Repiratory Flashcards
Phase 1 respiratory lectures, histology and anatomy
Name 4 Functions of the Nose
- Temperature control
- Humidity Control
- Filter / Defence function
- Olfactory
What are the Turbinates and what is their funtion?
Superior meatus
Middle meatus
Inferior meatus
Three large shelves that increase the SA for temp regulation.
What is the superior meatus proximal to?
Olfactory epithelium
Cribriform plate
Sphenoid Sinus
What is the Middle Meatus proximal to?
Sinus Openings
What is the inferior meatus proximal to?
Nasolacrimal duct
Label the Paranasal Sinuses
The Frontal Sinus is found…
It is innervated by….
Drains into….
…Within the frontal bone, Over Orbit and across superciliary arch
….Opthalmic division of V
…. middle meatus
The Ethmoid Sinus is found….
It opens up into the…
It is Innervated by…
…between the eyes
…superior and Middle Meatus
…Opthalmic and Maxillary V
LABRYINTH of air cells
icecream headache
The Maxillary Sinus is found…
It is …. shaped
It drains into the….
innervation?
….within the body of the maxilla
…pyramidal…
…Middle meatus (Semilunar Hiatus)
Maxillary (V2)
The Sphenoid Sinus is found medial to…
Inferior to…
It empties into the…
It is innervated by….
…Cavernous sinus: Carotid artery, III, IV, V VI (OTOMCAT)
…optic canal, dura, pituitary gland
…sphenoethmoidal recess, lateral to the attachment of the nasal septum
…Opthalmic V
name the three parts of the pharynx.
bonus: its muscles?
Nasopharynx
Oropharynx
Laryngopharynx
What is the function of the Larynx?
prevents liquids and foods entering lung
how many cartilages in larynx?
9
3 pairs, 3 singles
label the cartilages of larynx
where would an emergency airway be made?
cricothyroid membrane
What is the larynx innervated by?
the Vagus (X)
which divides into:
* Superior laryngeal nerve (internal external)
* Recurrent laryngeal nerve (left, right)
what is the function of the superior laryngeal nerve?
How many muscles does it innervate?
motor innervation to 1 muscle - the cricothyroid
The recurrent laryngeal nerve loops…
…into the thorax,
Left = under the aorta
Right = RSubArt
between the trachea and oesophagus
the cricothyroid is innervated by?
all other intrinsic muscles of the larynx innervated by?
cricothyroid = superior laryngeal nerve
all other intrinsic larynx = recurrent laryngeal nerve
ca
In 1 minute of breathing, how much air is bretahed in approximately?
5 litres
CardiacOutpt is about 5 literes per minute too
1 breath = 500ml approx
The trachea starts at the [a] and ends at the [b] where it bifurcates
bonus: at which level does the trachea bifurcate?
[a] larynx - cricoid cartilage
[b] carina
Carina = sternal angle = T4/5
The trachea is made from what kind of epithelium?
pseudo-stratified, ciliated, columnar Respiratory epithelium
with goblet cells
trachealis cartlidges form […]
incomplete semicircles
the trachea is very proximal to…
…the aorta and superior vena cava
which main bronchus is more likely to get things stuck in it and why?
right main bronchi - more vertically disposed
the right lung has […] lobes
what separates them?
three
superior, middle, inferior
serparated by horizontal and oblique fissure
the left lung has […] lobes
what separates them?
two
superior and inferior (plus lingula)
separated by Oblique fissure
What allows gas exchange and surfactant production in the alveoli?
Type 1 pneumocyte = gas exchange
Type II pneumocyte = surfactant production
a
adjacent alveoli are connected through [a] which allow the movement of [b]
[a] pores of Kohn
[b] marcophages
enodthelial capillaries of the lung have a
fused basement membrane, 1um thick
how many division from trachea to alveoli
24
what are the layers of gas exchange?
O2 → Type 1 Pneumocyte → Fused Basement Membrane → Vascular Endothelial Cell → RBC
which pulmonary pleura has nociception?
parietal = outside
What are the muscles of passive Inspiration?
what about active inspiration?
