Respiration Flashcards
Parts of the respiratory system
Nose and nasal cavity
Mouth
Sinuses
Pharynx
Larynx
Trachea
Bronchi
Lungs
Diaphragm
How many lobes in the heart
Right lung= 3
Left lung= 2
What are the line of defences in the respiratory system
First line of defence= filtration of inhaled particulate matter through the nose
Second line of defence= mucociliary escalator
Alveoli macrophages
Function of respiratory system
Gas exchange of oxygen and carbon dioxide
Metabolism
Filtration of the blood
Reservoir
Parasympathetic innervation
Innervation of bronchial smooth muscle predominates
Parasympathetic ganglia- walls of the bronchi and bronchiole
Postganglionic fibres innervation airway smooth muscle, vascular smooth muscle and glands
Sympathetic innervation
B adrenoceptors expressed on human airway smooth muscle
Relax bronchiom smooth muscle, inhibit mediator release from mast cells and increase mucociliary clearance
Physical or chemical stimuli acting on irritant receptors can cause coughing, bronchi constriction and mucus secretion
Ventilation
Combination of active and passive events
Regulated in the pons and medulla in the brain stem
Inhalation
Contraction of the skeletal muscles of the diaphragm and the inter coastal muscles between the ribs and is therefore active
Exhalation
Contraction of the skeletal muscles of the diaphragm and the inter coastal muscles between the ribs and is therefore active muscle relaxation and the recoil of the elastic tissues in the lungs so it is passive
Surfactant in the alveoli
Produced by type 2 alveolar cells
Helps lung inflate more easily when you breathe in and prevents the lungs from collapsing when you breathe out
Difference between resting and forced breathing
Resting= inspiration muscles contract
Dorsal respiratory group inhibited
Inspiratory muscles relax
Passive expiration
Forced= all of these but also expiratory muscles relax
Expiratory centre of VRG active
Expiratory muscles contract
Active expiration
Conditions affecting respiratory system
Acute respiratory distress syndrome
Asthma
Bronchitis
COPD
Hypersensitivity pneumonia is
Pneumonia
What is rate of diffusion proportional to
Partial pressure gradient
Surface area
Solubility of the gas in the membrane
Partial pressure gradient
Gas will diffuse from an area of higher pressure to an area of lower pressure
Surface area
Larger the surface the more area for gas exchange
Alveoli are folded to increase their surface area to volume ratio
Solubility of the gas in the membrane
In the alveoli wall carbon dioxide is around 20 times more soluble than oxygen
What is rate of diffusion inversely proportional to
Thickness of the membrane
Molecular mass of the gas
Thickness of the membrane
The thicker the membrane the slower the gas will move across it
Molecular mass of the gas
Smaller the mass of the gas the more rapidly it will diffuse
Structure and function of Haemoglobin
Protein contained in RBC
4 polypeptide chains heme group
Porphyria ring with an iron atom at its centre
Iron atom is able to bind to oxygen
Capacity to carry 4 molecules of oxygen
What happens when oxygen interacts with one heme group
Allosteric change which increases the affinity for the rest of the molecule to bind to oxygen
Once one oxygen molecule is bound, there is a greater affinity for oxygen
What happens when carbon dioxide bonds to haemoglobin
Conformational change that causes oxygen to be released
Relationship between the partial pressure of oxygen and the saturation of haemoglobin with bound oxygen
Binding of oxygen promotes more binding of oxygen= sigmoids shape to the curve
What does a left shift in the oxygen dissociation curve mean
Oxygen is more likely to be bound to the haemoglobin
Increase in pH
Decease in DPG (regulator of the allosteric properties of haemoglobin in RBF)
Decrease in temp
