The respiratory system Flashcards
What body parts make up the upper respiratory tract?
-nose
-nasal cavity
-pharynx
What body parts make up the lower respiratory tract?
-larynx
-trachea
-bronchi
-lungs
What is the branching of bronchial tree?
-trachea
-main bronchi
-lobar bronchi
-segmental bronchi
-bronchioles
-terminal bronchioles
What is the branching of the microscopic airway tree?
-respiratory bronchioles
-alveolar ducts
-alveolar sacs
-alveoli
What is surfactant and what is its function?
-a liquid which coates the alveoli which reduces surface tension (so the alveoli doesn’t collapse)
What is meant by the term partial pressure?
The pressure of a specific gas in a mixture of gases
In what direction does O2 and CO2 move in in both external and internal respiration?
Move from areas of high partial pressure to areas of low partial pressure
What is external respiration? (and what else is it known as)
-pulmonary gas exchange
-the exchange of gases between alveolar air and pulmonary blood capillaries
What is internal respiration? (and what else is it known as)
-systemic gas exchange
-the exchange of gases between systemic tissue capillaries and systemic tissue cells
How are the respiratory gases transported?
-in the blood between the lungs and body tissues
What percentage of blood oxygen is bound to haemoglobin in red blood cells?
98.5%
What 4 things affect the association of oxygen and haemoglobin?
-PO2
-pH
-temperature
-PCO2
What 3 ways is carbon dioxide transported around the body (and what percentage)?
-7% dissolved in plasma
-23% combines with the globin of haemoglobin
-70% converted to bicarbonate ions (HCO3-)
What are the 2 areas that the respiratory centre can be divided into?
-the medullary respiratory centre in the medulla oblongata
-the pontine respiratory group in the pons
What does the inspiratory area set?
The basic rhythm of respiration
Give examples of factors that may modify respiration
-cortical influence
-chemoreceptors
-limbic system stimulation
-proprioceptor stimulation
-temperature
-pain
-irritation of airways
-the inflation reflex (stretch receptors)
Explain the process of normal quiet inhalation when the Dorsal respiratory group is active
-Diaphragm contracts and external intercostal muscles contract during their most active phase
-Ribcage moves upwards and outwards
-Pressure decreases inside the lungs to below atmospheric pressure, drawing air in from the environment
Explain the process of normal quiet exhalation when the Dorsal respiratory group is inactive
-Diaphragm relaxes and external intercostal muscles becomes less active and relax, followed by elastic recoil of lungs
-Ribcage is pulled downwards and inwards
-Pressure increases inside the lung to above atmospheric pressure, forcing air out into the environment
Explain the process of forceful inhalation
-Dorsal respiratory group (DRG) activates the ventral respiratory group (VRG)
-Diaphragm contracts and external intercostal muscles contract during their most active stage
-Accessory muscles of inhalation contract
=forceful inhalation
Explain the process of forceful exhalation
-Ventral respiratory group causes accessory muscles of exhalation to contract
=forceful exhalation
What is the function of ciliated epithelium in the lungs?
Small hair-like structures that provides a synchronised waft to move mucus away from the lungs keeping them clean
What is the main anatomical difference between the right and left lung?
The right lung is larger then the left, and has 3 lobes (the superior, middle and interior) whereas the left lung is smaller and only has 2 lobes (superior and interior)
What fraction of air is not used in gas exchange and is ‘dead space’?
one third
What is the parietal pleura layer of the lungs?
The outer layer that attaches to the chest wall
