Respiratory System Anatomy Flashcards
Describe the role of nasal conchae
- Nasal conchae are a collection of turbinate (scroll-shaped bones)
- Increase surface area
- Induce turbulent air flow which increases efficiency of gas exchange with moist air as it slows down airflow
Describe the actions of the nasal cavity
- Warms and moistens inspired air to help gas exchange
- Recovers water from expired air
- Speech production (phonation)
- Olfaction
- Lined with coarse hairs to trap large particles in inhaled air - mucus further traps particles
Describe how the larynx protects the airway during swallowing
- During swallowing, the laryngeal inlet becomes narrowed, the epiglottis folds downwards over the laryngeal inlet and the vocal cords come together to act as a sphincter closing off the entrance of the trachea
- Movements of vocal cords caused by action of intrinsic laryngeal muscles
- Innervated by recurrent laryngeal nerve
Explain why hoarseness of voice /voice change may be a sign of intra thoracic disease
- Recurrent laryngeal nerve on left side has a long course
- Runs inside the thoracic cavity and when compressed leads to hoarse voice due to paralysis of left vocal cord
- Can be compressed through thoracic disease - aortic aneurysm, lung cancer
Describe rib movements during respiration
- Lateral dimension of thorax increases in breathing in
- Bucket handle movement
- Sternum moves anteriorly and superiority when breathing in
- Pump handle movement
Describe the location and innervation of the diaphragm
- Innervated by somatic system (not autonomic)
- Brain stem has circuit which autopilots control of breathing
- Innervates by phrenic nerves - C3-C5
- During development, diaphragm first developed in neck
- Shoulder pain caused by diaphragm problem
- Superior border on left side is 5th intercostal space and on right is 4th intercostal space
Describe the actions of the intercostal muscles in breathing
- External intercostals assist inhalation
- Run anteromedially (hands in pocket) to drag ribs up
- Deficiency anteriorly
- Internal intercostals assist in forced exhalation
- Pull ribs anteroposterior
- Deficient posteriorly
- Innermost intercostals assist in forced exhalation
- Only present on lateral sides
Describe where the neurovascular supply for intercostal muscles is located and how to avoid injuring it during when inserting needles
- Innervated intercostal nerves which run alongside intercostal artery and vein below each rib
- Always insert needles above rib to avoid damage
What is the azygos venous system
Azygos vein collects blood from intercostal veins and drains it into the superior vena cava
State the levels at which structures pass through the diaphragm
- Vena cava passes at T8 (8 letters)
- Oesophagus passes at T10 (10 letters)
- Aorta passes though aortic hiatus along with thoracic duct (12 letters)
Describe the role of the pleural cavity and pleural seal in lung expansion
- Pleura links the movement of the chest wall and lungs
- Pleural cavity contains few millilitres of pleural fluid
- Surface tension between the molecules of pleural fluid creates a seal which ensures that when the thorax expands, the lungs expand with it
Describe the nerve and blood supply to the intercostal muscles
- Parietal pleural is sensitive to pain, pressure and temperature
- Produces well localised pain and is innervated by the phrenic and intercostal nerves
- Blood supply from the intercostal arteries
- Visceral pleura is not sensitive to pain, only detect stretch
- Receives autonomic innervation from the pulmonary plexus
- Blood supply through bronchial circulation (internal thoracic arteries)
- Receives autonomic innervation from the pulmonary plexus
Describe the lobes of the lungs
- Right lung generally has 3 lobes (superior, middle, inferior)
- Left lung generally has 2 lobes (superior, inferior)
- Lobes separated by fissures
- Most of lung is inferior lobe
Describe the blood, nerve and lymph drainage of the lung
- Blood supply to lung from both pulmonary circulation as well as bronchial artery and vein
- Pulmonary artery superior to pulmonary vein - Lymphatic drainage of lung into hilar nodes
- Nerve supply of lung from right and left vagus nerves and the sympathetic trunk
State the recess that is formed at the base of the pleural cavity
- Costaldiaphragmatic recess / costophrenic recess located at base of pleural cavity
- Space allows lungs to expand into
- Can fill up with fluid - pleural effusion
- Space allows lungs to expand into
