Respiratory Physiology 1 + 2 Flashcards
What are the functions of the respiratory system?
Gas exchange
Acid base balance - regulation of body pH
Protection from infection
Communication via speech
Why is gas exchange so important?
Need to produce energy
Oxygen is metabolised p and produces CO2 as a waste product
What does the ability of tissues to transform fuel stored as chemical energy to physical energy depend on?
Integration of the CVS
Respiratory systems to deliver fuel to active cells within the tissues and remove waste products
What is cellular/internal respiration?
Biochemical process that releases energy from glucose via glycolysis or oxidative phosphorylation
Oxidative respiration requires oxygen and depends on external respiration
What is external respiration?
Movement of gases between the air and the body’s cells via both the respiratory and cardiovascular systems
What is the pulmonary circulation?
Delivers CO2 to the lungs
Collects O2 from the lungs
Consists of the pulmonary artery that carries deoxygenated blood and pulmonary vein which carries oxygenated blood
What does increased energy demand by working muscle lead to?
Increased rate and depth of breathing which speeds up substrate acquisition and waste disposal
Increased rate and force of contraction of heart which speeds up substrate delivery to muscle and waste removal via blood
What is the net volume of gas exchanged in the lungs per unit time?
In steady state - 250ml/min O2: 200ml/min CO2
Equal to net volume exchanged in the tissues
What is average respiration rate?
12-18 breaths per min at rest
Can reach 40-45 at max. when exercising as an adult
What does the respiratory system consist of?
Nose
Pharynx
Epiglottis
Trachea
Larynx
Lung
Bronchus
What does the upper respiratory tract consist of?
Pharynx, nasal cavity, tongue, vocal cords, oesophagus and larynx
What does the lower respiratory system consist of?
Trachea, left lung, right lung, left bronchus, right bronchus and diaphragm
It is enclosed in the thorax, bounded by the ribs , spine and diaphragm
What does right lung consist of?
Superior lobe
Horizontal fissure
Middle lobe
Oblique fissure
Inferior lobe
What does the left lung consist of?
Superior lobe
Oblique fissure
Inferior lobe
Describe the branching of airways?
The trachea branches into two bronchi. Each bronchi branches 22 more times which finally terminates in a cluster of alveoli. The trachea, primary bronchus and secondary bronchus are semi riding tubes that have c shaped rings of cartilage to maintain patency
How is patency maintained in the bronchioles and alveoli?
There is no cartilage so it is maintained by physical forces in the thorax
What is different between the left and right bronchi?
The right bronchi is wider and more vertical so more common for aspirated foreign bodies commonly lodge here
Explain airway branching and resistance to air flow
More resistance to air flow happens in the conducting zone compared to the respiratory zone as there is more branching in the respiratory zone. It can be altered by activity of bronchial smooth muscle:
Contraction decreases diameter - resistance increases
Relaxation increases diameter. - resistance decreases
What are elastic fibres responsible for?
Elastic fibres surround the alveoli. They allow expansion and contraction when breathing and loss of the elasticity can lead to emphysema.
Explain type l alveoli cells
Responsible for gas exchange
They are in bulk of the alveolar wall