Thoracic Anatomy
4-Station Circuit
Human Anatomy • Lab Circuit • Pre-Lab Structure Reference
1
Thoracic Wall & Spaces
Cavities • Pleura • Muscles • Diaphragm Openings
- Thoracic cavity
- Mediastinum
- Right pleural cavity
- Left pleural cavity
- Parietal pleura pain-sensitive; lines thoracic wall
- Visceral pleura no pain fibers; adheres to lung
- Diaphragm C3, C4, C5 phrenic nerve
- External intercostals hands in pockets • INSPIRATION
- Internal intercostals praying hands • forced EXPIRATION
- T8 — Caval opening IVC + R. phrenic n.
- T10 — Esophageal hiatus esophagus + vagal trunks
- T12 — Aortic hiatus aorta
📝 Exam Fill-In: Diaphragm Openings
T8
T10
T12
2
The Airway Tree
Glottis • Trachea • Bronchi • Lungs • Hilum Contents
- Glottis (rima glottidis)
- Trachea
- Tracheal cartilages (C-rings)
- Trachealis muscle posterior smooth muscle
- Carina bifurcation T4-T5; cough reflex
- R. primary bronchus wider, shorter, more vertical
- L. primary bronchus
- Secondary (lobar) bronchi R: 3 • L: 2
- Tertiary (segmental) bronchi
- Alveolar duct
- Alveoli Type I = exchange; Type II = surfactant
- R. lung — Superior, Middle, Inferior lobes
- L. lung — Superior, Inferior lobes
- Oblique fissure both lungs; inferior from upper lobe(s)
- Horizontal fissure RIGHT LUNG ONLY; superior from middle
- Alveolar sac cluster of alveoli at end of alveolar duct
- Hilum of R/L lungs
- Pulmonary artery at hilum most superior
- Superior & inferior pulmonary veins at hilum
- Primary bronchus at hilum posterior/inferior
- Bronchial arteries & veins nutritive; from thoracic aorta
3
Vascular Circuit
Pulmonary • Aortic Arch • Great Vessels • SVC
- R. pulmonary artery deoxygenated TO lung
- L. pulmonary artery
- R. pulmonary veins (x2) oxygenated FROM lung
- L. pulmonary veins (x2)
- Aortic arch T4; 3 branches
- Brachiocephalic trunk RIGHT SIDE ONLY; 1st branch
- R. subclavian artery
- L. subclavian artery 3rd arch branch
- R. common carotid artery
- L. common carotid artery 2nd arch branch
- Superior vena cava (SVC) drains upper body
- R. brachiocephalic vein
- L. brachiocephalic vein longer; crosses midline
- R/L subclavian veins
- R/L internal jugular veins
4
Nerves, Autonomics & Mediastinal
Phrenic • Vagus • Sympathetic Chain • Esophagus • Autonomics
- R. phrenic nerve C3,C4,C5 • through T8 with IVC
- L. phrenic nerve crosses left ventricle
- R. vagus nerve posterior vagal trunk; exits T10 hiatus
- L. vagus nerve anterior vagal trunk; exits T10 hiatus
- Sympathetic chain heads of ribs; T1-T12
- Esophagus posterior mediastinum; T10 hiatus
- Pulmonary nerve plexus
📝 Innervation of the diaphragm
5
Histology & Half Head Model — Self-Directed • All Groups Simultaneously
Half Head Model • Trachea Slide • Lung Slide • Esophagus Slide
- HALF HEAD MODEL
- Nasal cavity & nasal septum
- Superior nasal concha (turbinate)
- Middle nasal concha (turbinate)
- Inferior nasal concha (turbinate)
- Nasopharynx
- Oropharynx
- Laryngopharynx (hypopharynx)
- Epiglottis elastic cartilage
- Thyroid cartilage Adam's apple; hyaline
- Cricoid cartilage only complete ring; hyaline
- True vocal folds (vocal cords)
- False vocal folds (vestibular folds)
- Rima glottidis
- Soft palate & uvula
- Waldeyer's Ring
- Palatine tonsils tonsillar fossa; oropharynx
- Nasopharyngeal tonsil (adenoids) roof of nasopharynx
- Lingual tonsil base of tongue; posterior 1/3
- Paranasal Sinuses
- Frontal sinus above orbit; drains to middle meatus
- Maxillary sinus largest; cheek; most commonly infected
- Sphenoid sinus most posterior; near pituitary
- Ethmoid sinuses between orbit & nasal cavity
- TRACHEA SLIDE
- Pseudostratified ciliated columnar epithelium PCCE; mucociliary escalator
- Goblet cells mucus-secreting; pale on H&E
- Hyaline cartilage (C-rings on slide) lacunae, chondrocytes, matrix
- Trachealis smooth muscle posterior wall
- LUNG SLIDE
- Alveoli thin-walled air sacs
- Type I pneumocytes simple squamous; 95%; gas exchange
- Type II pneumocytes cuboidal; lamellar bodies; surfactant
- Alveolar macrophages (dust cells)
- Respiratory membrane ~0.5 μm; Type I + BM + endothelium
Esophageal histology (stratified squamous epithelium, muscularis layers) is covered in the GI unit.
