Wk.11 L1 - Anatomy of the Respiratory System Flashcards
(23 cards)
LO
- Describe the location and be able to draw the anatomical features of each structure in the upper (refresh from previous weeks) and lower respiratory system and outline the ordered anatomical pathway through which air flows (from nostrils to alveoli)
- Identify the external anatomical features of the lungs, compare and contrast right and left lungs and identify and describe the organisation of the hilum of both the right and the left lungs
- Discuss the features, anatomical relationships and function of the 2 layers of pleura covering the lungs
- Apply your knowledge to be able to locate the phrenic nerve, the vagus nerve and the sympathetic trunk and understand their contribution to innervation of the respiratory system
Resp. System overview
Extends from head to thorax (Nostrils to alveoli)
Split into upper and lower
Function:
- Supply O2 and remove CO2 from blood, and vocalisation, reliant on resp. muscles
Upper:
- Nasal cavity, Nasopharynx, Oropharynx, laryngopharynx, larynx
Lower:
- Trachea, Carina, brinchi, Bronchial tree, Alveoli, Lungs, pleura
Larynx
- Suspended from hyoid bone and attached to trachea by soft membranes and cartilage, allows high mobility
Hyoid bone
- Highly movable, firm anchor for tissues
- ‘U’ shaped
- Superior to larynx, medial to mandible
- Not directly articulated with other bones
Connects floor of oral cavity with pharynx, larynx and supports tongue:
- Superiorly attaches to floor of oral cavity
- Posteriorly attaches to pharynx at the constrictor muscles
- Inferiorly attaches to larynx by membrane
Larynx Function
Pretects the vocal folds
Goverened by 4 seperate cartilages:
1. Epiglottis (closes larynx on swallowing)
2. Thyroid cartilage (shield)
3. Crocoid cartilage (ring structure)
4. Arytenoid cartilage (x2 lateral)
[heft]
Larynx Cartilage
Epiglottis:
- Leaf shaped
- Closes larynx on swallowing
- Posterior to tongue & hyoid bone
- Anterior to arytenoid cartilages
- Inferior to oropharynx
Thyroid cartilage:
- Shield shaped
- Inferior to hyoid bone
- Anterior to arytenoid cartilages
- Encloses and protects vocal folds (& arytenoid)
Crocoid cartilage:
- Signet ring shaped
- Inferior to thyroid cartilage and arytenoid
- Anterior to laryngopharanx
- Superior to trachea
Arytenoid Cartilages:
- Pyramid-shaped
- Paired
- Posterior to vocal folds
- Medial (& within) to thyroid cartilage
- Superior to crocoid cartilage
Larynx internal features & spaces
- Internal cavity is between laryngeal inlet and treachea
- 2 pairs of folds (ligaments) running between aretynoid & thyroid cartilage
- Space between the 2 pairs of folds = Laryngeal ventricle
Folds:
- Vestibular folds = Superior
- Vocal folds = Inferior
(space between = Rima Glottis)
Trachea
- Fibromuscular/ fibroelastic tube with 16-20 ‘C’ shaped carilagenous rings
- Contains smooth muscle posteriorly
- Inferior to larynx
- Supplies air from laryngopharynx to the lungs
- Extends along vertebral bodies, suspended from the crocoid cartilage
- Splits at the Carina into L&R primary bronchi
Bronchi
- L&R lie posterior to heart
- Right primary bronchi is shorter, wider and more vertical
Brochial tree order
- Primary Bronchi
- Secondary Bronchi (3 RHS, 2LHS - 1 per lobe)
- Tertiary Bronchi (many, cartilage plates)
- Terminal Bronchioles (No cartilage)
- Respiratory Bronchioles
- Alveoli & Alveolar sacs
Lungs and Heart in Cavity
Lungs covered in pleura
Heart in Mediastinum
- In between pulmonary cavities
- Heart is anterior to bronchi
- Rests on diaphragm
Lungs
Apex:
- Extends into root of neck, above rib 1
Base:
- Rests on diaphragm
Costal Surface:
- Adjacent to ribs/ intercostal spaces
Mediastinal Surface:
- Area medial to lung, adjacent to mediastinum
Right lung
Larger
Shorter (liver pushes up)
Wider
3 Lobes (Sup. Mid. Inf.)
2 Fissures (Oblique, Horizontal)
Left Lung
Smaller
Longer
Narrower (Cardiac Notch & Lingula)
- Lingula licks around heart anteriorly
2 Lobes (Sup. Inf.)
1 Fissure (Oblique)
Lungs - Pulmonary Hilum
- Where structures entre and leave heart
- Medial
- Surrounded by Pleural Sleeve, draping inferiorly forming the pulmonary ligament
Veins = vAIns
Arteries = RALS
Pulmonary Hilum L vs R
2x Arteries = RALS
- (Right = ant ; Left = sup.)
2x Veins = vAIns
- (anterior & inferior)
Changes:
- Pulmonary arteries change in relation to bronchus as the heart is anterior
- Left P. Artery is superior to bronchus due to a twist with the left bronchus
Lungs - Pleura
Each lung is wrapped in 2 serous layers of pleura inner
Visceral pleura:
- Adheres to lungs and fissures
Parietal pleura:
- Adheres to thoracic wall
Both pleura are continuous at the hilum of the lung
Pleura function
Between the 2 is pleural fluid
- Keeps the layers stuck together under fluid surface tension
Surface tension prevents lung from collapsing and recoiling
If air or blood gets into pleural fluid space, the tension is broken
Innervation of respiratory system
Intercostal nerve
Phrenic nerve
Vagus nerve (parasympathetic)
Sympathetic nerve
Intercostal nerves
- Sensory innervation of costal pleura
- Motor innervation of intercostal muscles
Phrenic nerves
- Sensory innervation of diaphragmatic parietal pleura
- Motor innervation of diaphragm
Vagus nerve
Sensory innervation of visceral pleura
Parasympathetic autonomic (motor) innervation:
- Constricts bronchi
- Dilates pulmonary blood vessels
- increases secretions
- decrease respiratory rate
Sympathetic trunk
Sensory innervation of visceral pleura
Sympathetic autonomic innervation:
- Dilate bronchi
- Constricts Pulmonary blood vessels
- Reduce secretions
- Increase respiratory rate
