1 Flashcards
(28 cards)
What muscle causes vocal chords to move?
Intrinsic Laryngeal muscles
What 3 parts does the sternum consist of?
Manubrium, body, and xiphisternum
What is the junction of the manubrium and body known as?
The sternal angle (where 2nd rib can be identified)
What does a typical rib consist of? (Ribs 3-9)
Head, neck, costal cartilage, costal groove, internal and external surface
(See respiratory lecture 1 and 2 slide 10)
Describe the facets and joints on a rib
Head: 2 facets which articulate with the corresponding vertebral body and the vertebral body above
Tubercle: one facet which articulates with the transverse process of the corresponding thoracic vertebrae
Costovertebral joint: 2 synovial joints which connect the ribs with the thoracic vertebrae, joints help to move ribs during respiration
What is the midline of the thoracic cavity called?
Mediastinum
Describe the three intercostal muscles, innervation and role in respiration.
External intercostal: runs anteriorly and diagonal downwards (hands in pocket), responsible for 30% chest expansion during quiet respiration in a “bucket-handle” movement
Internal intercostal: runs perpendicular to external, active during forced expiration and pulls ribs down from chest expansion
Inner intercostal: runs same direction as internal, acts same as internal but less developed
ALL ARE INNERVATED AND SUPPLIED BY THE INTERCOSTAL NERVE, ARTERY, and VEIN
What innervates the diaphragm?
Phrenic nerves
Supplied by C3, C4, C5
3, 4, 5 keeps the diaphragm alive
Why must we inject above the rib?
Because the major vasculature is located below the rib so we do not want to damage it. Minor vasculature is located above the rib.
Describe the diaphragm and its role in respiration.
-Large dome-shaped muscle which bulges into thorax
-responsible for 70% of quiet respiration
-muscle fibres arise from lower margin of thoracic cavity and insert into central tendon
Has openings for:
-Vena cava (T8)
-Oesophagus (T10)
-Aortic hiatus (T12)
The right dome of the diaphragm lies AT the level of the 5th rib, and the left dome is slightly LOWER at the level of the 5th intercostal space.
Describe the movements of the thoracic wall and diaphragm during respiration
Bucket-handle: elevation of lateral shaft of rib
Pump-handle: superior and anterior movement of sternum
Decreasing pressure and increasing volume
Why do foreign objects usually end up in the right lung?
Because right bronchus is more shallow, shorter and wider and more vertical than left bronchus
How many lobes does each lung have? Why?
Right has 3
Left has 2 because heart is taking up space
Describe the two pleura of the pleural cavity
Parietal: lines inside of each hemisphere-thorax and is continuous of the hilum of the lung, richly innervated so pain is felt
Visceral: lines the outside of the lung and extends between the lobes of the lung to the oblique and transverse fissures, not as innervated
Contains a few millilitres of fluid to prevent friction
Top of pleura reaches supraclavicular fossa until the costaphrenic recess
What is the space called in which the parietal pleura reaches but not the lung?
Costaphrenic recess
Describe the fissures of the lungs
- fissures separate the lobes of the lungs
- oblique fissures separate the bottom half lobe
- transverse fissures separate the top half lobe
Describe the division of the bronchii
- Main right and left bronchi form at the sternal angle
- primary bronchi divide into lobar bronchi (3 for right, 2 for left)
- lobar bronchi divide into segmental bronchi
- segmental bronchi divide into bronchioles
- bronchioles divide into terminal bronchioles
What is the angle between the right and left main bronchi known as?
Carina
What is a bronchopulmonary segment?
- area of lung supplied by a segmental bronchus, and the accompanying segmental branch of the pulmonary artery
- drained by segmental branch of pulmonary vein
- useful in surgery because can be isolated and removed without much damage, resectable
What kind of blood supply do the lungs have?
- dual blood supply
- from bronchial arteries and the pulmonary arteries
- bronchial arteries supply bronchi but not alveoli and drain into pulmonary veins (not bronchial veins)
- small amount drains into bronchial veins, which goes to azygos veins
- pulmonary artery supplies alveoli
What is the lymphatic drainage of the lungs?
- drain into hilar nodes, also known as the bronchopulmonary node
- efferents drain into tracheobronchial nodes
Describe the parts of the mediastinum
- angle of Louis separates mediastinum into superior and inferior
- inferior further divided into anterior, middle, and posterior
- anterior is mainly fat
- middle is heart
- posterior is aorta, oesophagus, and azygos veins
What part of the lungs are you listening to when auscultating the back of a patient?
The inferior lobes
How does the respiratory system develop?
As an out-pouching of the gut
-develops as a diverticulum from the pharynx
