Tracheal Anatomy & Percutaneous Tracheostomy

Current · V5 (2025) → C1.v 1 exam appearance

2026A Q08

Exam question

a) On the diagram below, identify the anatomical structures labelled A-H (40% of marks).
b) Describe the structural anatomy of the trachea, excluding the anatomical relations (45% of marks).
c) Outline the ideal location for the insertion of percutaneous tracheostomy tube (15% of marks).

Black-and-white axial neck anatomy at C6 with A–H markers for anatomy identification

CICMWrecks answer

Master answer

a) Diagram labels

Labelled axial neck anatomy at C6 showing recurrent laryngeal nerve, cervical fascia, anterior and external jugular veins, strap muscles and carotid sheath contents — CICMWrecks original (2026) · Axial neck anatomy at C6

Label	Structure
A	Recurrent laryngeal nerve
B	Superficial fascia
C	Pretracheal fascia
D	Anterior jugular vein
E(i)	Sternocleidomastoid
E(ii)	Sternohyoid
E(iii)	Sternothyroid
E(iv)	Omohyoid
F	External jugular vein
G	Carotid sheath — internal jugular vein, common carotid artery and vagus nerve
H	Investing layer of deep cervical fascia

b) Structural anatomy of the trachea

Feature	Description
Origin	Continuation of the larynx at the lower border of the cricoid cartilage, approximately C6
Termination	Bifurcates at the carina, approximately at the sternal angle / T4–T5
Length	Approximately 10–12 cm in an adult; cervical and thoracic portions
Diameter	Approximately 2–2.5 cm in an adult
Framework	Approximately 16–20 C-shaped hyaline cartilage rings, incomplete posteriorly
Between rings	Adjacent cartilages are joined by fibroelastic annular ligaments
Posterior wall	Membranous wall; posterior ends of the cartilage rings are bridged by trachealis smooth muscle and fibroelastic tissue
Mucosa	Pseudostratified ciliated columnar respiratory epithelium with goblet cells
Submucosa	Connective tissue containing vessels, nerves and seromucous glands
Outer layer	Adventitia anchors the trachea to surrounding connective tissue
Cartilage function	Maintains luminal patency while allowing flexibility
Trachealis function	Changes tracheal calibre; contraction can narrow the lumen and increase expiratory airflow during cough

Blood supply and innervation

Arterial supply: cervical trachea mainly via branches of the inferior thyroid arteries; thoracic trachea via bronchial arteries.
Venous drainage: inferior thyroid venous plexus and bronchial veins.
Parasympathetic: vagal fibres, including recurrent laryngeal branches.
Sympathetic: fibres from cervical and upper thoracic sympathetic ganglia.

c) Ideal site for percutaneous tracheostomy

Midline anterior approach below the cricoid cartilage.
Insert through an intercartilaginous space within the first three tracheal rings.
In routine practice, the 2nd–3rd tracheal ring interspace is commonly targeted.
Avoid an excessively high puncture close to the cricoid because of subglottic/cartilage injury and stenosis.
Avoid an excessively low puncture because of increasing proximity to the brachiocephalic vessels and mediastinum.
Remain strictly midline to reduce vascular and recurrent laryngeal nerve injury.

Quick reference

Summary

Area	Exam anchor
Extent	C6 → carina at T4–T5
Framework	16–20 C-shaped hyaline cartilage rings
Posterior wall	Trachealis muscle
Lining	Pseudostratified ciliated columnar respiratory epithelium
Cervical blood supply	Inferior thyroid arteries
Percutaneous site	Midline; usually 2nd–3rd ring interspace

Past papers

Exam appearances

1 appearance

Exam	Exact exam wording	Candidate success
2026A Q08	a) On the diagram below, identify the anatomical structures labelled A-H (40% of marks). b) Describe the structural anatomy of the trachea, excluding the anatomical relations (45% of marks). c) Outline the ideal location for the insertion of percutaneous tracheostomy tube (15% of marks).	38.6%