Pat resp tutorial Flashcards
How many lobes does each lung have?
Right = 3
Left = 2
What is dichotomous branching?
Bronchioles continuously dividing into 2
What is the purpose of the cartilage in the airways?
Mechanical stability
What shape is the cartilage in the trachea and why?
C-shaped
due to oesophagus running behind it.
What are the 4 different cell types in the alveoli?
1) Type I cells
2) Type 2 cells
3) Macrophages
4) Fibroblasts
What do type I cells do?
very thin
delicate
facilitate gas exchange
What do type II cells do and secrete?
replicate to replace type I cells
secrete SURFACTANT and ANTIPROTEASES which accumulate on alveolar lumen surface
What do macrophages do?
phagocytose inhaled particulates/pathogens
What do fibroblasts do?
remodel ECM following lung injury
What does surfactant do?
reduces surface tension which prevent alveoli from collapsing inwards (making gas exchange possible)
What is the expulsion of mucus called by the movement of cilia?
mucociliary clearance
How do cilia beat?
metachronally
What are the 2 types of cells that submucosal glands contain?
1) Mucous cells (secrete mucous)
2) Serous cells (secrete anti-bacterial enzymes that help protect the airways)
How do you calculate minute ventilation?
Minute ventilation = respiratory rate x tidal volume
What happens during inflammation?
1) Airway smooth muscle increases in size (hypertrophy and proliferation)
2) Airway contracts so there is less space for air to flow through
3) Increased secretion of inflammatory mediators
What are the innverations of the airways? Relaxing and constricting
Relaxing: adrenaline and nitric oxide
Constricting: parasympathetic nerves (cholinergic)
What is the function of airway smooth muscle? (3)
1) Provide structure to the airway.
2) Help maintain tone of the airway (contraction and relaxation).
3) Secrete inflammatory mediators.
How do you calculate alveolar ventilation?
Alveolar ventilation = respiratory rate x (tidal volume - dead space)
What is the anatomical dead space?
‘conducting zone’
NO gas exchange in this area
~150ml in adults
What is the alveolar (functional) dead space?
NO gas exchange due to lack of perfusion
0ml in healthy adult
What is a pneumothorax?
Air in the pleural space between visceral and parietal pleura
What is left shift?
increased affinity for Hb for oxygen (doesn’t want to unload to tissues)
What is right shift?
decreased affinity of Hb for oxygen (wants to unload to tissues)
What happens to the oxygen-Hb dissociation curve when exercising?
Muscles undergo respiration, producing CO2 (hypercapnia)
pH decreases
right shift
Hb decreases affinity to oxygen to unload it to tissues in need
Temp in muscles increases
right shift
What happens to the oxygen-Hb dissociation curve during polycythaemia?
curve shifts UP
What happens to the oxygen-Hb dissociation curve during anaemia?
curve shifts DOWN
What is foetal haemoglobin’s affinity?
greater affinity than adult HbA to ‘extract’ oxygen from mothers blood in placenta
What is myoglobin’s affinity?
Much much greater affinity than adult HbA to ‘extract’ oxygen from circulating blood and store it
DIVE
dorsal inspiration
ventral expiration
What is the apenustic centre?
Located in pons
Activates dorsal resp group (DRG) = main ON switch
What is the pneumotaxic centre?
Loacted in pons
Inhibits dorsal resp group = main OFF switch
What can inhibit the apenustic centre?
ventral resp group
What happens to the proportions of oxygen and CO2 in your body when you hold your breath?
oxygen drops
CO2 rises
as soon as CO2 exceeds ‘CO2 threshold for breathing’ you struggle to hold your breath
What is alkalemia?
high blood pH
What is acidaemia?
low blood pH
What does hyperventilation lead to?
breathing CO2 out
decrease H+
alkalosis
What does hypoventilation lead to?
retaining CO2
increase H+
acidosis
What are the changes in CO2/proton conc of the blood detected by?
carotid bodies and aortic bodies = peripheral chemoreceptors
