Is the intrapleural pressure greater than or less than the pressure in the lungs
Intrapleural pressure is less than the pressure inside the lung
What nerve supplies the diaphragm and what are its roots
C3,4,5 keeps the diaphragm alive.
Phrenic nerve
Why does your lung collapse during pneumothorax/
Transmural pressure gradient is abolished
What are the accessory muscles on inspiration?
Sternocleidomastoid
Scalenus
Pectoral
What does parasympathetic stimulation do to the bronchioles /
Bronchoconstricition
What does sympathetic stimulation do to bronchioles?
Sympathetic causes bronchodilation
What factors shift the oxygen dissociation curve to the right?
Raised CO2
Raised H+
Raised Temperature
Raised 2,3-Biphosphoglycerate
How is CO2 transported in the blood
10% solution
60% Bicarbonate
30% Carbamino compounds
What are Carbamino compounds?
Combination of CO2 with amine groups in blood.
Carbamino-haemoglobin
What affect does parasympathetic stimulation have on the airways?
Smooth muscles contraction
Increased mucus secretion
What is responsible for mucus secretion in the lungs?
parasympathetic stimulation of M3 muscarinic receptors on goblet cells
What causes bronchial smooth muscle to relax?
Nitric oxide
and
Vasoactive intestinal peptide
How does the sympathetic system act to relax bronchial smooth muscles
Adrenaline relsease from adrenal gland acts on beta 2 adrenoreceptors
What do beta 2 adrenoreceptors do?
Decrease mucus secretion
Relax bronchial smooth muscle
Increase mucociliary clearance
What activates beta 2 adrenoreceptors?
Stimulated by adrenaline from the adrenal gland
What 5 changes do you find in the airways of chronic asthamtics?
- smooth muscle hyperplasia
- intersitial oedema
- Increased mucus
- epithelial damage
- sub epithelial fibrosis