged in the intercostal neurovascular bundle?
In the subcostal groove between innermost and internal intercostal muscle, lies the neurovascular buncle which is arranged from superior to inferior:
Vein
Artery
Nerve
How much space does 1 mol of an ideal gas occupy at 1 atm pressure?
22.4L
Which nerves supply parietal pleura?
Intercostals
How do pulmonary veins lie at the hilum?
Anterioinferior
What is the diffusing capacity (or transfer factor) of a gas?
The permeability of the lungs to a given gas x area. A measure of alveolar/capillary membrane function
What is PO2 of atmospheric air?
21 kPa
What forms the costal margin?
Anterior, inferior limit of the rib cage
What is thoracic outlet syndrome? What is the cause, what are the symptoms?
Caused by compression of neurovasculature passing through the thoracic INLET perhaps by an extra (cervical) rib, apical lung cancer or old fracture of the clavicle. Symptoms are pain, weakness, numbness, tingling, swelling, fatigue or coldness in the forearm or hand
What do type I pneumocytes do?
Gas exchange
What do normal lungs sound like on percussion?
Resonant
Where do intercostal nerves supply?
Intrinsic muscles, parietal pleura, fascia and skin.
How do some diseased lungs sound on percussion?
Dull
What is La Place’s law?
That pressure is proportional to surface tension divided by radius
What does interstitial lung disease refer to?
Abnormal material between airways
Where do posterior rami of the thoracic spinal nerves supply?
Post-vertebral muscles of chest and skin overlying these
What is haemoglobin concentration in normals blood?
150g/L
What is the nasal epithelium?
Pseudostratified columner ciliated epithelium
Why does hyperventilation or breathing 100% not usually increase O2 delivery to tissues?
Because haemoglobin is usually fully saturated with O2 anyway so raising PO2 will only be able to increase O2 dissolved in plasma a little.
What is the large muscle covering the anterior superior part of the rib cage called?
Pectoralis major
What kind of joint are the costochondral joints?
Synovial
What state must iron be in to bind with O2?
Ferrous (Fe2+) not ferric (Fe3+)
Which nerve supplies mediastinal and diaphragmatic pleura?
Phrenic
How much more soluble in water is CO2 than O2?
20 x
Which patients is cyanosis difficult to detect in?
Anaemic patients, as they have few haemoglobin so they must be severely hypoxic before a blue tinge will show
What are the extrinsic muscles of the anterior chest wall?
Pectoralis major and minor and serratus anterior
What kind of joint is the 2nd sternocostal joint?
Synovial
Where should a needle through the rib cage be placed?
In the middle of intercostal space
What is total lung capacity?
The whole volume of the lungs
Where does pharynx become oesophagus?
At the posterio-inferior limit
What is alveolar dead space?
Pathological, the volume of alveoli which can no longer exchange in gas exchange due to damage
What type of joint with what kind of movement is the manubrio-sternal joint in adults?
Symphysis with hinge movement
Where do bronchial veins drain?
Into the pulmonary veins
What kind of joint is the manubro sternal joint?
Symphysis
What kind of joint is the first sternocostal joint?
Primary cartilagious
How is the first rib anchored into place?
By the scalene muscles of the neck and sternocleidomastoid muscle of the head
What are the intrinsic muscles of the anterior chest wall?
The external, internal and innermost intercostal muscles
Which ribs do costochondral joints arise from?
8-10
When is breathing effort independent?
As residual capacity is reached during breathing out, no amount of force will empty the lungs further as inter pleural pressure becomes more positive.
What is the FEV1/FVC ratio in obstructive lung disease and why?
FEV1 reduced due to obstruction of air escaping the lungs so the FEV1/FVC ratio is reduced.
What bounds the thoracic outlet?
T12 posteriorly, 12th then 11th rib. 10th, 9th, 8th, 7th costal cartilages (costal margin) and finally xiphisternal joint.
Does HbF have lower or higher affinity for O2 than HbA? Why?
Higher so it can pick up O2 across the placenta
What kind of joint is the second sternocostal joint?
Synovial
Where are voice sounds produced?
Larynx
What is Boyle’s law?
Volume of a gas is inversely proportional to pressure
What is resonant percussion with absence of lung sounds a sign of?
Pneumothorax
How can the radius of the airway be decreased?
Parasympathetic stimulation of B2 receptors or inflammatory mediators such as histamine, prostaglandins and leukotrienes
What are the features of 1st and 2nd ribs?
Flatter than typical ribs with attachments for scalene muscles
What is the O2 saturation of mixed venous blood at rest?
75%
What is FEV1/FVC ratio in restrictive lung disease and why?
Normal as FEV1 and FVC are equally reduced due to fibrosis (or other non-obstructive pathology). The ratio may even be high due to increased FEV1 value because of the decreased lung compliance associated with fibrosis
Which ribs do sternochondral joints arise from?
1-7
What is the protein configuration of foetal haemoglobin?
2 alpha and 2 gamma chains
What kind of joints are costotransverse and costovertebral joints?
Synovial
How do bronchi lie at the hilum?
Posterior
What effect does increasing the partial pressure of a gas mixed with liquid have?
Causes the gas to dissolve more in the liquid (and vice versa, for example, when opening a can of coke, the pressure decreases therefore the gas escapes audibly)
What is vital capacity?
The total amount it is possible to breath in or out
What is the fascia attached to parietal pleura?
