Thoracic Wall, Pleura, Lungs Flashcards
Superior thoracic aperture
- Opening at top of thoracic cage
- Could be ‘inlet’ or ‘outlet’ depending on which structures you are looking at
Inferior thoracic aperture
- Opening at bottom of thoracic cage
Sternal angle
- Where manubrium meets sternum
- Where CC of rib #2 meets sternum
- At level of T4
ID features of a typical rib
- Head w/ 2 facets (sup + inf)
- Neck
- Tubercle w/ articular facet (for TP)
- Angle of rib
- Shaft/body of rib
- Costal groove (for neurovascular bundle)
- Site of articulation w/ costal cartilage
Synchondrosis
Articulation of rib w/ costal cartilage
What kind of joint is between articular facets of rib head + VB?
Synovial joint
Where are intercostal nerves in relation to their corresponding ribs?
Travel under same rib
How does the thorax move on inspiration?
- Ribs angle up (bucket handle effect) –> transverse diameter
- Sternum moves forward + up (pump handle effect) –> anterior-posterior diameter
- Vertical dimension increased by diaphragm
- This creates decreased pressure in pulmonary cavity. to draw air in.
Layers of thoracic wall
1) Skin
2) SC tissue
3) Serratus anterior
4) Ribs
5) External intercostal muscle
6) Internal intercostal muscle
7) Innermost intercostal muscle
8) Endothoracic fascia
9) Parietal pleura
How is intercostal neurovasculature ordered?
Vein
Artery
Nerve
Where does the intercostal neurovascular bundle lay?
In costal groove, NOT intercostap space
Name main components of blood supply to the thoracic wall
- Aorta gives off posterior intercostal arteries
- Subclavian gives off anterior intercostal arteries
- They anastomose more anteriorly (will bleed from both ends when cut)
Internal thoracic arteries
- Arises from subclavian
Anterior intercostal arteries
- Small
- Arise from internal thoracic + musculophrenic arteries
- Supply anterior portion
- Give off anterior cutaneous branches
Posterior intercostal arteries
- Large
- Arise from aorta
- Supply posterior + medial + some anterior
- Gives off dorsal & lateral cutaneous branches
Subcostal arteries
- 12th rib
- Arises from aorta
- Supply muscles of anterolateral abdominal wall + overlying skin
What does the internal thoracic artery become once it crosses into the abdomen?
1) Superior epigastric artery
2) Musculophrenic artery
Name main components of nerve supply of the thoracic wall
- Posterior rami (sensory) gives off lateral + medial cutaneous branches
- Anterior rami (motor) form intercostal nerves
- Have lateral cutaneous + anterior cutaneous branches
3 types of ribs
1) True = 1-7
2) False = 8-10
3) Floating = 11-12
Dermatomes
- Bandlike skin areas each supplied by sensory fibers of a single posterior root
- Considerable overlapping occurs
Sympathetic trunk
- Intercostal + subcostal nerves connected by rami communicantes
- Presynaptic fibers leave anterior rami by a white ramus communicans + pass to sympathetic ganglion
What is innervated by the intercostal nerves?
1) Skin and subcutaneous tissue
2) Intercostal muscles
3) Costovertebral and sternocostal joints
4) Parietal pleura
5) Peripheral parts of diaphragm (sensory)
Thoracentesis
- Remove excessive fluid in pleural cavity
- Do NOT pierce visceral pleura –> pierce lung
- Needle pierces on superior portion of rib to avoid hitting neurovascular bundle
Tracheoesophageal fistulas
- Most common group of malformations
- Abnormal separation of tracheal bud from esophagus
- Varieties of tracheoesophageal fistulas
all involve stenosis or atresia of a segment of trachea or esophagus with abnormal connection between them
Clinical presentation:
- Newborn’s choking or regurgitation of milk when feeding
4 regional names of parietal pleura
1) Costal pleura
2) Diaphragmatic pleura
3) Mediastinal pleura
4) Cervical/apical pleura
Visceral pleura
- Inner layer directly on lungs
- Extends into fissures dividing the lobes of the lung (tightly attached)
Parietal pleura
- Outer, deep to endothoracic fascia
Pleural cavity
In between parietal + visceral pleura
Costodiaphragmatic recess
- Space where diaphragm meets ribs
- Most lateral on frontal view
- Most posterior on lateral view
- Costophrenic angle
*Becomes blunted on imaging
Costomediastinal recesses
- Space where mediastinum meets ribs
- Most anterior on axial view
Sternal line of pleural reflection
Where costal pleura becomes mediastinal pleura
Lines of pleural reflection
Edges of the pleural cavity
What significant impressions are on the right lung?
Vena cava
What significant impressions are on the left lung?
- Cardiac notch
- Aorta + branches
Right lung hilum
- Find right bronchus
- Pulmonary artery should be ANTERIOR
- Rest are pulmonary veins
Left lung hilum
- Find left bronchus
- Pulmonary artery should be SUPERIOR
- Rest are pulmonary veins
Pleural effusion
Excessive fluid collection in pleural cavity
Hemothorax
Blood in pleural cavity
Chylothorax
Lymph in pleural cavity
Empyema
Pus in pleural cavity
Pneumothorax
Air in pleural cavity
What sort of cells prevent airway collapse in bronchioles?
Club cells
Terminal bronchioles
- Smallest part of conducting part of bronchial tree
- Gives rise to several respiratory bronchioles
Respiratory bronchioles
- 1st part of bronchial tree that allows gas exchange
- Each provides several alveolar ducts
What makes up bronchi?
Cartilage plates + circular layer of smooth muscle
Do bronchioles contain cartilage plates or glands?
No
Alveoli
Terminal air spaces in respiratory system
Interalveolar septa
Location for gas exchange between air + blood (air-blood barrier)
Alveolar epithelium (2 types)
1) Type I - pneumocytes (squamous cells) lining 95% of alveolar surface
2) Type II - secretory cells that produce + secrete surfactant to lower surface tension in alveoli
Alveolar macrophages
Present in alveolar air spaces
Right lung lobes
1) Upper
2) Middle
3) Lower
Left lung lobes
1) Upper
2) Lower
Lingula
Thin anterior portion of LUL that corresponds to RML
*Gives the heart a hug
Right lung fissures
1) Horizontal
2) Oblique
Left lung fissure
Oblique
Pleuritis
- Inflammation of pleura
- Can hear pleural rub on auscultation
Carina
- Ridge at bifurcation of trachea into main bronchi
Pulmonary alveolus
Basic structural unit of gas exhange in the lung