Passive =
* * Diaphragm mainly, 70% of volume change (phrenic C3-5 innervation)
* External intercostals – lift ribs 2-12, widen thoracic cavity
Accessory =
* Scalenes – lift ribs 1&2
* Pectoralis major – lift ribs 3-5
* Sternocleido. – elevates sternum
Muscles of Quiet expiration?
what about Active Expiration
Passive/Quiet expiration = elasitc recoil of lungs, rib cage and diaphram
Active:
* Internal intercostals – depresses ribs 1-11
* Rectus abdominis – depresses lower ribs, compresses
abdominal organs and diaphragm
which nerves innervate the diaphram?
C3, C4, C5
Keep diaphram alive
what is meant by the term static lungs?
Both the chest wall and lungs have elastic properties that require energy to change.
Gas Exchange happens via simple diffusion in the [a] and [b] and requires a balance of [c] and [d]
alveoli
capillaries
ventilation (high SA and minimal distance)
perfusion (blood supply)
Haemoglobin is fully saturated at [a]% way through the capillary bed
25%
think about heating a house with no one upstairs.
During Hypoxia, whay happens to the pulmonary circulation?
Pulmonary Vasoconstriction Occurs in the hypoxic areas
why: ultimately to rebalance the ventilation:perfusion ratio
If an area of lung not getting any oxygen, no point in perfusion. Lung shuts blood flow to that area/alveoli and concentrates on perfusing the areas that do have oxygen.
opposite to systemic circulation!
what is deadspace and where is it found?
the volume of air not contributing to ventilation.
Physiological = anatomical = alveolar
150ml anatomic (airways)
25ml Alveolar (damage)
how many orders of branching in lungs?
17 orders
perfusion of capillaries depends on:
pulmonary artery pressure
pulmonary venous pressure
alveolar pressure
what is PaCO2?
arterial CO2
what is PACO2?
alveolar CO2
What is PiO2?
Pressure of inspired O2
what is FiO2?
Fraction of inspired O2 = 0.21
what is the relationship between arterial CO2 and alveolar ventilation?
PaCO2 = kVCO2 / VA
arterial CO2 is inversely proportional to Alveolar ventilation.
If you hyperventilater (increase VA), will reduce arterial CO2
What is the alveolar gas equation?
Name four causes of Hypoxaemia (Low PaO2 in blood) (hypoxia = low o2 to tissues)
- Alveolar hypoventilation
- Reduced PiO2
- Ventilation:Perfusion mismatching
- Diffusion abnormality
Why is O2 / HbO2 curve sigmoid shape? (non-linear)
As each O2 molecule binds, it alters the confromation of haemoglobin, making subsequent binding easier
influences, by CO2, Temp
What can be measured from blood gases?
PaCO2
PaO2
pH
HCO3-
what is the normal pH of human body?
ACID BASE CONTROL
7.35-7.45
CO2 is predominantly controlled by…
Respitory control
HCO3- is predominantly under…
renal control
slower than rep. control of CO2
The respitory system is able to compensate for increased […] but elimination of fixed acids depends on the […]
carbonic acid production
renal system
what will happen to the blood pH if ventilation is impaired?
how will the renal system compensate
Henderson-Hasselbach equation:
Increase PCO2, decreases pH = repiratory acidosis
retention and prodcution of HCO3- and H+ secretion to compensate
during hyperventilation what happens to blood pH?
Resiratory alkalosis
Lung expansion is limited by [a]
[a] is determined by the amount of [b] and [c]
[c] is reduced by [d]
[a] compliance
[b] elastic tissue
[c] surface tension in alveoli
[d] surfactant
How is mucus removed from the lungs?
mucociliary escalator.
cillia beat in directional waves to move mucus up the airway to be swallowed
Chemical epithelial barriers, secreted from respiratory epithelial have multiple functions including:
antiproteinases
anti-fungal peptides
anti-microbial peptides
antiviral proteins
opsins
mucus is produced by which cells
goblet cells
what is airway mucus?
viscoelastic gel containing water, carbs, proteins and lipids.
mucus protects the epithelium from (2x)
foreign materials and fluid loss
coughing is a [a] reflex
expulsive
with some voluntary control
respiratory epithelium is able to regenerate largely due to its [a]
In other words they dont [b]
[a] functional plasticity
[b] terminally differentiate
what is functional plasiticity?