Endothoracic fascia
What is hypercapnia?
High PaCO2 due to hypoventilation
Where do sternochrondral joints arise from?
Ribs 1-7
Which nerve supplies mediastinal and diaphragmatic pleura?
Phrenic nerve
How many binding sites for O2 does myoglobin have?
One
Which thoracic vertebra are atypical?
T1, T10, T11, T12
When is breathing effort dependent?
At the beginning of a breath out until residual capacity is reached, breathing out harder will increase flow
Where do posterior intercostal arteries arise from?
Thoracic aorta
Which part of chest is fixed on breathing?
Vertebral column only
What protein chains does adult haemoglobin have?
2 alpha, 2 beta
Why does the haemoglobin binding curve begin to plateau when it reaches 75% saturation with O2?
The O2 sites are getting used up on haemoglobin
What do bronchial veins drain into?
Pulmonary veins
What bounds the thoracic space posteriorly?
The thoracic vertebral column
How does haemoglobin buffer CO2?
1) It forms carbamino compounds using CO2 at the N-terminals of it’s side chains arginine and lysine
2) Histidine residues accept protons from carbonic acid producing HCO3-
What is PCO2 of alveolar air?
5.3 kPa
What factors affect diffusion across the alveolar membrane and what laws govern these?
Fick’s law and Graham’s law - a large area and thin membrane will cause fastest diffusion
Name some obstructive lung diseases
Asthma, COPD (emphysema, chronic bronchitis)
What are well defined airways at the margins of the lung a sign of on a CT?
Pulmonary fibrosis
What kind of joint is the manbro sternal joint in young adults?
A hinge joint
What bounds the thoracic inlet?
T1, 1st rib and costal cartilage and upper margin of manubrium
What features do typical ribs have?
A head with two articular facets, neck, tubercle, angle, tear-shaped shaft, subcostal groove and costal cartilage anteriorly
What is static compliance?
Change in volume per unit of change in distending pressure (basically, can the lung expand with increasing pressures)
Which dermatome supplies the umbilicus?
T10
How many lobes does the left lung have?
2
Where do anterior intercostal arteries arise from?
Internal thoracic arteries
How is wheezing generated?
By turbulent flow in airways
Where are the two joints each rib makes with it’s own thoracic vertebra?
Between the body of the vertebra and with the transverse process of the vertebra
What are the joints that ribs make with vertebrae called?
Costotransverse and costovertebral joints
What do type II pneumocytes do?
Secrete surfactant
What is functional residual capacity?
The volume left in the lungs after a normal breath
What is the large muscle that covers the anterior superior part of the rib cage on each side?
Pectoralis major
Where does the epiglottis arise from?
Anterior of the larynx against the tongue
Where do anterior intercostal arteries arise from?
Internal thoracic arteries
What is atelectasis?
Collapsed alveloi
What is Henry’s law?
For gases dissolved in fluid, dissolved gas concentration is equal to the partial pressure of gas above the fluid x solubility of that gas in that liquid
How do healthy lungs sound on percussion?
Resonant
Where is the cough centre?
Medulla
Where is the neurovascular bundle located?
On the inferior aspect of the rib
Where are voice sounds produced?
Larynx
What is the blood supply of the posterior thoracic wall?
Posterior intercostal arteries from descending thoracic aorta
What is peak expiratory flow rate and when will it be reduced?
The maximum speed of exhalation measured using a peak flow meter. It will decrease when airway resistance increased such as in obstructive lung disease
What is anatomical dead space?
The volume of airway that does not undergo gas exchange even in healthy individuals e.g. trachea and bronchi
What is meant by a ‘diffusion limited’ gas? Give an example
Limited only by the rate of diffusion over the alveolar/capillary membrane because the gas binds so avidly to haemoglobin that the rate of transfer at low concentrations is not dependant on blood flow. E.g. carbon monoxide
Why is the haemoglobin binding curve steeper when it is 25% saturated with O2?
After the first O2 binds haemoglobin changes it’s configuration so it has a higher affinity for further O2 binding. Moves more to the relaxed state. Cooperative binding.
Which are the true ribs?
1-7
What is meant by a ‘perfusion limited’ gas?
A gas which is not so soluble, transfer depends on the amount of haemoglobin so increased blood flow will increase transfer
What is Darcy’s law?
That flow is equal to (alveolar pressure - mouth pressure) divided by resistance to flow
How far does visceral pleura extend inferolaterally?
As far as rib 8
What is a feature of T10?
One demi facet on its body
How does emphysema affect elastic recoil?
Decreases it
If the diaphragm contracts which way will it move?
Downwards
What is partial pressure?
The pressure that would be required to dissolve that amount of gas in the fluid according to Henry’s law.
What is PO2 of alveolar air?
13.5 kPa
What kind of bone is a rib?
Flat
What features do typical thoracic vertebra have?
Heart shaped with two articular facets on either side. From the posterior of the body arises the vertebral arch (pedicles, pars, interarticulates, transverse processes, laminae and spine) There is a central intervertebral foramen for the spinal nerves
What is Charles’s law?
Volume of a gas is proportional to absolute temperature
Where do posterior intercostal arteries arise from?
Thoracic aorta
How do pulmonary arteries lie at the hilum?
Anterior on R, superior on L
What is the majority of CO2 carried as?
HC03- in plasma
