ILA formatives Flashcards
What do central chemoreceptors in the ventral medulla respond to?
CSF pH
What cell provides cilia for mucocillary escalator?
Columnar epithelial cells
Equation for vital capacity
Tidal volume + Inspired reserve volume + Expired reserve volume
Arterial gas picture for type 1 respiratory failure
Low pO2
Normal/low pCO2
Where are the main peripheral chemoreceptors located?
Aortic arch and carotid arteries
What is the term used to describe a malignant tumour of the pleural membranes?
Mesothelioma
What can cause type 1 respiratory failure?
Conditions that affect oxygenation
- Low ambient oxygen (e.g. at high altitude)
- Ventilation-perfusion mismatch (e.g. pulmonary embolism)
- Alveolar hypoventilation due to reduced respiratory muscle activity, e.g. in acute neuromuscular disease (this form can also cause type 2 respiratory failure if severe)
- Diffusion problem ( e.g. in pneumonia)
- Shunt (oxygenated blood mixes with non-oxygenated blood from the venous system, e.g. right to left shunt)
What is the arterial blood gas picture for type 2 respiratory failure?
Low pO2
High pCO2
Normal/high HCO3
What factors cause bronchoconstriction?
Cold dry air
Parasympathetic stimulation
Histamine release
Beta-Blockers
If a peanut is inhaled, where in the airway is it most likely to become lodged?
Right main bronchus
Which nerve supplies motor function to the diaphragm?
Phrenic
Which changes in blood stimulate carotid chemoreceptors?
Oxygen, carbon dioxide and H+ ions
What can lead to type 2 respiratory failure?
Inadequate alveolar ventilation
- Increased airways resistance - COPD
- Reduced breathing effort (drug effects, brain stem lesion, extreme obesity)
- A decrease in the area of the lung available for gas exchange (chronic bronchitis)
- Neuromuscular problems
Which nerve are superior laryngeal and recurrent laryngeal branches of?
Vagus
In sickle cell, what does hypoxia cause the HbS to do?
Polymerise
What structure is a protein in multiple sub units?
Quaternary
How does hydroxyurea work in treating sickle cell?
Increases the synthesis of HbF (2 alpha 2 gamma chains, greater affinity for oxygen than HbA)
What causes sickle cell anaemia?
An autosomal recessive inherited condition substituting an amino acid in the beta globin chain
What causes the sickling in sickle cell?
Deoxygenated HbS polymerises and binds to the cell cytoskeleton which distorts the normal cell shape into the classic sickle shape
What is a disulphide bond?
A covalent bond between side chains of cysteine residues
What is a hydrogen bond?
A type of Vander Waals force. It is the strongest of them and is the interaction between dipoles, involving a hydrogen and an oxygen/nitrogen/fluorine
What is van der waals force?
A weak attractive interaction between two atoms due fluctuating electrical charges
What is hydrophobic force?
the attraction of hydrophobic protein side chains which form tightly packed cores on the interior of proteins which exclude water molecules
Which enzyme causes the double helix to unzip?
Helicase