When a cell is able to change their phenotype - redifferentiate into another type of cell
what is surfactant produced by and what is its function?
type II pneumocytes.
Reduce surface tension of lungs
How many layers in the aveolar blood-air barrier?
what are they?
Three:
(surfactant)
1. Type I pneumocyte
2. Fused Basement membrane of pneumocyte and capillary
3. Vascular Endothelial Cell
which types of alveolar cells make up most of the surface area?
which types are more numerous?
Type I pneumocytes make up 90% of SA (very thin!)
But Type II make up 60% of cell population
Alveolar macrophages are derived from [a] and [b] particulates including dust and bacteria and leave via the [c] or [d]
[a] Monocytes
[b] phagocytose
[c] lymphatics
[d] mucociliary escalator
where would serous glands of bowman be found and what is their function?
in the olfactory epithelium (apex of roof of nose and some of nasal cavity and septum)
secrete watery fluid which help wash the surface clean.
where would clara cells be found?
in the terminal bronchioles
uncertain purpose ? secrete lipoprotein which prevent bronchioles sticking tog? surfactant elimination?
What is the larynx comprised of?
What are the vocal chords comprised of?
Larynx: Respiratory epithelium; hyaline cartilage, with seromucinous glands.
Vocal chords = stratified squamous epithelium over loose irregular fibrous tissue (Reinke space) no Lymphatics.
What are the pores of Kohn and what do they do?
why can they cause issues?
Holes in the alveoli interstitium - connect alveoli
they help equalise pressure between adjacent alveoli
means that they can spread infection between alveoli.
What are the two circulatory sysstems of the lungs?
- Pulmonary (100% ofCardiac Output)
- Bronchial (2% of LV output)
what is the transit time of a RBC around the pulmonay circulation?
around 5 seconds
what is a normal pressure in the RA?
5mmHg
What is a normal pressure in the Left atrium?
5mmHg
What is a normal pressure in the Right Ventricle?
What is a normla pressure in the Left Ventricle?
Right Ventricle: 25/0
Left Ventricle: 120/0
what is a normal aortic pressure?
what is a normal pulmonary artery pressure?
aortic pressure: 120/80
pulmonary artery: 25/8
what does the pulmonary arterial wedge pressure measure? (PAWP)
pressure in the left atrium
what is the equation for calculation average blood pressure?
(Mean pulmonary arterial pressure - pulmonary arterial wedge pressure?
mPAP - PAWP = CO x PVR
mPAP = mean pulmonary arterial pressure
PAWP = pulmonary arterial wedge pressure
CO = Cardiac Output
PVR = Pulmonary vascular resistance
why does the radius of a blood vessel have such a disproprtionate effect of resistance?
Pouiseuilles Law
how is mPAP able to remain stable during exercise, despite increased CO?
mPAP - PAWP = CO x PVR
autoreuglation of blood flow
metabollic/myogenic
What are some causes of Type II Respiratory failure?
PaCO2 > 6 kPa
PaO2 < 8 kPa
WHOLE LUNG
Failure to ventilate: PUMP FAILURE.
*Hypoventilation
* Muscular weakness
* Obesity
* Posture
* Loss of respiratory drive eg opiods
* COPD
what are some causes of Type I Respiratory Failure?
PaCO2 < 6 kPa
PaO2 < 8 kPa
Hypoventilation
Diffusion Impairment - eg pneumonia
Shunting
V/Q mismatch - pulmonary embolism
(parts of the lung)
The average VQ ratio is [a].
[?] exceeds [?] towards the apex, and [?] exceeds [?] towards the base.
The different ratios for different areas are due to the relation of the area to the [?]. Areas of lung [?] have [?] perfusion relative to ventilation due to [?], reducing the V/Q ratio.
0.8
**ventilation ** exceeds perfusion towards the apex, and perfusion exceeds ventilation towards the base.
The different ratios for different areas are due to the relation of the area to the heart. Areas of lung below the heart have increased perfusion relative to ventilation due to gravity which increases blood flow, reducing the V/Q ratio.